1 files changed, 132 insertions, 143 deletions

diff --git a/minui/resources.c b/minui/resources.c
index fe1e99926..ed25e45a2 100644
--- a/minui/resources.c
+++ b/minui/resources.c
@@ -47,143 +47,15 @@ double pow(double x, double y) {
     return x * y;
 }
 
-int res_create_surface(const char* name, gr_surface* pSurface) {
-    char resPath[256];
-    GGLSurface* surface = NULL;
-    int result = 0;
-    unsigned char header[8];
-    png_structp png_ptr = NULL;
-    png_infop info_ptr = NULL;
-
-    *pSurface = NULL;
-
-    snprintf(resPath, sizeof(resPath)-1, "/res/images/%s.png", name);
-    resPath[sizeof(resPath)-1] = '\0';
-    FILE* fp = fopen(resPath, "rb");
-    if (fp == NULL) {
-        result = -1;
-        goto exit;
-    }
-
-    size_t bytesRead = fread(header, 1, sizeof(header), fp);
-    if (bytesRead != sizeof(header)) {
-        result = -2;
-        goto exit;
-    }
-
-    if (png_sig_cmp(header, 0, sizeof(header))) {
-        result = -3;
-        goto exit;
-    }
-
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-    if (!png_ptr) {
-        result = -4;
-        goto exit;
-    }
-
-    info_ptr = png_create_info_struct(png_ptr);
-    if (!info_ptr) {
-        result = -5;
-        goto exit;
-    }
-
-    if (setjmp(png_jmpbuf(png_ptr))) {
-        result = -6;
-        goto exit;
-    }
-
-    png_init_io(png_ptr, fp);
-    png_set_sig_bytes(png_ptr, sizeof(header));
-    png_read_info(png_ptr, info_ptr);
-
-    int color_type, bit_depth;
-    size_t width, height;
-
-    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth,
-            &color_type, NULL, NULL, NULL);
-
-    png_byte channels = png_get_channels(png_ptr, info_ptr);
-
-    if (!(bit_depth == 8 &&
-          ((channels == 3 && color_type == PNG_COLOR_TYPE_RGB) ||
-           (channels == 4 && color_type == PNG_COLOR_TYPE_RGBA) ||
-           (channels == 1 && (color_type == PNG_COLOR_TYPE_PALETTE ||
-                              color_type == PNG_COLOR_TYPE_GRAY))))) {
-        return -7;
-        goto exit;
-    }
-
-    size_t stride = (color_type == PNG_COLOR_TYPE_GRAY ? 1 : 4) * width;
-    size_t pixelSize = stride * height;
-
-    surface = malloc(sizeof(GGLSurface) + pixelSize);
-    if (surface == NULL) {
-        result = -8;
-        goto exit;
-    }
-    unsigned char* pData = (unsigned char*) (surface + 1);
-    surface->version = sizeof(GGLSurface);
-    surface->width = width;
-    surface->height = height;
-    surface->stride = width; /* Yes, pixels, not bytes */
-    surface->data = pData;
-    surface->format = (channels == 3) ? GGL_PIXEL_FORMAT_RGBX_8888 :
-        ((color_type == PNG_COLOR_TYPE_PALETTE ? GGL_PIXEL_FORMAT_RGBA_8888 : GGL_PIXEL_FORMAT_L_8));
-
-    int alpha = 0;
-    if (color_type == PNG_COLOR_TYPE_PALETTE) {
-        png_set_palette_to_rgb(png_ptr);
-    }
-    if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
-        png_set_tRNS_to_alpha(png_ptr);
-        alpha = 1;
-    }
-    if (color_type == PNG_COLOR_TYPE_GRAY) {
-        alpha = 1;
-    }
-
-    unsigned int y;
-    if (channels == 3 || (channels == 1 && !alpha)) {
-        for (y = 0; y < height; ++y) {
-            unsigned char* pRow = pData + y * stride;
-            png_read_row(png_ptr, pRow, NULL);
-
-            int x;
-            for(x = width - 1; x >= 0; x--) {
-                int sx = x * 3;
-                int dx = x * 4;
-                unsigned char r = pRow[sx];
-                unsigned char g = pRow[sx + 1];
-                unsigned char b = pRow[sx + 2];
-                unsigned char a = 0xff;
-                pRow[dx    ] = r; // r
-                pRow[dx + 1] = g; // g
-                pRow[dx + 2] = b; // b
-                pRow[dx + 3] = a;
-            }
-        }
-    } else {
-        for (y = 0; y < height; ++y) {
-            unsigned char* pRow = pData + y * stride;
-            png_read_row(png_ptr, pRow, NULL);
-        }
-    }
-
-    *pSurface = (gr_surface) surface;
-
-exit:
-    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
-
-    if (fp != NULL) {
-        fclose(fp);
-    }
-    if (result < 0) {
-        if (surface) {
-            free(surface);
-        }
-    }
-    return result;
+#define SURFACE_DATA_ALIGNMENT 8
+
+static GGLSurface* malloc_surface(size_t data_size) {
+    unsigned char* temp = malloc(sizeof(GGLSurface) + data_size + SURFACE_DATA_ALIGNMENT);
+    if (temp == NULL) return NULL;
+    GGLSurface* surface = (GGLSurface*) temp;
+    surface->data = temp + sizeof(GGLSurface) +
+        (SURFACE_DATA_ALIGNMENT - (sizeof(GGLSurface) % SURFACE_DATA_ALIGNMENT));
+    return surface;
 }
 
 static int open_png(const char* name, png_structp* png_ptr, png_infop* info_ptr,
@@ -270,6 +142,114 @@ static int open_png(const char* name, png_structp* png_ptr, png_infop* info_ptr,
     return result;
 }
 
