alphablending

What Direct3D render states should be used to implement Java's Porter-Duff compositing rules (CLEAR, SRC, SRCOVER, etc.)? I'm haven't used Java too much, but based on the white paper from 1984 , it should be a fairly straightforward mapping of render state blend modes. There are of course more that you can do than just these, like normal alpha blending (SourceAlpha, InvSourceAlpha) or additive (One, One) to name a few. (I assume that you are asking about these specifically because you are porting some existing functionality? In that cause you may not care about other combinations...) Anyway,

I've implemented a typical flood fill algorithm and it works as expected when solid colors are used where I use the Euclidean distance between the ARGB components to compare colors. My problem is that if you draw something like an anti-aliased red line on a transparent background my flood fill algorithm will not fill over most semi-transparent pixels, leaving fringes around objects. Specifically for this example, the center of the line is solid red (i.e. (255, 255, 0, 0) in ARGB format) and the fringes of the line are also solid red but the alpha of these pixels ranges down to 1% alpha (i.e.

I'm trying to write a fast transparency class in c#. How do I get PNG with transparency into GDI32 to use it with alphaBlend? I tried to put it directly via getHbitmap/selectObject, tried to paint it with setPixel on temporary DC, but all to no avail. In the result I found (afer a sleepless night), that simplest of getting transparency into GDI32 is to set Color.Black in GetHbitmap(). Like this: using (Bitmap tBMP = new Bitmap(@"myBitmap.png")) { BMPObject = tBMP.GetHbitmap(Color.Black); sz = tBMP.Size; } Any other color than black will give tinting in unexpected color of transparent areas.