TEST: PicoVector: alright-fonts bringup.

libraries/pico_vector/af-file-io.h

@@ -0,0 +1,16 @@
+#include <stdlib.h>
+#include <stdint.h>
+
+extern "C" {
+void* fileio_open(const char* filename);
+
+void fileio_close(void* fhandle);
+
+size_t fileio_read(void* fhandle, void *buf, size_t len);
+
+int fileio_getc(void* fhandle);
+
+size_t fileio_tell(void* fhandle);
+
+size_t fileio_seek(void* fhandle, size_t pos);
+}

libraries/pico_vector/af-memory.h

@@ -0,0 +1,5 @@
+extern "C" {
+    void *af_malloc(size_t size);
+    void *af_realloc(void *p, size_t size);
+    void af_free(void *p);
+}

libraries/pico_vector/alright-fonts.h

@@ -0,0 +1,361 @@
+/*
+
+  Alright Fonts 🖍 - a font format for embedded and low resource platforms.
+
+  Jonathan Williamson, August 2022
+  Examples, source, and more: https://github.com/lowfatcode/pretty-poly
+  MIT License https://github.com/lowfatcode/pretty-poly/blob/main/LICENSE
+
+  An easy way to render high quality text in embedded applications running 
+  on resource constrained microcontrollers such as the Cortex M0 and up.         
+
+    - OTF and TTF support: generate efficient packed fonts easily
+    - Minimal data: ~4kB (40 bytes per char) for printable ASCII set (Roboto)
+    - Tunable: trade off file size, contour complexity, and visual quality
+    - Metrics: advance and bounding box for fast layout
+    - UTF-8 or ASCII: support for non ASCII like Kanji or Cyrillic
+    - Fixed scale: coords scaled to ^2 bounds for fast scaling (no divide)
+    - C17 header only library: simply copy the header file into your project
+    - Customised font packs: include only the characters you need
+    - Simple outlines: all paths are simply polylines for easy rendering
+    - Easy antialiasing: combine with Pretty Poly for quick results!
+
+*/
+
+#ifndef AF_INCLUDE_H
+#define AF_INCLUDE_H
+
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <math.h>
+#include <stdbool.h>
+#include <wchar.h>
+
+#ifdef AF_MALLOC
+  #ifndef PP_MALLOC
+    #define PP_MALLOC(size)         AF_MALLOC(size)
+    #define PP_REALLOC(p, size)     AF_REALLOC(p, size)
+    #define PP_FREE(p)              AF_FREE(p)
+  #endif // PP_MALLOC
+#endif // AF_MALLOC
+
+#ifndef AF_MALLOC
+  #define AF_MALLOC(size)         malloc(size)
+  #define AF_REALLOC(p, size)     realloc(p, size)
+  #define AF_FREE(p)              free(p)
+#endif // AF_MALLOC
+
+#ifndef AF_FILE
+  #define AF_FILE FILE*
+  #define AF_FREAD(p, size, nmemb, stream) fread(p, size, nmemb, stream)
+  #define AF_FGETC(stream) fgetc(stream)
+#endif
+
+#include "pretty-poly.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+  int8_t x, y;
+} af_point_t;
+pp_point_t af_point_transform(pp_point_t *p, pp_mat3_t *m);
+
+typedef struct {
+  uint8_t point_count;
+  af_point_t *points;
+} af_path_t;
+
+typedef struct {
+  char codepoint;
+  int8_t x, y, w, h;
+  int8_t advance;
+  uint8_t path_count;
+  af_path_t *paths;    
+} af_glyph_t;
+
+typedef struct {
+  uint16_t flags;
+  uint16_t glyph_count;
+  af_glyph_t *glyphs;
+} af_face_t;
+
+typedef enum {
+  AF_H_ALIGN_LEFT = 0, AF_H_ALIGN_CENTER = 1, AF_H_ALIGN_RIGHT = 2, 
+  AF_H_ALIGN_JUSTIFY = 4,
+  AF_V_ALIGN_TOP = 8, AF_V_ALIGN_MIDDLE = 16, AF_V_ALIGN_BOTTOM = 32
+} af_align_t;  
+
+typedef struct  {
+  af_face_t *face;                  // font
+  float size;                       // text size in pixels
+  float line_height;                // spacing between lines (%)
+  float letter_spacing;             // spacing between characters (%)   
+  float word_spacing;               // spacing between words (%)
+  af_align_t align;                 // horizontal and vertical alignment
+  pp_mat3_t *transform;             // arbitrary transformation
+} af_text_metrics_t;
+
