Package org.lwjgl.opengles

Class EXTTessellationShader

java.lang.Object
org.lwjgl.opengles.EXTTessellationShader
public class EXTTessellationShader extends Object
Native bindings to the EXT_tessellation_shader extension.

This extension introduces new tessellation stages and two new shader types to the OpenGL ES primitive processing pipeline. These pipeline stages operate on a new basic primitive type, called a patch. A patch consists of a fixed-size collection of vertices, each with per-vertex attributes, plus a number of associated per-patch attributes. Tessellation control shaders transform an input patch specified by the application, computing per-vertex and per-patch attributes for a new output patch. A fixed-function tessellation primitive generator subdivides the patch, and tessellation evaluation shaders are used to compute the position and attributes of each vertex produced by the tessellator.

When tessellation is active, it begins by running the optional tessellation control shader. This shader consumes an input patch and produces a new fixed-size output patch. The output patch consists of an array of vertices, and a set of per-patch attributes. The per-patch attributes include tessellation levels that control how finely the patch will be tessellated. For each patch processed, multiple tessellation control shader invocations are performed -- one per output patch vertex. Each tessellation control shader invocation writes all the attributes of its corresponding output patch vertex. A tessellation control shader may also read the per-vertex outputs of other tessellation control shader invocations, as well as read and write shared per-patch outputs. The tessellation control shader invocations for a single patch effectively run as a group. A built-in barrier() function is provided to allow synchronization points where no shader invocation will continue until all shader invocations have reached the barrier.

The tessellation primitive generator then decomposes a patch into a new set of primitives using the tessellation levels to determine how finely tessellated the output should be. The primitive generator begins with either a triangle or a quad, and splits each outer edge of the primitive into a number of segments approximately equal to the corresponding element of the outer tessellation level array. The interior of the primitive is tessellated according to elements of the inner tessellation level array. The primitive generator has three modes: "triangles" and "quads" split a triangular or quad-shaped patch into a set of triangles that cover the original patch; "isolines" splits a quad-shaped patch into a set of line strips running across the patch horizontally. Each vertex generated by the tessellation primitive generator is assigned a (u,v) or (u,v,w) coordinate indicating its relative location in the subdivided triangle or quad.

For each vertex produced by the tessellation primitive generator, the tessellation evaluation shader is run to compute its position and other attributes of the vertex, using its (u,v) or (u,v,w) coordinate. When computing final vertex attributes, the tessellation evaluation shader can also read the attributes of any of the vertices of the patch written by the tessellation control shader. Tessellation evaluation shader invocations are completely independent, although all invocations for a single patch share the same collection of input vertices and per-patch attributes.

The tessellator operates on vertices after they have been transformed by a vertex shader. The primitives generated by the tessellator are passed further down the OpenGL ES pipeline, where they can be used as inputs to geometry shaders, transform feedback, and the rasterizer.

The tessellation control and evaluation shaders are both optional. If neither shader type is present, the tessellation stage has no effect. However, if either a tessellation control or a tessellation evaluation shader is present, the other must also be present.

Not all tessellation shader implementations have the ability to write the point size from a tessellation shader. Thus a second extension string and shading language enable are provided for implementations which do support tessellation shader point size.

This extension relies on the EXT_shader_io_blocks extension to provide the required functionality for declaring input and output blocks and interfacing between shaders.

This extension relies on the EXT_gpu_shader5 extension to provide the 'precise' and 'fma' functionality which are necessary to ensure crack-free tessellation.

Requires GLES 3.1.

  • Field Details

    • GL_PATCHES_EXT

      public static final int GL_PATCHES_EXT
      Accepted by the mode parameter of DrawArrays, DrawElements, and other commands which draw primitives.
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    • GL_PATCH_VERTICES_EXT

      public static final int GL_PATCH_VERTICES_EXT
      Accepted by the pname parameter of PatchParameteriEXT, GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_TESS_CONTROL_OUTPUT_VERTICES_EXT

      public static final int GL_TESS_CONTROL_OUTPUT_VERTICES_EXT
      Accepted by the pname parameter of GetProgramiv.
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    • GL_TESS_GEN_MODE_EXT

      public static final int GL_TESS_GEN_MODE_EXT
      Accepted by the pname parameter of GetProgramiv.
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    • GL_TESS_GEN_SPACING_EXT

      public static final int GL_TESS_GEN_SPACING_EXT
      Accepted by the pname parameter of GetProgramiv.
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    • GL_TESS_GEN_VERTEX_ORDER_EXT

      public static final int GL_TESS_GEN_VERTEX_ORDER_EXT
      Accepted by the pname parameter of GetProgramiv.
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    • GL_TESS_GEN_POINT_MODE_EXT

      public static final int GL_TESS_GEN_POINT_MODE_EXT
      Accepted by the pname parameter of GetProgramiv.
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    • GL_ISOLINES_EXT

      public static final int GL_ISOLINES_EXT
      Returned by GetProgramiv when pname is TESS_GEN_MODE_EXT.
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    • GL_QUADS_EXT

      public static final int GL_QUADS_EXT
      Returned by GetProgramiv when pname is TESS_GEN_MODE_EXT.
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    • GL_FRACTIONAL_ODD_EXT

      public static final int GL_FRACTIONAL_ODD_EXT
      Returned by GetProgramiv when pname is TESS_GEN_SPACING_EXT.
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    • GL_FRACTIONAL_EVEN_EXT

