Platform SDK: DirectX

Color Keying State

Setting a color key instructs Direct3D to treat the key color as transparent. When Direct3D applies a texture that was created with the DDSD_CKSRCBLT flag to a primitive, all texels that match the key color are not rendered on the primitive. Note that any textures that were not created with the DDSD_CKSRCBLT flag will not display color-key effects, even if they contain the color key.

[C++]

C++ applications set color keys with the IDirectDrawSurface7::SetColorKey method for the surface that will be using the color key (in this case, the render-target surface). However, color keying can be toggled on and off by calling the IDirect3DDevice7::SetRenderState method. Set the first parameter to D3DRENDERSTATE_COLORKEYENABLE. Your application should set the second parameter to TRUE to enable color keying and FALSE to disable it. The default is FALSE.

// This code fragment assumes that lpD3DDevice is a valid pointer to
// an IDirect3DDevice7 interface.
 
// Disable color keying.
lpD3DDevice->SetRenderState(D3DRENDERSTATE_COLORKEYENABLE, 
                            FALSE);
[Visual Basic]

Applications written in Visual Basic set color keys with the DirectDrawSurface7.SetColorKey method for the surface that will be using the color key (in this case, the render-target surface). However, color keying can be toggled on and off by calling the Direct3DDevice7.SetRenderState method. Set the first parameter to D3DRENDERSTATE_COLORKEYENABLE. Your application should set the second parameter to True to enable color keying and False to disable it. The default is False.

' This code fragment assumes that D3DDevice contains a valid reference 
' to a Direct3DDevice7 object.
 
' Disable color keying.
Call D3DDevice.SetRenderState(D3DRENDERSTATE_COLORKEYENABLE, _ 
                              FALSE)