// performs AlphaBlend
//static
void MapWindow::DoAlphaBlend(HDC dstHdc, const RECT dstRect, HDC srcHdc, const RECT srcRect, BYTE globalOpacity) {
if (AlphaBlendF == NULL)
return;
//BLENDFUNCTION bf = { AC_SRC_OVER, 0, globalOpacity, AC_SRC_ALPHA };
// we are not using per-pixel alpha, so do not use AC_SRC_ALPHA flag
BLENDFUNCTION bf = { AC_SRC_OVER, 0, globalOpacity, 0 };
AlphaBlendF(
dstHdc, dstRect.left, dstRect.top, dstRect.right - dstRect.left, dstRect.bottom - dstRect.top,
srcHdc, srcRect.left, srcRect.top, srcRect.right - srcRect.left, srcRect.bottom - srcRect.top, bf);
} // DoAlphaBlend()
bool LKSurface::AlphaBlend(const RECT& dstRect, const LKSurface& Surface, const RECT& srcRect, uint8_t globalOpacity) {
if(!AlphaBlendSupported()) {
return false;
}
#ifdef USE_GDI
#ifdef UNDER_CE
extern BOOL DoAlphaBlend_internal(HDC,int,int,int,int,HDC,int,int,int,int, DWORD);
static unsigned failedCount = 0;
static bool Success = false;
bool bOK = false;
if (AlphaBlendF) {
//BLENDFUNCTION bf = { AC_SRC_OVER, 0, globalOpacity, AC_SRC_ALPHA };
// we are not using per-pixel alpha, so do not use AC_SRC_ALPHA flag
BLENDFUNCTION bf = {AC_SRC_OVER, 0, globalOpacity, 0};
bOK = AlphaBlendF(
*this, dstRect.left, dstRect.top, dstRect.right - dstRect.left, dstRect.bottom - dstRect.top,
Surface, srcRect.left, srcRect.top, srcRect.right - srcRect.left, srcRect.bottom - srcRect.top, bf);
if (!Success) {
if (!bOK && dstRect.right - dstRect.left > 0 &&
dstRect.bottom - dstRect.top > 0 &&
srcRect.right - srcRect.left > 0 &&
srcRect.bottom - srcRect.top > 0) {
// after more 10 consecutive failed, we assume AlphaBlend is not supported, don't use it anymore
++failedCount;
if (failedCount > 10) {
AlphaBlendF = NULL;
}
}
Success = bOK;
}
}
if (!bOK) {
bOK = DoAlphaBlend_internal(
*this, dstRect.left, dstRect.top, dstRect.right - dstRect.left, dstRect.bottom - dstRect.top,
Surface, srcRect.left, srcRect.top, srcRect.right - srcRect.left, srcRect.bottom - srcRect.top, globalOpacity);
}
return bOK;
#else
//BLENDFUNCTION bf = { AC_SRC_OVER, 0, globalOpacity, AC_SRC_ALPHA };
// we are not using per-pixel alpha, so do not use AC_SRC_ALPHA flag
BLENDFUNCTION bf = {AC_SRC_OVER, 0, globalOpacity, 0};
::AlphaBlend(*this, dstRect.left, dstRect.top, dstRect.right - dstRect.left, dstRect.bottom - dstRect.top,
Surface, srcRect.left, srcRect.top, srcRect.right - srcRect.left, srcRect.bottom - srcRect.top, bf);
return true; // always return true because always implemented on Windows PC
#endif
#else
if(_pCanvas) {
_pCanvas->AlphaBlend(dstRect.left, dstRect.top, dstRect.right - dstRect.left, dstRect.bottom - dstRect.top,
Surface, srcRect.left, srcRect.top, srcRect.right - srcRect.left, srcRect.bottom - srcRect.top, globalOpacity);
return true;
}
return false;
#endif
}
