DX 提供了D3DXMatrixPerspectiveLH,D3DXMatrixPerspectiveOffCenterLH以及D3DXMatrixPerspectiveFovLH来实现透视投影。提供了D3DXMatrixOrthoLH和D3DXMatrixOrthoOffCenterLH来实现正投影

(以上各函数都有右手坐标系下面的版本,只是把后面的LH改成RH)

先看D3DXMatrixPerspectiveLH

D3DXMatrixPerspectiveLH

Builds a left-handed perspective projection matrix

D3DXMATRIX * D3DXMatrixPerspectiveLH(
  D3DXMATRIX * pOut,
  FLOAT w,
  FLOAT h,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX structure that is the result of the operation.

w

[in] Width of the view volume at the near view-plane.

h

[in] Height of the view volume at the near view-plane.

zn

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

zf

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

Return Values

Pointer to a D3DXMATRIX structure that is a left-handed perspective projection matrix.

这个函数的投影平面在z=n处

最后看下MSDN的结果

OK,为了完整把D3DXMatrixPerspectiveRH也推导下吧.囧....

D3DXMatrixPerspectiveRH

Builds a right-handed perspective projection matrix.

D3DXMATRIX * D3DXMatrixPerspectiveRH(
  D3DXMATRIX * pOut,
  FLOAT w,
  FLOAT h,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX structure that is the result of the operation.

w

[in] Width of the view volume at the near view-plane.

h

[in] Height of the view volume at the near view-plane.

zn

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

zf

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

Return Values

Pointer to a D3DXMATRIX structure that is a right-handed perspective projection matrix.

这个函数的投影平面在z=-n处

最后看下MSDN的结果

再看下D3DXMatrixPerspectiveOffCenterLH

D3DXMatrixPerspectiveOffCenterLH

Builds a customized, left-handed perspective projection matrix.

D3DXMATRIX * D3DXMatrixPerspectiveOffCenterLH(
  D3DXMATRIX *pOut,
  FLOAT l,
  FLOAT r,
  FLOAT b,
  FLOAT t,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX structure that is the result of the operation.

l

[in] Minimum x-value of the view volume.

r

[in] Maximum x-value of the view volume.

b

[in] Minimum y-value of the view volume.

t

[in] Maximum y-value of the view volume.

zn

[in] Minimum z-value of the view volume.

zf

[in] Maximum z-value of the view volume.

Return Values

Pointer to a D3DXMATRIX structure that is a customized, left-handed perspective projection matrix.

最后看下MSDN

接着看下D3DXMatrixPerspectiveOffCenterRH

D3DXMatrixPerspectiveOffCenterRH

Builds a customized, right-handed perspective projection matrix.

D3DXMATRIX * D3DXMatrixPerspectiveOffCenterRH(
  D3DXMATRIX *pOut,
  FLOAT l,
  FLOAT r,
  FLOAT b,
  FLOAT t,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX structure that is the result of the operation.

l

[in] Minimum x-value of the view volume.

r

[in] Maximum x-value of the view volume.

b

[in] Minimum y-value of the view volume.

t

[in] Maximum y-value of the view volume.

zn

[in] Minimum z-value of the view volume.

zf

[in] Maximum z-value of the view volume.

Return Values

Pointer to a D3DXMATRIX structure that is a customized, right-handed perspective projection matrix.

看下MSDN

继续看D3DXMatrixPerspectiveFovLH

D3DXMatrixPerspectiveFovLH

Builds a left-handed perspective projection matrix based on a field of view.

D3DXMATRIX * D3DXMatrixPerspectiveFovLH(
  D3DXMATRIX *pOut,
  FLOAT fovy,
  FLOAT Aspect,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX 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 Values

Pointer to a D3DXMATRIX structure that is a left-handed perspective projection matrix.

看MSDN

继续看D3DXMatrixPerspectiveFovRH

D3DXMatrixPerspectiveFovRH

Builds a right-handed perspective projection matrix based on a field of view.

D3DXMATRIX * D3DXMatrixPerspectiveFovRH(
  D3DXMATRIX *pOut,
  FLOAT fovy,
  FLOAT Aspect,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the D3DXMATRIX 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 Values

Pointer to a D3DXMATRIX structure that is a right-handed perspective projection matrix.

看结果

接着看几个正投影

先看D3DXMatrixOrthoLH

D3DXMatrixOrthoLH

Builds a left-handed orthographic projection matrix.

D3DXMATRIX * D3DXMatrixOrthoLH(
  D3DXMATRIX *pOut,
  FLOAT w,
  FLOAT h,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the resulting D3DXMATRIX.

w

[in] Width of the view volume.

h

[in] Height of the view volume.

zn

[in] Minimum z-value of the view volume which is referred to as z-near.

zf

[in] Maximum z-value of the view volume which is referred to as z-far.

Return Values

Pointer to the resulting D3DXMATRIX.

看结果 

接着看D3DXMatrixOrthoRH

D3DXMatrixOrthoRH

Builds a right-handed orthographic projection matrix.

D3DXMATRIX * D3DXMatrixOrthoRH(
  D3DXMATRIX *pOut,
  FLOAT w,
  FLOAT h,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the resulting D3DXMATRIX.

w

[in] Width of the view volume.

h

[in] Height of the view volume.

zn

[in] Minimum z-value of the view volume.

zf

[in] Maximum z-value of the view volume.

Return Values

Pointer to the resulting D3DXMATRIX.

看结果 

接着看D3DXMatrixOrthoOffCenterLH

D3DXMatrixOrthoOffCenterLH

Builds a customized, left-handed orthographic projection matrix.

D3DXMATRIX * D3DXMatrixOrthoOffCenterLH(
  D3DXMATRIX *pOut,
  FLOAT l,
  FLOAT r,
  FLOAT b,
  FLOAT t,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the resulting D3DXMATRIX.

l

[in] Minimum x-value of view volume.

r

[in] Maximum x-value of view volume.

b

[in] Minimum y-value of view volume.

t

[in] Maximum y-value of view volume.

zn

[in] Minimum z-value of the view volume.

zf

[in] Maximum z-value of the view volume.

Return Values

Pointer to the resulting D3DXMATRIX.

看结果

终于到最后一个了D3DXMatrixOrthoOffCenterRH

D3DXMatrixOrthoOffCenterRH

Builds a customized, right-handed orthographic projection matrix.

D3DXMATRIX * D3DXMatrixOrthoOffCenterRH(
  D3DXMATRIX *pOut,
  FLOAT l,
  FLOAT r,
  FLOAT b,
  FLOAT t,
  FLOAT zn,
  FLOAT zf
);

Parameters

pOut

[in, out] Pointer to the resulting D3DXMATRIX.

l

[in] Minimum x-value of view volume.

r

[in] Maximum x-value of view volume.

b

[in] Minimum y-value of view volume.

t

[in] Maximum y-value of view volume.

zn

[in] Minimum z-value of the view volume.

zf

[in] Maximum z-value of the view volume.

Return Values

Pointer to the resulting D3DXMATRIX.

看结果

尼玛,终于搞完了,本来还有世界坐标到视图坐标的转换,标准设备坐标到视口的转换..今晚先到这里,伤不起啊,6点了,以后补上