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Position Register

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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

Vertex Shader Registers