gdiplus: Use AlphaBlend for 32-bit images with alpha channels.
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7fdc0208e8
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895c6d8e1e
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@ -399,6 +399,25 @@ BOOL lengthen_path(GpPath *path, INT len)
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return TRUE;
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}
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void convert_32bppARGB_to_32bppPARGB(UINT width, UINT height,
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BYTE *dst_bits, INT dst_stride, const BYTE *src_bits, INT src_stride)
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{
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UINT x, y;
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for (y=0; y<height; y++)
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{
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const BYTE *src=src_bits+y*src_stride;
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BYTE *dst=dst_bits+y*dst_stride;
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for (x=0; x<width; x++)
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{
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BYTE alpha=src[3];
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*dst++ = *src++ * alpha / 255;
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*dst++ = *src++ * alpha / 255;
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*dst++ = *src++ * alpha / 255;
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*dst++ = *src++;
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}
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}
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}
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/* recursive deletion of GpRegion nodes */
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inline void delete_element(region_element* element)
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{
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@ -80,6 +80,9 @@ static inline REAL deg2rad(REAL degrees)
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extern const char *debugstr_rectf(CONST RectF* rc);
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extern void convert_32bppARGB_to_32bppPARGB(UINT width, UINT height,
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BYTE *dst_bits, INT dst_stride, const BYTE *src_bits, INT src_stride);
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struct GpPen{
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UINT style;
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GpUnit unit;
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@ -1877,8 +1877,8 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
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{
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HDC hdc;
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GpBitmap* bitmap = (GpBitmap*)image;
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int bm_is_selected;
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HBITMAP old_hbm=NULL;
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int temp_hdc=0, temp_bitmap=0;
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HBITMAP hbitmap, old_hbm=NULL;
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if (srcUnit == UnitInch)
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dx = dy = 96.0; /* FIXME: use the image resolution */
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@ -1887,24 +1887,73 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
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else
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return NotImplemented;
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hdc = bitmap->hdc;
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bm_is_selected = (hdc != 0);
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if (!bm_is_selected)
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if (bitmap->format == PixelFormat32bppARGB)
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{
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BITMAPINFOHEADER bih;
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BYTE *temp_bits;
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/* we need a bitmap with premultiplied alpha */
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hdc = CreateCompatibleDC(0);
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old_hbm = SelectObject(hdc, bitmap->hbitmap);
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temp_hdc = 1;
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temp_bitmap = 1;
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bih.biSize = sizeof(BITMAPINFOHEADER);
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bih.biWidth = bitmap->width;
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bih.biHeight = -bitmap->height;
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bih.biPlanes = 1;
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bih.biBitCount = 32;
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bih.biCompression = BI_RGB;
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bih.biSizeImage = 0;
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bih.biXPelsPerMeter = 0;
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bih.biYPelsPerMeter = 0;
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bih.biClrUsed = 0;
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bih.biClrImportant = 0;
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hbitmap = CreateDIBSection(hdc, (BITMAPINFO*)&bih, DIB_RGB_COLORS,
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(void**)&temp_bits, NULL, 0);
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convert_32bppARGB_to_32bppPARGB(bitmap->width, bitmap->height,
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temp_bits, bitmap->width*4, bitmap->bits, bitmap->stride);
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}
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else
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{
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hbitmap = bitmap->hbitmap;
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hdc = bitmap->hdc;
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temp_hdc = (hdc == 0);
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}
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/* FIXME: maybe alpha blend depending on the format */
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StretchBlt(graphics->hdc, pti[0].x, pti[0].y, pti[1].x-pti[0].x, pti[2].y-pti[0].y,
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hdc, srcx*dx, srcy*dy, srcwidth*dx, srcheight*dy, SRCCOPY);
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if (temp_hdc)
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{
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if (!hdc) hdc = CreateCompatibleDC(0);
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old_hbm = SelectObject(hdc, hbitmap);
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}
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if (!bm_is_selected)
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if (bitmap->format == PixelFormat32bppARGB || bitmap->format == PixelFormat32bppPARGB)
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{
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BLENDFUNCTION bf;
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bf.BlendOp = AC_SRC_OVER;
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bf.BlendFlags = 0;
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bf.SourceConstantAlpha = 255;
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bf.AlphaFormat = AC_SRC_ALPHA;
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GdiAlphaBlend(graphics->hdc, pti[0].x, pti[0].y, pti[1].x-pti[0].x, pti[2].y-pti[0].y,
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hdc, srcx*dx, srcy*dy, srcwidth*dx, srcheight*dy, bf);
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}
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else
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{
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StretchBlt(graphics->hdc, pti[0].x, pti[0].y, pti[1].x-pti[0].x, pti[2].y-pti[0].y,
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hdc, srcx*dx, srcy*dy, srcwidth*dx, srcheight*dy, SRCCOPY);
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}
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if (temp_hdc)
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{
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SelectObject(hdc, old_hbm);
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DeleteDC(hdc);
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}
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if (temp_bitmap)
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DeleteObject(hbitmap);
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}
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else
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{
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