GLTest.java

import java.awt.BorderLayout;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.media.opengl.GL;
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.awt.GLJPanel;
import javax.media.opengl.glu.GLU;
import javax.swing.JFrame;

public class GLTest {

	public static void main(String[] args) {
		GLProfile glprofile = GLProfile.getDefault();
		GLCapabilities glcapabilities = new GLCapabilities(glprofile);
		// glcapabilities.setAlphaBits(1);
		System.out.println(glcapabilities);
		final GLJPanel gljpanel = new GLJPanel(glcapabilities);

        gljpanel.addGLEventListener(new GLEventListener() {

			@Override
			public void reshape(GLAutoDrawable glautodrawable, int x, int y,
					int width, int height) {
				OneTriangle.setup(glautodrawable.getGL().getGL2(), width,
						height);
				System.out.println(gljpanel.getChosenGLCapabilities());
			}

			@Override
			public void init(GLAutoDrawable glautodrawable) {
			}

			@Override
			public void dispose(GLAutoDrawable glautodrawable) {
			}

			@Override
			public void display(GLAutoDrawable glautodrawable) {
				OneTriangle.render(glautodrawable.getGL().getGL2(),
						glautodrawable.getWidth(), glautodrawable.getHeight());
			}
		});

		final JFrame jframe = new JFrame("One Triangle Swing GLJPanel");
		jframe.addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent windowevent) {
				jframe.dispose();
				System.exit(0);
			}
		});

		jframe.getContentPane().add(gljpanel, BorderLayout.CENTER);
		jframe.setSize(640, 480);
		jframe.setVisible(true);
	}

	private static class OneTriangle {
		protected static void setup(GL2 gl2, int width, int height) {
			gl2.glMatrixMode(GL2.GL_PROJECTION);
			gl2.glLoadIdentity();

			// coordinate system origin at lower left with width and height same
			// as the window
			GLU glu = new GLU();
			glu.gluOrtho2D(0.0f, width, 0.0f, height);

			gl2.glMatrixMode(GL2.GL_MODELVIEW);
			gl2.glLoadIdentity();

			gl2.glViewport(0, 0, width, height);
		}

		protected static void render(GL2 gl2, int width, int height) {
			gl2.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

			// draw a triangle filling the window
			gl2.glLoadIdentity();
			gl2.glBegin(GL.GL_TRIANGLES);
			gl2.glColor3f(1, 0, 0);
			gl2.glVertex2f(0, 0);
			gl2.glColor3f(0, 1, 0);
			gl2.glVertex2f(width, 0);
			gl2.glColor3f(0, 0, 1);
			gl2.glVertex2f(width / 2, height);
			gl2.glEnd();
		}
	}

}