D3DTRIPATCH_INFO structure

Describes a triangular high-order patch.

Syntax

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

Members

StartVertexOffset

Type: UINT

Starting vertex offset, in number of vertices.

NumVertices

Type: UINT

Number of vertices.

Basis

Type: D3DBASISTYPE

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

Type: D3DDEGREETYPE

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 DrawTriPatch. The offset is the number of bytes to the first triangle patch vertex in the vertex buffer.

diagram of a triangular high-order patch with nine vertices

Requirements

Requirement Value
Header
D3D9Types.h

See also

Direct3D Structures

DrawTriPatch

D3DXTessellateTriPatch