1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 13:38:11 +00:00

LibGfx: Minor tweaks in PNG decoder

This commit is contained in:
Andreas Kling 2020-06-11 08:48:09 +02:00
parent 78155a6668
commit d59a308c7e

View file

@ -246,7 +246,7 @@ ALWAYS_INLINE static void unfilter_impl(Gfx::Bitmap& bitmap, int y, const void*
}
if constexpr (filter_type == 2) {
auto* pixels = (Pixel*)bitmap.scanline(y);
auto* pixels_y_minus_1 = y == 0 ? dummy_scanline : (Pixel*)bitmap.scanline(y - 1);
auto* pixels_y_minus_1 = y == 0 ? dummy_scanline : (const Pixel*)bitmap.scanline(y - 1);
for (int i = 0; i < bitmap.width(); ++i) {
auto& x = pixels[i];
swap(x.r, x.b);
@ -261,7 +261,7 @@ ALWAYS_INLINE static void unfilter_impl(Gfx::Bitmap& bitmap, int y, const void*
}
if constexpr (filter_type == 3) {
auto* pixels = (Pixel*)bitmap.scanline(y);
auto* pixels_y_minus_1 = y == 0 ? dummy_scanline : (Pixel*)bitmap.scanline(y - 1);
auto* pixels_y_minus_1 = y == 0 ? dummy_scanline : (const Pixel*)bitmap.scanline(y - 1);
for (int i = 0; i < bitmap.width(); ++i) {
auto& x = pixels[i];
swap(x.r, x.b);
@ -358,10 +358,10 @@ NEVER_INLINE FLATTEN static void unfilter(PNGLoadingContext& context)
auto mask = (1 << context.bit_depth) - 1;
for (int y = 0; y < context.height; ++y) {
auto* gray_values = (u8*)context.scanlines[y].data.data();
for (int i = 0; i < context.width; ++i) {
auto bit_offset = (8 - context.bit_depth) - (context.bit_depth * (i % pixels_per_byte));
auto value = (gray_values[i / pixels_per_byte] >> bit_offset) & mask;
auto& pixel = (Pixel&)context.bitmap->scanline(y)[i];
for (int x = 0; x < context.width; ++x) {
auto bit_offset = (8 - context.bit_depth) - (context.bit_depth * (x % pixels_per_byte));
auto value = (gray_values[x / pixels_per_byte] >> bit_offset) & mask;
auto& pixel = (Pixel&)context.bitmap->scanline(y)[x];
pixel.r = value * (0xff / pow(context.bit_depth, 2));
pixel.g = value * (0xff / pow(context.bit_depth, 2));
pixel.b = value * (0xff / pow(context.bit_depth, 2));