Position Register

This vertex shader output register contains per-vertex position data.

Vertex shader versions	1_1	2_0	2_sw	2_x	3_0	3_sw
Position Register	x	x	x	x	x	x

 

A register consists of properties that determine how each register behaves.

Property	Description
Name	oPos
Count	1 vector
I/O permissions	Write-only.

 

The value is the position in homogeneous clipping space. This value must be written by the vertex shader.

Example

    dcl_position v0
    
    def c40, 0.0f,0.0f,0.0f,0.0f;
    // transform into projection space
    m4x4 r0,v0,c8
    max r0.z,c40.z,r0.z //clamp to 0
    max r0.w,c12.x,r0.w //clamp to near clip plane
    mov oPos,r0   

Related topics

Vertex Shader Registers