OUTPUT REGISTERS

Unlike the vertex shaders, DirectX 8 pixel shaders do not have any specialized output, but use the temporary r0 register as the single color output. See the Temporary Registers section later in this chapter for more information. DirectX 9 shaders use the multi-element texture register as output, holding four colors and a depth value.

For Pixel Shaders 1.3

A texture register can hold an output depth value.

For Pixel Shaders 1.4

The r5 register can hold a depth value.

For Pixel Shaders 2.0

PS 2.0 now supports new types of render destinations. The output register for regular shader destinations is oC0. If you have multiple render targets you'll use the MRT or MET as render targets.