*How to use glCallLists in jogl<转>

package glredbook10;

/**

* This program demonstrates some characters of a stroke (vector) font. The

* characters are represented by display lists, which are given numbers which

* correspond to the ASCII values of the characters. Use of glCallLists() is

* demonstrated.

* @author Kiet Le (Java port)

import java.awt.event.*;

import javax.swing.*;

import java.nio.*;

import javax.media.opengl.*;

import javax.media.opengl.glu.*;

import com.sun.opengl.util.*;

public class stroke

extends JFrame

implements GLEventListener, KeyListener

{

private GLU glu;

private GLCapabilities caps;

private GLCanvas canvas;

private static final int PT = 1;

private static final int STROKE = 2;

private static final int END = 3;

// * C struct. Compare this to charpoint class.

// typedef struct charpoint

// {

// GLfloat x, y;

// int type;

// } CP;

private class charpoint

{

public float x;

public float y;

public int type;

public charpoint(float x, float y, int type)

{

this.x = x;

this.y = y;

this.type = type;

}

// * Saved here from original for you to see the difference

// CP Adata[] =

// {

// { 0, 0, PT}, {0, 9, PT}, {1, 10, PT}, {4, 10, PT},

// {5, 9, PT}, {5, 0, STROKE}, {0, 5, PT}, {5, 5, END}

// };

charpoint Adata[] =

{ new charpoint(0, 0, PT), new charpoint(0, 9, PT), //

new charpoint(1, 10, PT), new charpoint(4, 10, PT),//

new charpoint(5, 9, PT), new charpoint(5, 0, STROKE),//

new charpoint(0, 5, PT), new charpoint(5, 5, END) };

charpoint Edata[] =

{ new charpoint(5, 0, PT), new charpoint(0, 0, PT), //

new charpoint(0, 10, PT), new charpoint(5, 10, STROKE),//

new charpoint(0, 5, PT), new charpoint(4, 5, END) };

charpoint Pdata[] =

{ new charpoint(0, 0, PT), new charpoint(0, 10, PT),//

new charpoint(4, 10, PT), new charpoint(5, 9, PT),//

new charpoint(5, 6, PT), new charpoint(4, 5, PT), //

new charpoint(0, 5, END) };

charpoint Rdata[] =

{ new charpoint(0, 0, PT), new charpoint(0, 10, PT),//

new charpoint(4, 10, PT), new charpoint(5, 9, PT),//

new charpoint(5, 6, PT), new charpoint(4, 5, PT),//

new charpoint(0, 5, STROKE), new charpoint(3, 5, PT),//

new charpoint(5, 0, END) };

charpoint Sdata[] =

{ new charpoint(0, 1, PT), new charpoint(1, 0, PT), //

new charpoint(4, 0, PT), new charpoint(5, 1, PT),//

new charpoint(5, 4, PT), new charpoint(4, 5, PT), //

new charpoint(1, 5, PT), new charpoint(0, 6, PT), //

new charpoint(0, 9, PT), new charpoint(1, 10, PT),//

new charpoint(4, 10, PT), new charpoint(5, 9, END) };

// char *test1 = "A SPARE SERAPE APPEARS AS"; C char ptr to str

// char *test2 = "APES PREPARE RARE PEPPERS";

private String test1 = "A SPARE SERAPE APPEARS AS";// String object

private String test2 = "APES PREPARE RARE PEPPERS";

public stroke()

{

super("stroke");

caps = new GLCapabilities();

canvas = new GLCanvas(caps);

canvas.addGLEventListener(this);

canvas.addKeyListener(this);

getContentPane().add(canvas);

}

public void run()

{

setSize(440, 120);

setLocationRelativeTo(null);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setVisible(true);

canvas.requestFocusInWindow();

}

public static void main(String[] args)

{

new stroke().run();

}

/* Create a display list for each of 6 characters */

public void init(GLAutoDrawable drawable)

{

GL gl = drawable.getGL();

glu = new GLU();

int base;

gl.glShadeModel(GL.GL_FLAT);

base = gl.glGenLists(128);

gl.glListBase(base);

gl.glNewList(base + 'A', GL.GL_COMPILE);

drawLetter(gl, Adata);

gl.glEndList();

gl.glNewList(base + 'E', GL.GL_COMPILE);

drawLetter(gl, Edata);

gl.glEndList();

gl.glNewList(base + 'P', GL.GL_COMPILE);

drawLetter(gl, Pdata);

gl.glEndList();

gl.glNewList(base + 'R', GL.GL_COMPILE);

drawLetter(gl, Rdata);

gl.glEndList();

gl.glNewList(base + 'S', GL.GL_COMPILE);

drawLetter(gl, Sdata);

gl.glEndList();

gl.glNewList(base + ' ', GL.GL_COMPILE);

gl.glTranslatef(8.0f, 0.0f, 0.0f);

gl.glEndList();

}

public void display(GLAutoDrawable drawable)

{

GL gl = drawable.getGL();

gl.glClear(GL.GL_COLOR_BUFFER_BIT);

gl.glColor3f(1.0f, 1.0f, 1.0f);

gl.glPushMatrix();

gl.glScalef(2.0f, 2.0f, 2.0f);

gl.glTranslatef(10.0f, 30.0f, 0.0f);

this.printStrokedString(gl, test1);

gl.glPopMatrix();

gl.glPushMatrix();

gl.glScalef(2.0f, 2.0f, 2.0f);

gl.glTranslatef(10.0f, 13.0f, 0.0f);

this.printStrokedString(gl, test2);

gl.glPopMatrix();

gl.glFlush();

}

public void reshape(GLAutoDrawable drawable, int x, int y, int w, int h)

{

GL gl = drawable.getGL();

gl.glViewport(0, 0, w, h);

gl.glMatrixMode(GL.GL_PROJECTION);

gl.glLoadIdentity();

glu.gluOrtho2D(0, w, 0, h);

gl.glMatrixMode(GL.GL_MODELVIEW);

gl.glLoadIdentity();

}

public void displayChanged(GLAutoDrawable drawable, boolean modeChanged,

boolean deviceChanged)

{

}

* interprets the instructions from the array for that letter and renders the

* letter with line segments.

private void drawLetter(GL gl, charpoint[] l)

{

int i = 0;

gl.glBegin(GL.GL_LINE_STRIP);

while (i < l.length)

{

switch (l[i].type) {

case PT:

gl.glVertex2f(l[i].x, l[i].y);

break;

case STROKE:

gl.glVertex2f(l[i].x, l[i].y);

gl.glEnd();

gl.glBegin(GL.GL_LINE_STRIP);

break;

case END:

gl.glVertex2f(l[i].x, l[i].y);

gl.glEnd();

gl.glTranslatef(8.0f, 0.0f, 0.0f);

return;

}

i++;// System.out.println(i+" ");

}

// private void printStrokedString(char *s)

private void printStrokedString(GL gl, String s)

{

int len = s.length();

ByteBuffer str = BufferUtil.newByteBuffer(len);

str.put(s.getBytes());

str.rewind();

gl.glCallLists(len, GL.GL_BYTE, str);

}

public void keyTyped(KeyEvent key)

{

}

public void keyPressed(KeyEvent key)

{

switch (key.getKeyCode()) {

case KeyEvent.VK_ESCAPE:

System.exit(0);

break;

default:

break;

}

public void keyReleased(KeyEvent key)

{

}