com.auroraengine.opengl.model.IndexBuffer.java Source code

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Here is the source code for com.auroraengine.opengl.model.IndexBuffer.java

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/*
 * Copyright (C) 2017 LittleRover
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.auroraengine.opengl.model;

import com.auroraengine.client.ClientException;
import com.auroraengine.debug.AuroraLogs;
import com.auroraengine.opengl.GLException;
import com.auroraengine.opengl.GLObject;
import java.nio.IntBuffer;
import java.util.function.Supplier;
import java.util.logging.Logger;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GL15;

/**
 * The index buffer is an integer buffer which holds the primitive data in
 * reference to a vertex buffer.
 *
 * @author LittleRover
 */
public class IndexBuffer implements GLObject {
    private static final Logger LOG = AuroraLogs.getLogger(IndexBuffer.class.getName());

    /**
     * Creates a new index buffer using the supplier of the buffer. A supplier is
     * used to allow for loading from a file or generating by algorithm using
     * another thread and maintaining thread safety.
     *
     * @param source
     */
    public IndexBuffer(Supplier<IntBuffer> source) {
        this(source, GL15.GL_STATIC_DRAW);
    }

    public IndexBuffer(Supplier<IntBuffer> source, int permissions) {
        this.source = source;
        this.permissions = permissions;
    }

    private IntBuffer ib;
    private int index = 0;
    private int permissions;
    private Supplier<IntBuffer> source;

    public void bind() {
        if (index != 0) {
            GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, index);
        }
    }

    @Override
    public void create() throws GLException {
        if (index == 0) {
            index = GL15.glGenBuffers();
            if (index == 0) {
                throw new GLException("Buffer could not be generated.");
            }
            GLException.checkGL("Generating Buffer");
            GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, index);
            GLException.checkGL("Binding Buffer");
            GL15.glBufferData(GL15.GL_ELEMENT_ARRAY_BUFFER, ib, permissions);
            GLException.checkGL("Setting Buffer Data");
        }
    }

    @Override
    public void destroy() {
        if (index != 0) {
            GL15.glDeleteBuffers(index);
            index = 0;
        }
    }

    public void draw() {
        GL11.glDrawElements(GL11.GL_TRIANGLES, ib.remaining(), GL11.GL_UNSIGNED_INT, ib.position());
    }

    @Override
    public boolean isCreated() {
        return index != 0;
    }

    @Override
    public boolean isLoaded() {
        return ib != null;
    }

    @Override
    public void load() throws ClientException {
        if (ib != null) {
            ib = source.get();
            if (ib == null) {
                throw new ClientException("Failed to load the IndexBuffer!");
            }
        }
    }

    @Override
    public void unload() throws ClientException {
        ib = null; // Removes the stuff, needs to be sure it is destroyed.
    }

    @Override
    public void update() throws GLException {
        // Need to update the buffer if it is able to
        if (index != 0 && permissions != GL15.GL_STATIC_DRAW) {
            // Edit according to the modifications of the buffer.
            GL15.glBindBuffer(GL15.GL_ELEMENT_ARRAY_BUFFER, index);
            GLException.checkGL("Binding Buffer");
            GL15.glBufferSubData(GL15.GL_ELEMENT_ARRAY_BUFFER, ib.position(), ib);
            GLException.checkGL("Setting Buffer Data");
        }
    }

}