Conformance Test

    CTS_ARB_sparse_texture_clamp

Contributors

    Adam Czupryna, Mobica

Contacts

    Adam Czupryna, Mobica (adam.czupryna 'at' mobica.com)

Status

    In review

Version

    December 19, 2016 (version 1)

Dependencies

    OpenGL 4.5 is required.

    ARB_sparse_texture2 extension is required.

    This specification is written against:
      - ARB_sparse_texture_clamp specification,
      - OpenGL 4.5 (core) specification.

Overview

    This test verifies if functionality provided by ARB_sparse_texture_clamp
    works as expected:

      * Check if new built-in GLSL texture lookup functions that are provided
        by this extension could specify a minimum level of detail to use for
        lookups where level of detail is computed automatically.

New Tests

    Shader Extension Test

      * Create shader that require ARB_sparse_texture_clamp extension
        and check if ARB_sparse_texture_clamp is defined and equal 1.
        Check if shader compiles with no error.

    Sparse Texture Clamp Lookup Residency Tests

      * Iterate through all sparse supported targets.
        Allocate sparse texture for current <target> with committed and
          uncommitted regions.
        Create multiple fragment shaders that enable ARB_sparse_texture_clamp
          extension and each uses one of the function from list below
          (if supported by <target>):

          - sparseTextureClampARB
          - sparseTextureOffsetClampARB
          - sparseTextureGradClampARB
          - sparseTextureGradOffsetClampARB

        Shaders should check texture access residency information and pass
          vec4(1, 1, 1, 1) to the output if access committed region and
          vec4(0, 0, 0, 1) otherwise.

        Iterate through shaders, create and use program for current iteration
          and draw a full screen quad.

        Read back the contents of the color attachment on the CPU side. The test expects
          that the texels will be filled with (1, 1, 1, 1) if the areas of the sparse texture accessed
          in the shader would be in committed regions, (0, 0, 0, 1) otherwise.

        Run the test for different values of <lodClamp> argument.

    Sparse and Non-sparse Texture Clamp Lookup Color Tests

      * Iterate through all sparse and non-sparse supported targets.
        Allocate texture for current <target>.
        Fill the texture with different values for miplevels [0, lodClamp) that for miplevels [lodClamp, lastMipLevel].

        Create multiple fragment shaders that enables ARB_sparse_texture_clamp
          extension and each use one of the function from list below
          (if supported by <target>):

          - textureClampARB
          - textureOffsetClampARB
          - textureGradClampARB
          - textureGradOffsetClampARB
          - sparseTextureClampARB
          - sparseTextureOffsetClampARB
          - sparseTextureGradClampARB
          - sparseTextureGradOffsetClampARB

        Iterate through shaders, create and use program for current iteration
          and draw a full screen quad. In the shader sample the texture with the value lodClamp as <lodClamp> argument.

        Verify that the <lodClamp> argument was taken into account during automatic lod computations
          by reading pixels from framebuffer and checking if their values are as equal to the ones
          from the region [lodClamp, lastMipLevel].

        Run the test for different values of <lodClamp> argument.

Revision History

    Revision 1, 19th December, 2016 (Adam Czupryna)
     - Intial version;