/*
* Copyright 2016 MovingBlocks
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.terasology.rendering.dag.nodes;
import org.terasology.assets.ResourceUrn;
import org.terasology.monitoring.PerformanceMonitor;
import org.terasology.registry.In;
import org.terasology.rendering.dag.AbstractNode;
import org.terasology.rendering.dag.stateChanges.BindFBO;
import org.terasology.rendering.dag.stateChanges.EnableMaterial;
import org.terasology.rendering.dag.stateChanges.SetViewportToSizeOf;
import static org.terasology.rendering.opengl.DefaultDynamicFBOs.WRITE_ONLY_GBUFFER;
import org.terasology.rendering.opengl.FBO;
import org.terasology.rendering.opengl.FBOConfig;
import static org.terasology.rendering.opengl.ScalingFactors.FULL_SCALE;
import org.terasology.rendering.opengl.fbms.DisplayResolutionDependentFBOs;
import static org.terasology.rendering.opengl.OpenGLUtils.renderFullscreenQuad;
/**
* An instance of this class takes advantage of the content of a number of previously filled buffers
* to add screen-space ambient occlusion (SSAO), outlines, reflections [1], atmospheric haze and volumetric fog [2]
*
* As this node does not quite use 3D geometry and only relies on 2D sources and a 2D output buffer, it
* could be argued that, despite its name, it represents the first step of the PostProcessing portion
* of the rendering engine. This line of thinking draws a parallel from the film industry where
* Post-Processing (or Post-Production) is everything that happens -after- the footage for the film
* has been shot on stage or on location.
*
* [1] And refractions? To be verified.
* [2] Currently not working: the code is there but it is never enabled.
*/
public class PrePostCompositeNode extends AbstractNode {
private static final ResourceUrn REFLECTIVE_REFRACTIVE_FBO = new ResourceUrn("engine:fbo.reflectiveRefractive");
@In
private DisplayResolutionDependentFBOs displayResolutionDependentFBOs;
/**
* This method must be called once shortly after instantiation to fully initialize the node
* and make it ready for rendering.
*/
@Override
public void initialise() {
requiresFBO(new FBOConfig(REFLECTIVE_REFRACTIVE_FBO, FULL_SCALE, FBO.Type.HDR).useNormalBuffer(), displayResolutionDependentFBOs);
addDesiredStateChange(new EnableMaterial("engine:prog.prePostComposite"));
addDesiredStateChange(new BindFBO(WRITE_ONLY_GBUFFER));
addDesiredStateChange(new SetViewportToSizeOf(WRITE_ONLY_GBUFFER));
// TODO: bind input textures from ShaderParametersCombine class
}
/**
* Called every frame, the shader program used by this method only composites per-pixel information from a number
* of buffers and renders it into a full-screen quad, which is the only piece of geometry processed.
*/
@Override
public void process() {
PerformanceMonitor.startActivity("rendering/prePostComposite");
renderFullscreenQuad();
// TODO: review - the following line is necessary, but at this stage it's unclear why.
displayResolutionDependentFBOs.swapReadWriteBuffers();
// The following line doesn't seem to have an effect: for the time being I keep it here for safety.
// READ_ONLY_GBUFFER.attachDepthBufferTo(displayResolutionDependentFBOs.get(REFLECTIVE_REFRACTIVE_FBO));
PerformanceMonitor.endActivity();
}
}