From 9a8ae82ae3475dcfd1609d1a0075ad101a19b87b Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13@innerpaths.net>
Date: Sat, 17 Jan 2015 22:09:55 -0800
Subject: [PATCH 01/13] entered data for george, draws correctly

---
 src/escher/core.clj | 72 ++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 64 insertions(+), 8 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 6f8da5a..d541054 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -7,6 +7,8 @@
 
 (def draw-line q/line)
 
+;; origin, e1, and e2 (all 2-D vectors) define a frame
+
 (def whole-window {:origin [0 0]
                    :e1 [width 0]
                    :e2 [0 height]})
@@ -19,19 +21,32 @@
              :e1 [100 0]
              :e2 [0 200]})
 
+; gw
+(defn make-vect [x y]
+  [x y])
+
+
+; gw
+(defn make-segment [p1 p2]
+  [p1 p2])
+
+; gw
 (defn add-vec [[x1 y1] [x2 y2]]
-  ;; COMPLETE (Ex 2.46)
+  [(+ x1 x2) (+ y1 y2)]
  )
 
+; gw
 (defn sub-vec [[x1 y1] [x2 y2]]
-  ;; COMPLETE
+  [(- x1 x2) (- y1 y2)]
   )
 
 (defn scale-vec [[x y] s]
-  ;; COMPLETE
+  [(* x s) (* y s)]
   )
 
 (defn frame-coord-map
+  "Returns function that maps [x y] relative to the frame
+  defined by origin (a point) and vectors e1, e2."
   [{:keys [origin e1 e2]}]
   (fn [[x y]]
     (add-vec origin
@@ -39,6 +54,8 @@
                       (scale-vec e2 y)))))
 
 (defn frame-painter [{:keys [origin e1 e2]}]
+  "Draws parallelogram 'frame' based on origin and vectors e1 and e2.
+  Must execute within a sketch."
   (let [corner (add-vec origin (add-vec e1 e2))]
     (draw-line origin (add-vec origin e1))
     (draw-line origin (add-vec origin e2))
@@ -84,12 +101,18 @@
       (left frame)
       (right frame))))
 
+; gw
 (defn below [p1 p2]
-  ; COMPLETE (Ex 2.51)
+  (rotate (beside (rotate270 p1)
+                  (rotate270 p2)))
   )
 
-(defn path [& veclist]
-  ; COMPLETE
+; gw
+(defn path
+  "Creates a seq of pairs-of-points from a 'bare' list of points. Use to
+  draw a continuous line through the list of points."
+  [& veclist]
+  (partition 2 1 veclist)
   )
 
 
@@ -143,11 +166,43 @@
 (defn square-limit [p n]
   (combine-four (corner-split p n)))
 
+;; George data
+
+(def p1 (make-vect 0 0.35))
+(def p2 (make-vect 0.15 0.6))
+(def p3 (make-vect 0.3 0.4))
+(def p4 (make-vect 0.35 0.5))
+(def p5 (make-vect 0.25 1.0))
+(def p6 (make-vect 0.4 1.0))
+(def p7 (make-vect 0.5 0.7))
+(def p8 (make-vect 0.6 1.0))
+(def p9 (make-vect 0.75 1.0))
+(def p10 (make-vect 0.6 0.55))
+(def p11 (make-vect 1 0.85))
+(def p12 (make-vect 1 0.65))
+(def p13 (make-vect 0.75 0.35))
+(def p14 (make-vect 0.6 0.35))
+(def p15 (make-vect 0.65 0.15))
+(def p16 (make-vect 0.6 0))
+(def p17 (make-vect 0.4 0))
+(def p18 (make-vect 0.35 0.15))
+(def p19 (make-vect 0.4 0.35))
+(def p20 (make-vect 0.3 0.35))
+(def p21 (make-vect 0.15 0.4))
+(def p22 (make-vect 0.0 0.15))
+
 ; Ex2.49, Make these shapes with segment-painter/path
 (def box )
 (def x)
 (def diamond)
-(def george)
+; gw
+(def george-data
+  (path  p1  p2  p3  p4  p5  p6  p7  p8  p9 p10
+        p11 p12 p13 p14 p15 p16 p17 p18 p19 p20
+        p21 p22))
+; gw
+(def george (segment-painter george-data))
+
 
 (defn draw [picture]
   (picture whole-window))
@@ -172,7 +227,8 @@
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
-    ;; (george frame2)
+    ;; (george whole-window)
+    (draw george)
     ;; (draw (rotate george))
     ;; (draw (flip-horiz george))
     ;; (draw (beside box box))

From 2423a78194fd2c48ce0622325b69b464525f3386 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13@innerpaths.net>
Date: Sat, 17 Jan 2015 23:53:04 -0800
Subject: [PATCH 02/13] added flip-horiz, rotate, rotate180, rotate270

also added comments to help orient new users
---
 src/escher/core.clj | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index d541054..a2d74cc 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -2,12 +2,17 @@
   (require [quil.core :as q])
   (:gen-class))
 
+;; In Quil, [0 0] is upper left corner of window.
+;; Increasing x values move a point to the right.
+;; Increasing y values move a point downward.
+
 (def width 600)
 (def height 600)
 
 (def draw-line q/line)
 
-;; origin, e1, and e2 (all 2-D vectors) define a frame
+;; origin, e1, and e2 (all 2-D vectors) define a frame.
+;; Think of e1 as the x-axis, e2 as the y-axis.
 
 (def whole-window {:origin [0 0]
                    :e1 [width 0]
@@ -46,7 +51,8 @@
 
 (defn frame-coord-map
   "Returns function that maps [x y] relative to the frame
-  defined by origin (a point) and vectors e1, e2."
+  defined by origin (a vector to be interpreted as the point
+  describing the origin) and vectors e1 (x-axis), e2 (y-axis)."
   [{:keys [origin e1 e2]}]
   (fn [[x y]]
     (add-vec origin
@@ -80,12 +86,10 @@
   (transform-picture p [0 1] [1 1] [0 0]))
 
 (defn flip-horiz [p]
-  ;; COMPLETE (Ex 2.50)
-  )
+  (transform-picture p [1 0] [0 0] [1 1]))
 
 (defn rotate [p]
-  ;; COMPLETE
-  )
+  (transform-picture p [1 0] [1 1] [0 0]))
 
 (defn rotate180 [p]
   (rotate (rotate p)))
@@ -191,6 +195,10 @@
 (def p21 (make-vect 0.15 0.4))
 (def p22 (make-vect 0.0 0.15))
 
+;; Example usage of path:
+;; (path p1 p2 p3) -->
+;;    (([0 0.35] [0.15 0.6]) ([0.15 0.6] [0.3 0.4]))
+
 ; Ex2.49, Make these shapes with segment-painter/path
 (def box )
 (def x)
@@ -227,10 +235,10 @@
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
-    ;; (george whole-window)
-    (draw george)
+    ;; (draw george)
     ;; (draw (rotate george))
-    ;; (draw (flip-horiz george))
+    (draw (beside george (rotate180 george)))
+    ;; (draw (flip-vert george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
     ;; (draw (beside (below george george)

From 7711d3491cd3cf7604ee6dcfde79dc6435ec9eb1 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13@innerpaths.net>
Date: Thu, 22 Jan 2015 20:03:08 -0800
Subject: [PATCH 03/13] added shapes; fcns for flipping, rotating, below

shapes: box, x, diamond, george

segment-lists allow compound shapes to be drawn using
concat; see diamond-x

fcns: flip-horiz, flip-vert; rotate, rotate180, rotate270; below
---
 src/escher/core.clj | 66 +++++++++++++++++++++++++++++++--------------
 1 file changed, 46 insertions(+), 20 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index a2d74cc..473ca8f 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -26,21 +26,21 @@
              :e1 [100 0]
              :e2 [0 200]})
 
-; gw
+
 (defn make-vect [x y]
   [x y])
 
 
-; gw
+
 (defn make-segment [p1 p2]
   [p1 p2])
 
-; gw
+
 (defn add-vec [[x1 y1] [x2 y2]]
   [(+ x1 x2) (+ y1 y2)]
  )
 
-; gw
+
 (defn sub-vec [[x1 y1] [x2 y2]]
   [(- x1 x2) (- y1 y2)]
   )
@@ -105,19 +105,17 @@
       (left frame)
       (right frame))))
 
-; gw
+
 (defn below [p1 p2]
   (rotate (beside (rotate270 p1)
-                  (rotate270 p2)))
-  )
+                  (rotate270 p2))))
+
 
-; gw
 (defn path
-  "Creates a seq of pairs-of-points from a 'bare' list of points. Use to
+  "Creates a seq of line-segments from a 'bare' list of points. Use to
   draw a continuous line through the list of points."
   [& veclist]
-  (partition 2 1 veclist)
-  )
+  (partition 2 1 veclist))
 
 
 (defn quartet [p1 p2 p3 p4]
@@ -200,16 +198,41 @@
 ;;    (([0 0.35] [0.15 0.6]) ([0.15 0.6] [0.3 0.4]))
 
 ; Ex2.49, Make these shapes with segment-painter/path
-(def box )
-(def x)
-(def diamond)
-; gw
-(def george-data
+
+;; By defining segment-lists separately, you can combine figures
+;; by concat'ting their segment-lists--see diamond-x.
+
+(def box-segs
+  (path (make-vect 0 0) (make-vect 0.99 0)
+        (make-vect 0.99 0.99) (make-vect 0 0.99)
+        (make-vect 0 0)))
+(def box
+  (segment-painter box-segs))
+
+(def x-segs
+  (concat (path (make-vect 0 0) (make-vect 1 1))
+          (path (make-vect 1 0) (make-vect 0 1))))
+(def x
+  (segment-painter x-segs))
+
+
+(def diamond-segs
+  (path (make-vect 0.5 0) (make-vect 1 0.5)
+        (make-vect 0.5 1) (make-vect 0 0.5)
+        (make-vect 0.5 0)))
+
+(def diamond
+  (segment-painter diamond-segs))
+
+(def diamond-x
+  (segment-painter (concat diamond-segs x-segs)))
+
+(def george-segs
   (path  p1  p2  p3  p4  p5  p6  p7  p8  p9 p10
         p11 p12 p13 p14 p15 p16 p17 p18 p19 p20
         p21 p22))
-; gw
-(def george (segment-painter george-data))
+
+(def george (segment-painter george-segs))
 
 
 (defn draw [picture]
@@ -236,8 +259,11 @@
     ;; (draw x)
     ;; (draw box)
     ;; (draw george)
-    ;; (draw (rotate george))
-    (draw (beside george (rotate180 george)))
+    ;; (draw (rotate180 george))
+    ;; (draw (beside (flip-horiz george) (flip-vert george)))
+    ;; (draw (beside (flip-horiz george) george))
+    (draw (below (flip-horiz george) george))
+    ;; (draw (beside box x))
     ;; (draw (flip-vert george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))

From 9b218f6212cb0104ce2de058f18e4b5c2d7a6635 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13@innerpaths.net>
Date: Fri, 23 Jan 2015 21:16:09 -0800
Subject: [PATCH 04/13] docs, comments, split fcn, arrow picture, cleanup

Abstracted split-up, split-right into higher-level split function.
---
 src/escher/core.clj | 202 +++++++++++++++++++++++++++-----------------
 1 file changed, 126 insertions(+), 76 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 473ca8f..9d774f8 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -6,6 +6,8 @@
 ;; Increasing x values move a point to the right.
 ;; Increasing y values move a point downward.
 
+
+;; defines size of Quil window
 (def width 600)
 (def height 600)
 
@@ -27,14 +29,11 @@
              :e2 [0 200]})
 
 
-(defn make-vect [x y]
+(defn make-vec [x y]
   [x y])
 
-
-
-(defn make-segment [p1 p2]
-  [p1 p2])
-
+(defn make-segment [vec1 vec2]
+  [vec1 vec2])
 
 (defn add-vec [[x1 y1] [x2 y2]]
   [(+ x1 x2) (+ y1 y2)]
@@ -49,10 +48,12 @@
   [(* x s) (* y s)]
   )
 
+
 (defn frame-coord-map
   "Returns function that maps [x y] relative to the frame
   defined by origin (a vector to be interpreted as the point
-  describing the origin) and vectors e1 (x-axis), e2 (y-axis)."
+  describing the origin) and vectors e1 (x-axis), e2 (y-axis).
+   See SICP, 2nd ed., page 183."
   [{:keys [origin e1 e2]}]
   (fn [[x y]]
     (add-vec origin
@@ -61,20 +62,27 @@
 
 (defn frame-painter [{:keys [origin e1 e2]}]
   "Draws parallelogram 'frame' based on origin and vectors e1 and e2.
-  Must execute within a sketch."
+  Must execute within a Quil sketch."
   (let [corner (add-vec origin (add-vec e1 e2))]
     (draw-line origin (add-vec origin e1))
     (draw-line origin (add-vec origin e2))
     (draw-line (add-vec origin e2) corner)
     (draw-line (add-vec origin e1) corner)))
 
-(defn segment-painter [segment-list]
+(defn segment-painter
+  "Returns a function that, when given a frame as its argument, draws
+  the list of line segments in that frame."
+  [segment-list]
   (fn [frame]
     (let [m (frame-coord-map frame)]
       (doseq [[start end] segment-list]
         (draw-line (m start) (m end))))))
 
-(defn transform-picture [p origin e1 e2]
+(defn transform-picture
+  "Transforms a picture by into a different picture, based on new vectors
+  for origin, e1, and e2. See SICP, 2nd ed., page 187-8. (Note that SICP
+  calls pictures 'painters' because they know how to paint themselves."
+  [p origin e1 e2]
   (fn [frame]
     (let [map (frame-coord-map frame)
           new-origin (map origin)]
@@ -106,7 +114,9 @@
       (right frame))))
 
 
-(defn below [p1 p2]
+(defn below
+  "Draws p2 below p1."
+  [p1 p2]
   (rotate (beside (rotate270 p1)
                   (rotate270 p2))))
 
@@ -130,24 +140,24 @@
       (below top
              bottom))))
 
-(defn right-split [p n]
-  (if (= n 0)
-    p
-    (let [smaller (right-split p (dec n))]
-      (beside p (below smaller smaller)))))
-
-(defn up-split [p n]
-  ;; COMPLETE (Ex 2.44)
-  )
 
 
 (defn split [f g]
-  ; COMPLETE (Ex 2.45)
-  "Should be able to do
+  "Higher-order function that allows the
+  following redefinitions:
+
     (def right-split (split beside below))
-    (def up-split (split below beside)
-  and replace the existing *-split fns"
-  )
+    (def up-split (split below beside))"
+  (fn self-fn [p n]
+    (if (= n 0)
+      p
+      (let [smaller (self-fn p (dec n))]
+        (f p (g smaller smaller))))))
+
+(def right-split (split beside below))
+(def up-split (split below beside))
+
+
 
 (defn corner-split [p n]
   (if (= n 0)
@@ -160,82 +170,118 @@
       (beside (below p top-left)
               (below bottom-right corner)))))
 
-(def combine-four (square-of-four flip-horiz
-                                  identity
-                                  rotate180
-                                  flip-vert))
+
+(def combine-four (square-of-four rotate180
+                                  flip-vert
+                                  flip-horiz
+                                  identity))
 
 (defn square-limit [p n]
   (combine-four (corner-split p n)))
 
-;; George data
-
-(def p1 (make-vect 0 0.35))
-(def p2 (make-vect 0.15 0.6))
-(def p3 (make-vect 0.3 0.4))
-(def p4 (make-vect 0.35 0.5))
-(def p5 (make-vect 0.25 1.0))
-(def p6 (make-vect 0.4 1.0))
-(def p7 (make-vect 0.5 0.7))
-(def p8 (make-vect 0.6 1.0))
-(def p9 (make-vect 0.75 1.0))
-(def p10 (make-vect 0.6 0.55))
-(def p11 (make-vect 1 0.85))
-(def p12 (make-vect 1 0.65))
-(def p13 (make-vect 0.75 0.35))
-(def p14 (make-vect 0.6 0.35))
-(def p15 (make-vect 0.65 0.15))
-(def p16 (make-vect 0.6 0))
-(def p17 (make-vect 0.4 0))
-(def p18 (make-vect 0.35 0.15))
-(def p19 (make-vect 0.4 0.35))
-(def p20 (make-vect 0.3 0.35))
-(def p21 (make-vect 0.15 0.4))
-(def p22 (make-vect 0.0 0.15))
-
 ;; Example usage of path:
 ;; (path p1 p2 p3) -->
 ;;    (([0 0.35] [0.15 0.6]) ([0.15 0.6] [0.3 0.4]))
 
-; Ex2.49, Make these shapes with segment-painter/path
-
 ;; By defining segment-lists separately, you can combine figures
 ;; by concat'ting their segment-lists--see diamond-x.
 
