/******************************************************************************* * Copyright (c) 2000, 2005 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: *     Sebastian Davids - initial implementation *     IBM Corporation *******************************************************************************/package org.eclipse.swt.snippets;/* * SWT OpenGL snippet: draw a square *  * This snippet requires the experimental org.eclipse.swt.opengl plugin, which * is not included in SWT by default and should only be used with versions of * SWT prior to 3.2.  For information on using OpenGL in SWT see * http://www.eclipse.org/swt/opengl/ . *  * For a list of all SWT example snippets see * http://www.eclipse.org/swt/snippets/ *  * @since 3.2 */import org.eclipse.opengl.*;import org.eclipse.swt.SWT;import org.eclipse.swt.events.*;import org.eclipse.swt.graphics.*;import org.eclipse.swt.layout.*;import org.eclipse.swt.opengl.*;import org.eclipse.swt.widgets.*;public class Snippet174 {public static void main(String[] args) {    Display display = new Display();    Shell shell = new Shell(display);    shell.setText("OpenGL in SWT");    shell.setLayout(new FillLayout());    GLData data = new GLData();    data.doubleBuffer = true;    final GLCanvas canvas = new GLCanvas(shell, SWT.NO_BACKGROUND, data);    canvas.addControlListener(new ControlAdapter() {        public void controlResized(ControlEvent e) {            resize(canvas);        }    });    init(canvas);    new Runnable() {        public void run() {            if (canvas.isDisposed()) return;            render();            canvas.swapBuffers();            canvas.getDisplay().timerExec(50, this);        }    }.run();    shell.open();    while (!shell.isDisposed()) {        if (!display.readAndDispatch()) display.sleep();    }    display.dispose();}static void init(GLCanvas canvas) {    canvas.setCurrent();    resize(canvas);    GL.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);    GL.glColor3f(0.0f, 0.0f, 0.0f);    GL.glClearDepth(1.0f);    GL.glEnable(GL.GL_DEPTH_TEST);    GL.glHint(GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST);}static void render() {    GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);    GL.glLoadIdentity();    GL.glTranslatef(0.0f, 0.0f, -6.0f);    GL.glBegin(GL.GL_QUADS);    GL.glVertex3f(-1.0f, 1.0f, 0.0f);    GL.glVertex3f(1.0f, 1.0f, 0.0f);    GL.glVertex3f(1.0f, -1.0f, 0.0f);    GL.glVertex3f(-1.0f, -1.0f, 0.0f);    GL.glEnd();}static void resize(GLCanvas canvas) {    canvas.setCurrent();    Rectangle rect = canvas.getClientArea();    int width = rect.width;    int height = Math.max(rect.height, 1);    GL.glViewport(0, 0, width, height);    GL.glMatrixMode(GL.GL_PROJECTION);    GL.glLoadIdentity();    float aspect = (float) width / (float) height;    GLU.gluPerspective(45.0f, aspect, 0.5f, 400.0f);    GL.glMatrixMode(GL.GL_MODELVIEW);    GL.glLoadIdentity();}}