Java tutorial
/* * This file is part of Caustic LWJGL. * * Copyright (c) 2013 Spout LLC <http://www.spout.org/> * Caustic LWJGL is licensed under the Spout License Version 1. * * Caustic LWJGL is free software: you can redistribute it and/or modify it under * the terms of the GNU Lesser General Public License as published by the Free * Software Foundation, either version 3 of the License, or (at your option) * any later version. * * In addition, 180 days after any changes are published, you can use the * software, incorporating those changes, under the terms of the MIT license, * as described in the Spout License Version 1. * * Caustic LWJGL is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for * more details. * * You should have received a copy of the GNU Lesser General Public License, * the MIT license and the Spout License Version 1 along with this program. * If not, see <http://www.gnu.org/licenses/> for the GNU Lesser General Public * License and see <http://spout.in/licensev1> for the full license, including * the MIT license. */ package org.spout.renderer.lwjgl.gl30; import java.nio.ByteBuffer; import org.lwjgl.opengl.GL11; import org.lwjgl.opengl.GL15; import org.lwjgl.opengl.GL20; import org.lwjgl.opengl.GL30; import org.spout.renderer.api.data.VertexAttribute; import org.spout.renderer.api.data.VertexAttribute.DataType; import org.spout.renderer.api.data.VertexAttribute.UploadMode; import org.spout.renderer.api.data.VertexData; import org.spout.renderer.api.gl.VertexArray; import org.spout.renderer.lwjgl.LWJGLUtil; /** * An OpenGL 3.0 implementation of {@link VertexArray}. * * @see VertexArray */ public class GL30VertexArray extends VertexArray { private static final int[] EMPTY_ARRAY = {}; // Buffers IDs private int indicesBufferID = 0; private int[] attributeBufferIDs = EMPTY_ARRAY; // Size of the attribute buffers private int[] attributeBufferSizes = EMPTY_ARRAY; // Amount of indices to render private int indicesCount = 0; private int indicesDrawCount = 0; // First and last index to render private int indicesOffset = 0; // Drawing mode private DrawingMode drawingMode = DrawingMode.TRIANGLES; @Override public void create() { checkNotCreated(); // Generate the vao id = GL30.glGenVertexArrays(); // Update state super.create(); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void destroy() { checkCreated(); // Delete the indices buffer GL15.glDeleteBuffers(indicesBufferID); // Delete the attribute buffers for (int attributeBufferID : attributeBufferIDs) { GL15.glDeleteBuffers(attributeBufferID); } // Delete the vao GL30.glDeleteVertexArrays(id); // Reset the IDs and data indicesBufferID = 0; attributeBufferIDs = EMPTY_ARRAY; attributeBufferSizes = EMPTY_ARRAY; // Update the state super.destroy(); // Check for errors LWJGLUtil.checkForGLError(); } @Override public void setData(VertexData vertexData) { checkCreated(); // Generate a new indices buffer if we don't have one yet if (indicesBufferID == 0) { indicesBufferID = GL15.glGenBuffers(); } // Bind the indices buffer GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBufferID); // Get the new count of indices final int newIndicesCount = vertexData.getIndicesCount(); // If the new count is greater than or 50% smaller than the old one, we'll reallocate the memory // In the first case because we need more space, in the other to save space if (newIndicesCount > indicesCount || newIndicesCount <= indicesCount * 0.5) { GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, vertexData.getIndicesBuffer(), GL15.GL_STATIC_DRAW); } else { // Else, we replace the data with the new one, but we don't resize, so some old data might be left trailing in the buffer GL15.glBufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, 0, vertexData.getIndicesBuffer()); } // Unbind the indices buffer GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0); // Update the count to the new one indicesCount = newIndicesCount; indicesDrawCount = indicesCount; // Ensure that the indices offset and count fits inside the valid part of the buffer indicesOffset = Math.min(indicesOffset, indicesCount - 1); indicesDrawCount = indicesDrawCount - indicesOffset; // Bind the vao