Merge pull request #17 from RobLoach/stb_image

Add stb_image for image loading

README.md

@@ -24,7 +24,7 @@ Features :
  * OpenGL ES 2.0 rendering backend for Raspberry PI or through fbdev (tested on Nano PI Fire 3 board)
  * dispmanx rendering backend (Video Core IV; Raspberry PI)
  * Optional : Full parallelism, execute graphics code on multiple CPU cores **with a single function**
- * PNG/JPEG images loading (provided by [LodePNG](https://lodev.org/lodepng/) and [NanoJPEG](http://keyj.emphy.de/nanojpeg/))
+ * Image loading (provided by [LodePNG](https://lodev.org/lodepng/), [NanoJPEG](http://keyj.emphy.de/nanojpeg/), and [stb_image](https://github.com/nothings/stb/blob/master/stb_image.h))
  * Bitmap fonts for drawing texts
  * Bare-metal graphics primitive (pixels, rectangles, lines, polygon)
  * Easy to do fading, clipping and screen-clearing related effects (motion blur etc.)
@@ -393,7 +393,10 @@ To compile liblfds parallel examples, just copy `liblfds711.a` / `liblfds711.h`
 
 This library may be used for size optimized executable for things like [demos](https://en.wikipedia.org/wiki/Demoscene)
 
-PNG and JPEG support can be disabled with the `WITHOUT_JPEG` and `WITHOUT_PNG` define.
+Image support can be disabled with the following defines:
+- `WITHOUT_JPEG`
+- `WITHOUT_PNG`
+- `WITHOUT_STB_IMAGE`
 
 See `tiny` makefile rule inside the `custom_backend` or `examples` folder for some compiler optimizations related to executable size.
 

src/fbgraphics.c

@@ -38,6 +38,11 @@
 #include "nanojpeg/nanojpeg.c"
 #endif
 
+#ifndef WITHOUT_STB_IMAGE
+#define STB_IMAGE_IMPLEMENTATION
+#include "stb/stb_image.h"
+#endif
+
 #include "fbgraphics.h"
 
 #ifdef FBG_PARALLEL
@@ -1413,6 +1418,35 @@ struct _fbg_img *fbg_loadPNG(struct _fbg *fbg, const char *filename) {
 }
 #endif
 
+#ifndef WITHOUT_STB_IMAGE
+struct _fbg_img *fbg_loadSTBImage(struct _fbg *fbg, const char *filename) {
+    unsigned char *data;
+    int width;
+    int height;
+    int components;
+
+    data = stbi_load(filename, &width, &height, &components, fbg->components);
+    if (!data) {
+        fprintf(stderr, "fbg_loadSTBImage: %s\n", stbi_failure_reason());
+
+        return NULL;
+    }
+
+    struct _fbg_img *img = fbg_createImage(fbg, width, height);
+    if (!img) {
+        fprintf(stderr, "fbg_loadSTBImage: Image '%s' data allocation failed\n", filename);
+
+        stbi_image_free(data);
+
+        return NULL;
+    }
+
+    img->data = data;
+
+    return img;
+}
+#endif
+
 struct _fbg_img *fbg_loadImage(struct _fbg *fbg, const char *filename) {
     struct _fbg_img *img = NULL;
 
@@ -1426,6 +1460,12 @@ struct _fbg_img *fbg_loadImage(struct _fbg *fbg, const char *filename) {
     }
 #endif
 
+#ifndef WITHOUT_STB_IMAGE
+    if (img == NULL) {
+        img = fbg_loadSTBImage(fbg, filename);
+    }
+#endif
+
     return img;
 }
 

src/fbgraphics.h

@@ -611,6 +611,18 @@
     extern struct _fbg_img *fbg_loadJPEG(struct _fbg *fbg, const char *filename);
 #endif
 
+#ifndef WITHOUT_STB_IMAGE
+
+    //! load an image from a file (STB Image library)
+    /*!
+      \param fbg pointer to a FBG context / data structure
+      \param filename image filename
+      \return _fbg_img data structure pointer
+      \sa fbg_freeImage(), fbg_image(), fbg_imageFlip(), fbg_createFont(), fbg_imageClip(), fbg_loadImage(), fbg_imageEx(), fbg_imageScale(), fbg_imageColorkey()
+    */
+    extern struct _fbg_img *fbg_loadSTBImage(struct _fbg *fbg, const char *filename);
+#endif
+
     //! load an image (PNG or JPEG)
     /*!
       \param fbg pointer to a FBG context / data structure