Java tutorial
/* * This file is part of Caustic LWJGL, licensed under the MIT License (MIT). * * Copyright (c) 2013 Flow Powered <https://flowpowered.com/> * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.flowpowered.caustic.lwjgl.gl20; import java.nio.IntBuffer; import java.util.Arrays; import gnu.trove.set.TIntSet; import gnu.trove.set.hash.TIntHashSet; import org.lwjgl.opengl.EXTFramebufferObject; import org.lwjgl.opengl.GL11; import org.lwjgl.opengl.GL20; import org.lwjgl.opengl.GLContext; import com.flowpowered.caustic.api.gl.FrameBuffer; import com.flowpowered.caustic.api.gl.RenderBuffer; import com.flowpowered.caustic.api.gl.Texture; import com.flowpowered.caustic.api.util.CausticUtil; import com.flowpowered.caustic.lwjgl.LWJGLUtil; /** * An OpenGL 2.0 implementation of {@link FrameBuffer} using EXT. * * @see FrameBuffer */ public class GL20FrameBuffer extends FrameBuffer { private final TIntSet outputBuffers = new TIntHashSet(); /** * Constructs a new frame buffer for OpenGL 2.0. If no EXT extension for frame buffers is available, an exception is thrown. * * @throws UnsupportedOperationException If the hardware doesn't support EXT frame buffers */ public GL20FrameBuffer() { if (!GLContext.getCapabilities().GL_EXT_framebuffer_object) { throw new UnsupportedOperationException("Frame buffers are not supported by this hardware"); } } @Override public void create() { checkNotCreated(); // Generate and bind the frame buffer id = EXTFramebufferObject.glGenFramebuffersEXT(); EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, id); // Disable input buffers GL11.glReadBuffer(GL11.GL_NONE); // Unbind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); // Update the state super.create(); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void destroy() { checkCreated(); // Delete the frame buffer EXTFramebufferObject.glDeleteFramebuffersEXT(id); // Clear output buffers outputBuffers.clear(); // Update the state super.destroy(); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void attach(AttachmentPoint point, Texture texture) { checkCreated(); texture.checkCreated(); CausticUtil.checkVersion(this, texture); // Bind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, id); // Attach the texture EXTFramebufferObject.glFramebufferTexture2DEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, point.getGLConstant(), GL11.GL_TEXTURE_2D, texture.getID(), 0); // Add it to the color outputs if it's a color type if (point.isColor()) { outputBuffers.add(point.getGLConstant()); } // Update the list of output buffers updateOutputBuffers(); // Unbind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void attach(AttachmentPoint point, RenderBuffer buffer) { checkCreated(); CausticUtil.checkVersion(this, buffer); buffer.checkCreated(); // Bind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, id); // Attach the render buffer EXTFramebufferObject.glFramebufferRenderbufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, point.getGLConstant(), EXTFramebufferObject.GL_RENDERBUFFER_EXT, buffer.getID()); // Add it to the color outputs if it's a color type if (point.isColor()) { outputBuffers.add(point.getGLConstant()); } // Update the list of output buffers updateOutputBuffers(); // Unbind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void detach(AttachmentPoint point) { checkCreated(); // Bind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, id); // Detach the render buffer or texture EXTFramebufferObject.glFramebufferRenderbufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, point.getGLConstant(), EXTFramebufferObject.GL_RENDERBUFFER_EXT, 0); // Remove it from the color outputs if it's a color type if (point.isColor()) { outputBuffers.remove(point.getGLConstant()); } // Update the list of output buffers updateOutputBuffers(); // Unbind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); // Check for errors LWJGLUtil.checkForGLError(); } private void updateOutputBuffers() { // Set the output to the proper buffers if (outputBuffers.isEmpty()) { // No color to output GL20.glDrawBuffers(GL11.GL_NONE); } else { // Keep track of the buffers to output final int[] outputBuffersArray = outputBuffers.toArray(); // Sorting the array ensures that attachments are in order n, n + 1, n + 2... // This is important! Arrays.sort(outputBuffersArray); final IntBuffer buffer = CausticUtil.createIntBuffer(outputBuffers.size()); buffer.put(outputBuffersArray); buffer.flip(); GL20.glDrawBuffers(buffer); } } @Override public boolean isComplete() { checkCreated(); // Bind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, id); // Fetch the status and compare to the complete enum value final boolean complete = EXTFramebufferObject.glCheckFramebufferStatusEXT( EXTFramebufferObject.GL_FRAMEBUFFER_EXT) == EXTFramebufferObject.GL_FRAMEBUFFER_COMPLETE_EXT; // Unbind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); // Check for errors LWJGLUtil.checkForGLError(); return complete; } @Override public void bind() { checkCreated(); // Bind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, id); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void unbind() { checkCreated(); // Unbind the frame buffer EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0); // Check for errors LWJGLUtil.checkForGLError(); } @Override public GLVersion getGLVersion() { return GLVersion.GL20; } }