Microsoft DirectX 8.1 (vertex shader versions 1.0, 1.1)

Instructions

This section contains reference information for the instructions implemented by the Direct3DX vertex shader assembler. Vertex shaders can be generated in an ascii file or even an ascii string. Each vertex shader can consist of up to 128 instructions. Each instruction can have up to three input arguments.

Version Instructions	Version
Version Instructions	1.0	1.1
vs	x	x
def	x	x
General Instructions	Version
General Instructions	1.0	1.1
add	x	x
dp3	x	x
dp4	x	x
dst	x	x
expp	x	x
lit	x	x
logp	x	x
mad	x	x
max	x	x
min	x	x
mov	x	x
mul	x	x
rcp	x	x
rsq	x	x
sge	x	x
slt	x	x
sub	x	x
Macros	Version
Macros	1.0	1.1
exp	x	x
frc	x	x
log	x	x
m3x2	x	x
m3x3	x	x
m3x4	x	x
m4x3	x	x
m4x4	x	x

There are 4 types of vertex shader instructions.

A shader file must have a version instruction and it must be the first instruction in the file.

A shader file must write the vertex position to the output vertex position register. If the shader provides vertex color, the shader must write to the output vertex color register.

Macro instructions combine general instructions to provide higher level functionality.

Instruction modifiers can be applied to instruction arguments to mask, negate or swizzle the arguments. Modifiers are optional in a shader file. For more information see Modifiers