ref_iface_IVDXAContext_SetTextureMatrix - shekh/VirtualDub2 GitHub Wiki

VirtualDub Plugin SDK 1.2

IVDXAContext interface

IVDXAContext:: SetTextureMatrix

Sets a 4x3 matrix to use for generating texture sampling coordinates.

void SetTextureMatrix(uint32 coordIndex, uint32 textureHandle, float xoffset, float yoffset, const float uvMatrix[12]);

Parameters

coordIndex	Texture coordinate set to apply a matrix to (0-7).
textureHandle	Optional handle to texture to use as a basis for computing texture coordinates.
xoffset	Horizontal texel position of top-left coordinate of texture rectangle to sample.
yoffset	Vertical texel position of top-left coordinate of texture rectangle to sample.
uvMatrix	Optional affine UV matrix to use (12 elements).

Thread safety

This method is not thread-safe.

Remarks

If a texture is supplied, the entire source texture is mapped to the entire render target with the supplied offsets. This automatically applies any necessary scaling factors and also allows for easy offsetting for filter kernels.

If a matrix is supplied instead, an arbitrary affine transformation may be used to generate texture coordinates; this must be adjusted to accommodate the UV scaling factors if the generated coordinates are actually used for sampling. The format of the matrix is row-major, such that elements 8-11 of the matrix are the constant offset (w row).

If neither a texture nor a matrix are supplied, the identity matrix is applied.