Package org.lwjgl.opengl

Class AMDVertexShaderTessellator

java.lang.Object
org.lwjgl.opengl.AMDVertexShaderTessellator
public class AMDVertexShaderTessellator extends Object
Native bindings to the AMD_vertex_shader_tessellator extension.

The vertex shader tessellator gives new flexibility to the shader author to shade at a tessellated vertex, rather than just at a provided vertex.

In unextended vertex shading, the built-in attributes such as gl_Vertex, gl_Normal, and gl_MultiTexcoord0, together with the user defined attributes, are system provided values which are initialized prior to vertex shader invocation.

With vertex shading tessellation, additional vertex shader special values are available:


         ivec3 gl_VertexTriangleIndex; // indices of the three control
                                       // points for the vertex
         vec3 gl_BarycentricCoord;     // barycentric coordinates
                                       // of the vertex
 
     i o
       |\
       | \
       *--*
       |\ |\
       | \| \
       *--*--*
       |\ |\ |\
       | \| \| \
     j o--*--*--o k
 
     Figure 1  A Tessellated Triangle
     o = control point (and tessellated vertex)
     * = tessellated vertex
 
         ivec4 gl_VertexQuadIndex;   // indices for the four control
                                     // points for the vertex
         vec2 gl_UVCoord;            // UV coordinates of the vertex
 
     i o--*--*--o k
       |\ |\ |\ |
       | \| \| \|
       *--*--*--*
       |\ |\ |\ |
       | \| \| \|
       *--*--*--*
       |\ |\ |\ |
       | \| \| \|
     j o--*--*--o l
 
     Figure 2  A Tessellated Quad
     o = control point (and tessellated vertex)
     * = tessellated vertex

When this extension is enabled, conventional built-in attributes and user defined attributes are uninitialized. The shader writer is responsible for explicitly fetching all other vertex data either from textures, uniform buffers, or vertex buffers.

The shader writer is further responsible for interpolating the vertex data at the given barycentric coordinates or uv coordinates of the vertex.

Requires OpenGL 2.0.

  • Field Details

    • GL_SAMPLER_BUFFER_AMD

      public static final int GL_SAMPLER_BUFFER_AMD
      Returned by the type parameter of GetActiveUniform.
      See Also:

    • GL_INT_SAMPLER_BUFFER_AMD

      public static final int GL_INT_SAMPLER_BUFFER_AMD
      Returned by the type parameter of GetActiveUniform.
      See Also:

    • GL_UNSIGNED_INT_SAMPLER_BUFFER_AMD

      public static final int GL_UNSIGNED_INT_SAMPLER_BUFFER_AMD
      Returned by the type parameter of GetActiveUniform.
      See Also:

    • GL_DISCRETE_AMD

      public static final int GL_DISCRETE_AMD
      Accepted by TessellationModeAMD.
      See Also:

    • GL_CONTINUOUS_AMD

      public static final int GL_CONTINUOUS_AMD
      Accepted by TessellationModeAMD.
      See Also:

    • GL_TESSELLATION_MODE_AMD

      public static final int GL_TESSELLATION_MODE_AMD
      Accepted by GetIntegerv.
      See Also:

    • GL_TESSELLATION_FACTOR_AMD

      public static final int GL_TESSELLATION_FACTOR_AMD
      Accepted by GetFloatv.
      See Also:

  • Method Details

    • glTessellationFactorAMD

      public static void glTessellationFactorAMD(float factor)

    • glTessellationModeAMD

      public static void glTessellationModeAMD(int mode)