+
+;; making George drawing
+
+(def p1 (make-vec 0 0.35))
+(def p2 (make-vec 0.15 0.6))
+(def p3 (make-vec 0.3 0.4))
+(def p4 (make-vec 0.35 0.5))
+(def p5 (make-vec 0.25 1.0))
+(def p6 (make-vec 0.4 1.0))
+(def p7 (make-vec 0.5 0.7))
+(def p8 (make-vec 0.6 1.0))
+(def p9 (make-vec 0.75 1.0))
+(def p10 (make-vec 0.6 0.55))
+(def p11 (make-vec 1 0.85))
+(def p12 (make-vec 1 0.65))
+(def p13 (make-vec 0.75 0.35))
+(def p14 (make-vec 0.6 0.35))
+(def p15 (make-vec 0.65 0.15))
+(def p16 (make-vec 0.6 0))
+(def p17 (make-vec 0.4 0))
+(def p18 (make-vec 0.35 0.15))
+(def p19 (make-vec 0.4 0.35))
+(def p20 (make-vec 0.3 0.35))
+(def p21 (make-vec 0.15 0.4))
+(def p22 (make-vec 0.0 0.15))
+
+(def george-segs
+  (concat
+   (path  p1  p2  p3  p4  p5)
+   (path p6  p7  p8)
+   (path p9 p10 p11)
+   (path p12 p13 p14 p15 p16)
+   (path p17 p18 p19 p20 p21 p22)))
+
+(def george (segment-painter george-segs))
+
+
+;; making arrow drawing
+
+(def length-delta 0.1)
+(def arrow-dx 0.1)
+(def arrow-dy 0.3)
+
+(def a1 (make-vec 0.5 (- 1 length-delta)))
+(def a2 (make-vec 0.5 length-delta))
+(def shaft-segs   (path a1 a2))
+
+(def a3 (make-vec (- 0.5 arrow-dx) (+ arrow-dy length-delta)))
+(def a4 (make-vec (+ 0.5 arrow-dx) (+ arrow-dy length-delta)))
+(def head-segs   (path a3 a2 a4))
+
+(def arrow (segment-painter (concat shaft-segs head-segs)))
+
+
+;; making box drawing
+
 (def box-segs
-  (path (make-vect 0 0) (make-vect 0.99 0)
-        (make-vect 0.99 0.99) (make-vect 0 0.99)
-        (make-vect 0 0)))
+  (path (make-vec 0 0) (make-vec 1 0)
+        (make-vec 1 1) (make-vec 0 1)
+        (make-vec 0 0)))
 (def box
   (segment-painter box-segs))
 
 (def x-segs
-  (concat (path (make-vect 0 0) (make-vect 1 1))
-          (path (make-vect 1 0) (make-vect 0 1))))
+  (concat (path (make-vec 0 0) (make-vec 1 1))
+          (path (make-vec 1 0) (make-vec 0 1))))
 (def x
   (segment-painter x-segs))
 
 
+;; making diamond drawing
+
 (def diamond-segs
-  (path (make-vect 0.5 0) (make-vect 1 0.5)
-        (make-vect 0.5 1) (make-vect 0 0.5)
-        (make-vect 0.5 0)))
+  (path (make-vec 0.5 0) (make-vec 1 0.5)
+        (make-vec 0.5 1) (make-vec 0 0.5)
+        (make-vec 0.5 0)))
 
 (def diamond
   (segment-painter diamond-segs))
 
+
+;; making diamond-x drawing
+
 (def diamond-x
   (segment-painter (concat diamond-segs x-segs)))
 
-(def george-segs
-  (path  p1  p2  p3  p4  p5  p6  p7  p8  p9 p10
-        p11 p12 p13 p14 p15 p16 p17 p18 p19 p20
-        p21 p22))
 
-(def george (segment-painter george-segs))
+;; making diag drawing
+
+(def diag (segment-painter [[[0 0] [1 1]]]))
+
 
 
-(defn draw [picture]
+(defn draw
+  "Draws picture, using the entire Quil window."
+  [picture]
   (picture whole-window))
 
 (defn image-painter [img]
@@ -248,9 +294,10 @@
       ; COMPLETE
       )))
 
-(def diag (segment-painter [[[0 0] [1 1]]]))
-
-(defn draw-image []
+(defn draw-image
+  "'Container' for executing drawings within a Quil sketch.
+  Experiment by uncommenting one or more lines, or add your own."
+  []
   (let [man (image-painter (q/load-image "data/man.gif"))
         bruce (image-painter (q/load-image "data/bruce.jpg"))
         angels (image-painter (q/load-image "data/angels.jpg"))]
@@ -262,7 +309,9 @@
     ;; (draw (rotate180 george))
     ;; (draw (beside (flip-horiz george) (flip-vert george)))
     ;; (draw (beside (flip-horiz george) george))
-    (draw (below (flip-horiz george) george))
+    ;; (draw (below (flip-horiz george) george))
+    ;; (draw (right-split george 3))
+    ;; (draw (up-split george 3))
     ;; (draw (beside box x))
     ;; (draw (flip-vert george))
     ;; (draw (beside box box))
@@ -275,13 +324,14 @@
     ;; (draw ((square-of-four identity flip-vert
     ;;                        flip-horiz rotate)
     ;;        george))
+    (draw (square-limit arrow 4))
+
 
     ; Needs image-painter
     ;; (bruce frame1)
     ;; (bruce frame2)
     ;; (draw (beside george bruce))
-    ;; (draw (corner-split bruce 4))
-    ;; (draw (square-limit bruce 3))
+    ;; (draw (corner-split george 4))
     ;; (draw (beside  bruce (below  bruce
     ;;                              george)))
     ))

From f8dc53523901f84b162294b3ba8f2bd7a6a3ac6f Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Fri, 27 Feb 2015 22:04:49 -0800
Subject: [PATCH 05/13] mostly completed, w/docstrings & refactoring for
 beginners
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Source code refactored, with comments and docstrings added, to make it
easy for beginners to get up to speed quickly.

Does not implement image-painter.

To give yourself a chance to complete the exercise as ‘thattommyhall’
intended, delete the bodies of the following functions:

  add-vec
  sub-vec
  scale-vec
  flip-horiz
  rotate
  below
  path
  right-split (uncomment by removing “#_”)
  up-split (uncomment by removing “#_”)
  split

Just evaluate this file to see the “goal” function, square-limit, draw
itself. This version uses the “higher-level” versions of right-split
and up-split.

If you decide to write the code for up-split and derive the
higher-level function ‘split’, you will need to comment out or remove
the versions of right-split and up-split that follow split in the
source code and un-comment the versions that precede split in the
source code.

Enjoy, and please give me feedback if you find my version helpful!
---
 src/escher/core.clj | 525 ++++++++++++++++++++++++++++++++------------
 1 file changed, 380 insertions(+), 145 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 9d774f8..40a75b5 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -2,39 +2,15 @@
   (require [quil.core :as q])
   (:gen-class))
 
-;; In Quil, [0 0] is upper left corner of window.
-;; Increasing x values move a point to the right.
-;; Increasing y values move a point downward.
-
-
-;; defines size of Quil window
-(def width 600)
-(def height 600)
-
-(def draw-line q/line)
-
-;; origin, e1, and e2 (all 2-D vectors) define a frame.
-;; Think of e1 as the x-axis, e2 as the y-axis.
-
-(def whole-window {:origin [0 0]
-                   :e1 [width 0]
-                   :e2 [0 height]})
-
-(def frame1 {:origin [200 50]
-             :e1 [200 100]
-             :e2 [150 200]})
-
-(def frame2 {:origin [50 50]
-             :e1 [100 0]
-             :e2 [0 200]})
-
+;;==================================================================
+;;
+;;  vector-manipulation primitives
+;;
+;;==================================================================
 
 (defn make-vec [x y]
   [x y])
 
-(defn make-segment [vec1 vec2]
-  [vec1 vec2])
-
 (defn add-vec [[x1 y1] [x2 y2]]
   [(+ x1 x2) (+ y1 y2)]
  )
@@ -49,46 +25,138 @@
   )
 
 
+;;==================================================================
+;;
+;;  What is a frame?
+;;
+;;  A frame represents a transformation from one coordinate system
+;;  to another. The transformation described by:
+;;
+;;     {:origin [n1 n2], :e1 [n3 n4], :e2 [n5 n6]}
+;;
+;;  can express combinations of translation, scaling, shearing,
+;;  and reflection.
+;;
+;;==================================================================
+
+
 (defn frame-coord-map
   "Returns function that maps [x y] relative to the frame
   defined by origin (a vector to be interpreted as the point
-  describing the origin) and vectors e1 (x-axis), e2 (y-axis).
-   See SICP, 2nd ed., page 183."
+  describing the origin) and vectors e1 (x-axis), e2 (y-axis)--
+  see SICP, 2nd ed., page 183.
+
+  In this function, the frame describes the portion of the canvas
+  within which any untransformed picture will draw itself."
   [{:keys [origin e1 e2]}]
   (fn [[x y]]
     (add-vec origin
              (add-vec (scale-vec e1 x)
                       (scale-vec e2 y)))))
 
-(defn frame-painter [{:keys [origin e1 e2]}]
-  "Draws parallelogram 'frame' based on origin and vectors e1 and e2.
+
+;;==================================================================
+;;
+;;  What is a picture?
+;;
+;;  A picture is a function that, when given a frame, knows how to
+;;  draw itself in that frame. As such, it hides its implementation
+;;  details.
+;;
+;;  This file defines two functions that draw pictures:
+;;
+;;      segment-painter: creates a picture from line segments
+;;      image-painter: creates a picture from a GIF image
+;;
+;;==================================================================
+
+
+
+;;==================================================================
+;;
+;;  Utilities for drawing simple graphics using line segments
+;;
+;;==================================================================
+
+(defn make-segment
+  "Represent a line segment as a vector of two vectors--e.g.,
+  [[0 0] [1 0]] represents a line from [0 0] to [1 0]."
+  [vec1 vec2]
+  [vec1 vec2])
+
+(defn path
+  "Creates a seq of line-segments from a 'bare' list of points. Use to
+  draw a continuous line through the list of points--e.g.,
+
+      (path [[0 1] [0 0] [1 0]])
+
+  returns two line segments connecting the three points in sequence:
+
+      [ [[0 1] [0 0]] [[0 0] [1 0]] ]"
+  [& veclist]
+  (partition 2 1 veclist))
+
+(def draw-line q/line)
+
+
+
+;;==================================================================
+;;
+;;  for images drawn with line segments, this function returns
+;;  the picture (i.e., a function) that draws the desired image
+;;
+;;==================================================================
+
+(defn segment-painter
+  "Returns a picture that draws the given list of line segments.
   Must execute within a Quil sketch."
+    [segment-list]
+  ; xform-pt is a function that maps a point to the given frame
+  (fn [frame]
+    (let [xform-pt (frame-coord-map frame)]
+      (doseq [[start end] segment-list]
+        (draw-line (xform-pt start) (xform-pt end))))))
+
+
+(defn frame-painter [{:keys [origin e1 e2]}]
+  "Draws a parallelogram 'frame' based on origin and
+  vectors e1 and e2. Must execute within a Quil sketch.
+
+  (Used only to confirm minimal project functionality: in draw-image,
+  uncomment '(frame-painter frame1)' and evaluate the code
+  in this file.)"
   (let [corner (add-vec origin (add-vec e1 e2))]
     (draw-line origin (add-vec origin e1))
     (draw-line origin (add-vec origin e2))
     (draw-line (add-vec origin e2) corner)
     (draw-line (add-vec origin e1) corner)))
 
-(defn segment-painter
-  "Returns a function that, when given a frame as its argument, draws
-  the list of line segments in that frame."
-  [segment-list]
-  (fn [frame]
-    (let [m (frame-coord-map frame)]
-      (doseq [[start end] segment-list]
-        (draw-line (m start) (m end))))))
 
 (defn transform-picture
-  "Transforms a picture by into a different picture, based on new vectors
-  for origin, e1, and e2. See SICP, 2nd ed., page 187-8. (Note that SICP
-  calls pictures 'painters' because they know how to paint themselves."
+  "Returns a transformed picture based on the values of origin,
+  e1, and e2, which together describe a transformation frame.
+
+  Note that the returned picture will draw itself inside a
+  different frame (frame2), which can be considered to be a
+  drawing frame. The coordinates of origin, e1, and e2 are
+  usually within the range [0 1]--i.e.,a unit square with
+  origin [0 0]. Coordinates > 1 will draw outside the drawing
+  frame."
   [p origin e1 e2]
-  (fn [frame]
-    (let [map (frame-coord-map frame)
-          new-origin (map origin)]
+  (fn [frame2]
+    (let [unit-sq-xform (frame-coord-map frame2)
+          new-origin (unit-sq-xform origin)]
       (p {:origin new-origin
-          :e1 (sub-vec (map e1) new-origin)
-          :e2 (sub-vec (map e2) new-origin)}))))
+          :e1 (sub-vec (unit-sq-xform e1) new-origin)
+          :e2 (sub-vec (unit-sq-xform e2) new-origin)}))))
+
+
+
+;;==================================================================
+;;
+;;  basic transformations of a single picture
+;;
+;;==================================================================
 
