LibGfx: Minor tweaks in PNG decoder

AmusedNetwork · Jun 11, 2020 · d59a308 · d59a308
1 parent 78155a6
commit d59a308
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/Libraries/LibGfx/PNGLoader.cpp b/Libraries/LibGfx/PNGLoader.cpp
@@ -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));