GL30.glBindVertexArray(id); // Create a new array of attribute buffers ID of the correct size final int attributeCount = vertexData.getAttributeCount(); final int[] newAttributeBufferIDs = new int[attributeCount]; // Copy all the old buffer IDs that will fit in the new array so we can reuse them System.arraycopy(attributeBufferIDs, 0, newAttributeBufferIDs, 0, Math.min(attributeBufferIDs.length, newAttributeBufferIDs.length)); // Delete any buffers that we don't need (new array is smaller than the previous one) for (int i = newAttributeBufferIDs.length; i < attributeBufferIDs.length; i++) { GL15.glDeleteBuffers(attributeBufferIDs[i]); } // Create new buffers if necessary (new array is larger than the previous one) for (int i = attributeBufferIDs.length; i < newAttributeBufferIDs.length; i++) { newAttributeBufferIDs[i] = GL15.glGenBuffers(); } // Copy the old valid attribute buffer sizes final int[] newAttributeBufferSizes = new int[attributeCount]; System.arraycopy(attributeBufferSizes, 0, newAttributeBufferSizes, 0, Math.min(attributeBufferSizes.length, newAttributeBufferSizes.length)); // Upload the new vertex data for (int i = 0; i < attributeCount; i++) { final VertexAttribute attribute = vertexData.getAttribute(i); final ByteBuffer attributeData = attribute.getData(); // Get the current buffer size final int bufferSize = newAttributeBufferSizes[i]; // Get the new buffer size final int newBufferSize = attributeData.remaining(); // Bind the target buffer GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, newAttributeBufferIDs[i]); // If the new count is greater than or 50% smaller than the old one, we'll reallocate the memory if (newBufferSize > bufferSize || newBufferSize <= bufferSize * 0.5) { GL15.glBufferData(GL15.GL_ARRAY_BUFFER, attributeData, GL15.GL_STATIC_DRAW); } else { // Else, we replace the data with the new one, but we don't resize, so some old data might be left trailing in the buffer GL15.glBufferSubData(GL15.GL_ARRAY_BUFFER, 0, attributeData); } // Update the buffer size to the new one newAttributeBufferSizes[i] = newBufferSize; // Next, we add the pointer to the data in the vao // We have three ways to interpret integer data if (attribute.getType().isInteger() && attribute.getUploadMode() == UploadMode.KEEP_INT) { // Directly as an int GL30.glVertexAttribIPointer(i, attribute.getSize(), attribute.getType().getGLConstant(), 0, 0); } else { // Or as a float, normalized or not GL20.glVertexAttribPointer(i, attribute.getSize(), attribute.getType().getGLConstant(), attribute.getUploadMode().normalize(), 0, 0); } // Finally enable the attribute GL20.glEnableVertexAttribArray(i); } // Unbind the last vbo GL15.glBindBuffer(GL15.GL_ARRAY_BUFFER, 0); // Unbind the vao GL30.glBindVertexArray(0); // Update the attribute buffer IDs to the new ones attributeBufferIDs = newAttributeBufferIDs; // Update the attribute buffer sizes to the new ones attributeBufferSizes = newAttributeBufferSizes; // Check for errors LWJGLUtil.checkForGLError(); } @Override public void setDrawingMode(DrawingMode mode) { if (mode == null) { throw new IllegalArgumentException("Drawing mode cannot be null"); } this.drawingMode = mode; } @Override public void setIndicesOffset(int offset) { indicesOffset = Math.min(offset, indicesCount - 1); indicesDrawCount = Math.min(indicesDrawCount, indicesCount - indicesOffset); } @Override public void setIndicesCount(int count) { if (count < 0) { indicesDrawCount = indicesCount; } else { indicesDrawCount = count; } indicesDrawCount = Math.min(indicesDrawCount, indicesCount - indicesOffset); } @Override public void draw() { checkCreated(); // Bind the vao GL30.glBindVertexArray(id); // Bind the index buffer GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, indicesBufferID); // Draw all indices with the provided mode GL11.glDrawElements(drawingMode.getGLConstant(), indicesDrawCount, GL11.GL_UNSIGNED_INT, indicesOffset * DataType.INT.getByteSize()); // Unbind the index buffer GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, 0); // Unbind the vao GL30.glBindVertexArray(0); // Check for errors LWJGLUtil.checkForGLError(); } @Override public GLVersion getGLVersion() { return GLVersion.GL30; } }