PEXOCCSetBFSurfaceActiveTextures - Set Back-Facing Surface Active Textures (5.2)

Synopsis 

 
     void PEXOCCSetBFSurfaceActiveTextures(
          PEXOCC context,
          unsigned int count,
          PEXTableIndex *indices
)

Arguments

context
An OC context returned by a successful PEXCreateOCC call.

display (OCC)
A pointer to a display structure returned by a successful XOpenDisplay call.

resource_id (OCC)
The resource identifier of the renderer or structure.

req_type (OCC)
The request type for the output command (PEXOCRender, PEXOCStore, PEXOCRenderSingle or PEXOCStoreSingle).

count
The number of indices in the list.

indices
A list of table indices into the texture mapping lookup table.

Returns

None.

Description

Invoke PEXOCCSetBFSurfaceActiveTextures to create an attribute output command which sets the back-facing surface active textures attribute in the renderer's pipeline state according to the values specified by indices.

You use the pipeline state's active texture indices as an entry into the renderer's texture mapping lookup table. The indices are an ordered list that you use to select the textures that are sequentially applied to textured surfaces. The active texture specifies the texture map and an associated set of values. It applies only to surface primitives when the primitive's interior style is PEXInteriorStyleTexture and the active textures field is non-empty.

To apply the back-facing active texture to the back-facing surfaces of textured output primitives, you must set the facet distinguish flag to True (see PEXOCCSetFacetDistinguishFlag). If you set the flag to False, then the implementation uses the surface active textures to apply textures to back- facing surfaces (see PEXOCCSetSurfaceActiveTextures).

The indices are inserted into the renderer's texture mapping lookup table. If the number of indices you specify exceeds the maximum number of texture maps that your implementation simultaneously supports, then the implementation ignores textures defined beyond the limit. Inquire the maximum number of texture maps, which you can apply to a single surface, by invoking the PEXGetImpDepConstants function.

If you specify a texture mapping lookup table index of zero, then the implementation issues a BadPEXOutputCommand error.

This function is a member of the styled and shaded surface attribute set.

Errors

BadPEXOutputCommand
An index is zero.

BadPEXRenderer
The specified renderer resource identifier is invalid.

BadPEXStructure
The specified structure resource identifier is invalid.

See Also

For an overview and for a list of all output attribute functions, see Output Attribute Functions.