Processing Texture Stages

The driver uses the D3DDP2OP_TEXTURESTAGESTATE operation code and D3DHAL_DP2TEXTURESTAGESTATE structures that follow in the command stream to process changes to texture-stage states. For information about how the driver processes operation codes, see Command Stream.

For example, when the operation code is D3DDP2OP_TEXTURESTAGESTATE, and the value of the wStateCount member of the D3DHAL_DP2COMMAND structure is seven, then seven D3DHAL_DP2TEXTURESTAGESTATE structures follow before the next D3DHAL_DP2COMMAND instruction is reached. Each D3DHAL_DP2TEXTURESTAGESTATE structure contains a dwStage member that specifies which stage of the texture blending pipeline needs to have a texture state change. The TSState member of the same structure specifies which state of the D3DTEXTURESTAGESTATETYPE enumerated type to set, and the dwValue member of the D3DHAL_DP2TEXTURESTAGESTATE structure contains the value to which the specified state should be set.

The process is the same for all render states, or any other type of instruction. If the bCommand member of the D3DHAL_DP2COMMAND structure is D3DDP2OP_RENDERSTATE, then the structure to follow is a D3DHAL_DP2RENDERSTATE structure and the information in that structure is used to set the render state accordingly.

Rather than using distinct Boolean-valued render states to control the coordinates, each render state value is a set of flags composed with the D3DWRAP_U and D3DWRAP_V flags (defined in d3dtypes.h). This change was made for compatibility with higher-dimensional textures.

Other useful information pertaining to multiple texture implementation can be found in the DirectX SDK documentation, in the sections covering blend equations, semantics of per-texture states, color operations, and alpha operations. For more information about the texture stage state types enabled for DirectX 6.0 and later versions, see the D3DTEXTUREOP and D3DTEXTUREFILTERTYPE enumerated types.

Note   DirectX 9.0 and later applications can use values in the D3DSAMPLERSTATETYPE enumeration to control the characteristics of sampler texture-related render states. In DirectX 8.0 and earlier, these sampler states were included in the D3DTEXTURESTAGESTATETYPE enumeration. The runtime maps user-mode sampler states (D3DSAMP_Xxx) to kernel-mode D3DTSS_Xxx values so that drivers are not required to process user-mode sampler states. For more information about D3DSAMPLERSTATETYPE, see the latest DirectX SDK documentation.