 (defn flip-vert [p]
   (transform-picture p [0 1] [1 1] [0 0]))
@@ -103,9 +171,20 @@
   (rotate (rotate p)))
 
 (defn rotate270 [p]
-  (rotate (rotate (rotate p))))
+  (transform-picture p [0 1] [0 0] [1 1]))
+
 
-(defn beside [p1 p2]
+
+;;==================================================================
+;;
+;;  transformations that combine 2 or 4 pictures into a new picture
+;;
+;;==================================================================
+
+(defn beside
+  "Returns a picture that, splitting its frame in half vertically, draws
+  p1 in the left half and p2 in the right half."
+  [p1 p2]
   (let [split [0.5 0]
         left (transform-picture p1 [0 0] split [0 1])
         right (transform-picture p2 split [1 0] [0.5 1])]
@@ -113,53 +192,73 @@
       (left frame)
       (right frame))))
 
-
 (defn below
-  "Draws p2 below p1."
+  "Returns a picture that, splitting its frame in half horizintally,
+  draws p1 in the top half and p2 in the bottom half."
   [p1 p2]
   (rotate (beside (rotate270 p1)
                   (rotate270 p2))))
 
+(defn quartet
+  "Returns a picture that subdivides its frame into quarters and
+  draws p1-p4 in order, left-to-right and top-to-bottom."
+  [p1 p2 p3 p4]
+  (below (beside p1 p2)
+         (beside p3 p4)))
 
-(defn path
-  "Creates a seq of line-segments from a 'bare' list of points. Use to
-  draw a continuous line through the list of points."
-  [& veclist]
-  (partition 2 1 veclist))
 
 
-(defn quartet [p1 p2 p3 p4]
-  (below (beside p1 p2)
-         (beside p3 p4)))
+;;==================================================================
+;;
+;;  building-blocks for "goal" function, square-limit
+;;
+;;==================================================================
 
-(defn square-of-four [tl tr
-                      bl br]
-  (fn [p]
-    (let [top (beside (tl p) (tr p))
-          bottom (beside (bl p) (br p))]
-      (below top
-             bottom))))
+#_(defn right-split [p n]
+  (if (= n 0)
+    p
+    (let [smaller (right-split p (dec n))]
+      (beside p (below smaller smaller)))))
 
+#_(defn up-split [p n]
+  ;; COMPLETE (Ex 2.44)
+  )
 
 
 (defn split [f g]
-  "Higher-order function that allows the
-  following redefinitions:
-
-    (def right-split (split beside below))
-    (def up-split (split below beside))"
+  "Higher-order function that allows the functions right-split
+  and left-split to be defined without duplicated code. (Hint:
+  define each function independently, then analyze the resulting
+  code to enable each function's redefinition in terms of the
+  two picture transformations f and g.)"
   (fn self-fn [p n]
     (if (= n 0)
       p
       (let [smaller (self-fn p (dec n))]
         (f p (g smaller smaller))))))
 
-(def right-split (split beside below))
-(def up-split (split below beside))
-
-
-
-(defn corner-split [p n]
+(def right-split
+  "Returns a picture based on picture p and level-of-recursion n.
+  Draws p in the left half of the frame. Draws two copies of
+  (right-split p (- n 1)), stacked vertically, in the right half
+  of the frame. If n=0, draws p in the given frame."
+  (split beside below))
+
+(def up-split
+    "Returns a picture based on picture p and level-of-recursion n.
+  Draws p in the top half of the frame. Draws two copies of
+  (right-split p (- n 1)), one to the right of the other, in the
+  bottom half of the frame. If n=0, draws p in the current frame."
+  (split below beside))
+
+(defn corner-split
+    "Returns a picture based on picture p and level-of-recursion n.
+  Draws p in the upper-left quarter of frame. Draws two copies
+  of (right-split p (- n 1)) in upper-right quarter of frame.
+  Draws two copies of (top-split p (- n 1)) in the bottom-left
+  quarter of frame. Draws (corner-split p (- n 1)) in the bottom-
+  right quarter of frame. Wherever n=0, draws p in current frame."
+  [p n]
   (if (= n 0)
     p
     (let [up (up-split p (dec n))
@@ -170,60 +269,87 @@
       (beside (below p top-left)
               (below bottom-right corner)))))
 
+(defn square-of-four
+  "Returns a picture that subdivides its frame into quarters and
+  transforms the same picture p in four different ways, then
+  draws the results in order, left-to-right and top-to-bottom."
+  [tl tr
+   bl br]
+  (fn [p]
+    (let [top (beside (tl p) (tr p))
+          bottom (beside (bl p) (br p))]
+      (below top
+             bottom))))
 
 (def combine-four (square-of-four rotate180
                                   flip-vert
                                   flip-horiz
                                   identity))
 
-(defn square-limit [p n]
+(defn square-limit
+  "Returns a picture that has a 2 x 2 block of p in the center, encircled
+  by n borders of picture p, with each successive version of p being
+  half the size of the one that it immediately surrounds."
+  [p n]
   (combine-four (corner-split p n)))
 
-;; Example usage of path:
-;; (path p1 p2 p3) -->
-;;    (([0 0.35] [0.15 0.6]) ([0.15 0.6] [0.3 0.4]))
 
-;; By defining segment-lists separately, you can combine figures
-;; by concat'ting their segment-lists--see diamond-x.
 
+;;==================================================================
+;;==================================================================
+;;
+;;  Quil setup
+;;
+;;==================================================================
+;;==================================================================
 
-;; making George drawing
+;; In Quil, [0 0] is upper left corner of window.
+;; Increasing x values move a point to the right.
+;; Increasing y values move a point downward.
 
-(def p1 (make-vec 0 0.35))
-(def p2 (make-vec 0.15 0.6))
-(def p3 (make-vec 0.3 0.4))
-(def p4 (make-vec 0.35 0.5))
-(def p5 (make-vec 0.25 1.0))
-(def p6 (make-vec 0.4 1.0))
-(def p7 (make-vec 0.5 0.7))
-(def p8 (make-vec 0.6 1.0))
-(def p9 (make-vec 0.75 1.0))
-(def p10 (make-vec 0.6 0.55))
-(def p11 (make-vec 1 0.85))
-(def p12 (make-vec 1 0.65))
-(def p13 (make-vec 0.75 0.35))
-(def p14 (make-vec 0.6 0.35))
-(def p15 (make-vec 0.65 0.15))
-(def p16 (make-vec 0.6 0))
-(def p17 (make-vec 0.4 0))
-(def p18 (make-vec 0.35 0.15))
-(def p19 (make-vec 0.4 0.35))
-(def p20 (make-vec 0.3 0.35))
-(def p21 (make-vec 0.15 0.4))
-(def p22 (make-vec 0.0 0.15))
 
-(def george-segs
-  (concat
-   (path  p1  p2  p3  p4  p5)
-   (path p6  p7  p8)
-   (path p9 p10 p11)
-   (path p12 p13 p14 p15 p16)
-   (path p17 p18 p19 p20 p21 p22)))
+;; defines size of Quil window
+
+(def width 600)
+(def height 600)
+
+;; origin, e1, and e2 (all 2-D vectors) define a frame.
+;; Think of origin as a point, e1 as the x-axis, e2 as the y-axis.
+
+(def whole-window {:origin [0 0]
+                   :e1 [width 0]
+                   :e2 [0 height]})
+
+(def frame1 {:origin [200 50]
+             :e1 [200 100]
+             :e2 [150 200]})
+
+(def frame2 {:origin [50 50]
+             :e1 [100 0]
+             :e2 [0 200]})
+
+(defn draw
+  "Draws picture, using the entire Quil window."
+  [picture]
+  (picture whole-window))
+
 
-(def george (segment-painter george-segs))
 
+;;==================================================================
+;;==================================================================
+;;
+;;  PICTURES THAT ARE DRAWN USING SEGMENT-PAINTER
+;;
+;;==================================================================
+;;==================================================================
 
-;; making arrow drawing
+
+;;==================================================================
+;;
+;;  arrow: a picture that draws an arrow pointing toward the
+;;  top of the screen
+;;
+;;==================================================================
 
 (def length-delta 0.1)
 (def arrow-dx 0.1)
@@ -240,23 +366,45 @@
 (def arrow (segment-painter (concat shaft-segs head-segs)))
 
 
-;; making box drawing
+
+;;==================================================================
+;;
+;;  box: a picture that draws a square
+;;
+;;==================================================================
+
 
 (def box-segs
   (path (make-vec 0 0) (make-vec 1 0)
         (make-vec 1 1) (make-vec 0 1)
         (make-vec 0 0)))
+
 (def box
   (segment-painter box-segs))
 
+
+
+;;==================================================================
+;;
+;;  x: a picture that draws an "x" (as if from the vertices of 'box')
+;;
+;;==================================================================
+
 (def x-segs
   (concat (path (make-vec 0 0) (make-vec 1 1))
           (path (make-vec 1 0) (make-vec 0 1))))
+
 (def x
   (segment-painter x-segs))
 
 
-;; making diamond drawing
+
+;;==================================================================
+;;
+;;  diamond: a picture that draws a square for which one diagonal
+;;  is horizontal and the other is vertical
+;;
+;;==================================================================
 
 (def diamond-segs
   (path (make-vec 0.5 0) (make-vec 1 0.5)
@@ -267,22 +415,100 @@
   (segment-painter diamond-segs))
 
 
-;; making diamond-x drawing
+
+;;==================================================================
+;;
+;;  diamond-x: a picture that draws both 'x' and 'diamond' (in
+;;  the same frame)
+;;
+;;==================================================================
+
+;; Note that you can use (concat path1 path2 ... pathN)
+;; to combine multiple non-connected paths into a single
+;; sequence of line segments (for use with segment-painter).
 
 (def diamond-x
   (segment-painter (concat diamond-segs x-segs)))
 
 
-;; making diag drawing
 
+;;==================================================================
+;;
+;; george: a "man" figure using line segments
+;;
+;;==================================================================
+
+(def p1 (make-vec 0 0.35))
+(def p2 (make-vec 0.15 0.6))
+(def p3 (make-vec 0.3 0.4))
+(def p4 (make-vec 0.35 0.5))
+(def p5 (make-vec 0.25 1.0))
+(def p6 (make-vec 0.4 1.0))
+(def p7 (make-vec 0.5 0.7))
+(def p8 (make-vec 0.6 1.0))
+(def p9 (make-vec 0.75 1.0))
+(def p10 (make-vec 0.6 0.55))
+(def p11 (make-vec 1 0.85))
+(def p12 (make-vec 1 0.65))
+(def p13 (make-vec 0.75 0.35))
+(def p14 (make-vec 0.6 0.35))
+(def p15 (make-vec 0.65 0.15))
+(def p16 (make-vec 0.6 0))
+(def p17 (make-vec 0.4 0))
+(def p18 (make-vec 0.35 0.15))
+(def p19 (make-vec 0.4 0.35))
+(def p20 (make-vec 0.3 0.35))
+(def p21 (make-vec 0.15 0.4))
+(def p22 (make-vec 0.0 0.15))
+
+;; draws a small square in the upper left corner
+;(def p23 (make-vec 0.0 0.0))
+;(def p24 (make-vec 0.03 0.0))
+;(def p25 (make-vec 0.03 0.03))
+;(def p26 (make-vec 0.0 0.03))
+
+;; draws a slightly larger square in the lower right corner
+;(def p27 (make-vec 1 1))
+;(def p28 (make-vec 0.94 1))
+;(def p29 (make-vec 0.94 0.94))
+;(def p30 (make-vec 1 0.94))
+
+(def george-segs
+  (concat
+   (path p1  p2  p3  p4  p5)
+   (path p6  p7  p8)
+   (path p9 p10 p11)
+   (path p12 p13 p14 p15 p16)
+   (path p17 p18 p19 p20 p21 p22)
+
+;   (path p23 p24 p25 p26 p23) ; dot for origin
+;   (path p27 p28 p29 p30 p27) ; larger dot for opposite corner
+      ))
+
+(def george (segment-painter george-segs))
+
+
+; unused by other code, as far as I can tell
 (def diag (segment-painter [[[0 0] [1 1]]]))
 
 
 
-(defn draw
-  "Draws picture, using the entire Quil window."
-  [picture]
-  (picture whole-window))
+
+;;==================================================================
+;;==================================================================
+;;
+;;  for images drawn with GIFs and JPGs, this function returns
+;;  the picture (i.e., a function) that draws the desired image
+;;
+;;  (This function needs to be completed. People have found
+;;  the following URLs helpful:
+;;
+;;    http://quil.info/api/transform
+;;    http://homepages.inf.ed.ac.uk/rbf/HIPR2/affine.htm
+;;    http://www.cs.colorado.edu/~mcbryan/5229.03/mail/55.htm )
+;;
+;;==================================================================
+;;==================================================================
 
 (defn image-painter [img]
   (fn [{[ox oy] :origin
@@ -294,8 +520,12 @@
       ; COMPLETE
       )))
 
-(defn draw-image
-  "'Container' for executing drawings within a Quil sketch.
+
+
+
+
+(defn draw-pictures
+  "'Container' for executing drawing(s) within a Quil sketch.
   Experiment by uncommenting one or more lines, or add your own."
   []
   (let [man (image-painter (q/load-image "data/man.gif"))
@@ -305,40 +535,45 @@
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
-    ;; (draw george)
-    ;; (draw (rotate180 george))
-    ;; (draw (beside (flip-horiz george) (flip-vert george)))
-    ;; (draw (beside (flip-horiz george) george))
-    ;; (draw (below (flip-horiz george) george))
-    ;; (draw (right-split george 3))
-    ;; (draw (up-split george 3))
-    ;; (draw (beside box x))
-    ;; (draw (flip-vert george))
+    ;; (george frame2)
+    ;; (draw (rotate george))
+    ;; (draw (flip-horiz george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
     ;; (draw (beside (below george george)
-    ;;               (flip-horiz (below george george))))
+    ;; (flip-horiz (below george george))))
     ;; (draw (below (beside george (flip-horiz george))
-    ;;              (beside george (flip-horiz george))))
+    ;; (beside george (flip-horiz george))))
 
     ;; (draw ((square-of-four identity flip-vert
     ;;                        flip-horiz rotate)
-    ;;        george))
-    (draw (square-limit arrow 4))
+    ;;       george))
+
+    (draw (square-limit george 3))
 
