/// <summary>
/// this helps clear stencil buffer because `glClear(GL_STENCIL_BUFFER_BIT);` doesn't work on my laptop.
/// </summary>
/// <returns></returns>
public static ClearStencilNode Create()
{
var model = new ClearStencilModel();
var vs = new VertexShader(vertexCode);
var fs = new FragmentShader(fragmentCode);
var array = new ShaderArray(vs, fs);
var map = new AttributeMap();
var builder = new RenderMethodBuilder(array, map, new DepthMaskState(false), new ColorMaskState(false, false, false, false));
var node = new ClearStencilNode(model, builder);
node.Initialize();
return(node);
}
/// <summary>
/// Render depth buffer, extrude shadow volume, record occlusions by stencil operation, light up the scene according to stencil test and finally render the ambient color.
/// </summary>
/// <param name="scene"></param>
public ShadowVolumeAction(Scene scene)
{
this.scene = scene;
this.clearStencilNode = ClearStencilNode.Create();
}