/*******************************************************************************
 * Copyright (c) 2011 LWJGL Project 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, and under the terms of the 
 * BSD license, see http://lwjgl.org/license.php for details.
 *
 * Contributors:
 *    Jens von Pilgrim - initial implementation
 ******************************************************************************/

package org.lwjgl.info;

import org.eclipse.core.runtime.IBundleGroup;
import org.eclipse.core.runtime.IBundleGroupProvider;
import org.eclipse.core.runtime.Platform;
import org.eclipse.jface.action.IStatusLineManager;
import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.opengl.GLCanvas;
import org.eclipse.swt.opengl.GLData;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.ui.part.ViewPart;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GLContext;
import org.lwjgl.util.glu.GLU;

/**
 * Simple view for testing whether LWJGL is installed correctly on your 
 * system.
 * The example is based on 
 * <a href="http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.swt.snippets/src/org/eclipse/swt/snippets/Snippet195.java?view=markup&content-type=text%2Fvnd.viewcvs-markup&revision=HEAD">snippet 195</a>.
 *
 * @author 	Jens von Pilgrim
 * @version	$Revision$
 * @since 	16.07.2007
 * @headurl $HeadURL$
 */
public class LWJGLTestView extends ViewPart {

	GLCanvas canvas;

	FpsStatusLineItem fpsstatuslineitem;

	static String getFeatureVersion(String myFeatureId) {
		IBundleGroupProvider[] providers = Platform.getBundleGroupProviders();
		if (providers != null) {
			for (int i = 0; i < providers.length; ++i) {
				IBundleGroup[] bundleGroups = providers[i].getBundleGroups();
				for (IBundleGroup bg : bundleGroups) {
					if (bg.getIdentifier().equals(myFeatureId)) {
						return bg.getVersion();
					}
				}
			}
		}
		return "Feature not found";
	}

	/** 
	 * {@inheritDoc}
	 * @see org.eclipse.ui.part.WorkbenchPart#createPartControl(org.eclipse.swt.widgets.Composite)
	 */
	@Override
	public void createPartControl(Composite parent) {

		String strVersion = getFeatureVersion("org.lwjgl");
		this.setPartName("org.lwjgl " + strVersion);

		IStatusLineManager statusLine = this.getViewSite().getActionBars()
				.getStatusLineManager();

		fpsstatuslineitem = new FpsStatusLineItem();
		statusLine.add(fpsstatuslineitem);

		GLData data = new GLData();
		data.doubleBuffer = true;
		canvas = new GLCanvas(parent, SWT.NONE, data);

		canvas.setCurrent();
		try {
			GLContext.useContext(canvas);
		} catch (LWJGLException e) {
			e.printStackTrace();
		}

		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();
				try {
					GLContext.useContext(canvas);
				} catch (LWJGLException e) {
					e.printStackTrace();
				}
				GL11.glViewport(0, 0, bounds.width, bounds.height);
				GL11.glMatrixMode(GL11.GL_PROJECTION);
				GL11.glLoadIdentity();
				GLU.gluPerspective(45.0f, fAspect, 0.5f, 400.0f);
				GL11.glMatrixMode(GL11.GL_MODELVIEW);
				GL11.glLoadIdentity();
			}
		});

		GL11.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
		GL11.glColor3f(1.0f, 0.0f, 0.0f);
		GL11.glHint(GL11.GL_PERSPECTIVE_CORRECTION_HINT, GL11.GL_NICEST);
		GL11.glClearDepth(1.0);
		GL11.glLineWidth(2);
		GL11.glEnable(GL11.GL_DEPTH_TEST);

		Display.getCurrent().asyncExec(initRunnable());

	}

	/** 
	 * {@inheritDoc}
	 * @see org.eclipse.ui.part.WorkbenchPart#setFocus()
	 */
	@Override
	public void setFocus() {
		canvas.setFocus();
	}

	static void drawTorus(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);
			GL11.glBegin(GL11.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;
				GL11
						.glNormal3f(cosTheta1 * cosPhi, -sinTheta1 * cosPhi,
								sinPhi);
				GL11
						.glVertex3f(cosTheta1 * dist, -sinTheta1 * dist, r
								* sinPhi);
				GL11.glNormal3f(cosTheta * cosPhi, -sinTheta * cosPhi, sinPhi);
				GL11.glVertex3f(cosTheta * dist, -sinTheta * dist, r * sinPhi);
			}
			GL11.glEnd();
			theta = theta1;
			cosTheta = cosTheta1;
			sinTheta = sinTheta1;
		}
	}

	Runnable initRunnable() {
		return new Runnable() {
			int rot = 0;

			public void run() {
				if (!canvas.isDisposed() && canvas.isVisible()) {

					fpsstatuslineitem.renderPassStarted();

					canvas.setCurrent();
					try {
						GLContext.useContext(canvas);
					} catch (LWJGLException e) {
						e.printStackTrace();
					}
					GL11.glClear(GL11.GL_COLOR_BUFFER_BIT
							| GL11.GL_DEPTH_BUFFER_BIT);
					GL11.glClearColor(.2f, .7f, .2f, 1.0f);
					GL11.glLoadIdentity();
					GL11.glTranslatef(0.0f, 0.0f, -10.0f);
					float frot = rot;
					GL11
							.glRotatef(0.15f * rot, 2.0f * frot, 10.0f * frot,
									1.0f);
					GL11.glRotatef(0.3f * rot, 3.0f * frot, 1.0f * frot, 1.0f);
					rot++;
					GL11.glPolygonMode(GL11.GL_FRONT_AND_BACK, GL11.GL_LINE);
					GL11.glColor3f(0.9f, 0.9f, 0.9f);
					drawTorus(1, 1.9f + ((float) Math.sin((0.004f * frot))),
							15, 15);

					canvas.swapBuffers();

					fpsstatuslineitem.renderPassFinished();
					Display.getCurrent().asyncExec(this);

				}
			}
		};
	}

}
