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LibGfx: PNGLoader support for grayscale images with alpha.

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This commit is contained in:
LepkoQQ 2020-04-26 20:02:30 +02:00 • committed by Andreas Kling
parent d009df074f
commit e5a598414f
1 changed files with 41 additions and 3 deletions
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44
Libraries/LibGfx/PNGLoader.cpp
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@ -67,6 +67,18 @@ struct [[gnu::packed]] PaletteEntry
//u8 a; //u8 a;
}; };
struct [[gnu::packed]] Tuple
{
u8 gray;
u8 a;
};
struct [[gnu::packed]] Tuple16
{
u16 gray;
u16 a;
};
struct [[gnu::packed]] Triplet struct [[gnu::packed]] Triplet
{ {
u8 r; u8 r;
@ -331,6 +343,33 @@ template<bool has_alpha, u8 filter_type>
ASSERT_NOT_REACHED(); ASSERT_NOT_REACHED();
} }
break; break;
case 4:
if (context.bit_depth == 8) {
for (int y = 0; y < context.height; ++y) {
auto* tuples = (Tuple*)context.scanlines[y].data.data();
for (int i = 0; i < context.width; ++i) {
auto& pixel = (Pixel&)context.bitmap->scanline(y)[i];
pixel.r = tuples[i].gray;
pixel.g = tuples[i].gray;
pixel.b = tuples[i].gray;
pixel.a = tuples[i].a;
}
}
} else if (context.bit_depth == 16) {
for (int y = 0; y < context.height; ++y) {
auto* tuples = (Tuple16*)context.scanlines[y].data.data();
for (int i = 0; i < context.width; ++i) {
auto& pixel = (Pixel&)context.bitmap->scanline(y)[i];
pixel.r = tuples[i].gray & 0xFF;
pixel.g = tuples[i].gray & 0xFF;
pixel.b = tuples[i].gray & 0xFF;
pixel.a = tuples[i].a & 0xFF;
}
}
} else {
ASSERT_NOT_REACHED();
}
break;
case 2: case 2:
if (context.bit_depth == 8) { if (context.bit_depth == 8) {
for (int y = 0; y < context.height; ++y) { for (int y = 0; y < context.height; ++y) {
@ -617,9 +656,8 @@ static bool process_IHDR(const ByteBuffer& data, PNGLoadingContext& context, boo
context.bytes_per_pixel = ihdr.bit_depth / 8; context.bytes_per_pixel = ihdr.bit_depth / 8;
break; break;
case 4: // Each pixel is a grayscale sample, followed by an alpha sample. case 4: // Each pixel is a grayscale sample, followed by an alpha sample.
// FIXME: Implement grayscale PNG support. context.bytes_per_pixel = 2 * ihdr.bit_depth / 8;
dbgprintf("PNGLoader::process_IHDR: Unsupported grayscale format.\n"); break;
return false;
case 2: case 2:
context.bytes_per_pixel = 3 * (ihdr.bit_depth / 8); context.bytes_per_pixel = 3 * (ihdr.bit_depth / 8);
break; break;