def - ps
Defines pixel shader floating-point constants.
|def dst, fVvalue1, fValue2, fValue3, fValue4|
- dst is the destination register.
- fValue1 to fValue4 are floating-point values..
|Pixel shader versions||1_1||1_2||1_3||1_4||2_0||2_x||2_sw||3_0||3_sw|
There are two ways to set a floating-point constant in a pixel shader.
- Use def to define the constant directly inside a shader.
- Use the API to set a constant with SetPixelShaderConstantF.
def defines a shader constant whose value is loaded any time a shader is set to a device. These are called immediate constants. Immediate constants take precedence over constants set by the API method.
- Must appear before the first arithmetic or addressing instruction in shader.
- Can be intermixed with dcl - (sm2, sm3 - ps asm) instructions (which are the other type of instruction that resides at the beginning of a shader).
- dst register must be a constant register.
- Write mask must be full (default).
- If a constant register is defined multiple times in a shader, the last one persists.