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Fix 2-bit bmp rendering

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Dave Allie 2025-12-21 17:50:55 +11:00
parent 2a27c6d068
commit 7e6bd5f952
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GPG Key ID: F2FDDB3AD8D0276F
1 changed files with 25 additions and 14 deletions
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39
lib/GfxRenderer/Bitmap.cpp
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@ -128,7 +128,7 @@ BmpReaderError Bitmap::readRow(uint8_t* data, uint8_t* rowBuffer) const {
int bitShift = 6;
// Helper lambda to pack 2bpp color into the output stream
auto packPixel = [&](uint8_t lum) {
auto packPixel = [&](const uint8_t lum) {
uint8_t color = (lum >> 6); // Simple 2-bit reduction: 0-255 -> 0-3
currentOutByte |= (color << bitShift);
if (bitShift == 0) {
@ -140,38 +140,49 @@ BmpReaderError Bitmap::readRow(uint8_t* data, uint8_t* rowBuffer) const {
}
};
uint8_t lum;
switch (bpp) {
case 8: {
case 32: {
const uint8_t* p = rowBuffer;
for (int x = 0; x < width; x++) {
packPixel(paletteLum[rowBuffer[x]]);
lum = (77u * p[2] + 150u * p[1] + 29u * p[0]) >> 8;
packPixel(lum);
p += 4;
}
break;
}
case 24: {
const uint8_t* p = rowBuffer;
for (int x = 0; x < width; x++) {
uint8_t lum = (77u * p[2] + 150u * p[1] + 29u * p[0]) >> 8;
lum = (77u * p[2] + 150u * p[1] + 29u * p[0]) >> 8;
packPixel(lum);
p += 3;
}
break;
}
case 8: {
for (int x = 0; x < width; x++) {
packPixel(paletteLum[rowBuffer[x]]);
}
break;
}
case 2: {
for (int x = 0; x < width; x++) {
lum = paletteLum[(rowBuffer[x >> 2] >> (6 - ((x & 3) * 2))) & 0x03];
packPixel(lum);
}
break;
}
case 1: {
for (int x = 0; x < width; x++) {
uint8_t lum = (rowBuffer[x >> 3] & (0x80 >> (x & 7))) ? 0xFF : 0x00;
lum = (rowBuffer[x >> 3] & (0x80 >> (x & 7))) ? 0xFF : 0x00;
packPixel(lum);
}
break;
}
case 32: {
const uint8_t* p = rowBuffer;
for (int x = 0; x < width; x++) {
uint8_t lum = (77u * p[2] + 150u * p[1] + 29u * p[0]) >> 8;
packPixel(lum);
p += 4;
}
break;
}
default:
return BmpReaderError::UnsupportedBpp;
}
// Flush remaining bits if width is not a multiple of 4