texdp3tex - ps
Performs a three-component dot product and uses the result to do a 1D texture lookup.
|texdp3tex dst, src|
- dst is the destination register.
- src is a source register.
|Pixel shader versions||1_1||1_2||1_3||1_4||2_0||2_x||2_sw||3_0||3_sw|
Texture registers must use the following sequence.
tex t(n) // Define tn as a standard 3-vector (tn must be // defined in some way before texdp3tex uses it) texdp3tex t(m), t(n) // where m > n // Perform a three-component dot product between t(n) and // the texture coordinate set m. Use the scalar result to // do a 1D texture lookup at texturestage m and place // the result in t(m)
Here is more detail about how the dot product and texture lookup are done.
The texdp3tex instruction performs a three-component dot product.
u' = TextureCoordinates(stage m)UVW * t(n)RGB
The result is used to sample the texture at texture stage m by performing a 1D lookup.
t(m)RGBA = TextureSample(stage m)RGBA using (u',0,0) as coordinates