unit u_test2;

type
  TForm1 = class [...]

procedure TForm1.glDraw();
begin
  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
                           

  glslprogram.Enable;
  glslprogram.SetI('Tex0', 0);

  glBindVertexArray(vaoID[0]);      
   glDrawArrays(GL_PATCHES, 0, 3);   
 
  glBindVertexArray(0);

  glslprogram.Disable;
end;

procedure TForm1.glInit();
var
  vert: array[0..8] of GLFloat;   //vertex array 1
  col: array[0..8] of GLFloat;    //Color array 1
  tex: array[0..8] of GLFloat;    //TexCoord array 1
  testdata1: array[0..3] of GLFloat;
  testdata2: array[0..1] of GLFloat;
begin
  LoadTexture('blitz.jpg', tex0);

  glslprogram := TGLSLProgram.Create();
  glslvert := TGLSLShader.Create('tess.vert');
  glsltcs := TGLSLShader.Create('tess.tcs', GL_TESS_CONTROL_SHADER);
  glsltes := TGLSLShader.Create('tess.tes', GL_TESS_EVALUATION_SHADER);
  glslfrag := TGLSLShader.Create('tess.frag', GL_FRAGMENT_SHADER_ARB);

  glslprogram.Attach(glslvert);
  showmessage(glslvert.Log);
//glslprogram.Attach(glsltcs);
//showmessage(glsltcs.Log);
  glslprogram.Attach(glsltes);
  showmessage(glsltes.Log);
  glslprogram.Attach(glslfrag); 
  showmessage(glslfrag.Log);

  glslprogram.BindAttribLocation('in_Position',0);
  glslprogram.BindAttribLocation('in_Color',1);
  glslprogram.BindAttribLocation('in_TexCoord',2);

  glslprogram.Link;

  // VAO erstellen

  glClearColor(0.3, 0.3, 0.3, 0.0);
 
  //Tessellation
                             
  glPatchParameteri(GL_TESS_GEN_MODE, GL_TRIANGLES);
  glPatchParameteri(GL_PATCH_VERTICES, 3);
  testdata1[0] := 20.0;
  testdata1[1] := 20.0;
  testdata1[2] := 20.0;
  testdata1[3] := 20.0;
 
  testdata2[0] := 20.0;
  testdata2[1] := 20.0;

  glPatchParameterfv(GL_PATCH_DEFAULT_OUTER_LEVEL, @testdata1[0]);
  glPatchParameterfv(GL_PATCH_DEFAULT_INNER_LEVEL, @testdata2[0]);

  glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);

  Timer1.Enabled := true;
end;

[...]

procedure TForm1.FormCreate(Sender: TObject);     
begin
  //OGL 4.0 Context erstellen
end;

procedure TForm1.FormResize(Sender: TObject);
begin
  glViewport(0, 0, Width, Height);
end;

end.

Tessellation Control Shader:

#version 150

#extension GL_EXT_tessellation_shader : require

//Tessellation Control Shader

      in gl_PerVertex {
        vec4 gl_Position;
        float gl_PointSize;
        float gl_ClipDistance[];
      } gl_in[gl_MaxPatchVertices];

      out gl_PerVertex {
        vec4 gl_Position;
        float gl_PointSize;
        float gl_ClipDistance[];
      } gl_out[gl_VerticesOut];


void main(void)
{
  gl_out[gl_InvocationID] = gl_in[gl_InvocationID];
/*  gl_TessLevelOuter[0] = 3.0;
  gl_TessLevelOuter[1] = 3.0;
  gl_TessLevelOuter[2] = 3.0;
  gl_TessLevelOuter[3] = 3.0;
  gl_TessLevelInner[0] = 2.0;
  gl_TessLevelInner[1] = 2.0;*/
}

Tessellation Evaluation Shader:

#version 150

#extension GL_EXT_tessellation_shader : require
#define GL_ARB_tessellation_shader 1

//Tessellation Control Shader

      in gl_PerVertex {
        vec4 gl_Position;
        float gl_PointSize;
        float gl_ClipDistance[];
      } gl_in[gl_MaxPatchVertices];

      out gl_PerVertex {
        vec4 gl_Position;
        float gl_PointSize;
        float gl_ClipDistance[];
      };
    
   in vec3 ex1_Color[];
   in vec3 ex1_TexCoord[];
   out vec3 ex_Color;
   out vec3 ex_TexCoord;


void main(void)
{
  gl_Position = vec4(0.0);
  if ((gl_TessCoord.x >= 0.0) && (gl_TessCoord.y >= 0.0) && (gl_TessCoord.z >= 0.0)) //ohne diese Zeile erscheint das doppelte Dreieck
  {
    ex_Color = vec3(0.0);
    ex_TexCoord = vec3(0.0);
    for(int i = 0; i < 3; i++)
    {
      gl_Position += gl_in[gl_PrimitiveID*3+i].gl_Position*gl_TessCoord[i];
     ex_Color += ex1_Color[gl_PrimitiveID*3+i]*gl_TessCoord[i];
     ex_TexCoord += ex1_TexCoord[gl_PrimitiveID*3+i]*gl_TessCoord[i];
   }
  }
}

#version 150

#extension GL_ARB_tessellation_shader : require
#define GL_ARB_tessellation_shader 1

layout (vertices = 3) out;

//Tessellation Control Shader
   
  in vec3 ex1_Color[];
  in vec3 ex1_TexCoord[];

  out vec3 ex2_Color[];
  out vec3 ex2_TexCoord[];

void main(void)
{
  gl_out[gl_InvocationID].gl_Position = gl_in[gl_InvocationID].gl_Position;
  ex2_Color[gl_InvocationID] = ex1_Color[gl_InvocationID];
  ex2_TexCoord[gl_InvocationID] = ex1_TexCoord[gl_InvocationID];
  gl_TessLevelOuter[0] = 20.0;
  gl_TessLevelOuter[1] = 20.0;
  gl_TessLevelOuter[2] = 20.0;
  gl_TessLevelOuter[3] = 20.0;
  gl_TessLevelInner[0] = 20.0;
  gl_TessLevelInner[1] = 20.0;
}

#version 150

#extension GL_ARB_tessellation_shader : require
#define GL_ARB_tessellation_shader 1

layout (triangles) in;
layout (fractional_even_spacing) in;

uniform sampler2D Tex0;

//Tessellation Control Shader

  in vec3 ex2_Color[];
  in vec3 ex2_TexCoord[];
  out vec3 ex_Color;
  out vec3 ex_TexCoord;

void main(void)
{
  gl_Position = vec4(0.0);
    ex_Color = vec3(0.0);
    ex_TexCoord = vec3(0.0);
    for(int i = 0; i < 3; i++)
    {
       gl_Position += gl_in[i].gl_Position*gl_TessCoord[i];
       ex_Color += ex2_Color[i]*gl_TessCoord[i];
       ex_TexCoord += ex2_TexCoord[i]*gl_TessCoord[i];
    }
}

      gl_Position += gl_in[gl_PrimitiveID*3+i].gl_Position*gl_TessCoord[i];
       ex_Color += ex2_Color[gl_PrimitiveID*3+i]*gl_TessCoord[i];
       ex_TexCoord += ex2_TexCoord[gl_PrimitiveID*3+i]*gl_TessCoord[i];

      gl_Position += gl_in[i].gl_Position*gl_TessCoord[i];
       ex_Color += ex2_Color[i]*gl_TessCoord[i];
       ex_TexCoord += ex2_TexCoord[i]*gl_TessCoord[i];