/*******************************************************************************
/** 
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
// package org.eclipse.swt.snippets;
package demos.swt;

/*
 * SWT OpenGL snippet: use JOGL to draw to an SWT GLCanvas
 *
 * For a list of all SWT example snippets see
 * http://www.eclipse.org/swt/snippets/
 * 
 * @since 3.2
 */
import org.eclipse.swt.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.opengl.GLCanvas;
import org.eclipse.swt.opengl.GLData;

import javax.media.opengl.GLProfile;
import javax.media.opengl.GL2;
import javax.media.opengl.GLContext;
import javax.media.opengl.GLDrawableFactory;
import javax.media.opengl.glu.GLU;

public class Snippet209 {
  static void drawTorus(GL2 gl, float r, float R, int nsides, int rings) {
    float ringDelta = 2.0f * (float) Math.PI / rings;
    float sideDelta = 2.0f * (float) Math.PI / nsides;
    float theta = 0.0f, cosTheta = 1.0f, sinTheta = 0.0f;
    for (int i = rings - 1; i >= 0; i--) {
      float theta1 = theta + ringDelta;
      float cosTheta1 = (float) Math.cos(theta1);
      float sinTheta1 = (float) Math.sin(theta1);
      gl.glBegin(gl.GL_QUAD_STRIP);
      float phi = 0.0f;
      for (int j = nsides; j >= 0; j--) {
        phi += sideDelta;
        float cosPhi = (float) Math.cos(phi);
        float sinPhi = (float) Math.sin(phi);
        float dist = R + r * cosPhi;
        gl.glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi, sinPhi);
        gl.glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, r * sinPhi);
        gl.glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
        gl.glVertex3f(cosTheta * dist, -sinTheta * dist, r * sinPhi);
      }
      gl.glEnd();
      theta = theta1;
      cosTheta = cosTheta1;
      sinTheta = sinTheta1;
    }
  }

  public static void main(String [] args) {
    final GLProfile gl2Profile = GLProfile.get(GLProfile.GL2);
    final Display display = new Display();
    Shell shell = new Shell(display);
    shell.setLayout(new FillLayout());
    Composite comp = new Composite(shell, SWT.NONE);
    comp.setLayout(new FillLayout());
    GLData data = new GLData ();
    data.doubleBuffer = true;
    final GLCanvas canvas = new GLCanvas(comp, SWT.NONE, data);

    canvas.setCurrent();
    final GLContext context = GLDrawableFactory.getFactory(gl2Profile).createExternalGLContext();

    canvas.addListener(SWT.Resize, new Listener() {
      public void handleEvent(Event event) {
        Rectangle bounds = canvas.getBounds();
        float fAspect = (float) bounds.width / (float) bounds.height;
        canvas.setCurrent();
        context.makeCurrent();
        GL2 gl = context.getGL().getGL2();
        gl.glViewport(0, 0, bounds.width, bounds.height);
        gl.glMatrixMode(gl.GL_PROJECTION);
        gl.glLoadIdentity();
        GLU glu = new GLU();
        glu.gluPerspective(45.0f, fAspect, 0.5f, 400.0f);
        gl.glMatrixMode(gl.GL_MODELVIEW);
        gl.glLoadIdentity();
        context.release();
      }
    });

    context.makeCurrent();
    GL2 gl = context.getGL().getGL2();
    gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
    gl.glColor3f(1.0f, 0.0f, 0.0f);
    gl.glHint(gl.GL_PERSPECTIVE_CORRECTION_HINT, gl.GL_NICEST);
    gl.glClearDepth(1.0);
    gl.glLineWidth(2);
    gl.glEnable(gl.GL_DEPTH_TEST);
    context.release();

    shell.setText("SWT/JOGL Example");
    shell.setSize(640, 480);
    shell.open();

    display.asyncExec(new Runnable() {
      int rot = 0;
      public void run() {
        if (!canvas.isDisposed()) {
          canvas.setCurrent();
          context.makeCurrent();
          GL2 gl = context.getGL().getGL2();
          gl.glClear(gl.GL_COLOR_BUFFER_BIT | gl.GL_DEPTH_BUFFER_BIT);
          gl.glClearColor(.3f, .5f, .8f, 1.0f);
          gl.glLoadIdentity();
          gl.glTranslatef(0.0f, 0.0f, -10.0f);
          float frot = rot;
          gl.glRotatef(0.15f * rot, 2.0f * frot, 10.0f * frot, 1.0f);
          gl.glRotatef(0.3f * rot, 3.0f * frot, 1.0f * frot, 1.0f);
          rot++;
          gl.glPolygonMode(gl.GL_FRONT_AND_BACK, gl.GL_LINE);
          gl.glColor3f(0.9f, 0.9f, 0.9f);
          drawTorus(gl, 1, 1.9f + ((float) Math.sin((0.004f * frot))), 15, 15);
          canvas.swapBuffers();
          context.release();
          display.asyncExec(this);
        }
      }
    });

    while (!shell.isDisposed()) {
      if (!display.readAndDispatch())
        display.sleep();
    }
    display.dispose();
  }
}