playdate->graphics->getBitmapData pixel format notes

pd_bitmap_notes.c

int width = 0;
int height = 0;
int stride = 0;
int hasMask = 0;
u8* bitmapBuffer;

pd->graphics->getBitmapData(bitmap, &width, &height, &stride, &hasMask, &bitmapBuffer);

// bitmap data is comprised of two maps for each channel, one after the other
int mapSize = height * stride;
void* color = bitmapBuffer; // each bit is 0 for black, 1 for white

if (hasMask)
{
  void* alpha = bitmapBuffer + mapSize; // each bit is 0 for transparent, 1 for opaque
  memset(alpha, 0xFF, mapSize); // fill alpha map - so all pixels are opaque
}