From 3b1b68d6c764a4f60d034e57a94879b7df65fd43 Mon Sep 17 00:00:00 2001 From: Matt Sarett Date: Mon, 14 Dec 2015 13:08:33 -0500 Subject: Allow ninepatches to be encoded using non-RGBA modes The original intention for forcing ninepatches to be encoded as RGBA (with alpha) was to avoid the possibility of the decoder producing 565 output. 565 output is bad for ninepatches because dithering tiny images that we intend to scale later leads to bad results. I would argue that, since the new BitmapFactory does not dither, we might now be ok to allow 565 decodes for ninepatches. However, we will maintain the old behavior by disabling 565 decodes for ninepatch. There are two changes to PNG encodings: (1) Allows ninepatch images to be encoded in any mode. Forcing them to RGBA makes things awkward for the decoder. Currently, BitmapFactory's png decoder checks every pixel for alpha. That way, RGBA images that are actually opaque can be marked as opaque, in order to optimize drawing. We want to remove this complexity from the decoder. (2) Make sure ninepatch chunks are stored in the png header. That way we know immediately that the png is a ninepatch, and can refuse to decode to 565 (if we feel this is best). Change-Id: I724f5dbefb1be7b412f9b362dff83cbc0603f0bf --- tools/aapt/Images.cpp | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) (limited to 'tools') diff --git a/tools/aapt/Images.cpp b/tools/aapt/Images.cpp index e4738f5eda7d..5ad337949bee 100644 --- a/tools/aapt/Images.cpp +++ b/tools/aapt/Images.cpp @@ -1095,13 +1095,6 @@ static void write_png(const char* imageName, analyze_image(imageName, imageInfo, grayscaleTolerance, rgbPalette, alphaPalette, &paletteEntries, &hasTransparency, &color_type, outRows); - // If the image is a 9-patch, we need to preserve it as a ARGB file to make - // sure the pixels will not be pre-dithered/clamped until we decide they are - if (imageInfo.is9Patch && (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_GRAY || color_type == PNG_COLOR_TYPE_PALETTE)) { - color_type = PNG_COLOR_TYPE_RGB_ALPHA; - } - if (kIsDebug) { switch (color_type) { case PNG_COLOR_TYPE_PALETTE: @@ -1180,18 +1173,11 @@ static void write_png(const char* imageName, } for (int i = 0; i < chunk_count; i++) { - unknowns[i].location = PNG_HAVE_PLTE; + unknowns[i].location = PNG_HAVE_IHDR; } png_set_keep_unknown_chunks(write_ptr, PNG_HANDLE_CHUNK_ALWAYS, chunk_names, chunk_count); png_set_unknown_chunks(write_ptr, write_info, unknowns, chunk_count); -#if PNG_LIBPNG_VER < 10600 - /* Deal with unknown chunk location bug in 1.5.x and earlier */ - png_set_unknown_chunk_location(write_ptr, write_info, 0, PNG_HAVE_PLTE); - if (imageInfo.haveLayoutBounds) { - png_set_unknown_chunk_location(write_ptr, write_info, 1, PNG_HAVE_PLTE); - } -#endif } -- cgit v1.2.3-59-g8ed1b