Is gl_DepthRange supported? If so, how can we enable its use in our shaders?

[nolankramer]

I've tried using a shader with gl_DepthRange, however glslang spits out:

ERROR: 0:38: 'gl_DepthRange' : undeclared identifier

I did make sure that the GraphicsPipeline had it's DepthStencilState::depthTestEnable = true.

[robertosfield]

It doesn't look like Vulkan supports gl_DepthRange:

GL_KHR_vulkan_glsl.txt

Bit of document that mentions gl_DepthRange:

Overview

    This is version 100 of the GL_KHR_vulkan_glsl extension.

    This extension modifies GLSL to be used as a high-level language for the
    Vulkan API.  GLSL is compiled down to SPIR-V, which the Vulkan API
    consumes.

    The following features are removed:
        * default uniforms (uniform variables not inside a uniform block),
          except for opaque types
        * atomic-counters (those based on atomic_uint)
        * subroutines
        * shared and packed block layouts
        * the already deprecated texturing functions (e.g., texture2D())
        * the already deprecated noise functions (e.g., noise1())
        * compatibility-mode-only features
        * gl_DepthRangeParameters and gl_NumSamples
        * gl_VertexID and gl_InstanceID
        * aliasing of vertex input components
          (see the Vulkan API specification)
        * Rectangle textures (sampler*Rect, image*Rect)

[robertosfield]

So the question then is, what are you trying to achieve and what you are using gl_DepthRange for.

[nolankramer]

Ah, I was going to use it in a fragment shader for some fade-out with distance techniques.

However I think I can do the calculation myself after passing some relevant information from the vertex shader.

[nolankramer]

Also, it looks like the depth range in Vulkan is always 0.0 to 1.0 (unless otherwise configured).