SetTransform() for texture coordinates

You need to set the texture transformation matrices as you did, but you also need to enable the texture transform using the D3DTSS_TEXTURETRANSFORMFLAGS texture stage state.

Thankyou. I have got it partially working now - I am able to set a scaling matrix but I'm not able to set a translation. Is this not supported for texture matrices? I tried manually setting D3DXMATRIX::_41 & D3DXMATRIX::_42 as well as creating a translation matrix with D3DXMatrixTranslation() but no luck. I set the texture stage state to use 2D texture coordinates since the textures are 2D - is there any change I can make to get what I want?

Anyone know about this? If I can only set a scaling matrix with no transform it's still of use to me but not nearly as much. I generate thousands of vertices each frame and scaling/multplying the texture coordinates is quite a performance hit. Plus in theory I could have both textures using only one set of texture coordinates with a different matrix, reducing the vertex size signigicantly...

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Original post by d000hg Thankyou. I have got it partially working now - I am able to set a scaling matrix but I'm not able to set a translation. Is this not supported for texture matrices? I tried manually setting D3DXMATRIX::_41 & D3DXMATRIX::_42 as well as creating a translation matrix with D3DXMatrixTranslation() but no luck. I set the texture stage state to use 2D texture coordinates since the textures are 2D - is there any change I can make to get what I want?

Weird. Texture coordinate transforms work by applying the 4x4 matrix (here) , so translation should work. There's even a couple of examples in the documentation page linked above that do this.
- Are you sure the translation you applied would've changed the visual effect?
- Are the results the same on refrast?

Hmm, it looks like what I was doing but maybe not. Unless the matrix elements I would set for translations are different for 2D coordinates than 3D coordinates... that could be it. Sounds like it should work, will report back.

For 2D transforms set _31 and _32 for translation.

Yes that fixed it. Currently I set my texcoords like this when building vertices each frame (I store my data in 6byte-per-vertex format to save space but this must be expanded):
u0 = X * constant1
v0 = Y * constant1
u1 = X * constant1 + constant2
u2 = Y * constant1 + constant2

Now I can dispense with the 2nd texture coordinates entirely and use transforms to do it. On hardware T&L cards this will be a fair bit quicker I think; will D3D'x software version be faster or slower than what I was doing do you think? In either case I can shrink the vertex size by 8 bytes.

Thanks guys.