void BitmapContainer::clipRect(_R<BitmapContainer> source, const RECT& sourceRect,
int32_t destX, int32_t destY, RECT& outputSourceRect,
int32_t& outputX, int32_t& outputY) const
{
int sLeft = imax(sourceRect.Xmin, 0);
int sTop = imax(sourceRect.Ymin, 0);
int sRight = imax(imin(sourceRect.Xmax, source->getWidth()), 0);
int sBottom = imax(imin(sourceRect.Ymax, source->getHeight()), 0);
int dLeft = destX;
int dTop = destY;
if (dLeft < 0)
{
sLeft += -dLeft;
dLeft = 0;
}
if (dTop < 0)
{
sTop += -dTop;
dTop = 0;
}
int clippedWidth = imax(imin(sRight - sLeft, getWidth() - dLeft), 0);
int clippedHeight = imax(imin(sBottom - sTop, getHeight() - dTop), 0);
outputSourceRect.Xmin = sLeft;
outputSourceRect.Xmax = sLeft + clippedWidth;
outputSourceRect.Ymin = sTop;
outputSourceRect.Ymax = sTop + clippedHeight;
outputX = dLeft;
outputY = dTop;
}
void BitmapContainer::copyRectangle(_R<BitmapContainer> source,
const RECT& sourceRect,
int32_t destX, int32_t destY,
bool mergeAlpha)
{
RECT clippedSourceRect;
int32_t clippedX;
int32_t clippedY;
clipRect(source, sourceRect, destX, destY, clippedSourceRect, clippedX, clippedY);
int copyWidth = clippedSourceRect.Xmax - clippedSourceRect.Xmin;
int copyHeight = clippedSourceRect.Ymax - clippedSourceRect.Ymin;
if (copyWidth <= 0 || copyHeight <= 0)
return;
int sx = clippedSourceRect.Xmin;
int sy = clippedSourceRect.Ymin;
if (mergeAlpha==false)
{
//Fast path using memmove
for (int i=0; i<copyHeight; i++)
{
memmove(&data[(clippedY+i)*stride + 4*clippedX],
&source->data[(sy+i)*source->stride + 4*sx],
4*copyWidth);
}
}
else
{
//Slow path using Cairo
CairoRenderContext ctxt(&data[0], width, height);
ctxt.simpleBlit(clippedX, clippedY, &source->data[0],
source->getWidth(), source->getHeight(),
sx, sy, copyWidth, copyHeight);
}
}