+    ; these pictures need image-painter to be implemented
 
-    ; Needs image-painter
     ;; (bruce frame1)
     ;; (bruce frame2)
     ;; (draw (beside george bruce))
-    ;; (draw (corner-split george 4))
-    ;; (draw (beside  bruce (below  bruce
-    ;;                              george)))
+    ;; (draw (corner-split bruce 4))
+    ;; (draw (square-limit bruce 3))
+    ;; (draw (beside bruce (below bruce
+    ;; george)))
     ))
 
+
+
+;;==================================================================
+;;
+;;  this is the code that sets the size of the Quil window and
+;;  causes draw-pictures to be executed
+;;
+;;==================================================================
+
 (q/defsketch escher
   :title "Escher"
-  :draw draw-image
+  :draw draw-pictures
   :size [width height])
 
 (defn -main [])

From 2666ba0e4c98867bf2cd9c5832f225ee6141c262 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Sat, 21 Mar 2015 20:48:00 -0700
Subject: [PATCH 06/13] "over" xform, basic HSB color

---
 src/escher/core.clj | 45 +++++++++++++++++++++++++++++++++++++++------
 1 file changed, 39 insertions(+), 6 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 40a75b5..7e9243d 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -206,6 +206,10 @@
   (below (beside p1 p2)
          (beside p3 p4)))
 
+(defn over [p1 p2]
+  (fn [frame]
+    (p2 frame)
+    (p1 frame)))
 
 
 ;;==================================================================
@@ -520,7 +524,15 @@
       ; COMPLETE
       )))
 
+(def red   [0 100 100])
+(def green [33 100 100])
+(def blue  [66 100 100])
 
+(defn hsbpic
+  [p [h s b]]
+  (fn [frame]
+    (q/with-stroke [h s b]
+      (p frame))))
 
 
 
@@ -530,8 +542,12 @@
   []
   (let [man (image-painter (q/load-image "data/man.gif"))
         bruce (image-painter (q/load-image "data/bruce.jpg"))
-        angels (image-painter (q/load-image "data/angels.jpg"))]
-    (q/background 255)
+        angels (image-painter (q/load-image "data/angels.jpg"))
+        ]
+    (q/stroke-weight 4)
+    (q/color-mode :hsb 100)
+
+    (q/background 0 0 100)
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
@@ -540,8 +556,12 @@
     ;; (draw (flip-horiz george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
-    ;; (draw (beside (below george george)
-    ;; (flip-horiz (below george george))))
+    #_(draw (beside (hsvpic (below george george) red)
+                    (hsvpic (flip-horiz (below george george)) blue)))
+
+    (draw (over (hsbpic george red)
+                (hsbpic (rotate george) blue)))
+
     ;; (draw (below (beside george (flip-horiz george))
     ;; (beside george (flip-horiz george))))
 
@@ -549,7 +569,15 @@
     ;;                        flip-horiz rotate)
     ;;       george))
 
-    (draw (square-limit george 3))
+    ;(q/stroke 133 20 50)
+
+    #_(q/with-stroke [200 50 50]
+        (draw (square-limit george 3)))
+
+
+    ;(draw (color-picture (square-limit george 2) 255 0 0))
+
+    ;(println (format "%x" (q/current-stroke)))
 
     ; these pictures need image-painter to be implemented
 
@@ -571,9 +599,14 @@
 ;;
 ;;==================================================================
 
+(defn setup []
+  ; draw will be called 4 times per second
+  ;(q/frame-rate 4)
+  )
+
 (q/defsketch escher
   :title "Escher"
   :draw draw-pictures
   :size [width height])
 
-(defn -main [])
+;(defn -main [])

From 9c020b3147d8ac39e78917f15e4381db05566a1a Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Mon, 23 Mar 2015 11:45:55 -0700
Subject: [PATCH 07/13] adds definition of 'over' picture xformation

This reverts commit f8dc53523901f84b162294b3ba8f2bd7a6a3ac6f.

Conflicts:
	src/escher/core.clj
---
 src/escher/core.clj | 521 ++++++++++++++------------------------------
 1 file changed, 160 insertions(+), 361 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 7e9243d..59e958e 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -2,15 +2,39 @@
   (require [quil.core :as q])
   (:gen-class))
 
-;;==================================================================
-;;
-;;  vector-manipulation primitives
-;;
-;;==================================================================
+;; In Quil, [0 0] is upper left corner of window.
+;; Increasing x values move a point to the right.
+;; Increasing y values move a point downward.
+
+
+;; defines size of Quil window
+(def width 600)
+(def height 600)
+
+(def draw-line q/line)
+
+;; origin, e1, and e2 (all 2-D vectors) define a frame.
+;; Think of e1 as the x-axis, e2 as the y-axis.
+
+(def whole-window {:origin [0 0]
+                   :e1 [width 0]
+                   :e2 [0 height]})
+
+(def frame1 {:origin [200 50]
+             :e1 [200 100]
+             :e2 [150 200]})
+
+(def frame2 {:origin [50 50]
+             :e1 [100 0]
+             :e2 [0 200]})
+
 
 (defn make-vec [x y]
   [x y])
 
+(defn make-segment [vec1 vec2]
+  [vec1 vec2])
+
 (defn add-vec [[x1 y1] [x2 y2]]
   [(+ x1 x2) (+ y1 y2)]
  )
@@ -25,138 +49,46 @@
   )
 
 
-;;==================================================================
-;;
-;;  What is a frame?
-;;
-;;  A frame represents a transformation from one coordinate system
-;;  to another. The transformation described by:
-;;
-;;     {:origin [n1 n2], :e1 [n3 n4], :e2 [n5 n6]}
-;;
-;;  can express combinations of translation, scaling, shearing,
-;;  and reflection.
-;;
-;;==================================================================
-
-
 (defn frame-coord-map
   "Returns function that maps [x y] relative to the frame
   defined by origin (a vector to be interpreted as the point
-  describing the origin) and vectors e1 (x-axis), e2 (y-axis)--
-  see SICP, 2nd ed., page 183.
-
-  In this function, the frame describes the portion of the canvas
-  within which any untransformed picture will draw itself."
+  describing the origin) and vectors e1 (x-axis), e2 (y-axis).
+   See SICP, 2nd ed., page 183."
   [{:keys [origin e1 e2]}]
   (fn [[x y]]
     (add-vec origin
              (add-vec (scale-vec e1 x)
                       (scale-vec e2 y)))))
 
-
-;;==================================================================
-;;
-;;  What is a picture?
-;;
-;;  A picture is a function that, when given a frame, knows how to
-;;  draw itself in that frame. As such, it hides its implementation
-;;  details.
-;;
-;;  This file defines two functions that draw pictures:
-;;
-;;      segment-painter: creates a picture from line segments
-;;      image-painter: creates a picture from a GIF image
-;;
-;;==================================================================
-
-
-
-;;==================================================================
-;;
-;;  Utilities for drawing simple graphics using line segments
-;;
-;;==================================================================
-
-(defn make-segment
-  "Represent a line segment as a vector of two vectors--e.g.,
-  [[0 0] [1 0]] represents a line from [0 0] to [1 0]."
-  [vec1 vec2]
-  [vec1 vec2])
-
-(defn path
-  "Creates a seq of line-segments from a 'bare' list of points. Use to
-  draw a continuous line through the list of points--e.g.,
-
-      (path [[0 1] [0 0] [1 0]])
-
-  returns two line segments connecting the three points in sequence:
-
-      [ [[0 1] [0 0]] [[0 0] [1 0]] ]"
-  [& veclist]
-  (partition 2 1 veclist))
-
-(def draw-line q/line)
-
-
-
-;;==================================================================
-;;
-;;  for images drawn with line segments, this function returns
-;;  the picture (i.e., a function) that draws the desired image
-;;
-;;==================================================================
-
-(defn segment-painter
-  "Returns a picture that draws the given list of line segments.
-  Must execute within a Quil sketch."
-    [segment-list]
-  ; xform-pt is a function that maps a point to the given frame
-  (fn [frame]
-    (let [xform-pt (frame-coord-map frame)]
-      (doseq [[start end] segment-list]
-        (draw-line (xform-pt start) (xform-pt end))))))
-
-
 (defn frame-painter [{:keys [origin e1 e2]}]
-  "Draws a parallelogram 'frame' based on origin and
-  vectors e1 and e2. Must execute within a Quil sketch.
-
-  (Used only to confirm minimal project functionality: in draw-image,
-  uncomment '(frame-painter frame1)' and evaluate the code
-  in this file.)"
+  "Draws parallelogram 'frame' based on origin and vectors e1 and e2.
+  Must execute within a Quil sketch."
   (let [corner (add-vec origin (add-vec e1 e2))]
     (draw-line origin (add-vec origin e1))
     (draw-line origin (add-vec origin e2))
     (draw-line (add-vec origin e2) corner)
     (draw-line (add-vec origin e1) corner)))
 
+(defn segment-painter
+  "Returns a function that, when given a frame as its argument, draws
+  the list of line segments in that frame."
+  [segment-list]
+  (fn [frame]
+    (let [m (frame-coord-map frame)]
+      (doseq [[start end] segment-list]
+        (draw-line (m start) (m end))))))
 
 (defn transform-picture
-  "Returns a transformed picture based on the values of origin,
-  e1, and e2, which together describe a transformation frame.
-
-  Note that the returned picture will draw itself inside a
-  different frame (frame2), which can be considered to be a
-  drawing frame. The coordinates of origin, e1, and e2 are
-  usually within the range [0 1]--i.e.,a unit square with
-  origin [0 0]. Coordinates > 1 will draw outside the drawing
-  frame."
+  "Transforms a picture by into a different picture, based on new vectors
+  for origin, e1, and e2. See SICP, 2nd ed., page 187-8. (Note that SICP
+  calls pictures 'painters' because they know how to paint themselves."
   [p origin e1 e2]
-  (fn [frame2]
-    (let [unit-sq-xform (frame-coord-map frame2)
-          new-origin (unit-sq-xform origin)]
+  (fn [frame]
+    (let [map (frame-coord-map frame)
+          new-origin (map origin)]
       (p {:origin new-origin
-          :e1 (sub-vec (unit-sq-xform e1) new-origin)
-          :e2 (sub-vec (unit-sq-xform e2) new-origin)}))))
-
-
-
-;;==================================================================
-;;
-;;  basic transformations of a single picture
-;;
-;;==================================================================
+          :e1 (sub-vec (map e1) new-origin)
+          :e2 (sub-vec (map e2) new-origin)}))))
 
 (defn flip-vert [p]
   (transform-picture p [0 1] [1 1] [0 0]))
@@ -171,20 +103,9 @@
   (rotate (rotate p)))
 
 (defn rotate270 [p]
-  (transform-picture p [0 1] [0 0] [1 1]))
-
-
-
-;;==================================================================
-;;
-;;  transformations that combine 2 or 4 pictures into a new picture
-;;
-;;==================================================================
+  (rotate (rotate (rotate p))))
 
-(defn beside
-  "Returns a picture that, splitting its frame in half vertically, draws
-  p1 in the left half and p2 in the right half."
-  [p1 p2]
+(defn beside [p1 p2]
   (let [split [0.5 0]
         left (transform-picture p1 [0 0] split [0 1])
         right (transform-picture p2 split [1 0] [0.5 1])]
@@ -192,19 +113,14 @@
       (left frame)
       (right frame))))
 
+
 (defn below
-  "Returns a picture that, splitting its frame in half horizintally,
-  draws p1 in the top half and p2 in the bottom half."
+  "Draws p2 below p1."
   [p1 p2]
   (rotate (beside (rotate270 p1)
                   (rotate270 p2))))
 
-(defn quartet
-  "Returns a picture that subdivides its frame into quarters and
-  draws p1-p4 in order, left-to-right and top-to-bottom."
-  [p1 p2 p3 p4]
-  (below (beside p1 p2)
-         (beside p3 p4)))
+
 
 (defn over [p1 p2]
   (fn [frame]
@@ -212,57 +128,44 @@
     (p1 frame)))
 
 
-;;==================================================================
-;;
-;;  building-blocks for "goal" function, square-limit
-;;
-;;==================================================================
+(defn path
+  "Creates a seq of line-segments from a 'bare' list of points. Use to
+  draw a continuous line through the list of points."
+  [& veclist]
+  (partition 2 1 veclist))
 
-#_(defn right-split [p n]
-  (if (= n 0)
-    p
-    (let [smaller (right-split p (dec n))]
-      (beside p (below smaller smaller)))))
+(defn quartet [p1 p2 p3 p4]
+  (below (beside p1 p2)
+         (beside p3 p4)))
+
+(defn square-of-four [tl tr
+                      bl br]
+  (fn [p]
+    (let [top (beside (tl p) (tr p))
+          bottom (beside (bl p) (br p))]
+      (below top
+             bottom))))
 
-#_(defn up-split [p n]
-  ;; COMPLETE (Ex 2.44)
-  )
 
 
 (defn split [f g]
-  "Higher-order function that allows the functions right-split
-  and left-split to be defined without duplicated code. (Hint:
-  define each function independently, then analyze the resulting
-  code to enable each function's redefinition in terms of the
-  two picture transformations f and g.)"
+  "Higher-order function that allows the
+  following redefinitions:
+
+    (def right-split (split beside below))
+    (def up-split (split below beside))"
   (fn self-fn [p n]
     (if (= n 0)
       p
       (let [smaller (self-fn p (dec n))]
         (f p (g smaller smaller))))))
 
-(def right-split
-  "Returns a picture based on picture p and level-of-recursion n.
-  Draws p in the left half of the frame. Draws two copies of
-  (right-split p (- n 1)), stacked vertically, in the right half
-  of the frame. If n=0, draws p in the given frame."
-  (split beside below))
-
-(def up-split
-    "Returns a picture based on picture p and level-of-recursion n.
-  Draws p in the top half of the frame. Draws two copies of
-  (right-split p (- n 1)), one to the right of the other, in the
-  bottom half of the frame. If n=0, draws p in the current frame."
-  (split below beside))
-
-(defn corner-split
-    "Returns a picture based on picture p and level-of-recursion n.
-  Draws p in the upper-left quarter of frame. Draws two copies
-  of (right-split p (- n 1)) in upper-right quarter of frame.
-  Draws two copies of (top-split p (- n 1)) in the bottom-left
-  quarter of frame. Draws (corner-split p (- n 1)) in the bottom-
-  right quarter of frame. Wherever n=0, draws p in current frame."
-  [p n]
+(def right-split (split beside below))
+(def up-split (split below beside))
+
+
+
+(defn corner-split [p n]
   (if (= n 0)
     p
     (let [up (up-split p (dec n))
@@ -273,87 +176,60 @@
       (beside (below p top-left)
               (below bottom-right corner)))))
 
-(defn square-of-four
-  "Returns a picture that subdivides its frame into quarters and
-  transforms the same picture p in four different ways, then
-  draws the results in order, left-to-right and top-to-bottom."
-  [tl tr
-   bl br]
-  (fn [p]
-    (let [top (beside (tl p) (tr p))
-          bottom (beside (bl p) (br p))]
-      (below top
-             bottom))))
 
 (def combine-four (square-of-four rotate180
                                   flip-vert
                                   flip-horiz
                                   identity))
 
-(defn square-limit
-  "Returns a picture that has a 2 x 2 block of p in the center, encircled
-  by n borders of picture p, with each successive version of p being
-  half the size of the one that it immediately surrounds."
-  [p n]
+(defn square-limit [p n]
   (combine-four (corner-split p n)))
 
+;; Example usage of path:
+;; (path p1 p2 p3) -->
+;;    (([0 0.35] [0.15 0.6]) ([0.15 0.6] [0.3 0.4]))
 
+;; By defining segment-lists separately, you can combine figures
+;; by concat'ting their segment-lists--see diamond-x.
 
