1 files changed, 67 insertions, 100 deletions

diff --git a/minui/resources.c b/minui/resources.c
index 5beb6a6..7ecfeef 100644
--- a/minui/resources.c
+++ b/minui/resources.c
@@ -29,97 +29,84 @@
 
 #include <pixelflinger/pixelflinger.h>
 
+#include <png.h>
+
 #include "minui.h"
 
-// File signature for BMP files.
-// The letters 'BM' as a little-endian unsigned short.
-
-#define BMP_SIGNATURE 0x4d42
-
-typedef struct {
-    // constant, value should equal BMP_SIGNATURE
-    unsigned short  bfType;
-    // size of the file in bytes.
-    unsigned long   bfSize;
-    // must always be set to zero.
-    unsigned short  bfReserved1;
-    // must always be set to zero.
-    unsigned short  bfReserved2;
-    // offset from the beginning of the file to the bitmap data.
-    unsigned long   bfOffBits;
-
-    // The BITMAPINFOHEADER:
-    // size of the BITMAPINFOHEADER structure, in bytes.
-    unsigned long   biSize;
-    // width of the image, in pixels.
-    unsigned long   biWidth;
-    // height of the image, in pixels.
-    unsigned long   biHeight;
-    // number of planes of the target device, must be set to 1.
-    unsigned short  biPlanes;
-    // number of bits per pixel.
-    unsigned short  biBitCount;
-    // type of compression, zero means no compression.
-    unsigned long   biCompression;
-    // size of the image data, in bytes. If there is no compression,
-    // it is valid to set this member to zero.
-    unsigned long   biSizeImage;
-    // horizontal pixels per meter on the designated targer device,
-    // usually set to zero.
-    unsigned long   biXPelsPerMeter;
-    // vertical pixels per meter on the designated targer device,
-    // usually set to zero.
-    unsigned long   biYPelsPerMeter;
-    // number of colors used in the bitmap, if set to zero the
-    // number of colors is calculated using the biBitCount member.
-    unsigned long   biClrUsed;
-    // number of color that are 'important' for the bitmap,
-    // if set to zero, all colors are important.
-    unsigned long   biClrImportant;
-} __attribute__((packed)) BitMapFileHeader;
+// libpng gives "undefined reference to 'pow'" errors, and I have no
+// idea how to convince the build system to link with -lm.  We don't
+// need this functionality (it's used for gamma adjustment) so provide
+// a dummy implementation to satisfy the linker.
+double pow(double x, double y) {
+    return x;
+}
 
 int res_create_surface(const char* name, gr_surface* pSurface) {
     char resPath[256];
-    BitMapFileHeader header;
     GGLSurface* surface = NULL;
     int result = 0;
-    
-    snprintf(resPath, sizeof(resPath)-1, "/res/images/%s.bmp", name);
+    unsigned char header[8];
+    png_structp png_ptr = NULL;
+    png_infop info_ptr = NULL;
+
+    snprintf(resPath, sizeof(resPath)-1, "/res/images/%s.png", name);
     resPath[sizeof(resPath)-1] = '\0';
-    int fd = open(resPath, O_RDONLY);
-    if (fd == -1) {
+    FILE* fp = fopen(resPath, "rb");
+    if (fp == NULL) {
         result = -1;
         goto exit;
     }
-    size_t bytesRead = read(fd, &header, sizeof(header));
+
+    size_t bytesRead = fread(header, 1, sizeof(header), fp);
     if (bytesRead != sizeof(header)) {
         result = -2;
         goto exit;
     }
-    if (header.bfType != BMP_SIGNATURE) {
-        result = -3; // Not a legal header
+
+    if (png_sig_cmp(header, 0, sizeof(header))) {
+        result = -3;
         goto exit;
     }
-    if (header.biPlanes != 1) {
+
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+    if (!png_ptr) {
         result = -4;
         goto exit;
     }
-    if (!(header.biBitCount == 24 || header.biBitCount == 32)) {
+
+    info_ptr = png_create_info_struct(png_ptr);
+    if (!info_ptr) {
         result = -5;
         goto exit;
     }
-    if (header.biCompression != 0) {
+
+    if (setjmp(png_jmpbuf(png_ptr))) {
         result = -6;
         goto exit;
     }
-    size_t width = header.biWidth;
-    size_t height = header.biHeight;
+
+    png_init_io(png_ptr, fp);
+    png_set_sig_bytes(png_ptr, sizeof(header));
+    png_read_info(png_ptr, info_ptr);
+
+    size_t width = info_ptr->width;
+    size_t height = info_ptr->height;
     size_t stride = 4 * width;
     size_t pixelSize = stride * height;
-    
+
+    int color_type = info_ptr->color_type;
+    int bit_depth = info_ptr->bit_depth;
+    int channels = info_ptr->channels;
+    if (bit_depth != 8 || (channels != 3 && channels != 4) ||
+        (color_type != PNG_COLOR_TYPE_RGB &&
+         color_type != PNG_COLOR_TYPE_RGBA)) {
+        return -7;
+        goto exit;
+    }
+
     surface = malloc(sizeof(GGLSurface) + pixelSize);
     if (surface == NULL) {
-        result = -7;
+        result = -8;
         goto exit;
     }
     unsigned char* pData = (unsigned char*) (surface + 1);
@@ -128,63 +115,43 @@ int res_create_surface(const char* name, gr_surface* pSurface) {
     surface->height = height;
     surface->stride = width; /* Yes, pixels, not bytes */
     surface->data = pData;
-    surface->format = (header.biBitCount == 24) ?
+    surface->format = (channels == 3) ?
             GGL_PIXEL_FORMAT_RGBX_8888 : GGL_PIXEL_FORMAT_RGBA_8888;
 
-    // Source pixel bytes are stored B G R {A}
-    
-    lseek(fd, header.bfOffBits, SEEK_SET);
-    size_t y;
-    if (header.biBitCount == 24) { // RGB
-        size_t inputStride = (((3 * width + 3) >> 2) << 2);
-        for (y = 0; y < height; y++) {
-            unsigned char* pRow = pData + (height - (y + 1)) * stride;
-            bytesRead = read(fd,  pRow, inputStride);
-            if (bytesRead != inputStride) {
-                result = -8;
-                goto exit;
-            }
+    int y;
+    if (channels == 3) {
+        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 b = pRow[sx];
+                unsigned char r = pRow[sx];
                 unsigned char g = pRow[sx + 1];
-                unsigned char r = pRow[sx + 2];
+                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 + 2] = b; // b
                 pRow[dx + 3] = a;
             }
         }
-    } else { // RGBA
-        for (y = 0; y < height; y++) {
-            unsigned char* pRow = pData + (height - (y + 1)) * stride;
-            bytesRead = read(fd,  pRow, stride);
-            if (bytesRead != stride) {
-                result = -9;
-                goto exit;
-            }
-            size_t x;
-            for(x = 0; x < width; x++) {
-                size_t xx = x * 4;
-                unsigned char b = pRow[xx];
-                unsigned char g = pRow[xx + 1];
-                unsigned char r = pRow[xx + 2];
-                unsigned char a = pRow[xx + 3];
-                pRow[xx    ] = r;
-                pRow[xx + 1] = g;
-                pRow[xx + 2] = b;
-                pRow[xx + 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:
-    if (fd >= 0) {
-        close(fd);
+    png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+
+    if (fp != NULL) {
+        fclose(fp);
     }
     if (result < 0) {
         if (surface) {