private void ApplyNormalMatrix(OpenGL gl)
{
gl.UniformMatrix3(Uniforms["NormalMatrix"], 1, false, NormalMatrix.to_array());
}
private void DrawTrefoilCelShaded(OpenGL gl)
{
// Use the shader program.
gl.UseProgram(shaderProgram.ProgramObject);
// Set the variables for the shader program.
gl.Uniform3(toonUniforms.DiffuseMaterial, 0f, 0.75f, 0.75f);
gl.Uniform3(toonUniforms.AmbientMaterial, 0.04f, 0.04f, 0.04f);
gl.Uniform3(toonUniforms.SpecularMaterial, 0.5f, 0.5f, 0.5f);
gl.Uniform1(toonUniforms.Shininess, 50f);
// Set the light position.
gl.Uniform3(toonUniforms.LightPosition, 1, new float[4] { 0.25f, 0.25f, 1f, 0f });
// Set the matrices.
gl.UniformMatrix4(toonUniforms.Projection, 1, false, projection.AsColumnMajorArrayFloat);
gl.UniformMatrix4(toonUniforms.Modelview, 1, false, modelView.AsColumnMajorArrayFloat);
gl.UniformMatrix3(toonUniforms.NormalMatrix, 1, false, normalMatrix.AsColumnMajorArrayFloat);
// Bind the vertex and index buffer.
gl.BindBuffer(OpenGL.GL_ARRAY_BUFFER, vertexBuffer);
gl.BindBuffer(OpenGL.GL_ELEMENT_ARRAY_BUFFER, indexBuffer);
gl.EnableVertexAttribArray(attrPosition);
gl.EnableVertexAttribArray(attrNormal);
// Draw the geometry, straight from the vertex buffer.
gl.VertexAttribPointer(attrPosition, 3, OpenGL.GL_FLOAT, false, Marshal.SizeOf(typeof(Vertex)), IntPtr.Zero);
int normalOffset = Marshal.SizeOf(typeof(Vertex));
gl.VertexAttribPointer(attrNormal, 3, OpenGL.GL_FLOAT, false, Marshal.SizeOf(typeof(Vertex)), IntPtr.Add(new IntPtr(0), normalOffset));
gl.DrawElements(OpenGL.GL_TRIANGLES, (int)trefoilKnot.IndexCount, OpenGL.GL_UNSIGNED_SHORT, IntPtr.Zero);
}
