texdp3 - ps
Performs a three-component dot product between data in the texture register number and the texture coordinate set corresponding to the destination register number.
|texdp3 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 texdp3 uses it) texdp3 t(m), t(n) // where m > n // Perform a three-component dot product between tn and // the texture coordinate set m. The scalar result is // replicated to all components of t(m)
Here is more detail about how the dot product is accomplished.
The texdp3 instruction performs a three-component dot product and replicates it to all four color channels.
t(m)RGBA = TextureCoordinates(stage m)UVW * t(n)RGB