ShadowColor

uniform sampler2D shadowcolorN;

layout (<format>) uniform image2D shadowcolorimgN;

The shadow pass supplies two color attachments for outputing color/data, shadowcolor0 and shadowcolor1. These buffers can be read from any program, and can be written to from the fragment stage of the shadow and shadowcomp programs.

Writing

Any shadow or shadowcomp program can write to a shadowcolor buffer. The buffers to write to can be selected with the RENDERTARGETS or DRAWBUFFERS directive.

Additionally, you can read and write to shadowcolor0 and shadowcolor1 using the image bindings shadowcolorimg0 through shadowcolorimg1 in any program. This is the only way to write to shadowcolor buffers from compute shaders. For more information on image load/store, see the Khronos Wiki.

Size

These buffers default to the shadow pass resolution, which can be controlled with the shadowMapResolution constant.

Format / precision

These buffers default RGBA format (which defaults to RGBA8 on most systems), but this can be configured as described in the Image Format section.

Clearing

By default these buffers clear their values after each frame to solid white (vec4(1.0, 1.0, 1.0, 1.0)). This behavior can be configured with the shadowcolorNClear directive, and the clear color can be configured with the shadowcolorNClearColor directive.

Flipping

Each shadowcolor sampler actually contains two buffers, which allows you to read from and write to the same buffer in the same pass. The buffer flipping behavior can be controlled with the flip.<program>.<buffer> directive.

Aliases Legacy

The sampler shadowcolor0 is also accessible through the legacy alias shadowcolor.

Extended shadowcolor Iris Exclusive

The Feature Flag HIGHER_SHADOWCOLOR enables additional shadowcolor buffers, shadowcolor2 through shadowcolor7. These are identical to the other shadowcolor buffers outside of their name.