/// <summary>
/// Render
/// </summary>
public override void Render()
{
// reset the model view matrix.
m_ModelViewMatrix = Matrix4.Identity;
// apply a rotation to the model view.
m_ModelViewMatrix = Matrix4.Mult(m_ModelViewMatrix, Matrix4.CreateRotationZ(MathHelper.DegreesToRadians(angle)));
// begin using the shader.
m_Shader.Begin();
// update the model and projection matrix
m_Shader.UpdateProjectionMatrix(m_ProjectionMatrix);
m_Shader.UpdateModelViewMatrix(m_ModelViewMatrix);
// ensure vertex and color attrib arrays are enabled.
GL.EnableVertexAttribArray(m_Shader.VertexAttribLocation);
GL.BindBuffer(BufferTarget.ArrayBuffer, m_VertexBuffer);
GL.VertexAttribPointer(m_Shader.VertexAttribLocation, 3, VertexAttribPointerType.Float, true, Vector3.SizeInBytes, 0);
// now the texture coordinates
GL.EnableVertexAttribArray(m_Shader.TextureCoordAttribLocation);
GL.BindBuffer(BufferTarget.ArrayBuffer, m_TexCoordBuffer);
GL.VertexAttribPointer(m_Shader.TextureCoordAttribLocation, 2, VertexAttribPointerType.Float, true, Vector2.SizeInBytes, 0);
// bind our texture into slot 0. Try changing this so the shader looks at texture slot 5. You will notice
// that the texture goes black. To fix it we then set the ActiveTexture to 5 and bind our texture data into
// it..
m_Shader.SetTextureSlot(3);
GL.ActiveTexture(TextureUnit.Texture3);
GL.BindTexture(TextureTarget.Texture2D, m_Texture1);
// draw a quad (made up of two triangles)
GL.DrawArrays(BeginMode.TriangleStrip, 0, 4);
// finished with the shader.
m_Shader.End();
// this will clear the texture data from the slot were are using. If we don't do this our texture
// data will be left in the slot and could interfere with other drawing we are doing elsewhere.
GL.BindTexture(TextureTarget.Texture2D, 0);
// increment our rotation
angle += 1;
if (angle > 360)
{
angle = 0f;
}
;
}