void IGraphicsBackend.BeginRendering(IDrawDevice device, RenderOptions options, RenderStats stats)
{
DebugCheckOpenGLErrors();
// ToDo: AA is disabled for now
//this.CheckContextCaps();
this.currentDevice = device;
this.renderOptions = options;
this.renderStats = stats;
// Prepare the target surface for rendering
NativeRenderTarget.Bind(options.Target as NativeRenderTarget);
// Determine the available size on the active rendering surface
//Point2 availableSize;
//if (NativeRenderTarget.BoundRT != null) {
// availableSize = new Point2(NativeRenderTarget.BoundRT.Width, NativeRenderTarget.BoundRT.Height);
//} else {
// availableSize = this.externalBackbufferSize;
//}
Rect openGLViewport = options.Viewport;
// Setup viewport and scissor rects
GL.Viewport((int)openGLViewport.X, (int)openGLViewport.Y, (int)MathF.Ceiling(openGLViewport.W), (int)MathF.Ceiling(openGLViewport.H));
GL.Scissor((int)openGLViewport.X, (int)openGLViewport.Y, (int)MathF.Ceiling(openGLViewport.W), (int)MathF.Ceiling(openGLViewport.H));
// Clear buffers
if (options.ClearFlags != ClearFlag.None)
{
uint glClearMask = 0;
ColorRgba clearColor = options.ClearColor;
if ((options.ClearFlags & ClearFlag.Color) != ClearFlag.None)
{
glClearMask |= WebGLRenderingContextBase.COLOR_BUFFER_BIT;
}
if ((options.ClearFlags & ClearFlag.Depth) != ClearFlag.None)
{
glClearMask |= WebGLRenderingContextBase.DEPTH_BUFFER_BIT;
}
GL.ClearColor(clearColor.R / 255.0f, clearColor.G / 255.0f, clearColor.B / 255.0f, clearColor.A / 255.0f);
GL.ClearDepth(options.ClearDepth);
GL.Clear(glClearMask);
}
// Configure Rendering params
GL.Enable(WebGLRenderingContextBase.SCISSOR_TEST);
GL.Enable(WebGLRenderingContextBase.DEPTH_TEST);
if (options.DepthTest)
{
GL.DepthFunc(WebGLRenderingContextBase.LEQUAL);
}
else
{
GL.DepthFunc(WebGLRenderingContextBase.ALWAYS);
}
Matrix4 view = options.ViewMatrix;
Matrix4 projection = options.ProjectionMatrix;
if (NativeRenderTarget.BoundRT != null)
{
Matrix4 flipOutput = Matrix4.CreateScale(1.0f, -1.0f, 1.0f);
projection = projection * flipOutput;
}
// Convert matrices to float arrays
GetArrayMatrix(ref view, viewData);
GetArrayMatrix(ref projection, projectionData);
// All EBOs can be used again
lastUsedEBO = 0;
}