D3DMXMatrixPerspectiveFovLHFxd

A version of this page is also available for

Windows Embedded CE 6.0 R3

4/8/2010

Builds a left-handed perspective projection matrix in fixed point format based on a field of view.

Syntax

D3DMXMATRIXFXD* WINAPI D3DMXMatrixPerspectiveFovLHFxd(
  D3DMXMATRIXFXD* pOut,
  FIXED           fovy,
  FIXED           Aspect,
  FIXED           zn,
  FIXED           zf
);

Parameters

• pOut
  [in, out] Pointer to the D3DMXMATRIXFXD structure that is the result of the operation.

• fovY
  [in] Field of view, in the y direction, in radians.

• Aspect
  [in] Aspect ratio, defined as view space width divided by height.

• zn
  [in] Z-value of the near view-plane.

• zf
  [in] Z-value of the far view-plane.

Return Value

Pointer to a D3DMXMATRIXFXD structure that is a left-handed perspective projection matrix.

Remarks

The return value for this function is the same value returned in the pOut parameter. In this way, the D3DMXMatrixPerspectiveFovLHFxd function can be used as a parameter for another function.

This function computes the returned matrix as shown. For clarity, the conversions to fixed point numbers are omitted from the matrix.

xScale  0       0               0
0       yScale  0               0
0       0       zf/(zf-zn)      1
0       0       -zn*zf/(zf-zn)  0

These variables are calculated from the following formulas.

FIXED yScale = D3DMXDivFxd(D3DMXToFixed(cos(0.5f * D3DMXToFloat(fovy))),
                           D3DMXToFixed(sin(0.5f * D3DMXToFloat(fovy))))
FIXED xScale = D3DMXDivFxd(yScale, aspect)

Requirements

See Also

Reference

D3DMX Functions
D3DMXMATRIXFXD
D3DMXMatrixPerspectiveFovLH