-;;==================================================================
-;;==================================================================
-;;
-;;  Quil setup
-;;
-;;==================================================================
-;;==================================================================
-
-;; In Quil, [0 0] is upper left corner of window.
-;; Increasing x values move a point to the right.
-;; Increasing y values move a point downward.
-
-
-;; defines size of Quil window
-
-(def width 600)
-(def height 600)
-
-;; origin, e1, and e2 (all 2-D vectors) define a frame.
-;; Think of origin as a point, e1 as the x-axis, e2 as the y-axis.
-
-(def whole-window {:origin [0 0]
-                   :e1 [width 0]
-                   :e2 [0 height]})
-
-(def frame1 {:origin [200 50]
-             :e1 [200 100]
-             :e2 [150 200]})
-
-(def frame2 {:origin [50 50]
-             :e1 [100 0]
-             :e2 [0 200]})
 
-(defn draw
-  "Draws picture, using the entire Quil window."
-  [picture]
-  (picture whole-window))
+;; making George drawing
 
+(def p1 (make-vec 0 0.35))
+(def p2 (make-vec 0.15 0.6))
+(def p3 (make-vec 0.3 0.4))
+(def p4 (make-vec 0.35 0.5))
+(def p5 (make-vec 0.25 1.0))
+(def p6 (make-vec 0.4 1.0))
+(def p7 (make-vec 0.5 0.7))
+(def p8 (make-vec 0.6 1.0))
+(def p9 (make-vec 0.75 1.0))
+(def p10 (make-vec 0.6 0.55))
+(def p11 (make-vec 1 0.85))
+(def p12 (make-vec 1 0.65))
+(def p13 (make-vec 0.75 0.35))
+(def p14 (make-vec 0.6 0.35))
+(def p15 (make-vec 0.65 0.15))
+(def p16 (make-vec 0.6 0))
+(def p17 (make-vec 0.4 0))
+(def p18 (make-vec 0.35 0.15))
+(def p19 (make-vec 0.4 0.35))
+(def p20 (make-vec 0.3 0.35))
+(def p21 (make-vec 0.15 0.4))
+(def p22 (make-vec 0.0 0.15))
 
+(def george-segs
+  (concat
+   (path  p1  p2  p3  p4  p5)
+   (path p6  p7  p8)
+   (path p9 p10 p11)
+   (path p12 p13 p14 p15 p16)
+   (path p17 p18 p19 p20 p21 p22)))
 
-;;==================================================================
-;;==================================================================
-;;
-;;  PICTURES THAT ARE DRAWN USING SEGMENT-PAINTER
-;;
-;;==================================================================
-;;==================================================================
+(def george (segment-painter george-segs))
 
 
-;;==================================================================
-;;
-;;  arrow: a picture that draws an arrow pointing toward the
-;;  top of the screen
-;;
-;;==================================================================
+;; making arrow drawing
 
 (def length-delta 0.1)
 (def arrow-dx 0.1)
@@ -370,45 +246,23 @@
 (def arrow (segment-painter (concat shaft-segs head-segs)))
 
 
-
-;;==================================================================
-;;
-;;  box: a picture that draws a square
-;;
-;;==================================================================
-
+;; making box drawing
 
 (def box-segs
   (path (make-vec 0 0) (make-vec 1 0)
         (make-vec 1 1) (make-vec 0 1)
         (make-vec 0 0)))
-
 (def box
   (segment-painter box-segs))
 
-
-
-;;==================================================================
-;;
-;;  x: a picture that draws an "x" (as if from the vertices of 'box')
-;;
-;;==================================================================
-
 (def x-segs
   (concat (path (make-vec 0 0) (make-vec 1 1))
           (path (make-vec 1 0) (make-vec 0 1))))
-
 (def x
   (segment-painter x-segs))
 
 
-
-;;==================================================================
-;;
-;;  diamond: a picture that draws a square for which one diagonal
-;;  is horizontal and the other is vertical
-;;
-;;==================================================================
+;; making diamond drawing
 
 (def diamond-segs
   (path (make-vec 0.5 0) (make-vec 1 0.5)
@@ -419,100 +273,22 @@
   (segment-painter diamond-segs))
 
 
-
-;;==================================================================
-;;
-;;  diamond-x: a picture that draws both 'x' and 'diamond' (in
-;;  the same frame)
-;;
-;;==================================================================
-
-;; Note that you can use (concat path1 path2 ... pathN)
-;; to combine multiple non-connected paths into a single
-;; sequence of line segments (for use with segment-painter).
+;; making diamond-x drawing
 
 (def diamond-x
   (segment-painter (concat diamond-segs x-segs)))
 
 
+;; making diag drawing
 
-;;==================================================================
-;;
-;; george: a "man" figure using line segments
-;;
-;;==================================================================
-
-(def p1 (make-vec 0 0.35))
-(def p2 (make-vec 0.15 0.6))
-(def p3 (make-vec 0.3 0.4))
-(def p4 (make-vec 0.35 0.5))
-(def p5 (make-vec 0.25 1.0))
-(def p6 (make-vec 0.4 1.0))
-(def p7 (make-vec 0.5 0.7))
-(def p8 (make-vec 0.6 1.0))
-(def p9 (make-vec 0.75 1.0))
-(def p10 (make-vec 0.6 0.55))
-(def p11 (make-vec 1 0.85))
-(def p12 (make-vec 1 0.65))
-(def p13 (make-vec 0.75 0.35))
-(def p14 (make-vec 0.6 0.35))
-(def p15 (make-vec 0.65 0.15))
-(def p16 (make-vec 0.6 0))
-(def p17 (make-vec 0.4 0))
-(def p18 (make-vec 0.35 0.15))
-(def p19 (make-vec 0.4 0.35))
-(def p20 (make-vec 0.3 0.35))
-(def p21 (make-vec 0.15 0.4))
-(def p22 (make-vec 0.0 0.15))
-
-;; draws a small square in the upper left corner
-;(def p23 (make-vec 0.0 0.0))
-;(def p24 (make-vec 0.03 0.0))
-;(def p25 (make-vec 0.03 0.03))
-;(def p26 (make-vec 0.0 0.03))
-
-;; draws a slightly larger square in the lower right corner
-;(def p27 (make-vec 1 1))
-;(def p28 (make-vec 0.94 1))
-;(def p29 (make-vec 0.94 0.94))
-;(def p30 (make-vec 1 0.94))
-
-(def george-segs
-  (concat
-   (path p1  p2  p3  p4  p5)
-   (path p6  p7  p8)
-   (path p9 p10 p11)
-   (path p12 p13 p14 p15 p16)
-   (path p17 p18 p19 p20 p21 p22)
-
-;   (path p23 p24 p25 p26 p23) ; dot for origin
-;   (path p27 p28 p29 p30 p27) ; larger dot for opposite corner
-      ))
-
-(def george (segment-painter george-segs))
-
-
-; unused by other code, as far as I can tell
 (def diag (segment-painter [[[0 0] [1 1]]]))
 
 
 
-
-;;==================================================================
-;;==================================================================
-;;
-;;  for images drawn with GIFs and JPGs, this function returns
-;;  the picture (i.e., a function) that draws the desired image
-;;
-;;  (This function needs to be completed. People have found
-;;  the following URLs helpful:
-;;
-;;    http://quil.info/api/transform
-;;    http://homepages.inf.ed.ac.uk/rbf/HIPR2/affine.htm
-;;    http://www.cs.colorado.edu/~mcbryan/5229.03/mail/55.htm )
-;;
-;;==================================================================
-;;==================================================================
+(defn draw
+  "Draws picture, using the entire Quil window."
+  [picture]
+  (picture whole-window))
 
 (defn image-painter [img]
   (fn [{[ox oy] :origin
@@ -524,6 +300,7 @@
       ; COMPLETE
       )))
 
+<<<<<<< HEAD
 (def red   [0 100 100])
 (def green [33 100 100])
 (def blue  [66 100 100])
@@ -538,6 +315,10 @@
 
 (defn draw-pictures
   "'Container' for executing drawing(s) within a Quil sketch.
+=======
+(defn draw-image
+  "'Container' for executing drawings within a Quil sketch.
+>>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
   Experiment by uncommenting one or more lines, or add your own."
   []
   (let [man (image-painter (q/load-image "data/man.gif"))
@@ -551,22 +332,34 @@
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
-    ;; (george frame2)
-    ;; (draw (rotate george))
-    ;; (draw (flip-horiz george))
+    ;; (draw george)
+    ;; (draw (rotate180 george))
+    ;; (draw (beside (flip-horiz george) (flip-vert george)))
+    ;; (draw (beside (flip-horiz george) george))
+    ;; (draw (below (flip-horiz george) george))
+    ;; (draw (right-split george 3))
+    ;; (draw (up-split george 3))
+    ;; (draw (beside box x))
+    ;; (draw (flip-vert george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
+<<<<<<< HEAD
     #_(draw (beside (hsvpic (below george george) red)
                     (hsvpic (flip-horiz (below george george)) blue)))
 
     (draw (over (hsbpic george red)
                 (hsbpic (rotate george) blue)))
 
+=======
+    ;; (draw (beside (below george george)
+    ;;               (flip-horiz (below george george))))
+>>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
     ;; (draw (below (beside george (flip-horiz george))
-    ;; (beside george (flip-horiz george))))
+    ;;              (beside george (flip-horiz george))))
 
     ;; (draw ((square-of-four identity flip-vert
     ;;                        flip-horiz rotate)
+<<<<<<< HEAD
     ;;       george))
 
     ;(q/stroke 133 20 50)
@@ -578,18 +371,22 @@
     ;(draw (color-picture (square-limit george 2) 255 0 0))
 
     ;(println (format "%x" (q/current-stroke)))
+=======
+    ;;        george))
+    (draw (square-limit arrow 4))
+>>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
 
-    ; these pictures need image-painter to be implemented
 
+    ; Needs image-painter
     ;; (bruce frame1)
     ;; (bruce frame2)
     ;; (draw (beside george bruce))
-    ;; (draw (corner-split bruce 4))
-    ;; (draw (square-limit bruce 3))
-    ;; (draw (beside bruce (below bruce
-    ;; george)))
+    ;; (draw (corner-split george 4))
+    ;; (draw (beside  bruce (below  bruce
+    ;;                              george)))
     ))
 
+<<<<<<< HEAD
 
 
 ;;==================================================================
@@ -604,9 +401,11 @@
   ;(q/frame-rate 4)
   )
 
+=======
+>>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
 (q/defsketch escher
   :title "Escher"
-  :draw draw-pictures
+  :draw draw-image
   :size [width height])
 
 ;(defn -main [])

From 85cf553895cb827bb18d53c7dd3e27c958bba5f2 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Mon, 23 Mar 2015 12:39:47 -0700
Subject: [PATCH 08/13] now uses clj-tuple for creating vectors, hash maps

---
 project.clj         |  1 +
 src/escher/core.clj | 71 ++++++++++++++++++++++-----------------------
 2 files changed, 36 insertions(+), 36 deletions(-)

diff --git a/project.clj b/project.clj
index 9e76180..8364b82 100644
--- a/project.clj
+++ b/project.clj
@@ -4,6 +4,7 @@
   :license {:name "Eclipse Public License"
             :url "http://www.eclipse.org/legal/epl-v10.html"}
   :dependencies [[org.clojure/clojure "1.6.0"]
+                 [clj-tuple "0.2.0"]
                  [quil "2.2.4"]]
   :main ^:skip-aot escher.core
   :target-path "target/%s"
diff --git a/src/escher/core.clj b/src/escher/core.clj
index 7e9243d..174888c 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -1,5 +1,6 @@
 (ns escher.core
-  (require [quil.core :as q])
+  (require [quil.core :as q]
+           [clj-tuple :as tup])
   (:gen-class))
 
 ;;==================================================================
@@ -9,20 +10,17 @@
 ;;==================================================================
 
 (defn make-vec [x y]
-  [x y])
+  (tup/vector x y))
 
 (defn add-vec [[x1 y1] [x2 y2]]
-  [(+ x1 x2) (+ y1 y2)]
- )
+  (tup/vector (+ x1 x2) (+ y1 y2)))
 
 
 (defn sub-vec [[x1 y1] [x2 y2]]
-  [(- x1 x2) (- y1 y2)]
-  )
+  (tup/vector (- x1 x2) (- y1 y2)))
 
 (defn scale-vec [[x y] s]
-  [(* x s) (* y s)]
-  )
+  (tup/vector (* x s) (* y s)))
 
 
 ;;==================================================================
@@ -82,7 +80,7 @@
   "Represent a line segment as a vector of two vectors--e.g.,
   [[0 0] [1 0]] represents a line from [0 0] to [1 0]."
   [vec1 vec2]
-  [vec1 vec2])
+  (tup/vector vec1 vec2))
 
 (defn path
   "Creates a seq of line-segments from a 'bare' list of points. Use to
@@ -146,9 +144,9 @@
   (fn [frame2]
     (let [unit-sq-xform (frame-coord-map frame2)
           new-origin (unit-sq-xform origin)]
-      (p {:origin new-origin
-          :e1 (sub-vec (unit-sq-xform e1) new-origin)
-          :e2 (sub-vec (unit-sq-xform e2) new-origin)}))))
+      (p (tup/hash-map :origin new-origin
+                       :e1 (sub-vec (unit-sq-xform e1) new-origin)
+                       :e2 (sub-vec (unit-sq-xform e2) new-origin))))))
 
 
 
@@ -159,19 +157,19 @@
 ;;==================================================================
 
 (defn flip-vert [p]
-  (transform-picture p [0 1] [1 1] [0 0]))
+  (transform-picture p (tup/vector 0 1) (tup/vector 1 1) (tup/vector 0 0)))
 
 (defn flip-horiz [p]
-  (transform-picture p [1 0] [0 0] [1 1]))
+  (transform-picture p (tup/vector 1 0) (tup/vector 0 0) (tup/vector 1 1)))
 
 (defn rotate [p]
-  (transform-picture p [1 0] [1 1] [0 0]))
+  (transform-picture p (tup/vector 1 0) (tup/vector 1 1) (tup/vector 0 0)))
 
 (defn rotate180 [p]
   (rotate (rotate p)))
 
 (defn rotate270 [p]
-  (transform-picture p [0 1] [0 0] [1 1]))
+  (transform-picture p (tup/vector 0 1) (tup/vector 0 0) (tup/vector 1 1)))
 
 
 
@@ -185,9 +183,9 @@
   "Returns a picture that, splitting its frame in half vertically, draws
   p1 in the left half and p2 in the right half."
   [p1 p2]
-  (let [split [0.5 0]
-        left (transform-picture p1 [0 0] split [0 1])
-        right (transform-picture p2 split [1 0] [0.5 1])]
+  (let [split (tup/vector 0.5 0)
+        left (transform-picture p1 (tup/vector 0 0) split (tup/vector 0 1))
+        right (transform-picture p2 split (tup/vector 1 0) (tup/vector 0.5 1))]
     (fn [frame]
       (left frame)
       (right frame))))
@@ -320,17 +318,17 @@
 ;; origin, e1, and e2 (all 2-D vectors) define a frame.
 ;; Think of origin as a point, e1 as the x-axis, e2 as the y-axis.
 
