private unsafe void SimpleCube_Paint(object sender, PaintEventArgs e)
{
_Context.MakeCurrent();
_Lookat = mat4.LookAt(_CameraPosition, new vec3(0.1f, 0.1f, 0.1f), new vec3(0.0f, 1.0f, 0.0f));
int positionAttribIndex = _Shader.GetAttribLocation("in_Position");
int projectionMatrix = _Shader.GetUniformLocation("projectionMatrix");
_Context.DrawBuffer(Ratchet.Drawing.OpenGL.glContext.DrawBufferMode.GL_BACK);
_Context.ClearDepth(1.0f);
_Context.ClearColor(0.1f, 0.7f, 1.0f, 1.0f);
_Context.Clear(Ratchet.Drawing.OpenGL.glContext.ClearTarget.GL_COLOR_BUFFER | Ratchet.Drawing.OpenGL.glContext.ClearTarget.GL_DEPTH_BUFFER);
_Shader.UseProgram();
mat4 matrix = _Projection * _Lookat;
_Context.SetUniformMatrix4(projectionMatrix, false, new IntPtr(&matrix));
_VertexBuffer.BindBuffer(Ratchet.Drawing.OpenGL.glBuffer.BindTarget.GL_ARRAY_BUFFER);
_IndexBuffer.BindBuffer(Ratchet.Drawing.OpenGL.glBuffer.BindTarget.GL_ELEMENT_ARRAY_BUFFER);
_Context.EnableVertexAttribArray(positionAttribIndex);
_Context.VertexAttribPointer(positionAttribIndex, 4, Ratchet.Drawing.OpenGL.glContext.VertexAttributeType.GL_FLOAT, false, 6 * sizeof(float), new IntPtr(0));
_Context.DrawElements(Ratchet.Drawing.OpenGL.glContext.PrimitivesType.GL_TRIANGLES, 36, Ratchet.Drawing.OpenGL.glContext.IndiceType.GL_UNSIGNED_INT);
_Context.Flush();
_Context.SwapBuffers();
}