+// "display" surfaces are transformed into the framebuffer's required
+// pixel format (currently only RGBX is supported) at load time, so
+// gr_blit() can be nothing more than a memcpy() for each row.  The
+// next two functions are the only ones that know anything about the
+// framebuffer pixel format; they need to be modified if the
+// framebuffer format changes (but nothing else should).
+
+// Allocate and return a gr_surface sufficient for storing an image of
+// the indicated size in the framebuffer pixel format.
+static GGLSurface* init_display_surface(png_uint_32 width, png_uint_32 height) {
+    GGLSurface* surface;
+
+    surface = (GGLSurface*) malloc_surface(width * height * 4);
+    if (surface == NULL) return NULL;
+
+    surface->version = sizeof(GGLSurface);
+    surface->width = width;
+    surface->height = height;
+    surface->stride = width;
+
+    return surface;
+}
+
+// Copy 'input_row' to 'output_row', transforming it to the
+// framebuffer pixel format.  The input format depends on the value of
+// 'channels':
+//
+//   1 - input is 8-bit grayscale
+//   3 - input is 24-bit RGB
+//   4 - input is 32-bit RGBA/RGBX
+//
+// 'width' is the number of pixels in the row.
+static void transform_rgb_to_draw(unsigned char* input_row,
+                                  unsigned char* output_row,
+                                  int channels, int width) {
+    int x;
+    unsigned char* ip = input_row;
+    unsigned char* op = output_row;
+
+    switch (channels) {
+        case 1:
+            // expand gray level to RGBX
+            for (x = 0; x < width; ++x) {
+                *op++ = *ip;
+                *op++ = *ip;
+                *op++ = *ip;
+                *op++ = 0xff;
+                ip++;
+            }
+            break;
+
+        case 3:
+            // expand RGBA to RGBX
+            for (x = 0; x < width; ++x) {
+                *op++ = *ip++;
+                *op++ = *ip++;
+                *op++ = *ip++;
+                *op++ = 0xff;
+            }
+            break;
+
+        case 4:
+            // copy RGBA to RGBX
+            memcpy(output_row, input_row, width*4);
+            break;
+    }
+}
+
+int res_create_surface(const char* name, gr_surface* pSurface) {
+    GGLSurface* surface = NULL;
+    int result = 0;
+    png_structp png_ptr = NULL;
+    png_infop info_ptr = NULL;
+    png_uint_32 width, height;
+    png_byte channels;
+
+    *pSurface = NULL;
+
+    result = open_png(name, &png_ptr, &info_ptr, &width, &height, &channels);
+    if (result < 0) return result;
+
+    surface = init_display_surface(width, height);
+    if (surface == NULL) {
+        result = -8;
+        goto exit;
+    }
+
+    unsigned char* p_row = malloc(width * 4);
+    unsigned int y;
+    for (y = 0; y < height; ++y) {
+        png_read_row(png_ptr, p_row, NULL);
+        transform_rgb_to_draw(p_row, surface->data + y * width * 4, channels, width);
+    }
+    free(p_row);
+
+    if (channels == 3)
+        surface->format = GGL_PIXEL_FORMAT_RGBX_8888;
+    else
+        surface->format = GGL_PIXEL_FORMAT_RGBA_8888;
+
+    *pSurface = (gr_surface) surface;
+
+  exit:
+    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+    if (result < 0 && surface != NULL) free(surface);
+    return result;
+}
+
 int res_create_multi_display_surface(const char* name, int* frames, gr_surface** pSurface) {
     gr_surface* surface = NULL;
     int result = 0;
@@ -304,29 +284,38 @@ int res_create_multi_display_surface(const char* name, int* frames, gr_surface**
         goto exit;
     }
 
-    surface = malloc(*frames * sizeof(gr_surface));
+    surface = malloc(*frames * sizeof(GGLSurface));
     if (surface == NULL) {
         result = -8;
         goto exit;
     }
     for (i = 0; i < *frames; ++i) {
-        surface[i] = NULL;//init_display_surface(width, height / *frames);
+        surface[i] = init_display_surface(width, height / *frames);
         if (surface[i] == NULL) {
             result = -8;
             goto exit;
         }
     }
 
-    /*unsigned char* p_row = malloc(width * 4);
+    unsigned char* p_row = malloc(width * 4);
     unsigned int y;
     for (y = 0; y < height; ++y) {
         png_read_row(png_ptr, p_row, NULL);
         int frame = y % *frames;
-        unsigned char* out_row = surface[frame]->data +
-            (y / *frames) * surface[frame]->row_bytes;
+        GGLSurface* p = (GGLSurface*) surface[frame];
+        unsigned char* out_row = p->data +
+            (y / *frames) * width * 4;
         transform_rgb_to_draw(p_row, out_row, channels, width);
     }
-    free(p_row); this will need to be brought in line with the older resources and graphics code */
+    free(p_row);
+
+    for (i = 0; i < *frames; ++i) {
+        GGLSurface* p = (GGLSurface*) surface[i];
+        if (channels == 3)
+            p->format = GGL_PIXEL_FORMAT_RGBX_8888;
+        else
+            p->format = GGL_PIXEL_FORMAT_RGBA_8888;
+    }
 
     *pSurface = (gr_surface*) surface;