Fixed Unix monochrome cursor implementation with non-power-of-two images

This commit is contained in:
Corentin Schreiber 2020-08-21 09:57:59 +01:00 committed by Lukas Dürrenberger
parent 603bc9ee41
commit d93cd6dd30

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@ -101,6 +101,9 @@ bool CursorImpl::loadFromPixelsARGB(const Uint8* pixels, Vector2u size, Vector2u
bool CursorImpl::loadFromPixelsMonochrome(const Uint8* pixels, Vector2u size, Vector2u hotspot)
{
// Convert the image into a bitmap (monochrome!).
// The bit data is stored packed into bytes. If the number of pixels on each row of the image
// does not fit exactly into (width/8) bytes, one extra byte is allocated at the end of each
// row to store the extra pixels.
std::size_t bytes = (size.x + 7) / 8 * size.y;
std::vector<Uint8> mask(bytes, 0); // Defines which pixel is transparent.
std::vector<Uint8> data(bytes, 1); // Defines which pixel is white/black.
@ -110,8 +113,9 @@ bool CursorImpl::loadFromPixelsMonochrome(const Uint8* pixels, Vector2u size, Ve
for (std::size_t i = 0; i < size.x; ++i)
{
std::size_t pixelIndex = i + j * size.x;
std::size_t byteIndex = pixelIndex / 8;
std::size_t bitIndex = i % 8;
std::size_t pixelIndexMask = i + j * (size.x + 7);
std::size_t byteIndex = pixelIndexMask / 8;
std::size_t bitIndex = pixelIndexMask % 8;
// Turn on pixel that are not transparent
Uint8 opacity = pixels[pixelIndex * 4 + 3] > 0 ? 1 : 0;