| Microsoft DirectX 8.1 (Visual Basic) |
Applications associate a blending stage with each texture in the set of current textures. Microsoft® Direct3D® evaluates each blending stage in order, beginning with the first texture in the set and ending with the eighth.
Direct3D applies the information from each texture in the set of current textures to the blending stage that is associated with it. Applications control what information from a texture stage is used by calling Direct3DDevice8.SetTextureStageState. You can set separate operations for the color and alpha channels, and each operation uses two arguments. Specify color channel operations by using the D3DTSS_COLOROP stage state, and alpha operations by using D3DTSS_ALPHAOP. Both stage states use values from the CONST_D3DTEXTUREOP enumeration.
Texture blending arguments use the D3DTSS_COLORARG1, D3DTSS_COLORARG2, D3DTSS_ALPHARG1, and D3DTSS_ALPHARG2 members of the CONST_D3DTEXTURESTAGESTATETYPE enumeration. The corresponding argument values are identified using Texture Argument Flags.
Note You can disable a texture stage—and any subsequent texture blending stages in the cascade—by setting the color operation for that stage to D3DTOP_DISABLE. Disabling the color operation effectively disables the alpha operation as well. Alpha operations cannot be disabled when color operations are enabled. Setting the alpha operation to D3DTOP_DISABLE when color blending is enabled causes undefined behavior.
To determine the supported texture blending operations of a device, query the TextureCaps member of the D3DCAPS8 type.