import java.util.HashSet;
import java.util.Set;

import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.opengl.GL;
import org.eclipse.swt.opengl.GLCanvas;
import org.eclipse.swt.opengl.GLFormatData;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GLContext;
import org.lwjgl.opengl.glu.GLU;

public class GLTest {

	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;
		float cosTheta = 1.0f;
		float 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) {
		Display display = new Display();
		Shell shell = new Shell(display);
		FillLayout layout = new FillLayout();
		layout.marginWidth = layout.marginHeight = 20;
		shell.setLayout(layout);
		GLFormatData data = new GLFormatData ();
		GLCanvas canvas = new GLCanvas(shell, SWT.NONE, data);
		GLCanvas canvas2 = new GLCanvas(shell, SWT.NONE, data);
		int xrot = 0, yrot = 0;
		int width = 640, height = 480;
		float fAspect = (float) width / (float) height;

		canvas.setCurrent();
		try {
        		org.lwjgl.opengl.GLContext.useContext(canvas);
        } catch(Exception e) {
        		e.printStackTrace();
        }

		GL11.glViewport(0, 0, width, height);
		GL11.glMatrixMode(GL11.GL_PROJECTION);	// select the projection matrix
		GL11.glLoadIdentity();				// reset the projection matrix
		GLU.gluPerspective(45.0f, fAspect, 0.5f, 400.0f);
		GL11.glMatrixMode(GL11.GL_MODELVIEW);	// select the modelview matrix
		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);
		
		canvas2.setCurrent();
		try {
        		org.lwjgl.opengl.GLContext.useContext(canvas2);
        } catch(Exception e) {
        		e.printStackTrace();
        }

		GL11.glViewport(0, 0, width, height);
		GL11.glMatrixMode(GL11.GL_PROJECTION);	// select the projection matrix
		GL11.glLoadIdentity();				// reset the projection matrix
		GLU.gluPerspective(45.0f, fAspect, 0.5f, 400.0f);
		GL11.glMatrixMode(GL11.GL_MODELVIEW);	// select the modelview matrix
		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);

		shell.setSize(640, 480);
		shell.open();
		while(!shell.isDisposed()) {
			width = 40; height = 40; int depth = 40;
			canvas.setCurrent();
			try {
				org.lwjgl.opengl.GLContext.useContext(canvas);
			} catch(Exception e) {
				e.printStackTrace();
			}
			GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
			GL11.glClearColor(.3f, .5f, .8f, 1.0f);
			GL11.glLoadIdentity();
			GL11.glTranslatef(0.0f, 0.0f, -10.0f);
			GL11.glRotatef(0.15f * xrot, 2.0f * ((float) xrot), 10.0f * ((float) yrot), 1.0f);
			GL11.glRotatef(0.3f * yrot, 3.0f * ((float) xrot), 1.0f * ((float) yrot), 1.0f);
			xrot++; yrot++;
			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 * xrot))), 15, 15);
			canvas.swapBuffers();
			
			canvas2.setCurrent();
			try {
				org.lwjgl.opengl.GLContext.useContext(canvas2);
			} catch(Exception e) {
				e.printStackTrace();
			}
			GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
			GL11.glClearColor(.8f, .5f, .3f, 1.0f);
			GL11.glLoadIdentity();
			GL11.glTranslatef(0.0f, 0.0f, -10.0f);
			GL11.glRotatef(0.15f * xrot, 2.0f * ((float) xrot), 10.0f * ((float) yrot), 1.0f);
			GL11.glRotatef(0.3f * yrot, 3.0f * ((float) xrot), 1.0f * ((float) yrot), 1.0f);
			xrot++; yrot++;
			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 * xrot))), 15, 15);
			canvas2.swapBuffers();

			while (display.readAndDispatch());
//			display.sleep();
		}
		display.dispose();
	}
}