Fix for changing frame size and disposal method issues

This commit is contained in:
gamblor21 2023-02-12 09:11:12 -06:00
parent da9b6fb0e2
commit 29e91e0d4f

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@ -79,7 +79,16 @@ static void GIFDraw(GIFDRAW *pDraw) {
uint8_t *s;
uint16_t *d;
int32_t row_start = pDraw->y * bitmap->stride;
int iWidth = pDraw->iWidth;
if (iWidth + pDraw->iX > bitmap->width) {
iWidth = bitmap->width - pDraw->iX;
}
if (pDraw->iY + pDraw->y >= bitmap->height || pDraw->iX >= bitmap->width || iWidth < 1) {
return;
}
int32_t row_start = (pDraw->y + pDraw->iY) * bitmap->stride;
uint32_t *row = bitmap->data + row_start;
s = pDraw->pPixels;
d = (uint16_t *)row;
@ -88,20 +97,30 @@ static void GIFDraw(GIFDRAW *pDraw) {
pPal = (uint16_t *)pDraw->pPalette;
if (pDraw->ucDisposalMethod == 2) { // restore to background color
memset(d, pDraw->ucBackground, pDraw->iWidth);
// Not supported currently. Need to reset the area the previous frame occupied
// to the background color before the previous frame was drawn
// See: https://github.com/bitbank2/AnimatedGIF/issues/3
// To workaround clear the gif.bitmap object yourself as required.
}
// We always check for transpancy even if the gif does not have it
// as we also convert the color to the palette here
// Could separate it but would not sure it would be much a speed up
uint8_t c, ucTransparent = pDraw->ucTransparent;
for (int x = 0; x < pDraw->iWidth; x++)
{
c = *s++;
if (c != ucTransparent) {
*d = pPal[c];
d += pDraw->iX;
if (pDraw->ucHasTransparency == 1) {
for (int x = 0; x < iWidth; x++)
{
c = *s++;
if (c != ucTransparent) {
*d = pPal[c];
}
d++;
}
} else {
for (int x = 0; x < iWidth; x++)
{
c = *s++;
*d++ = pPal[c];
}
d++;
}
}