      public static final int GL_FRACTIONAL_EVEN_EXT
      Returned by GetProgramiv when pname is TESS_GEN_SPACING_EXT.
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    • GL_MAX_PATCH_VERTICES_EXT

      public static final int GL_MAX_PATCH_VERTICES_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_GEN_LEVEL_EXT

      public static final int GL_MAX_TESS_GEN_LEVEL_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_UNIFORM_COMPONENTS_EXT

      public static final int GL_MAX_TESS_CONTROL_UNIFORM_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_UNIFORM_COMPONENTS_EXT

      public static final int GL_MAX_TESS_EVALUATION_UNIFORM_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS_EXT

      public static final int GL_MAX_TESS_CONTROL_TEXTURE_IMAGE_UNITS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS_EXT

      public static final int GL_MAX_TESS_EVALUATION_TEXTURE_IMAGE_UNITS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_OUTPUT_COMPONENTS_EXT

      public static final int GL_MAX_TESS_CONTROL_OUTPUT_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_PATCH_COMPONENTS_EXT

      public static final int GL_MAX_TESS_PATCH_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS_EXT

      public static final int GL_MAX_TESS_CONTROL_TOTAL_OUTPUT_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_OUTPUT_COMPONENTS_EXT

      public static final int GL_MAX_TESS_EVALUATION_OUTPUT_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS_EXT

      public static final int GL_MAX_TESS_CONTROL_UNIFORM_BLOCKS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS_EXT

      public static final int GL_MAX_TESS_EVALUATION_UNIFORM_BLOCKS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_INPUT_COMPONENTS_EXT

      public static final int GL_MAX_TESS_CONTROL_INPUT_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_INPUT_COMPONENTS_EXT

      public static final int GL_MAX_TESS_EVALUATION_INPUT_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_COMBINED_TESS_CONTROL_UNIFORM_COMPONENTS_EXT

      public static final int GL_MAX_COMBINED_TESS_CONTROL_UNIFORM_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_COMBINED_TESS_EVALUATION_UNIFORM_COMPONENTS_EXT

      public static final int GL_MAX_COMBINED_TESS_EVALUATION_UNIFORM_COMPONENTS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_ATOMIC_COUNTER_BUFFERS_EXT

      public static final int GL_MAX_TESS_CONTROL_ATOMIC_COUNTER_BUFFERS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_ATOMIC_COUNTER_BUFFERS_EXT

      public static final int GL_MAX_TESS_EVALUATION_ATOMIC_COUNTER_BUFFERS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_ATOMIC_COUNTERS_EXT

      public static final int GL_MAX_TESS_CONTROL_ATOMIC_COUNTERS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_ATOMIC_COUNTERS_EXT

      public static final int GL_MAX_TESS_EVALUATION_ATOMIC_COUNTERS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_IMAGE_UNIFORMS_EXT

      public static final int GL_MAX_TESS_CONTROL_IMAGE_UNIFORMS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_IMAGE_UNIFORMS_EXT

      public static final int GL_MAX_TESS_EVALUATION_IMAGE_UNIFORMS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_CONTROL_SHADER_STORAGE_BLOCKS_EXT

      public static final int GL_MAX_TESS_CONTROL_SHADER_STORAGE_BLOCKS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_MAX_TESS_EVALUATION_SHADER_STORAGE_BLOCKS_EXT

      public static final int GL_MAX_TESS_EVALUATION_SHADER_STORAGE_BLOCKS_EXT
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_PRIMITIVE_RESTART_FOR_PATCHES_SUPPORTED

      public static final int GL_PRIMITIVE_RESTART_FOR_PATCHES_SUPPORTED
      Accepted by the pname parameter of GetBooleanv, GetFloatv, GetIntegerv, and GetInteger64v.
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    • GL_IS_PER_PATCH_EXT

      public static final int GL_IS_PER_PATCH_EXT
      Accepted by the props parameter of GetProgramResourceiv.
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    • GL_REFERENCED_BY_TESS_CONTROL_SHADER_EXT

      public static final int GL_REFERENCED_BY_TESS_CONTROL_SHADER_EXT
      Accepted by the props parameter of GetProgramResourceiv.
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    • GL_REFERENCED_BY_TESS_EVALUATION_SHADER_EXT

      public static final int GL_REFERENCED_BY_TESS_EVALUATION_SHADER_EXT
      Accepted by the props parameter of GetProgramResourceiv.
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    • GL_TESS_EVALUATION_SHADER_EXT

      public static final int GL_TESS_EVALUATION_SHADER_EXT
      Accepted by the type parameter of CreateShader, by the pname parameter of GetProgramPipelineiv, and returned by the params parameter of GetShaderiv.
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    • GL_TESS_CONTROL_SHADER_EXT

      public static final int GL_TESS_CONTROL_SHADER_EXT
      Accepted by the type parameter of CreateShader, by the pname parameter of GetProgramPipelineiv, and returned by the params parameter of GetShaderiv.
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    • GL_TESS_CONTROL_SHADER_BIT_EXT

      public static final int GL_TESS_CONTROL_SHADER_BIT_EXT
      Accepted by the stages parameter of UseProgramStages.
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    • GL_TESS_EVALUATION_SHADER_BIT_EXT

      public static final int GL_TESS_EVALUATION_SHADER_BIT_EXT
      Accepted by the stages parameter of UseProgramStages.
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  • Method Details

    • glPatchParameteriEXT

      public static void glPatchParameteriEXT(int pname, int value)