D3DTRIPATCH_INFO

Describes a triangular high-order patch.

typedef struct D3DTRIPATCH_INFO {
    UINT StartVertexOffset;
    UINT NumVertices;
    D3DBASISTYPE Basis;
    D3DDEGREETYPE Degree;
} D3DTRIPATCH_INFO, *LPD3DTRIPATCH_INFO;

Members

StartVertexOffset
Starting vertex offset, in number of vertices.
NumVertices
Number of vertices.
Basis
Member of the D3DBASISTYPE enumerated type, which defines the basis type for the triangular high-order patch. The only valid value for this member is D3DBASIS_BEZIER.
Degree
Member of the D3DDEGREETYPE enumerated type, defining the degree type for the triangular high-order patch.
Value Number of vertices
D3DDEGREE_CUBIC 10
D3DDEGREE_LINEAR 3
D3DDEGREE_QUADRATIC N/A
D3DDEGREE_QUINTIC 21

N/A - Not available. Not supported.

Remarks

For example, the following diagram identifies the vertex order and segment numbers for a cubic Bézier triangle patch. The vertex order determines the segment numbers used by IDirect3DDevice9::DrawTriPatch. The offset is the number of bytes to the first triangle patch vertex in the vertex buffer.

Triangular high-order patch with nine vertices

See Also

IDirect3DDevice9::DrawTriPatch, D3DXTessellateTriPatch