diff options
| -rw-r--r-- | tools/aapt/Images.cpp | 112 |
1 files changed, 83 insertions, 29 deletions
diff --git a/tools/aapt/Images.cpp b/tools/aapt/Images.cpp index 5ad337949bee..867a6ffa97bc 100644 --- a/tools/aapt/Images.cpp +++ b/tools/aapt/Images.cpp @@ -873,14 +873,15 @@ static void dump_image(int w, int h, png_bytepp rows, int color_type) static void analyze_image(const char *imageName, image_info &imageInfo, int grayscaleTolerance, png_colorp rgbPalette, png_bytep alphaPalette, - int *paletteEntries, bool *hasTransparency, int *colorType, - png_bytepp outRows) + int *paletteEntries, int *alphaPaletteEntries, bool *hasTransparency, + int *colorType, png_bytepp outRows) { int w = imageInfo.width; int h = imageInfo.height; - int i, j, rr, gg, bb, aa, idx; - uint32_t colors[256], col; - int num_colors = 0; + int i, j, rr, gg, bb, aa, idx;; + uint32_t opaqueColors[256], alphaColors[256]; + uint32_t col; + int numOpaqueColors = 0, numAlphaColors = 0; int maxGrayDeviation = 0; bool isOpaque = true; @@ -891,6 +892,10 @@ static void analyze_image(const char *imageName, image_info &imageInfo, int gray // 1. Every pixel has R == G == B (grayscale) // 2. Every pixel has A == 255 (opaque) // 3. There are no more than 256 distinct RGBA colors + // We will track opaque colors separately from colors with + // alpha. This allows us to reencode the color table more + // efficiently (color tables entries without a corresponding + // alpha value are assumed to be opaque). if (kIsDebug) { printf("Initial image data:\n"); @@ -943,26 +948,53 @@ static void analyze_image(const char *imageName, image_info &imageInfo, int gray if (isPalette) { col = (uint32_t) ((rr << 24) | (gg << 16) | (bb << 8) | aa); bool match = false; - for (idx = 0; idx < num_colors; idx++) { - if (colors[idx] == col) { - match = true; - break; + + if (aa == 0xff) { + for (idx = 0; idx < numOpaqueColors; idx++) { + if (opaqueColors[idx] == col) { + match = true; + break; + } + } + + if (!match) { + if (numOpaqueColors < 256) { + opaqueColors[numOpaqueColors] = col; + } + numOpaqueColors++; + } + + // Write the palette index for the pixel to outRows optimistically. + // We might overwrite it later if we decide to encode as gray or + // gray + alpha. We may also need to overwrite it when we combine + // into a single palette. + *out++ = idx; + } else { + for (idx = 0; idx < numAlphaColors; idx++) { + if (alphaColors[idx] == col) { + match = true; + break; + } } - } - // Write the palette index for the pixel to outRows optimistically - // We might overwrite it later if we decide to encode as gray or - // gray + alpha - *out++ = idx; - if (!match) { - if (num_colors == 256) { - if (kIsDebug) { - printf("Found 257th color at %d, %d\n", i, j); + if (!match) { + if (numAlphaColors < 256) { + alphaColors[numAlphaColors] = col; } - isPalette = false; - } else { - colors[num_colors++] = col; + numAlphaColors++; } + + // Write the palette index for the pixel to outRows optimistically. + // We might overwrite it later if we decide to encode as gray or + // gray + alpha. + *out++ = idx; + } + + if (numOpaqueColors + numAlphaColors > 256) { + if (kIsDebug) { + printf("Found 257th color at %d, %d\n", i, j); + } + isPalette = false; } } } @@ -970,9 +1002,9 @@ static void analyze_image(const char *imageName, image_info &imageInfo, int gray *paletteEntries = 0; *hasTransparency = !isOpaque; - int bpp = isOpaque ? 3 : 4; - int paletteSize = w * h + bpp * num_colors; + int paletteSize = w * h + 3 * numOpaqueColors + 4 * numAlphaColors; + int bpp = isOpaque ? 3 : 4; if (kIsDebug) { printf("isGrayscale = %s\n", isGrayscale ? "true" : "false"); printf("isOpaque = %s\n", isOpaque ? "true" : "false"); @@ -1017,16 +1049,37 @@ static void analyze_image(const char *imageName, image_info &imageInfo, int gray // color type chosen if (*colorType == PNG_COLOR_TYPE_PALETTE) { + // Combine the alphaColors and the opaqueColors into a single palette. + // The alphaColors must be at the start of the palette. + uint32_t* colors = alphaColors; + memcpy(colors + numAlphaColors, opaqueColors, 4 * numOpaqueColors); + + // Fix the indices of the opaque colors in the image. + for (j = 0; j < h; j++) { + png_bytep row = imageInfo.rows[j]; + png_bytep out = outRows[j]; + for (i = 0; i < w; i++) { + uint32_t pixel = ((uint32_t*) row)[i]; + if (pixel >> 24 == 0xFF) { + out[i] += numAlphaColors; + } + } + } + // Create separate RGB and Alpha palettes and set the number of colors - *paletteEntries = num_colors; + int numColors = numOpaqueColors + numAlphaColors; + *paletteEntries = numColors; + *alphaPaletteEntries = numAlphaColors; // Create the RGB and alpha palettes - for (int idx = 0; idx < num_colors; idx++) { + for (int idx = 0; idx < numColors; idx++) { col = colors[idx]; rgbPalette[idx].red = (png_byte) ((col >> 24) & 0xff); rgbPalette[idx].green = (png_byte) ((col >> 16) & 0xff); rgbPalette[idx].blue = (png_byte) ((col >> 8) & 0xff); - alphaPalette[idx] = (png_byte) (col & 0xff); + if (idx < numAlphaColors) { + alphaPalette[idx] = (png_byte) (col & 0xff); + } } } else if (*colorType == PNG_COLOR_TYPE_GRAY || *colorType == PNG_COLOR_TYPE_GRAY_ALPHA) { // If the image is gray or gray + alpha, compact the pixels into outRows @@ -1090,10 +1143,10 @@ static void write_png(const char* imageName, png_color rgbPalette[256]; png_byte alphaPalette[256]; bool hasTransparency; - int paletteEntries; + int paletteEntries, alphaPaletteEntries; analyze_image(imageName, imageInfo, grayscaleTolerance, rgbPalette, alphaPalette, - &paletteEntries, &hasTransparency, &color_type, outRows); + &paletteEntries, &alphaPaletteEntries, &hasTransparency, &color_type, outRows); if (kIsDebug) { switch (color_type) { @@ -1124,7 +1177,8 @@ static void write_png(const char* imageName, if (color_type == PNG_COLOR_TYPE_PALETTE) { png_set_PLTE(write_ptr, write_info, rgbPalette, paletteEntries); if (hasTransparency) { - png_set_tRNS(write_ptr, write_info, alphaPalette, paletteEntries, (png_color_16p) 0); + png_set_tRNS(write_ptr, write_info, alphaPalette, alphaPaletteEntries, + (png_color_16p) 0); } png_set_filter(write_ptr, 0, PNG_NO_FILTERS); } else { |