public OpenGLSceneProcessor(IServiceProvider serviceProvider, IRenderWindow renderWindow, SceneGraph sceneGraph)
{
_serviceProvider = serviceProvider;
_cancellationTokenManager = _serviceProvider.GetRequiredService <CancellationTokenSource>();
_logger = _serviceProvider.GetRequiredService <ILogger <RenderWindow> >();
_shaderCompiler = _serviceProvider.GetRequiredService <IShaderCompiler>();
_textureLoader = _serviceProvider.GetRequiredService <ITextureLoader>();
_renderWindow = renderWindow; // This cannot be passed via the service provider otherwise there will be a cycle in the DI graph
_sceneGraph = sceneGraph;
_renderList = new LinkedList <IRenderCommand>();
_renderInfo = new RenderInfo();
_requestPicking = null;
GL.LoadBindings(new GLFWBindingsContext());
// Get human readable log messages during debugging
if (Debugger.IsAttached)
{
GL.Enable(EnableCap.DebugOutput);
_debugProc = DebugMessageCallback;
_gcHandle = GCHandle.Alloc(_debugProc);
GL.DebugMessageCallback(_debugProc, IntPtr.Zero);
}
GL.Enable(EnableCap.DepthTest);
// Save default frame buffer id for later blitting
GL.GetInteger(GetPName.FramebufferBinding, out _defaultFrameBufferId);
GL.BindFramebuffer(FramebufferTarget.Framebuffer, _defaultFrameBufferId);
InitFrameBuffer(640, 360);
}
public void UpdateState(IRenderCommand renderCommand)
{
if (renderCommand is RequestPickingInfo requestPicking)
{
_requestPicking = requestPicking;
}
renderCommand.SetState(_renderInfo);
InsertCommandInRenderOrder(renderCommand);
}
public void Render(double timeSinceLastFrameSeconds)
{
_renderInfo.TotalRenderTime += timeSinceLastFrameSeconds;
_renderInfo.FrameRate = 1.0 / timeSinceLastFrameSeconds;
_renderInfo.CurrentViewMatrix = _sceneGraph.ViewMatrix;
_renderInfo.CurrentProjectionMatrix = _sceneGraph.ProjectionMatrix;
// Resize frame buffer object (FBO) to account for resized window
if (_windowSizeChanged)
{
GL.BindFramebuffer(FramebufferTarget.Framebuffer, _defaultFrameBufferId);
GL.Viewport(0, 0, _renderInfo.Width, _renderInfo.Height);
// Clean up existing frame buffer
GL.DeleteFramebuffer(_mrtFrameBufferId);
GL.DeleteTextures(2, new[] { _mrtFrameBufferPickingTextureId, _mrtFrameBufferMainTextureId });
GL.DeleteRenderbuffer(_mrtFrameBufferDepthId);
// Create new MRT frameobuffer with resized dimensions
InitFrameBuffer(_renderInfo.Width, _renderInfo.Height);
_windowSizeChanged = false;
_logger.LogInformation($"Window resized to {_renderInfo.Width}x{_renderInfo.Height}={_renderInfo.Width * _renderInfo.Height} pixels");
}
GL.BindFramebuffer(FramebufferTarget.Framebuffer, _mrtFrameBufferId);
GL.DrawBuffers(2, new[] { DrawBuffersEnum.ColorAttachment0, DrawBuffersEnum.ColorAttachment1 });
if (!_renderList.Any())
{
return;
}
// Render content
GL.Clear(ClearBufferMask.DepthBufferBit);
GL.ClearBuffer(ClearBuffer.Color, 1, new float[] { 0, 0, 0, 0 });
var currentNode = _renderList.First;
while (currentNode != null)
{
var command = currentNode.Value;
command.Render(_renderInfo);
var next = currentNode.Next;
if (command.SelfDestruct)
{
_renderList.Remove(currentNode);
if (command is IDisposable disposable)
{
disposable.Dispose();
}
}
currentNode = next;
}
// Process picking request
if (_requestPicking != null)
{
var pickingInfo = GetPickingInfo(_renderInfo, _requestPicking.ScreenX, _requestPicking.ScreenY);
var writeTask = Task.Run(async() =>
{
await _renderWindow.EventChannel.Writer.WriteAsync(new PickingFeedback(pickingInfo),
_cancellationTokenManager.Token);
});
writeTask.Wait();
_requestPicking = null;
}
// Blit MRT source to default frame buffer to display it
GL.ReadBuffer(ReadBufferMode.ColorAttachment0); // copy main texture
GL.BindFramebuffer(FramebufferTarget.ReadFramebuffer, _mrtFrameBufferId);
GL.BindFramebuffer(FramebufferTarget.DrawFramebuffer, _defaultFrameBufferId);
GL.BlitFramebuffer(0, 0, _renderInfo.Width - 1, _renderInfo.Height - 1, // source
0, 0, _renderInfo.Width - 1, _renderInfo.Height - 1, // destination
ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit, BlitFramebufferFilter.Nearest);
}
