kubex.gui.DepthPeelingLiquidRenderer.java Source code

Introduction

Here is the source code for kubex.gui.DepthPeelingLiquidRenderer.java

Source

package kubex.gui;

import static org.lwjgl.opengl.GL11.GL_TEXTURE_2D;
import static org.lwjgl.opengl.GL11.glClear;
import static org.lwjgl.opengl.GL30.GL_COLOR_ATTACHMENT0;
import static org.lwjgl.opengl.GL30.GL_DEPTH_ATTACHMENT;
import static org.lwjgl.opengl.GL30.GL_FRAMEBUFFER;
import static org.lwjgl.opengl.GL30.glBindFramebuffer;
import static org.lwjgl.opengl.GL30.glGenFramebuffers;

import java.nio.IntBuffer;

import org.lwjgl.BufferUtils;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GL13;
import org.lwjgl.opengl.GL20;
import org.lwjgl.opengl.GL30;

import kubex.KubexGame;
import kubex.shaders.DepthPeelingShaderProgram;

/**
 * This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
 * 
 * @author Vctor Arellano Vicente (Ivelate)
 * 
 * Perform depth peeling over the scene liquids, with as many layers as specified
 */
public class DepthPeelingLiquidRenderer extends LiquidRenderer {
    private int[] layersFbos; //One fbo for each layer
    private DepthPeelingShaderProgram DPS;

    public DepthPeelingLiquidRenderer(int layers) {
        super(layers);
        this.layersFbos = new int[layers];
        this.DPS = new DepthPeelingShaderProgram(true);
    }

    /**
     * Resources had been initcialized on KubexGame class, but here they are propperly configured.
     */
    @Override
    public void initResources(int layersTex, int currentNormalTex) {
        for (int i = 0; i < this.layersFbos.length; i++) {
            this.layersFbos[i] = glGenFramebuffers();
            glBindFramebuffer(GL_FRAMEBUFFER, this.layersFbos[i]);
            GL30.glFramebufferTextureLayer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, layersTex, 0, i); //assign one layer of the texture array to each layer fbo

            IntBuffer drawBuffers = null;

            if (i == 0) { //The first layer will render the normal of the water to a texture, too.
                drawBuffers = BufferUtils.createIntBuffer(1);
                GL30.glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, currentNormalTex,
                        0);

                drawBuffers.put(GL_COLOR_ATTACHMENT0);
                drawBuffers.flip();
            } else {
                drawBuffers = BufferUtils.createIntBuffer(0);
            }

            GL20.glDrawBuffers(drawBuffers);

        }
    }

    /**
     * Performs the depth peeling rendering
     */
    @Override
    public void renderLayers(World w, int xres, int yres) {
        this.DPS.enable();
        int upperLimitDepth = GL20.glGetUniformLocation(this.DPS.getID(), "upperLimitDepth");
        int lowerLimitDepth = GL20.glGetUniformLocation(this.DPS.getID(), "lowerLimitDepth");
        int upperLimitIndex = GL20.glGetUniformLocation(this.DPS.getID(), "upperLimitIndex");

        GL20.glUniform1i(upperLimitDepth, KubexGame.LIQUIDLAYERS_TEXTURE_LOCATION);
        GL20.glUniform1i(lowerLimitDepth, KubexGame.BASEFBO_DEPTH_TEXTURE_LOCATION);

        GL20.glUniform1i(GL20.glGetUniformLocation(this.DPS.getID(), "xres"), xres);
        GL20.glUniform1i(GL20.glGetUniformLocation(this.DPS.getID(), "yres"), yres);

        w.overrideCurrentShader(this.DPS); //Makes world use the depth peeling shader when drawing chunks

        //Writes each liquid layer to a texture
        for (int i = 0; i < this.getNumLayers(); i++) {
            GL20.glUniform1i(upperLimitIndex, i - 1);
            glBindFramebuffer(GL_FRAMEBUFFER, this.layersFbos[i]);
            glClear(GL11.GL_DEPTH_BUFFER_BIT);
            GL11.glViewport(0, 0, xres, yres);

            w.drawLiquids();
        }

        this.DPS.disable();
    }

}