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LibGfx: PNGLoader support for grayscale images with 8/16bpp.

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LepkoQQ 2020-04-26 18:30:11 +02:00 • committed by Andreas Kling
parent 2778d077e5
commit d009df074f
1 changed files with 34 additions and 0 deletions
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34
Libraries/LibGfx/PNGLoader.cpp
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@ -304,6 +304,33 @@ template<bool has_alpha, u8 filter_type>
{ {
// First unpack the scanlines to RGBA: // First unpack the scanlines to RGBA:
switch (context.color_type) { switch (context.color_type) {
case 0:
if (context.bit_depth == 8) {
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& pixel = (Pixel&)context.bitmap->scanline(y)[i];
pixel.r = gray_values[i];
pixel.g = gray_values[i];
pixel.b = gray_values[i];
pixel.a = 0xff;
}
}
} else if (context.bit_depth == 16) {
for (int y = 0; y < context.height; ++y) {
auto* gray_values = (u16*)context.scanlines[y].data.data();
for (int i = 0; i < context.width; ++i) {
auto& pixel = (Pixel&)context.bitmap->scanline(y)[i];
pixel.r = gray_values[i] & 0xFF;
pixel.g = gray_values[i] & 0xFF;
pixel.b = gray_values[i] & 0xFF;
pixel.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) {
@ -582,6 +609,13 @@ static bool process_IHDR(const ByteBuffer& data, PNGLoadingContext& context, boo
switch (context.color_type) { switch (context.color_type) {
case 0: // Each pixel is a grayscale sample. case 0: // Each pixel is a grayscale sample.
// FIXME: Implement support for 1/2/4 bit grayscale based images.
if (ihdr.bit_depth != 8 && ihdr.bit_depth != 16) {
dbgprintf("PNGLoader::process_IHDR: Unsupported grayscale format (%d bpp).\n", context.bit_depth);
return false;
}
context.bytes_per_pixel = ihdr.bit_depth / 8;
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. // FIXME: Implement grayscale PNG support.
dbgprintf("PNGLoader::process_IHDR: Unsupported grayscale format.\n"); dbgprintf("PNGLoader::process_IHDR: Unsupported grayscale format.\n");