D3DXVec2CCW

Returns the z-component by taking the cross product of two 2D vectors.

FLOAT D3DXVec2CCW(
  CONST D3DXVECTOR2 * pV1,
  CONST D3DXVECTOR2 * pV2
);

Parameters

pV1

[in] Pointer to a source D3DXVECTOR2 structure.

pV2

[in] Pointer to a source D3DXVECTOR2 structure.

Return Values

The z-component.

Remarks

This function determines the z-component by determining the cross-product based on the following formula: ((x1,y1,0) cross (x2,y2,0)). Or as shown in the following example.

pV1->x * pV2->y - pV1->y * pV2->x

If the value of the z-component is positive, the vector V2 is counterclockwise from the vector V1. This information is useful for back-face culling.

Requirements

Header: Declared in D3dx9math.h.

See Also

D3DXVec2Dot