IDirect3DDevice8::MultiplyTransform

Multiplies a device's world, view, or projection matrices by a specified matrix.

HRESULT MultiplyTransform(
  D3DTRANSFORMSTATETYPE State,
  CONST D3DMATRIX* pMatrix
);

Parameters

State

[in] Member of the D3DTRANSFORMSTATETYPE enumerated type, or the D3DTS_WORLDMATRIX macro that identifies which device matrix is to be modified. The most common setting, D3DTS_WORLDMATRIX(0), modifies the world matrix, but you can specify that the method modify the view or projection matrices, if needed.

pMatrix

[in] Pointer to a D3DMATRIX structure that modifies the current transformation.

Return Values

If the method succeeds, the return value is D3D_OK.

D3DERR_INVALIDCALL if one of the arguments is invalid.

Remarks

The multiplication order is pMatrix times State.

An application might use the MultiplyTransform method to work with hierarchies of transformations. For example, the geometry and transformations describing an arm might be arranged in the following hierarchy.

shoulder_transformation
    upper_arm geometry
    elbow transformation
        lower_arm geometry
        wrist transformation
            hand geometry

An application might use the following series of calls to render this hierarchy. Not all the parameters are shown in this pseudocode.

IDirect3DDevice8::SetTransform(D3DTS_WORLDMATRIX(0), 
    shoulder_transform)
IDirect3DDevice8::DrawPrimitive(upper_arm)
IDirect3DDevice8::MultiplyTransform(D3DTS_WORLDMATRIX(0), 
    elbow_transform)
IDirect3DDevice8::DrawPrimitive(lower_arm)
IDirect3DDevice8::MultiplyTransform(D3DTS_WORLDMATRIX(0), 
    wrist_transform)
IDirect3DDevice8::DrawPrimitive(hand)

Requirements

  Header: Declared in D3d8.h.
  Import Library: Use D3d8.lib.

See Also

IDirect3DDevice8::DrawPrimitive, IDirect3DDevice8::SetTransform, D3DTS_WORLD, D3DTS_WORLDn, D3DTS_WORLDMATRIX