+bool af_load_font_file(AF_FILE file, af_face_t *face);
+void af_render_character(af_face_t *face, wchar_t codepoint, af_text_metrics_t *tm);
+void af_render(af_face_t *face, wchar_t *text, af_text_metrics_t *tm);
+pp_rect_t af_measure(af_face_t *face, const wchar_t *text, af_text_metrics_t *tm);
+
+#ifdef AF_USE_PRETTY_POLY
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef AF_IMPLEMENTATION
+
+
+/*
+  helper functions
+*/
+
+// big endian file reading helpers
+uint16_t  ru16(AF_FILE file) {uint8_t  w[2]; AF_FREAD((char *) w, 1, 2, file); return  w[0] <<  8 |  w[1];}
+int16_t   rs16(AF_FILE file) {uint8_t  w[2]; AF_FREAD((char *) w, 1, 2, file); return  w[0] <<  8 |  w[1];}
+uint32_t  ru32(AF_FILE file) {uint8_t dw[4]; AF_FREAD((char *)dw, 1, 4, file); return dw[0] << 24 | dw[1] << 16 | dw[2] << 8 | dw[3];}
+uint8_t    ru8(AF_FILE file) {return AF_FGETC(file);}
+int8_t     rs8(AF_FILE file) {return AF_FGETC(file);}
+
+bool af_load_font_file(AF_FILE file, af_face_t *face) {
+  // check header magic bytes are present
+  char marker[4]; AF_FREAD(marker, 1, 4, file);
+  if(memcmp(marker, "af!?", 4) != 0) {    
+    return false; // doesn't start with magic marker
+  }
+
+  // extract flags and ensure none set
+  face->flags = ru16(file);
+  if(face->flags != 0) {    
+    return false; // unknown flags set
+  }
+
+  // number of glyphs, paths, and points in font
+  uint16_t glyph_count = ru16(file);
+  uint16_t path_count  = ru16(file);
+  uint16_t point_count = ru16(file);
+
+  // allocate buffer to store font glyph, path, and point data
+  void *buffer = AF_MALLOC(sizeof(af_glyph_t) * glyph_count + \
+                           sizeof( af_path_t) *  path_count + \
+                           sizeof(af_point_t) * point_count);
+  af_glyph_t *glyphs = (af_glyph_t *) buffer;
+  af_path_t   *paths = ( af_path_t *)(glyphs + (sizeof(af_glyph_t) * glyph_count));
+  af_point_t *points = (af_point_t *)( paths + (sizeof( af_path_t) *  path_count));
+
+  // load glyph dictionary
+  face->glyph_count = glyph_count;
+  face->glyphs      = glyphs;
+  for(int i = 0; i < glyph_count; i++) {
+    af_glyph_t *glyph = &face->glyphs[i];
+    glyph->codepoint  = ru16(file);
+    glyph->x          =  rs8(file);
+    glyph->y          =  rs8(file);
+    glyph->w          =  ru8(file);
+    glyph->h          =  ru8(file);
+    glyph->advance    =  ru8(file);
+    glyph->path_count =  ru8(file);
+    glyph->paths      =      paths;
+    paths += sizeof(af_path_t) * glyph->path_count;
+  }
+
+  // load the glyph paths
+  for(int i = 0; i < glyph_count; i++) {
+    af_glyph_t *glyph = &face->glyphs[i];
+    for(int j = 0; j < glyph->path_count; j++) {
+      af_path_t *path = &glyph->paths[j];
+      path->point_count = ru8(file);
+      path->points = points;
+      points += sizeof(af_point_t) * path->point_count;
+    }
+  }
+
+  // load the glyph points
+  for(int i = 0; i < glyph_count; i++) {
+    af_glyph_t *glyph = &face->glyphs[i];
+    for(int j = 0; j < glyph->path_count; j++) {
+      af_path_t *path = &glyph->paths[j];
+      for(int k = 0; k < path->point_count; k++) {
+        af_point_t *point = &path->points[k];
+        point->x = ru8(file);
+        point->y = ru8(file);
+      }
+    }
+  }
+
+  return true;
+}
+
+af_glyph_t *find_glyph(af_face_t *face, wchar_t c) {
+  for(int i = 0; i < face->glyph_count; i++) {
+    if(face->glyphs[i].codepoint == c) {
+      return &face->glyphs[i];
+    }
+  }
+  return NULL;
+}
+
+void af_render_glyph(af_glyph_t* glyph, af_text_metrics_t *tm) {
+  assert(glyph != NULL);
+
+  pp_poly_t poly;
+  poly.count = glyph->path_count;
+  poly.paths = (pp_path_t *)AF_MALLOC(poly.count * sizeof(pp_path_t));
+  for(uint32_t i = 0; i < poly.count; i++) {
+    pp_path_t *path = &poly.paths[i];
