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using colorkey in C# and Directx 9.0

how to use the ColorKey and also what are the tricks about using the Colorkey ,what i should be careful about the Draw method...or other SurfaceDescription or SurfaceCaps or anything else...
Thank You Very Much!!!

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mikeant78

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dcgames

You don't specify if you are using DirectDraw or Direct3D. It makes a difference.

I am using DirectX 9.0 and DirectDraw. Under this scenario, if you specify a ColorKey, the color (or colors) described by the colorkey are treated as FULLY TRANSPARENT. The following code creates an off-screen DirectDraw surface ready to "Blit" into a BackBuffer which is then FLIPed onto the primary buffer.

SurfaceCaps caps = new SurfaceCaps();
caps.OffScreenPlain = true;
SurfaceDescription desc = new SurfaceDescription(caps);
ColorKey clrKey = new ColorKey();
clrKey.ColorSpaceLowValue = 0;
clrKey.ColorSpaceHighValue = 0;
desc.SourceDraw = clrKey;
surface = new Surface(bitmap,desc,dev);

Notice I set the color key to Low & High to 0. This are INT32 values. A setting of 0/0 means that the PURE BLACK color in the bitmap will be treated as FULLY TRANSPARENT when you blit it onto the destination surface as follows:

dstSurface.DrawFast(
dstX, dstY,
this.surface,
srcRectangle,
DrawFastFlags.Wait | DrawFastFlags.SourceColorKey );

The SourceColorKey flag specifies that the color key of the SOURCE surface (desc.SourceDraw value) be treated as the transparent color. Other combinations are valid.

The question I have been unable to answer is: How do I set the color key to a different color than black!

I tried
clrKey.ColorSpaceValueLow =
clrKey.ColorSpaceValueHigh = Color.FromArgb(255,255,133,255).ToArgb();

But it didn't work.