-(def whole-window {:origin [0 0]
-                   :e1 [width 0]
-                   :e2 [0 height]})
+(def whole-window {:origin (tup/vector 0 0)
+                   :e1 (tup/vector width 0)
+                   :e2 (tup/vector 0 height)})
 
-(def frame1 {:origin [200 50]
-             :e1 [200 100]
-             :e2 [150 200]})
+(def frame1 {:origin (tup/vector 200 50)
+             :e1 (tup/vector 200 100)
+             :e2 (tup/vector 150 200)})
 
-(def frame2 {:origin [50 50]
-             :e1 [100 0]
-             :e2 [0 200]})
+(def frame2 {:origin (tup/vector 50 50)
+             :e1 (tup/vector 100 0)
+             :e2 (tup/vector 0 200)})
 
 (defn draw
   "Draws picture, using the entire Quil window."
@@ -524,9 +522,9 @@
       ; COMPLETE
       )))
 
-(def red   [0 100 100])
-(def green [33 100 100])
-(def blue  [66 100 100])
+(def red   (tup/vector 0 100 100))
+(def green (tup/vector 33 100 100))
+(def blue  (tup/vector 66 100 100))
 
 (defn hsbpic
   [p [h s b]]
@@ -544,10 +542,10 @@
         bruce (image-painter (q/load-image "data/bruce.jpg"))
         angels (image-painter (q/load-image "data/angels.jpg"))
         ]
-    (q/stroke-weight 4)
-    (q/color-mode :hsb 100)
+    #_(q/stroke-weight 4)
+    #_(q/color-mode :hsb 100)
 
-    (q/background 0 0 100)
+    #_(q/background 0 0 100)
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
@@ -559,7 +557,7 @@
     #_(draw (beside (hsvpic (below george george) red)
                     (hsvpic (flip-horiz (below george george)) blue)))
 
-    (draw (over (hsbpic george red)
+   #_(draw (over (hsbpic george red)
                 (hsbpic (rotate george) blue)))
 
     ;; (draw (below (beside george (flip-horiz george))
@@ -574,6 +572,7 @@
     #_(q/with-stroke [200 50 50]
         (draw (square-limit george 3)))
 
+    (draw (square-limit george 3))
 
     ;(draw (color-picture (square-limit george 2) 255 0 0))
 
@@ -609,4 +608,4 @@
   :draw draw-pictures
   :size [width height])
 
-;(defn -main [])
+(defn -main [])

From 15a11980725c61982f32080825a68d377695f29a Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Mon, 23 Mar 2015 20:41:26 -0700
Subject: [PATCH 09/13] revert to more 'intelligent' code for segment-painter

This reverts commit f8dc53523901f84b162294b3ba8f2bd7a6a3ac6f.

Conflicts:
	src/escher/core.clj
---
 src/escher/core.clj | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 174888c..0e8d2d8 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -105,16 +105,6 @@
 ;;
 ;;==================================================================
 
-(defn segment-painter
-  "Returns a picture that draws the given list of line segments.
-  Must execute within a Quil sketch."
-    [segment-list]
-  ; xform-pt is a function that maps a point to the given frame
-  (fn [frame]
-    (let [xform-pt (frame-coord-map frame)]
-      (doseq [[start end] segment-list]
-        (draw-line (xform-pt start) (xform-pt end))))))
-
 
 (defn frame-painter [{:keys [origin e1 e2]}]
   "Draws a parallelogram 'frame' based on origin and
@@ -129,6 +119,15 @@
     (draw-line (add-vec origin e2) corner)
     (draw-line (add-vec origin e1) corner)))
 
+(defn segment-painter
+  "Returns a picture that draws the given list of line segments.
+  Must execute within a Quil sketch."
+    [segment-list]
+  ; xform-pt is a function that maps a point to the given frame
+  (fn [frame]
+    (let [xform-pt (frame-coord-map frame)]
+      (doseq [[start end] segment-list]
+        (draw-line (xform-pt start) (xform-pt end))))))
 
 (defn transform-picture
   "Returns a transformed picture based on the values of origin,

From 711dcdabd6a2c9ca235ef64368f220f1ed1c48b4 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Mon, 23 Mar 2015 20:46:55 -0700
Subject: [PATCH 10/13] added dependency for clj-tuple

---
 project.clj         |   1 +
 src/escher/core.clj | 189 ++++++++++++++++++++++++++++++++++----------
 2 files changed, 149 insertions(+), 41 deletions(-)

diff --git a/project.clj b/project.clj
index 9e76180..8364b82 100644
--- a/project.clj
+++ b/project.clj
@@ -4,6 +4,7 @@
   :license {:name "Eclipse Public License"
             :url "http://www.eclipse.org/legal/epl-v10.html"}
   :dependencies [[org.clojure/clojure "1.6.0"]
+                 [clj-tuple "0.2.0"]
                  [quil "2.2.4"]]
   :main ^:skip-aot escher.core
   :target-path "target/%s"
diff --git a/src/escher/core.clj b/src/escher/core.clj
index 59e958e..1b2290e 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -1,5 +1,6 @@
 (ns escher.core
-  (require [quil.core :as q])
+  (require [quil.core :as q]
+           [clj-tuple :as tup])
   (:gen-class))
 
 ;; In Quil, [0 0] is upper left corner of window.
@@ -30,23 +31,20 @@
 
 
 (defn make-vec [x y]
-  [x y])
+  (tup/vector x y))
 
 (defn make-segment [vec1 vec2]
   [vec1 vec2])
 
 (defn add-vec [[x1 y1] [x2 y2]]
-  [(+ x1 x2) (+ y1 y2)]
- )
+  (tup/vector (+ x1 x2) (+ y1 y2)))
 
 
 (defn sub-vec [[x1 y1] [x2 y2]]
-  [(- x1 x2) (- y1 y2)]
-  )
+  (tup/vector (- x1 x2) (- y1 y2)))
 
 (defn scale-vec [[x y] s]
-  [(* x s) (* y s)]
-  )
+  (tup/vector (* x s) (* y s)))
 
 
 (defn frame-coord-map
@@ -60,6 +58,71 @@
              (add-vec (scale-vec e1 x)
                       (scale-vec e2 y)))))
 
+
+;;==================================================================
+;;
+;;  What is a picture?
+;;
+;;  A picture is a function that, when given a frame, knows how to
+;;  draw itself in that frame. As such, it hides its implementation
+;;  details.
+;;
+;;  This file defines two functions that draw pictures:
+;;
+;;      segment-painter: creates a picture from line segments
+;;      image-painter: creates a picture from a GIF image
+;;
+;;==================================================================
+
+
+
+;;==================================================================
+;;
+;;  Utilities for drawing simple graphics using line segments
+;;
+;;==================================================================
+
+(defn make-segment
+  "Represent a line segment as a vector of two vectors--e.g.,
+  [[0 0] [1 0]] represents a line from [0 0] to [1 0]."
+  [vec1 vec2]
+  (tup/vector vec1 vec2))
+
+(defn path
+  "Creates a seq of line-segments from a 'bare' list of points. Use to
+  draw a continuous line through the list of points--e.g.,
+
+      (path [[0 1] [0 0] [1 0]])
+
+  returns two line segments connecting the three points in sequence:
+
+      [ [[0 1] [0 0]] [[0 0] [1 0]] ]"
+  [& veclist]
+  (partition 2 1 veclist))
+
+(def draw-line q/line)
+
+
+
+;;==================================================================
+;;
+;;  for images drawn with line segments, this function returns
+;;  the picture (i.e., a function) that draws the desired image
+;;
+;;==================================================================
+
+(defn segment-painter
+  "Returns a picture that draws the given list of line segments.
+  Must execute within a Quil sketch."
+    [segment-list]
+  ; xform-pt is a function that maps a point to the given frame
+  (fn [frame]
+    (let [xform-pt (frame-coord-map frame)]
+      (doseq [[start end] segment-list]
+        (draw-line (xform-pt start) (xform-pt end))))))
+
+
+>>>>>>> color-anim
 (defn frame-painter [{:keys [origin e1 e2]}]
   "Draws parallelogram 'frame' based on origin and vectors e1 and e2.
   Must execute within a Quil sketch."
@@ -83,21 +146,29 @@
   for origin, e1, and e2. See SICP, 2nd ed., page 187-8. (Note that SICP
   calls pictures 'painters' because they know how to paint themselves."
   [p origin e1 e2]
-  (fn [frame]
-    (let [map (frame-coord-map frame)
-          new-origin (map origin)]
-      (p {:origin new-origin
-          :e1 (sub-vec (map e1) new-origin)
-          :e2 (sub-vec (map e2) new-origin)}))))
+  (fn [frame2]
+    (let [unit-sq-xform (frame-coord-map frame2)
+          new-origin (unit-sq-xform origin)]
+      (p (tup/hash-map :origin new-origin
+                       :e1 (sub-vec (unit-sq-xform e1) new-origin)
+                       :e2 (sub-vec (unit-sq-xform e2) new-origin))))))
+
+
+
+;;==================================================================
+;;
+;;  basic transformations of a single picture
+;;
+;;==================================================================
 
 (defn flip-vert [p]
-  (transform-picture p [0 1] [1 1] [0 0]))
+  (transform-picture p (tup/vector 0 1) (tup/vector 1 1) (tup/vector 0 0)))
 
 (defn flip-horiz [p]
-  (transform-picture p [1 0] [0 0] [1 1]))
+  (transform-picture p (tup/vector 1 0) (tup/vector 0 0) (tup/vector 1 1)))
 
 (defn rotate [p]
-  (transform-picture p [1 0] [1 1] [0 0]))
+  (transform-picture p (tup/vector 1 0) (tup/vector 1 1) (tup/vector 0 0)))
 
 (defn rotate180 [p]
   (rotate (rotate p)))
@@ -109,6 +180,23 @@
   (let [split [0.5 0]
         left (transform-picture p1 [0 0] split [0 1])
         right (transform-picture p2 split [1 0] [0.5 1])]
+  (transform-picture p (tup/vector 0 1) (tup/vector 0 0) (tup/vector 1 1))))
+
+
+
+;;==================================================================
+;;
+;;  transformations that combine 2 or 4 pictures into a new picture
+;;
+;;==================================================================
+
+(defn beside
+  "Returns a picture that, splitting its frame in half vertically, draws
+  p1 in the left half and p2 in the right half."
+  [p1 p2]
+  (let [split (tup/vector 0.5 0)
+        left (transform-picture p1 (tup/vector 0 0) split (tup/vector 0 1))
+        right (transform-picture p2 split (tup/vector 1 0) (tup/vector 0.5 1))]
     (fn [frame]
       (left frame)
       (right frame))))
@@ -193,6 +281,40 @@
 ;; by concat'ting their segment-lists--see diamond-x.
 
 
+;;==================================================================
+;;==================================================================
+;;
+;;  Quil setup
+;;
+;;==================================================================
+;;==================================================================
+
+;; In Quil, [0 0] is upper left corner of window.
+;; Increasing x values move a point to the right.
+;; Increasing y values move a point downward.
+
+
+;; defines size of Quil window
+
+(def width 600)
+(def height 600)
+
+;; origin, e1, and e2 (all 2-D vectors) define a frame.
+;; Think of origin as a point, e1 as the x-axis, e2 as the y-axis.
+
+(def whole-window {:origin (tup/vector 0 0)
+                   :e1 (tup/vector width 0)
+                   :e2 (tup/vector 0 height)})
+
+(def frame1 {:origin (tup/vector 200 50)
+             :e1 (tup/vector 200 100)
+             :e2 (tup/vector 150 200)})
+
+(def frame2 {:origin (tup/vector 50 50)
+             :e1 (tup/vector 100 0)
+             :e2 (tup/vector 0 200)})
+>>>>>>> color-anim
+
 ;; making George drawing
 
 (def p1 (make-vec 0 0.35))
@@ -300,10 +422,9 @@
       ; COMPLETE
       )))
 
-<<<<<<< HEAD
-(def red   [0 100 100])
-(def green [33 100 100])
-(def blue  [66 100 100])
+(def red   (tup/vector 0 100 100))
+(def green (tup/vector 33 100 100))
+(def blue  (tup/vector 66 100 100))
 
 (defn hsbpic
   [p [h s b]]
@@ -313,22 +434,18 @@
 
 
 
-(defn draw-pictures
-  "'Container' for executing drawing(s) within a Quil sketch.
-=======
 (defn draw-image
   "'Container' for executing drawings within a Quil sketch.
->>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
   Experiment by uncommenting one or more lines, or add your own."
   []
   (let [man (image-painter (q/load-image "data/man.gif"))
         bruce (image-painter (q/load-image "data/bruce.jpg"))
         angels (image-painter (q/load-image "data/angels.jpg"))
         ]
-    (q/stroke-weight 4)
-    (q/color-mode :hsb 100)
+    #_(q/stroke-weight 4)
+    #_(q/color-mode :hsb 100)
 
-    (q/background 0 0 100)
+    #_(q/background 0 0 100)
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
@@ -343,23 +460,17 @@
     ;; (draw (flip-vert george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
-<<<<<<< HEAD
     #_(draw (beside (hsvpic (below george george) red)
                     (hsvpic (flip-horiz (below george george)) blue)))
 
-    (draw (over (hsbpic george red)
+   #_(draw (over (hsbpic george red)
                 (hsbpic (rotate george) blue)))
 
