import javax.media.opengl.GL2;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCapabilities;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.GLProfile;
import javax.media.opengl.glu.GLU;

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;

import com.jogamp.newt.opengl.GLWindow;
import com.jogamp.newt.swt.NewtCanvasSWT;
import com.jogamp.opengl.util.Animator;

public class NewtTest
{
	public static void main(String[] args)
	{
		Display display = new Display();
		Shell shell = new Shell(display);
		shell.setLayout(new RowLayout());

		final NewtCanvasSWT canvas1 = init(shell, false);
		final NewtCanvasSWT canvas2 = init(shell, true);

		Button button1 = new Button(shell, SWT.PUSH);
		button1.setText("Set size to 0,0");
		button1.addSelectionListener(new SelectionAdapter()
		{
			@Override
			public void widgetSelected(SelectionEvent e)
			{
				canvas1.setSize(0, 0);
				canvas2.setSize(0, 0);
			}
		});

		Button button2 = new Button(shell, SWT.PUSH);
		button2.setText("Set size to 50,50");
		button2.addSelectionListener(new SelectionAdapter()
		{
			@Override
			public void widgetSelected(SelectionEvent e)
			{
				canvas1.setSize(50, 50);
				canvas2.setSize(50, 50);
			}
		});

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

	public static NewtCanvasSWT init(Composite parent, final boolean applyFix)
	{
		GLCapabilities caps = new GLCapabilities(GLProfile.get(GLProfile.GL2));
		final GLWindow glWindow = GLWindow.create(caps);
		NewtCanvasSWT canvas = new NewtCanvasSWT(parent, SWT.NONE, glWindow)
		{
			@Override
			public void setSize(int width, int height)
			{
				//do not allow a size of 0,0, because NEWT window becomes invisible (https://jogamp.org/bugzilla/show_bug.cgi?id=822)
				if (applyFix)
				{
					super.setSize(Math.max(1, width), Math.max(1, height));
				}
				else
				{
					super.setSize(width, height);
				}
			}
		};

		glWindow.addGLEventListener(new MyGlEventListener());

		Animator animator = new Animator(glWindow);
		animator.setUpdateFPSFrames(1, null);
		animator.start();

		return canvas;
	}

	/**
	 * GLEventListener which draws a spinning torus. From
	 * https://github.com/sgothel
	 * /jogl-demos/blob/master/src/demos/swt/Snippet209.java.
	 */
	private static class MyGlEventListener implements GLEventListener
	{
		private int rot = 0;

		@Override
		public void init(GLAutoDrawable drawable)
		{
			GL2 gl = drawable.getGL().getGL2();
			gl.setSwapInterval(1);
			gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
			gl.glColor3f(1.0f, 0.0f, 0.0f);
			gl.glHint(GL2.GL_PERSPECTIVE_CORRECTION_HINT, GL2.GL_NICEST);
			gl.glClearDepth(1.0);
			gl.glLineWidth(2);
			gl.glEnable(GL2.GL_DEPTH_TEST);
		}

		@Override
		public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height)
		{
			float fAspect = (float) width / (float) height;
			GL2 gl = drawable.getGL().getGL2();
			gl.glViewport(0, 0, width, height);
			gl.glMatrixMode(GL2.GL_PROJECTION);
			gl.glLoadIdentity();
			GLU glu = new GLU();
			glu.gluPerspective(45.0f, fAspect, 0.5f, 400.0f);
			gl.glMatrixMode(GL2.GL_MODELVIEW);
			gl.glLoadIdentity();
		}

		@Override
		public void display(GLAutoDrawable drawable)
		{
			GL2 gl = drawable.getGL().getGL2();
			gl.glClear(GL2.GL_COLOR_BUFFER_BIT | GL2.GL_DEPTH_BUFFER_BIT);
			gl.glClearColor(.3f, .5f, .8f, 1.0f);
			gl.glLoadIdentity();
			gl.glTranslatef(0.0f, 0.0f, -10.0f);
			gl.glRotatef(0.15f * rot, 2.0f * rot, 10.0f * rot, 1.0f);
			gl.glRotatef(0.3f * rot, 3.0f * rot, 1.0f * rot, 1.0f);
			rot++;
			gl.glPolygonMode(GL2.GL_FRONT_AND_BACK, GL2.GL_LINE);
			gl.glColor3f(0.9f, 0.9f, 0.9f);
			drawTorus(gl, 1, 1.9f + ((float) Math.sin((0.004f * rot))), 15, 15);
		}

		@Override
		public void dispose(GLAutoDrawable drawable)
		{
		}

		protected 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(GL2.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;
			}
		}
	}
}