import java.applet.Applet;
import java.awt.Graphics;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;

// must import jgl.GL....
import jgl.GL;
import jgl.GLAUX;

public class texgen extends Applet
		    implements ComponentListener {
    // must use GL to use jGL.....
    // and use GLAUX to use the aux functions.....
    // remember to give GL to initialize GLAUX
    GL myGL = new GL ();
    GLAUX myAUX = new GLAUX (myGL);

    private static final int stripeImageWidth = 32;
    private byte stripeImage[][] = new byte [stripeImageWidth][3];

    private void makeStripeImage () {
	int j;

	for (j = 0; j < stripeImageWidth; j++) {
	    if (j<=4) stripeImage[j][0] = (byte)255;
	    else      stripeImage[j][0] = (byte)0;
	    if (j> 4) stripeImage[j][1] = (byte)255;
	    else      stripeImage[j][1] = (byte)0;
	    stripeImage[j][2] = 0;
	}
    }

    /* glTexGen stuff: */
    float sgenparams[] = {1.0f, 1.0f, 1.0f, 0.0f};

    private void myinit () {
	myGL.glClearColor (0.0f, 0.0f, 0.0f, 0.0f);

	makeStripeImage();
	myGL.glPixelStorei(GL.GL_UNPACK_ALIGNMENT, 1);
	myGL.glTexEnvf(GL.GL_TEXTURE_ENV, GL.GL_TEXTURE_ENV_MODE, GL.GL_MODULATE);
	myGL.glTexParameterf(GL.GL_TEXTURE_1D, GL.GL_TEXTURE_WRAP_S, GL.GL_REPEAT);
	myGL.glTexParameterf(GL.GL_TEXTURE_1D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_LINEAR);
	myGL.glTexParameterf(GL.GL_TEXTURE_1D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR);
	myGL.glTexImage1D(GL.GL_TEXTURE_1D, 0, 3, stripeImageWidth, 0,
                 GL.GL_RGB, GL.GL_UNSIGNED_BYTE, stripeImage);

	myGL.glTexGeni(GL.GL_S, GL.GL_TEXTURE_GEN_MODE, GL.GL_OBJECT_LINEAR);
	myGL.glTexGenfv(GL.GL_S, GL.GL_OBJECT_PLANE, sgenparams);

	myGL.glEnable (GL.GL_DEPTH_TEST);
	myGL.glDepthFunc (GL.GL_LESS);
	myGL.glEnable (GL.GL_TEXTURE_GEN_S);
	myGL.glEnable (GL.GL_TEXTURE_1D);
	myGL.glEnable (GL.GL_CULL_FACE);
	myGL.glEnable (GL.GL_LIGHTING);
	myGL.glEnable (GL.GL_LIGHT0);
	myGL.glEnable (GL.GL_AUTO_NORMAL);
	myGL.glEnable (GL.GL_NORMALIZE);
	myGL.glFrontFace (GL.GL_CW);
	myGL.glCullFace (GL.GL_BACK);
	myGL.glMaterialf (GL.GL_FRONT, GL.GL_SHININESS, 64.0f);
    }

    private void display () {
	myGL.glClear (GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
	myGL.glPushMatrix ();
	myGL.glRotatef (45.0f, 0.0f, 0.0f, 1.0f);
	myAUX.auxSolidTeapot (2.0);
	myGL.glPopMatrix ();
	myGL.glFlush();
    }

    private void myReshape (int w, int h) {
        myGL.glViewport (0, 0, w, h);
        myGL.glMatrixMode (GL.GL_PROJECTION);
        myGL.glLoadIdentity ();
        if (w <= h) {
            myGL.glOrtho (-3.5f, 3.5f,
			  -3.5f*(float)h/(float)w, 
			   3.5f*(float)h/(float)w, 
			  -3.5f, 3.5f);
        } else {
            myGL.glOrtho (-3.5f*(float)w/(float)h,
			   3.5f*(float)w/(float)h,
			  -3.5f, 3.5f,
			  -3.5f, 3.5f);
        }
        myGL.glMatrixMode (GL.GL_MODELVIEW);
        myGL.glLoadIdentity ();
    }

    public void componentMoved (ComponentEvent e) {}
    public void componentShown (ComponentEvent e) {}
    public void componentHidden (ComponentEvent e) {}

    public void componentResized (ComponentEvent e) {
        // get window width and height by myself
        myReshape (getSize ().width, getSize ().height);
        display ();
        repaint ();
    }

    public void update (Graphics g) {
    	// skip the clear screen command....
	paint (g);
    }

    public void paint (Graphics g) {
	myGL.glXSwapBuffers (g, this);
    }

    public void init () {
	myAUX.auxInitPosition (0, 0, 200, 200);
	myAUX.auxInitWindow (this);
	myinit ();

	// as call auxReshapeFunc()
        addComponentListener (this);
        myReshape (getSize ().width, getSize ().height);

        // call display as call auxIdleFunc(display)
	display ();
    }

}