UIDisplayRenderer.java

/*
 * Copyright 2012 Benjamin Glatzel <benjamin.glatzel@me.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.terasology.rendering.gui.framework;

import org.lwjgl.opengl.Display;

import java.util.Collections;

import static org.lwjgl.opengl.GL11.*;

/**
 * Extends UIDisplayContainer to transparently init. OpenGL for 2D rendering.
 *
 * @author Benjamin Glatzel <benjamin.glatzel@me.com>
 */
public class UIDisplayRenderer extends UIDisplayContainer {

    @Override
    public void renderTransformed() {
        render();
    }

    @Override
    public void render() {
        if (isVisible()) {
            glMatrixMode(GL_PROJECTION);
            glPushMatrix();
            glLoadIdentity();
            glOrtho(0, Display.getWidth(), Display.getHeight(), 0, -32, 32);
            glMatrixMode(GL_MODELVIEW);
            glPushMatrix();
            glLoadIdentity();

            glDisable(GL_CULL_FACE);
            glDisable(GL_DEPTH_TEST);
            glEnable(GL_BLEND);
            glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

            super.render();

            glDisable(GL_BLEND);
            glEnable(GL_DEPTH_TEST);
            glEnable(GL_CULL_FACE);

            glPopMatrix();
            glMatrixMode(GL_PROJECTION);
            glPopMatrix();
            glMatrixMode(GL_MODELVIEW);
        }
    }

    public void changeElementDepth(int elementPosition, int forwardToPosistion) {
        Collections.rotate(_displayElements.subList(elementPosition, forwardToPosistion + 1), -1);
    }
}