+    path->count = glyph->paths[i].point_count;
+    path->points = (pp_point_t *)AF_MALLOC(glyph->paths[i].point_count * sizeof(pp_point_t));
+    for(uint32_t j = 0; j < path->count; j++) {
+      pp_point_t *point = &path->points[j];
+      point->x = glyph->paths[i].points[j].x;
+      point->y = glyph->paths[i].points[j].y;
+    }
+  }
+
+  pp_render(&poly);
+
+  for(uint32_t i = 0; i < poly.count; i++) {
+    pp_path_t *path = &poly.paths[i];
+    free(path->points);
+  }
+  free(poly.paths);
+}
+
+void af_render_character(af_face_t *face, wchar_t c, af_text_metrics_t *tm) {
+  af_glyph_t *glyph = find_glyph(face, c);
+  if(!glyph) {
+    return;
+  }
+  af_render_glyph(glyph, tm);
+}
+
+int get_line_width(af_face_t *face, wchar_t *text, af_text_metrics_t *tm) {
+  int line_width = 0;
+  wchar_t *end = wcschr(text, L'\n');
+  for(wchar_t c = *text; text < end; text++, c = *text) {
+    af_glyph_t *glyph = find_glyph(face, c);
+    if(!glyph) {
+      continue;
+    }
+
+    if(c == L' ') {
+      line_width += (glyph->advance * tm->word_spacing) / 100.0f;
+    } else {
+      line_width += (glyph->advance * tm->letter_spacing) / 100.0f;
+    }
+  }
+  return line_width;
+}
+
+int get_max_line_width(af_face_t *face, wchar_t *text, af_text_metrics_t *tm) {
+  int max_width = 0;
+
+  wchar_t *end = wcschr(text, L'\n');
+  while(end) {
+    int width = get_line_width(face, text, tm);
+    max_width = max_width < width ? width : max_width;
+    text = end + 1;
+    end = wcschr(text, L'\n');
+  }
+
+  return max_width;
+}
+
+
+void af_render(af_face_t *face, wchar_t *text, af_text_metrics_t *tm) {
+  pp_mat3_t *old = pp_transform(NULL);
+
+  float line_height = (tm->line_height * 128.0f) / 100.0f;
+  float scale = tm->size / 128.0f;
+
+  // find maximum line length
+  int max_line_width = get_max_line_width(face, text, tm);
+
+  struct {
+    float x, y;
+  } caret;
+
+  caret.x = 0;
+  caret.y = 0;
+
+  wchar_t *end = wcschr(text, L'\n');
+  while(end) {
+    int line_width = get_line_width(face, text, tm);
+
+    for(wchar_t c = *text; text < end; text++, c = *text) {
+      af_glyph_t *glyph = find_glyph(face, c);
+      if(!glyph) {
+        continue;
+      }
+
+      pp_mat3_t caret_transform = *tm->transform;
+      pp_mat3_scale(&caret_transform, scale, scale);
+      pp_mat3_translate(&caret_transform, caret.x, caret.y);
+
+      if(tm->align == AF_H_ALIGN_CENTER) {
+        pp_mat3_translate(&caret_transform, (max_line_width - line_width) / 2, 0);
+      }
+
+      if(tm->align == AF_H_ALIGN_RIGHT) {
+        pp_mat3_translate(&caret_transform, (max_line_width - line_width), 0);
+      }
+
+      pp_transform(&caret_transform);
+
+      af_render_glyph(glyph, tm);
+
+      if(c == L' ') {
+        caret.x += (glyph->advance * tm->word_spacing) / 100.0f;
+      } else {
+        caret.x += (glyph->advance * tm->letter_spacing) / 100.0f;
+      }
+
+    }
+
+    text = end + 1;
+    end = wcschr(text, L'\n');
+
+    caret.x = 0;
+    caret.y += line_height;
+  }
+
+
+
+  pp_transform(old);
+}
+
+pp_rect_t af_measure(af_face_t *face, const wchar_t *text, af_text_metrics_t *tm) {
+  pp_rect_t result;
+  bool first = true;
+  pp_mat3_t t = *tm->transform;
+
+  for(size_t i = 0; i < wcslen(text); i++) {
+    af_glyph_t *glyph = find_glyph(face, text[i]);
+    if(!glyph) {
+      continue;
+    }
+    pp_rect_t r = {glyph->x, glyph->y, glyph->x + glyph->w, glyph->y + glyph->h};
+    r = pp_rect_transform(&r, &t);
+    pp_mat3_translate(&t, glyph->advance, 0);
+
+    if(first) {
+      result = r;
+      first = false;
+    }else{
+      result = pp_rect_merge(&result, &r);
+    }
+  }
+
+  return result;
+}
+
+#endif // AF_IMPLEMENTATION
+
+#endif // AF_INCLUDE_H