Vincent Povirk : gdiplus: Use AlphaBlend for 32-bit images with alpha channels.
Alexandre Julliard
julliard at winehq.org
Sat Aug 29 11:36:23 CDT 2009
Module: wine
Branch: master
Commit: 895c6d8e1ea81ae10f927463692c01bffd58fda5
URL: http://source.winehq.org/git/wine.git/?a=commit;h=895c6d8e1ea81ae10f927463692c01bffd58fda5
Author: Vincent Povirk <vincent at codeweavers.com>
Date: Fri Aug 28 17:21:10 2009 -0500
gdiplus: Use AlphaBlend for 32-bit images with alpha channels.
---
dlls/gdiplus/gdiplus.c | 19 +++++++++++
dlls/gdiplus/gdiplus_private.h | 3 ++
dlls/gdiplus/graphics.c | 71 +++++++++++++++++++++++++++++++++------
3 files changed, 82 insertions(+), 11 deletions(-)
diff --git a/dlls/gdiplus/gdiplus.c b/dlls/gdiplus/gdiplus.c
index 06019a2..ec956f3 100644
--- a/dlls/gdiplus/gdiplus.c
+++ b/dlls/gdiplus/gdiplus.c
@@ -399,6 +399,25 @@ BOOL lengthen_path(GpPath *path, INT len)
return TRUE;
}
+void convert_32bppARGB_to_32bppPARGB(UINT width, UINT height,
+ BYTE *dst_bits, INT dst_stride, const BYTE *src_bits, INT src_stride)
+{
+ UINT x, y;
+ for (y=0; y<height; y++)
+ {
+ const BYTE *src=src_bits+y*src_stride;
+ BYTE *dst=dst_bits+y*dst_stride;
+ for (x=0; x<width; x++)
+ {
+ BYTE alpha=src[3];
+ *dst++ = *src++ * alpha / 255;
+ *dst++ = *src++ * alpha / 255;
+ *dst++ = *src++ * alpha / 255;
+ *dst++ = *src++;
+ }
+ }
+}
+
/* recursive deletion of GpRegion nodes */
inline void delete_element(region_element* element)
{
diff --git a/dlls/gdiplus/gdiplus_private.h b/dlls/gdiplus/gdiplus_private.h
index 5e615e1..e87176e 100644
--- a/dlls/gdiplus/gdiplus_private.h
+++ b/dlls/gdiplus/gdiplus_private.h
@@ -80,6 +80,9 @@ static inline REAL deg2rad(REAL degrees)
extern const char *debugstr_rectf(CONST RectF* rc);
+extern void convert_32bppARGB_to_32bppPARGB(UINT width, UINT height,
+ BYTE *dst_bits, INT dst_stride, const BYTE *src_bits, INT src_stride);
+
struct GpPen{
UINT style;
GpUnit unit;
diff --git a/dlls/gdiplus/graphics.c b/dlls/gdiplus/graphics.c
index a455d45..1df3eee 100644
--- a/dlls/gdiplus/graphics.c
+++ b/dlls/gdiplus/graphics.c
@@ -1877,8 +1877,8 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
{
HDC hdc;
GpBitmap* bitmap = (GpBitmap*)image;
- int bm_is_selected;
- HBITMAP old_hbm=NULL;
+ int temp_hdc=0, temp_bitmap=0;
+ HBITMAP hbitmap, old_hbm=NULL;
if (srcUnit == UnitInch)
dx = dy = 96.0; /* FIXME: use the image resolution */
@@ -1887,24 +1887,73 @@ GpStatus WINGDIPAPI GdipDrawImagePointsRect(GpGraphics *graphics, GpImage *image
else
return NotImplemented;
- hdc = bitmap->hdc;
- bm_is_selected = (hdc != 0);
-
- if (!bm_is_selected)
+ if (bitmap->format == PixelFormat32bppARGB)
{
+ BITMAPINFOHEADER bih;
+ BYTE *temp_bits;
+
+ /* we need a bitmap with premultiplied alpha */
hdc = CreateCompatibleDC(0);
- old_hbm = SelectObject(hdc, bitmap->hbitmap);
+ temp_hdc = 1;
+ temp_bitmap = 1;
+
+ bih.biSize = sizeof(BITMAPINFOHEADER);
+ bih.biWidth = bitmap->width;
+ bih.biHeight = -bitmap->height;
+ bih.biPlanes = 1;
+ bih.biBitCount = 32;
+ bih.biCompression = BI_RGB;
+ bih.biSizeImage = 0;
+ bih.biXPelsPerMeter = 0;
+ bih.biYPelsPerMeter = 0;
+ bih.biClrUsed = 0;
+ bih.biClrImportant = 0;
+
+ hbitmap = CreateDIBSection(hdc, (BITMAPINFO*)&bih, DIB_RGB_COLORS,
+ (void**)&temp_bits, NULL, 0);
+
+ convert_32bppARGB_to_32bppPARGB(bitmap->width, bitmap->height,
+ temp_bits, bitmap->width*4, bitmap->bits, bitmap->stride);
+ }
+ else
+ {
+ hbitmap = bitmap->hbitmap;
+ hdc = bitmap->hdc;
+ temp_hdc = (hdc == 0);
+ }
+
+ if (temp_hdc)
+ {
+ if (!hdc) hdc = CreateCompatibleDC(0);
+ old_hbm = SelectObject(hdc, hbitmap);
}
- /* FIXME: maybe alpha blend depending on the format */
- StretchBlt(graphics->hdc, pti[0].x, pti[0].y, pti[1].x-pti[0].x, pti[2].y-pti[0].y,
- hdc, srcx*dx, srcy*dy, srcwidth*dx, srcheight*dy, SRCCOPY);
+ if (bitmap->format == PixelFormat32bppARGB || bitmap->format == PixelFormat32bppPARGB)
+ {
+ BLENDFUNCTION bf;
+
+ bf.BlendOp = AC_SRC_OVER;
+ bf.BlendFlags = 0;
+ bf.SourceConstantAlpha = 255;
+ bf.AlphaFormat = AC_SRC_ALPHA;
+
+ GdiAlphaBlend(graphics->hdc, pti[0].x, pti[0].y, pti[1].x-pti[0].x, pti[2].y-pti[0].y,
+ hdc, srcx*dx, srcy*dy, srcwidth*dx, srcheight*dy, bf);
+ }
+ else
+ {
+ StretchBlt(graphics->hdc, pti[0].x, pti[0].y, pti[1].x-pti[0].x, pti[2].y-pti[0].y,
+ hdc, srcx*dx, srcy*dy, srcwidth*dx, srcheight*dy, SRCCOPY);
+ }
- if (!bm_is_selected)
+ if (temp_hdc)
{
SelectObject(hdc, old_hbm);
DeleteDC(hdc);
}
+
+ if (temp_bitmap)
+ DeleteObject(hbitmap);
}
else
{
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