-=======
-    ;; (draw (beside (below george george)
-    ;;               (flip-horiz (below george george))))
->>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
     ;; (draw (below (beside george (flip-horiz george))
     ;;              (beside george (flip-horiz george))))
 
     ;; (draw ((square-of-four identity flip-vert
     ;;                        flip-horiz rotate)
-<<<<<<< HEAD
     ;;       george))
 
     ;(q/stroke 133 20 50)
@@ -367,14 +478,13 @@
     #_(q/with-stroke [200 50 50]
         (draw (square-limit george 3)))
 
+    (draw (square-limit george 3))
 
     ;(draw (color-picture (square-limit george 2) 255 0 0))
 
     ;(println (format "%x" (q/current-stroke)))
-=======
     ;;        george))
     (draw (square-limit arrow 4))
->>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
 
 
     ; Needs image-painter
@@ -386,7 +496,6 @@
     ;;                              george)))
     ))
 
-<<<<<<< HEAD
 
 
 ;;==================================================================
@@ -401,11 +510,9 @@
   ;(q/frame-rate 4)
   )
 
-=======
->>>>>>> parent of f8dc535... mostly completed, w/docstrings & refactoring for beginners
 (q/defsketch escher
   :title "Escher"
   :draw draw-image
   :size [width height])
 
-;(defn -main [])
+(defn -main [])

From db075d902a858bd25dca310227465e0db62ce2fa Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Mon, 23 Mar 2015 21:03:30 -0700
Subject: [PATCH 11/13] replaced entire file by contents in color-anim branch

---
 src/escher/core.clj | 365 +++++++++++++++++++++++++++-----------------
 1 file changed, 228 insertions(+), 137 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 7257e7e..0e8d2d8 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -3,32 +3,11 @@
            [clj-tuple :as tup])
   (:gen-class))
 
-;; In Quil, [0 0] is upper left corner of window.
-;; Increasing x values move a point to the right.
-;; Increasing y values move a point downward.
-
-
-;; defines size of Quil window
-(def width 600)
-(def height 600)
-
-(def draw-line q/line)
-
-;; origin, e1, and e2 (all 2-D vectors) define a frame.
-;; Think of e1 as the x-axis, e2 as the y-axis.
-
-(def whole-window {:origin [0 0]
-                   :e1 [width 0]
-                   :e2 [0 height]})
-
-(def frame1 {:origin [200 50]
-             :e1 [200 100]
-             :e2 [150 200]})
-
-(def frame2 {:origin [50 50]
-             :e1 [100 0]
-             :e2 [0 200]})
-
+;;==================================================================
+;;
+;;  vector-manipulation primitives
+;;
+;;==================================================================
 
 (defn make-vec [x y]
   (tup/vector x y))
@@ -62,8 +41,11 @@
 (defn frame-coord-map
   "Returns function that maps [x y] relative to the frame
   defined by origin (a vector to be interpreted as the point
-  describing the origin) and vectors e1 (x-axis), e2 (y-axis).
-   See SICP, 2nd ed., page 183."
+  describing the origin) and vectors e1 (x-axis), e2 (y-axis)--
+  see SICP, 2nd ed., page 183.
+
+  In this function, the frame describes the portion of the canvas
+  within which any untransformed picture will draw itself."
   [{:keys [origin e1 e2]}]
   (fn [[x y]]
     (add-vec origin
@@ -125,8 +107,12 @@
 
 
 (defn frame-painter [{:keys [origin e1 e2]}]
-  "Draws parallelogram 'frame' based on origin and vectors e1 and e2.
-  Must execute within a Quil sketch."
+  "Draws a parallelogram 'frame' based on origin and
+  vectors e1 and e2. Must execute within a Quil sketch.
+
+  (Used only to confirm minimal project functionality: in draw-image,
+  uncomment '(frame-painter frame1)' and evaluate the code
+  in this file.)"
   (let [corner (add-vec origin (add-vec e1 e2))]
     (draw-line origin (add-vec origin e1))
     (draw-line origin (add-vec origin e2))
@@ -144,9 +130,15 @@
         (draw-line (xform-pt start) (xform-pt end))))))
 
 (defn transform-picture
-  "Transforms a picture by into a different picture, based on new vectors
-  for origin, e1, and e2. See SICP, 2nd ed., page 187-8. (Note that SICP
-  calls pictures 'painters' because they know how to paint themselves."
+  "Returns a transformed picture based on the values of origin,
+  e1, and e2, which together describe a transformation frame.
+
+  Note that the returned picture will draw itself inside a
+  different frame (frame2), which can be considered to be a
+  drawing frame. The coordinates of origin, e1, and e2 are
+  usually within the range [0 1]--i.e.,a unit square with
+  origin [0 0]. Coordinates > 1 will draw outside the drawing
+  frame."
   [p origin e1 e2]
   (fn [frame2]
     (let [unit-sq-xform (frame-coord-map frame2)
@@ -176,13 +168,7 @@
   (rotate (rotate p)))
 
 (defn rotate270 [p]
-  (rotate (rotate (rotate p))))
-
-(defn beside [p1 p2]
-  (let [split [0.5 0]
-        left (transform-picture p1 [0 0] split [0 1])
-        right (transform-picture p2 split [1 0] [0.5 1])]
-  (transform-picture p (tup/vector 0 1) (tup/vector 0 0) (tup/vector 1 1))))
+  (transform-picture p (tup/vector 0 1) (tup/vector 0 0) (tup/vector 1 1)))
 
 
 
@@ -203,14 +189,19 @@
       (left frame)
       (right frame))))
 
-
 (defn below
-  "Draws p2 below p1."
+  "Returns a picture that, splitting its frame in half horizintally,
+  draws p1 in the top half and p2 in the bottom half."
   [p1 p2]
   (rotate (beside (rotate270 p1)
                   (rotate270 p2))))
 
-
+(defn quartet
+  "Returns a picture that subdivides its frame into quarters and
+  draws p1-p4 in order, left-to-right and top-to-bottom."
+  [p1 p2 p3 p4]
+  (below (beside p1 p2)
+         (beside p3 p4)))
 
 (defn over [p1 p2]
   (fn [frame]
@@ -218,44 +209,57 @@
     (p1 frame)))
 
 
-(defn path
-  "Creates a seq of line-segments from a 'bare' list of points. Use to
-  draw a continuous line through the list of points."
-  [& veclist]
-  (partition 2 1 veclist))
-
-(defn quartet [p1 p2 p3 p4]
-  (below (beside p1 p2)
-         (beside p3 p4)))
+;;==================================================================
+;;
+;;  building-blocks for "goal" function, square-limit
+;;
+;;==================================================================
 
-(defn square-of-four [tl tr
-                      bl br]
-  (fn [p]
-    (let [top (beside (tl p) (tr p))
-          bottom (beside (bl p) (br p))]
-      (below top
-             bottom))))
+#_(defn right-split [p n]
+  (if (= n 0)
+    p
+    (let [smaller (right-split p (dec n))]
+      (beside p (below smaller smaller)))))
 
+#_(defn up-split [p n]
+  ;; COMPLETE (Ex 2.44)
+  )
 
 
 (defn split [f g]
-  "Higher-order function that allows the
-  following redefinitions:
-
-    (def right-split (split beside below))
-    (def up-split (split below beside))"
+  "Higher-order function that allows the functions right-split
+  and left-split to be defined without duplicated code. (Hint:
+  define each function independently, then analyze the resulting
+  code to enable each function's redefinition in terms of the
+  two picture transformations f and g.)"
   (fn self-fn [p n]
     (if (= n 0)
       p
       (let [smaller (self-fn p (dec n))]
         (f p (g smaller smaller))))))
 
-(def right-split (split beside below))
-(def up-split (split below beside))
-
-
-
-(defn corner-split [p n]
+(def right-split
+  "Returns a picture based on picture p and level-of-recursion n.
+  Draws p in the left half of the frame. Draws two copies of
+  (right-split p (- n 1)), stacked vertically, in the right half
+  of the frame. If n=0, draws p in the given frame."
+  (split beside below))
+
+(def up-split
+    "Returns a picture based on picture p and level-of-recursion n.
+  Draws p in the top half of the frame. Draws two copies of
+  (right-split p (- n 1)), one to the right of the other, in the
+  bottom half of the frame. If n=0, draws p in the current frame."
+  (split below beside))
+
+(defn corner-split
+    "Returns a picture based on picture p and level-of-recursion n.
+  Draws p in the upper-left quarter of frame. Draws two copies
+  of (right-split p (- n 1)) in upper-right quarter of frame.
+  Draws two copies of (top-split p (- n 1)) in the bottom-left
+  quarter of frame. Draws (corner-split p (- n 1)) in the bottom-
+  right quarter of frame. Wherever n=0, draws p in current frame."
+  [p n]
   (if (= n 0)
     p
     (let [up (up-split p (dec n))
@@ -266,21 +270,30 @@
       (beside (below p top-left)
               (below bottom-right corner)))))
 
+(defn square-of-four
+  "Returns a picture that subdivides its frame into quarters and
+  transforms the same picture p in four different ways, then
+  draws the results in order, left-to-right and top-to-bottom."
+  [tl tr
+   bl br]
+  (fn [p]
+    (let [top (beside (tl p) (tr p))
+          bottom (beside (bl p) (br p))]
+      (below top
+             bottom))))
 
 (def combine-four (square-of-four rotate180
                                   flip-vert
                                   flip-horiz
                                   identity))
 
-(defn square-limit [p n]
+(defn square-limit
+  "Returns a picture that has a 2 x 2 block of p in the center, encircled
+  by n borders of picture p, with each successive version of p being
+  half the size of the one that it immediately surrounds."
+  [p n]
   (combine-four (corner-split p n)))
 
-;; Example usage of path:
-;; (path p1 p2 p3) -->
-;;    (([0 0.35] [0.15 0.6]) ([0.15 0.6] [0.3 0.4]))
-
-;; By defining segment-lists separately, you can combine figures
-;; by concat'ting their segment-lists--see diamond-x.
 
 
 ;;==================================================================
@@ -316,43 +329,28 @@
              :e1 (tup/vector 100 0)
              :e2 (tup/vector 0 200)})
 
-;; making George drawing
+(defn draw
+  "Draws picture, using the entire Quil window."
+  [picture]
+  (picture whole-window))
 
-(def p1 (make-vec 0 0.35))
-(def p2 (make-vec 0.15 0.6))
-(def p3 (make-vec 0.3 0.4))
-(def p4 (make-vec 0.35 0.5))
-(def p5 (make-vec 0.25 1.0))
-(def p6 (make-vec 0.4 1.0))
-(def p7 (make-vec 0.5 0.7))
-(def p8 (make-vec 0.6 1.0))
-(def p9 (make-vec 0.75 1.0))
-(def p10 (make-vec 0.6 0.55))
-(def p11 (make-vec 1 0.85))
-(def p12 (make-vec 1 0.65))
-(def p13 (make-vec 0.75 0.35))
-(def p14 (make-vec 0.6 0.35))
-(def p15 (make-vec 0.65 0.15))
-(def p16 (make-vec 0.6 0))
-(def p17 (make-vec 0.4 0))
-(def p18 (make-vec 0.35 0.15))
-(def p19 (make-vec 0.4 0.35))
-(def p20 (make-vec 0.3 0.35))
-(def p21 (make-vec 0.15 0.4))
-(def p22 (make-vec 0.0 0.15))
 
-(def george-segs
-  (concat
-   (path  p1  p2  p3  p4  p5)
-   (path p6  p7  p8)
-   (path p9 p10 p11)
-   (path p12 p13 p14 p15 p16)
-   (path p17 p18 p19 p20 p21 p22)))
 
-(def george (segment-painter george-segs))
+;;==================================================================
+;;==================================================================
+;;
+;;  PICTURES THAT ARE DRAWN USING SEGMENT-PAINTER
+;;
+;;==================================================================
+;;==================================================================
 
 
-;; making arrow drawing
+;;==================================================================
+;;
+;;  arrow: a picture that draws an arrow pointing toward the
+;;  top of the screen
+;;
+;;==================================================================
 
 (def length-delta 0.1)
 (def arrow-dx 0.1)
@@ -369,23 +367,45 @@
 (def arrow (segment-painter (concat shaft-segs head-segs)))
 
 
-;; making box drawing
+
+;;==================================================================
+;;
+;;  box: a picture that draws a square
+;;
+;;==================================================================
+
 
 (def box-segs
   (path (make-vec 0 0) (make-vec 1 0)
         (make-vec 1 1) (make-vec 0 1)
         (make-vec 0 0)))
+
 (def box
   (segment-painter box-segs))
 
+
+
+;;==================================================================
+;;
+;;  x: a picture that draws an "x" (as if from the vertices of 'box')
+;;
+;;==================================================================
+
 (def x-segs
   (concat (path (make-vec 0 0) (make-vec 1 1))
           (path (make-vec 1 0) (make-vec 0 1))))
+
 (def x
   (segment-painter x-segs))
 
 
-;; making diamond drawing
+
+;;==================================================================
+;;
+;;  diamond: a picture that draws a square for which one diagonal
+;;  is horizontal and the other is vertical
+;;
+;;==================================================================
 
 (def diamond-segs
   (path (make-vec 0.5 0) (make-vec 1 0.5)
@@ -396,22 +416,100 @@
   (segment-painter diamond-segs))
 
 
-;; making diamond-x drawing
+
+;;==================================================================
+;;
+;;  diamond-x: a picture that draws both 'x' and 'diamond' (in
+;;  the same frame)
+;;
+;;==================================================================
+
+;; Note that you can use (concat path1 path2 ... pathN)
+;; to combine multiple non-connected paths into a single
+;; sequence of line segments (for use with segment-painter).
 
