itdelatrisu.opsu.render.Rendertarget.java Source code

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Here is the source code for itdelatrisu.opsu.render.Rendertarget.java

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/*
 *  opsu! - an open-source osu! client
 *  Copyright (C) 2014, 2015 Jeffrey Han
 *
 *  opsu! 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.
 *
 *  opsu! 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 opsu!.  If not, see <http://www.gnu.org/licenses/>.
 */
package itdelatrisu.opsu.render;

import java.nio.ByteBuffer;

import org.lwjgl.opengl.EXTFramebufferObject;
import org.lwjgl.opengl.GL11;

/**
 * Represents a rendertarget. For now this maps to an OpenGL FBO via LWJGL.
 *
 * @author Bigpet {@literal <dravorek (at) gmail.com>}
 */
public class Rendertarget {
    /** The dimensions. */
    public final int width, height;

    /** The FBO ID. */
    private final int fboID;

    /** The texture ID for the color buffer this rendertarget renders into. */
    private final int textureID;

    /** The renderbuffer ID for the depth buffer that this rendertarget renders into. */
    private final int depthBufferID;

    /**
     * Create a new FBO.
     * @param width the width
     * @param height the height
     */
    private Rendertarget(int width, int height) {
        this.width = width;
        this.height = height;
        fboID = EXTFramebufferObject.glGenFramebuffersEXT();
        textureID = GL11.glGenTextures();
        depthBufferID = EXTFramebufferObject.glGenRenderbuffersEXT();
    }

    /**
     * Bind this rendertarget as the primary framebuffer.
     */
    public void bind() {
        EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, fboID);
    }

    /**
     * Returns the FBO ID.
     */
    // NOTE: use judiciously, try to avoid if possible and consider adding a
    // method to this class if you find yourself calling this repeatedly.
    public int getID() {
        return fboID;
    }

    /**
     * Returns the texture ID.
     */
    // NOTE: try not to use, could be moved into separate class.
    public int getTextureID() {
        return textureID;
    }

    /**
     * Bind the default framebuffer.
     */
    public static void unbind() {
        EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, 0);
    }

    /**
     * Creates a Rendertarget with a Texture that it renders the color buffer in
     * and a renderbuffer that it renders the depth to.
     * @param width the width
     * @param height the height
    */
    public static Rendertarget createRTTFramebuffer(int width, int height) {
        int old_framebuffer = GL11.glGetInteger(EXTFramebufferObject.GL_FRAMEBUFFER_BINDING_EXT);
        int old_texture = GL11.glGetInteger(GL11.GL_TEXTURE_BINDING_2D);
        Rendertarget buffer = new Rendertarget(width, height);
        buffer.bind();

        int fboTexture = buffer.textureID;
        GL11.glBindTexture(GL11.GL_TEXTURE_2D, fboTexture);
        GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, 4, width, height, 0, GL11.GL_RGBA, GL11.GL_UNSIGNED_INT,
                (ByteBuffer) null);
        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_NEAREST);
        GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAREST);

        EXTFramebufferObject.glBindRenderbufferEXT(EXTFramebufferObject.GL_RENDERBUFFER_EXT, buffer.depthBufferID);
        EXTFramebufferObject.glRenderbufferStorageEXT(EXTFramebufferObject.GL_RENDERBUFFER_EXT,
                GL11.GL_DEPTH_COMPONENT, width, height);
        EXTFramebufferObject.glFramebufferRenderbufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT,
                EXTFramebufferObject.GL_DEPTH_ATTACHMENT_EXT, EXTFramebufferObject.GL_RENDERBUFFER_EXT,
                buffer.depthBufferID);

        EXTFramebufferObject.glFramebufferTexture2DEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT,
                EXTFramebufferObject.GL_COLOR_ATTACHMENT0_EXT, GL11.GL_TEXTURE_2D, fboTexture, 0);

        GL11.glBindTexture(GL11.GL_TEXTURE_2D, old_texture);
        EXTFramebufferObject.glBindFramebufferEXT(EXTFramebufferObject.GL_FRAMEBUFFER_EXT, old_framebuffer);

        return buffer;
    }

    /**
     * Destroy the OpenGL objects associated with this Rendertarget. Do not try
     * to use this rendertarget with OpenGL after calling this method.
     */
    public void destroyRTT() {
        EXTFramebufferObject.glDeleteFramebuffersEXT(fboID);
        EXTFramebufferObject.glDeleteRenderbuffersEXT(depthBufferID);
        GL11.glDeleteTextures(textureID);
    }
}