public void Render()
{
// Update hulls internal data structures.
Hulls.Update();
// We want to use clamping sampler state throughout the lightmap rendering process.
// This is required when drawing lights. Since light rendering and alpha clearing is done
// in a single step, light is rendered with slightly larger quad where tex coords run out of the [0..1] range.
Device.SamplerStates[0] = SamplerState.LinearClamp;
// Switch render target to lightmap.
Device.SetRenderTargets(Textures.LightmapBindings);
// Clear lightmap color, depth and stencil data.
Device.Clear(ClearOptions.DepthBuffer | ClearOptions.Stencil | ClearOptions.Target, _ambientColor, 1f, 0);
// Set per frame shader data.
ShadowRenderer.PreRender();
// Generate lightmap. For each light, mask the shadowed areas determined by hulls and render light.
int lightCount = Lights.Count;
for (int i = 0; i < lightCount; i++)
{
Light light = Lights[i];
// Continue only if light is enabled and not inside any hull.
if (!light.Enabled || Hulls.Contains(light))
{
continue;
}
// Update light's internal data structures.
light.Update();
// Continue only if light is within camera view.
if (!light.Intersects(Camera))
{
continue;
}
// Set scissor rectangle to clip any shadows outside of light's range.
BoundingRectangle scissor;
Camera.GetScissorRectangle(light, out scissor);
Device.SetScissorRectangle(ref scissor);
// Mask shadowed areas by reducing alpha.
ShadowRenderer.Render(light);
// Draw light and clear alpha (reset it to 1 [fully lit] for next light).
LightRenderer.Render(light);
// Clear light's dirty flag.
light.Dirty = false;
}
// Switch render target back to default.
Device.SetRenderTargets(Textures.GetOriginalRenderTargetBindings());
// Blend original scene and lightmap and present to backbuffer.
LightMapRenderer.Present();
// Clear hulls dirty flag.
Hulls.Dirty = false;
}
//--------------------------------------------------------------
#region Methods
//--------------------------------------------------------------
public void Render(IList <SceneNode> lights, RenderContext context)
{
var graphicsService = context.GraphicsService;
var graphicsDevice = graphicsService.GraphicsDevice;
var renderTargetPool = graphicsService.RenderTargetPool;
var target = context.RenderTarget;
var viewport = context.Viewport;
var width = viewport.Width;
var height = viewport.Height;
RenderTarget2D aoRenderTarget = null;
if (_ssaoFilter != null)
{
// Render ambient occlusion info into a render target.
aoRenderTarget = renderTargetPool.Obtain2D(new RenderTargetFormat(
width / _ssaoDownsampleFactor,
height / _ssaoDownsampleFactor,
false,
SurfaceFormat.Color,
DepthFormat.None));
// PostProcessors require that context.SourceTexture is set. But since
// _ssaoFilter.CombineWithSource is set to false, the SourceTexture is not
// used and we can set it to anything except null.
context.SourceTexture = aoRenderTarget;
context.RenderTarget = aoRenderTarget;
context.Viewport = new Viewport(0, 0, aoRenderTarget.Width, aoRenderTarget.Height);
_ssaoFilter.Process(context);
context.SourceTexture = null;
}
// The light buffer consists of two full-screen render targets into which we
// render the accumulated diffuse and specular light intensities.
var lightBufferFormat = new RenderTargetFormat(width, height, false, SurfaceFormat.HdrBlendable, DepthFormat.Depth24Stencil8);
context.LightBuffer0 = renderTargetPool.Obtain2D(lightBufferFormat);
context.LightBuffer1 = renderTargetPool.Obtain2D(lightBufferFormat);
// Set the device render target to the light buffer.
_renderTargetBindings[0] = new RenderTargetBinding(context.LightBuffer0); // Diffuse light accumulation
_renderTargetBindings[1] = new RenderTargetBinding(context.LightBuffer1); // Specular light accumulation
graphicsDevice.SetRenderTargets(_renderTargetBindings);
context.RenderTarget = context.LightBuffer0;
context.Viewport = graphicsDevice.Viewport;
// Clear the light buffer. (The alpha channel is not used. We can set it to anything.)
graphicsDevice.Clear(new Color(0, 0, 0, 255));
// Restore the depth buffer (which XNA destroys in SetRenderTarget).
// (This is only needed if lights can use a clip geometry (LightNode.Clip).)
var rebuildZBufferRenderer = (RebuildZBufferRenderer)context.Data[RenderContextKeys.RebuildZBufferRenderer];
rebuildZBufferRenderer.Render(context, true);
// Render all lights into the light buffers.
LightRenderer.Render(lights, context);
if (aoRenderTarget != null)
{
// Render the ambient occlusion texture using multiplicative blending.
// This will darken the light buffers depending on the ambient occlusion term.
// Note: Theoretically, this should be done after the ambient light renderer
// and before the directional light renderer because AO should not affect
// directional lights. But doing this here has more impact.
context.SourceTexture = aoRenderTarget;
graphicsDevice.BlendState = GraphicsHelper.BlendStateMultiply;
_copyFilter.Process(context);
}
// Clean up.
graphicsService.RenderTargetPool.Recycle(aoRenderTarget);
context.SourceTexture = null;
context.RenderTarget = target;
context.Viewport = viewport;
_renderTargetBindings[0] = new RenderTargetBinding();
_renderTargetBindings[1] = new RenderTargetBinding();
}