 (def diamond-x
   (segment-painter (concat diamond-segs x-segs)))
 
 
-;; making diag drawing
 
+;;==================================================================
+;;
+;; george: a "man" figure using line segments
+;;
+;;==================================================================
+
+(def p1 (make-vec 0 0.35))
+(def p2 (make-vec 0.15 0.6))
+(def p3 (make-vec 0.3 0.4))
+(def p4 (make-vec 0.35 0.5))
+(def p5 (make-vec 0.25 1.0))
+(def p6 (make-vec 0.4 1.0))
+(def p7 (make-vec 0.5 0.7))
+(def p8 (make-vec 0.6 1.0))
+(def p9 (make-vec 0.75 1.0))
+(def p10 (make-vec 0.6 0.55))
+(def p11 (make-vec 1 0.85))
+(def p12 (make-vec 1 0.65))
+(def p13 (make-vec 0.75 0.35))
+(def p14 (make-vec 0.6 0.35))
+(def p15 (make-vec 0.65 0.15))
+(def p16 (make-vec 0.6 0))
+(def p17 (make-vec 0.4 0))
+(def p18 (make-vec 0.35 0.15))
+(def p19 (make-vec 0.4 0.35))
+(def p20 (make-vec 0.3 0.35))
+(def p21 (make-vec 0.15 0.4))
+(def p22 (make-vec 0.0 0.15))
+
+;; draws a small square in the upper left corner
+;(def p23 (make-vec 0.0 0.0))
+;(def p24 (make-vec 0.03 0.0))
+;(def p25 (make-vec 0.03 0.03))
+;(def p26 (make-vec 0.0 0.03))
+
+;; draws a slightly larger square in the lower right corner
+;(def p27 (make-vec 1 1))
+;(def p28 (make-vec 0.94 1))
+;(def p29 (make-vec 0.94 0.94))
+;(def p30 (make-vec 1 0.94))
+
+(def george-segs
+  (concat
+   (path p1  p2  p3  p4  p5)
+   (path p6  p7  p8)
+   (path p9 p10 p11)
+   (path p12 p13 p14 p15 p16)
+   (path p17 p18 p19 p20 p21 p22)
+
+;   (path p23 p24 p25 p26 p23) ; dot for origin
+;   (path p27 p28 p29 p30 p27) ; larger dot for opposite corner
+      ))
+
+(def george (segment-painter george-segs))
+
+
+; unused by other code, as far as I can tell
 (def diag (segment-painter [[[0 0] [1 1]]]))
 
 
 
-(defn draw
-  "Draws picture, using the entire Quil window."
-  [picture]
-  (picture whole-window))
+
+;;==================================================================
+;;==================================================================
+;;
+;;  for images drawn with GIFs and JPGs, this function returns
+;;  the picture (i.e., a function) that draws the desired image
+;;
+;;  (This function needs to be completed. People have found
+;;  the following URLs helpful:
+;;
+;;    http://quil.info/api/transform
+;;    http://homepages.inf.ed.ac.uk/rbf/HIPR2/affine.htm
+;;    http://www.cs.colorado.edu/~mcbryan/5229.03/mail/55.htm )
+;;
+;;==================================================================
+;;==================================================================
 
 (defn image-painter [img]
   (fn [{[ox oy] :origin
@@ -435,8 +533,8 @@
 
 
 
-(defn draw-image
-  "'Container' for executing drawings within a Quil sketch.
+(defn draw-pictures
+  "'Container' for executing drawing(s) within a Quil sketch.
   Experiment by uncommenting one or more lines, or add your own."
   []
   (let [man (image-painter (q/load-image "data/man.gif"))
@@ -450,25 +548,19 @@
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
-    ;; (draw george)
-    ;; (draw (rotate180 george))
-    ;; (draw (beside (flip-horiz george) (flip-vert george)))
-    ;; (draw (beside (flip-horiz george) george))
-    ;; (draw (below (flip-horiz george) george))
-    ;; (draw (right-split george 3))
-    ;; (draw (up-split george 3))
-    ;; (draw (beside box x))
-    ;; (draw (flip-vert george))
+    ;; (george frame2)
+    ;; (draw (rotate george))
+    ;; (draw (flip-horiz george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
     #_(draw (beside (hsvpic (below george george) red)
                     (hsvpic (flip-horiz (below george george)) blue)))
 
-    #_(draw (over (hsbpic george red)
+   #_(draw (over (hsbpic george red)
                 (hsbpic (rotate george) blue)))
 
     ;; (draw (below (beside george (flip-horiz george))
-    ;;              (beside george (flip-horiz george))))
+    ;; (beside george (flip-horiz george))))
 
     ;; (draw ((square-of-four identity flip-vert
     ;;                        flip-horiz rotate)
@@ -484,17 +576,16 @@
     ;(draw (color-picture (square-limit george 2) 255 0 0))
 
     ;(println (format "%x" (q/current-stroke)))
-    ;;        george))
-    (draw (square-limit arrow 4))
 
+    ; these pictures need image-painter to be implemented
 
-    ; Needs image-painter
     ;; (bruce frame1)
     ;; (bruce frame2)
     ;; (draw (beside george bruce))
-    ;; (draw (corner-split george 4))
-    ;; (draw (beside  bruce (below  bruce
-    ;;                              george)))
+    ;; (draw (corner-split bruce 4))
+    ;; (draw (square-limit bruce 3))
+    ;; (draw (beside bruce (below bruce
+    ;; george)))
     ))
 
 
@@ -513,7 +604,7 @@
 
 (q/defsketch escher
   :title "Escher"
-  :draw draw-image
+  :draw draw-pictures
   :size [width height])
 
 (defn -main [])

From 0fed3274733f2b73ee693843face7cc188acc42f Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Thu, 16 Apr 2015 21:03:36 -0700
Subject: [PATCH 12/13] added support for midje autotest

---
 project.clj               | 11 +++++++++--
 repl/scratch.clj          |  4 ++++
 src/escher/core.clj       | 14 +++++++-------
 test/escher/core_test.clj | 11 -----------
 test/escher/t_core.clj    | 15 +++++++++++++++
 5 files changed, 35 insertions(+), 20 deletions(-)
 create mode 100644 repl/scratch.clj
 delete mode 100644 test/escher/core_test.clj
 create mode 100644 test/escher/t_core.clj

diff --git a/project.clj b/project.clj
index 8364b82..66633cd 100644
--- a/project.clj
+++ b/project.clj
@@ -4,8 +4,15 @@
   :license {:name "Eclipse Public License"
             :url "http://www.eclipse.org/legal/epl-v10.html"}
   :dependencies [[org.clojure/clojure "1.6.0"]
-                 [clj-tuple "0.2.0"]
+                 [clj-tuple "0.2.1"]
                  [quil "2.2.4"]]
   :main ^:skip-aot escher.core
   :target-path "target/%s"
-  :profiles {:uberjar {:aot :all}})
+  :profiles {:uberjar {:aot :all}
+             :dev {:dependencies [[midje "1.6.3"]]}}
+  :plugins [[lein-midje "3.1.3"]]
+  )
+;; To start a development session, in a terminal window, do:
+;;
+;;     cd /Users/gr/GitHub/escher
+;;     lein midje :autotest
diff --git a/repl/scratch.clj b/repl/scratch.clj
new file mode 100644
index 0000000..3764ee0
--- /dev/null
+++ b/repl/scratch.clj
@@ -0,0 +1,4 @@
+(ns scratch
+  (:require [clojure.repl :refer :all]
+            [clojure.test :refer :all]
+            [escher.core :refer :all]))
diff --git a/src/escher/core.clj b/src/escher/core.clj
index 0e8d2d8..10a3766 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -541,10 +541,10 @@
         bruce (image-painter (q/load-image "data/bruce.jpg"))
         angels (image-painter (q/load-image "data/angels.jpg"))
         ]
-    #_(q/stroke-weight 4)
-    #_(q/color-mode :hsb 100)
+    (q/stroke-weight 4)
+    (q/color-mode :hsb 100)
 
-    #_(q/background 0 0 100)
+    (q/background 0 0 100)
     ;; (frame-painter frame1)
     ;; (draw x)
     ;; (draw box)
@@ -553,8 +553,8 @@
     ;; (draw (flip-horiz george))
     ;; (draw (beside box box))
     ;; (draw (combine-four george))
-    #_(draw (beside (hsvpic (below george george) red)
-                    (hsvpic (flip-horiz (below george george)) blue)))
+    (draw (beside (hsbpic (below george george) red)
+                    (hsbpic (flip-horiz (below george george)) blue)))
 
    #_(draw (over (hsbpic george red)
                 (hsbpic (rotate george) blue)))
@@ -571,7 +571,7 @@
     #_(q/with-stroke [200 50 50]
         (draw (square-limit george 3)))
 
-    (draw (square-limit george 3))
+    #_(draw (square-limit george 3))
 
     ;(draw (color-picture (square-limit george 2) 255 0 0))
 
@@ -607,4 +607,4 @@
   :draw draw-pictures
   :size [width height])
 
-(defn -main [])
+;;(defn -main [])
diff --git a/test/escher/core_test.clj b/test/escher/core_test.clj
deleted file mode 100644
index a4e8639..0000000
--- a/test/escher/core_test.clj
+++ /dev/null
@@ -1,11 +0,0 @@
-(ns escher.core-test
-  (:require [clojure.test :refer :all]
-            [escher.core :refer :all]))
-
-(deftest vectors
-  (is (= (scale-vec [2 3] 4)
-         [8 12]))
-  (is (=  (add-vec [-1 2] [3 -2])
-          [2 0]))
-  (is (= (sub-vec [2 -3] [-1 -2])
-         [3 -1])))
diff --git a/test/escher/t_core.clj b/test/escher/t_core.clj
new file mode 100644
index 0000000..d37a64c
--- /dev/null
+++ b/test/escher/t_core.clj
@@ -0,0 +1,15 @@
+(ns escher.t-core
+  (:use midje.sweet)
+  (:require
+;;            [clojure.test :refer :all]
+            [escher.core :refer :all])
+;;            [escher.core :as core])
+  )
+
+(facts "about utility fcns"
+  (fact (scale-vec [2 3] 4) =>
+         [8 12])
+  (fact  (add-vec [-1 2] [3 -2]) =>
+          [2 0])
+  (fact (sub-vec [2 -3] [-1 -2]) =>
+         [3 -1]))

From cd5f4ba75b86ce430b45b8df02a04b225992b204 Mon Sep 17 00:00:00 2001
From: Gregg Williams <gregg13 AT innerpaths.net>
Date: Thu, 16 Apr 2015 21:26:06 -0700
Subject: [PATCH 13/13] replaced t/vector with make-vec, as appropriate

---
 src/escher/core.clj | 52 ++++++++++++++++++++++-----------------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/src/escher/core.clj b/src/escher/core.clj
index 10a3766..0cb8f5c 100644
--- a/src/escher/core.clj
+++ b/src/escher/core.clj
@@ -1,6 +1,6 @@
 (ns escher.core
   (require [quil.core :as q]
-           [clj-tuple :as tup])
+           [clj-tuple :as t])
   (:gen-class))
 
 ;;==================================================================
@@ -10,17 +10,17 @@
 ;;==================================================================
 
 (defn make-vec [x y]
-  (tup/vector x y))
+  (t/vector x y))
 
 (defn add-vec [[x1 y1] [x2 y2]]
-  (tup/vector (+ x1 x2) (+ y1 y2)))
+  (make-vec (+ x1 x2) (+ y1 y2)))
 
 
 (defn sub-vec [[x1 y1] [x2 y2]]
-  (tup/vector (- x1 x2) (- y1 y2)))
+  (make-vec (- x1 x2) (- y1 y2)))
 
 (defn scale-vec [[x y] s]
-  (tup/vector (* x s) (* y s)))
+  (make-vec (* x s) (* y s)))
 
 
 ;;==================================================================
@@ -80,7 +80,7 @@
   "Represent a line segment as a vector of two vectors--e.g.,
   [[0 0] [1 0]] represents a line from [0 0] to [1 0]."
   [vec1 vec2]
-  (tup/vector vec1 vec2))
+  (make-vec vec1 vec2))
 
 (defn path
   "Creates a seq of line-segments from a 'bare' list of points. Use to
@@ -143,7 +143,7 @@
   (fn [frame2]
     (let [unit-sq-xform (frame-coord-map frame2)
           new-origin (unit-sq-xform origin)]
-      (p (tup/hash-map :origin new-origin
+      (p (t/hash-map :origin new-origin
                        :e1 (sub-vec (unit-sq-xform e1) new-origin)
                        :e2 (sub-vec (unit-sq-xform e2) new-origin))))))
 
@@ -156,19 +156,19 @@
 ;;==================================================================
 
 (defn flip-vert [p]
-  (transform-picture p (tup/vector 0 1) (tup/vector 1 1) (tup/vector 0 0)))
+  (transform-picture p (make-vec 0 1) (make-vec 1 1) (make-vec 0 0)))
 
 (defn flip-horiz [p]
-  (transform-picture p (tup/vector 1 0) (tup/vector 0 0) (tup/vector 1 1)))
+  (transform-picture p (make-vec 1 0) (make-vec 0 0) (make-vec 1 1)))
 
 (defn rotate [p]
-  (transform-picture p (tup/vector 1 0) (tup/vector 1 1) (tup/vector 0 0)))
+  (transform-picture p (make-vec 1 0) (make-vec 1 1) (make-vec 0 0)))
 
 (defn rotate180 [p]
   (rotate (rotate p)))
 
 (defn rotate270 [p]
-  (transform-picture p (tup/vector 0 1) (tup/vector 0 0) (tup/vector 1 1)))
+  (transform-picture p (make-vec 0 1) (make-vec 0 0) (make-vec 1 1)))
 
 
 
@@ -182,9 +182,9 @@
   "Returns a picture that, splitting its frame in half vertically, draws
   p1 in the left half and p2 in the right half."
   [p1 p2]
-  (let [split (tup/vector 0.5 0)
-        left (transform-picture p1 (tup/vector 0 0) split (tup/vector 0 1))
-        right (transform-picture p2 split (tup/vector 1 0) (tup/vector 0.5 1))]
+  (let [split (make-vec 0.5 0)
+        left (transform-picture p1 (make-vec 0 0) split (make-vec 0 1))
+        right (transform-picture p2 split (make-vec 1 0) (make-vec 0.5 1))]
     (fn [frame]
       (left frame)
       (right frame))))
@@ -317,17 +317,17 @@
 ;; origin, e1, and e2 (all 2-D vectors) define a frame.
 ;; Think of origin as a point, e1 as the x-axis, e2 as the y-axis.
 
-(def whole-window {:origin (tup/vector 0 0)
-                   :e1 (tup/vector width 0)
-                   :e2 (tup/vector 0 height)})
+(def whole-window {:origin (make-vec 0 0)
+                   :e1 (make-vec width 0)
+                   :e2 (make-vec 0 height)})
 
-(def frame1 {:origin (tup/vector 200 50)
-             :e1 (tup/vector 200 100)
-             :e2 (tup/vector 150 200)})
+(def frame1 {:origin (make-vec 200 50)
+             :e1 (make-vec 200 100)
+             :e2 (make-vec 150 200)})
 
-(def frame2 {:origin (tup/vector 50 50)
-             :e1 (tup/vector 100 0)
-             :e2 (tup/vector 0 200)})
+(def frame2 {:origin (make-vec 50 50)
+             :e1 (make-vec 100 0)
+             :e2 (make-vec 0 200)})
 
 (defn draw
   "Draws picture, using the entire Quil window."
@@ -521,9 +521,9 @@
       ; COMPLETE
       )))
 
-(def red   (tup/vector 0 100 100))
-(def green (tup/vector 33 100 100))
-(def blue  (tup/vector 66 100 100))
+(def red   (t/vector 0 100 100))
+(def green (t/vector 33 100 100))
+(def blue  (t/vector 66 100 100))
 
 (defn hsbpic
   [p [h s b]]