package glredbook10;
import java.awt.event.*;
import javax.swing.*;
import java.nio.*;
import javax.media.opengl.*;
import javax.media.opengl.glu.*;
import com.sun.opengl.util.*;
/**
* This program uses evaluators to draw a Bezier curve.
*
* @author Kiet Le (Java conversion)
*/
public class bezcurve
extends JFrame
implements GLEventListener, KeyListener
{
private GLU glu;
private GLUT glut;
private GLCapabilities caps;
private GLCanvas canvas;
private float ctrlpoints[][] = new float[][]
{
{ -4.0f, -4.0f, 0.0f },
{ -2.0f, 4.0f, 0.0f },
{ 2.0f, -4.0f, 0.0f },
{ 4.0f, 4.0f, 0.0f } };
private FloatBuffer ctrlpointBuf = //
FloatBuffer.allocate(ctrlpoints[0].length * ctrlpoints.length);
public bezcurve()
{
super("bezcurve");
caps = new GLCapabilities();
canvas = new GLCanvas(caps);
canvas.addGLEventListener(this);
canvas.addKeyListener(this);
getContentPane().add(canvas);
}
public void run()
{
setSize(500, 500);
setLocationRelativeTo(null);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
canvas.requestFocusInWindow();
}
public static void main(String[] args)
{
new bezcurve().run();
}
public void init(GLAutoDrawable drawable)
{
GL gl = drawable.getGL();
glu = new GLU();
glut = new GLUT();
// need to convert 2d array to buffer type
for (int i = 0; i < ctrlpoints.length; i++)
{
for (int j = 0; j < 3; j++)
{
ctrlpointBuf.put(ctrlpoints[i][j]);
}
}
ctrlpointBuf.rewind();
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
gl.glShadeModel(GL.GL_FLAT);
gl.glMap1f(GL.GL_MAP1_VERTEX_3, 0.0f, 1.0f, 3, 4, ctrlpointBuf);
gl.glEnable(GL.GL_MAP1_VERTEX_3);
}
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.glBegin(GL.GL_LINE_STRIP);
for (int i = 0; i <= 30; i++)
{
gl.glEvalCoord1f((float) i / (float) 30.0);
}
gl.glEnd();
/* The following code displays the control points as dots. */
gl.glPointSize(5.0f);
gl.glColor3f(1.0f, 1.0f, 0.0f);
gl.glBegin(GL.GL_POINTS);
for (int i = 0; i < 4; i++)
{
gl.glVertex3fv(ctrlpointBuf);
ctrlpointBuf.position(i * 3);
}
gl.glEnd();
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();
if (w <= h) //
gl.glOrtho(-5.0, 5.0, -5.0 * (float) h / (float) w, //
5.0 * (float) h / (float) w, -5.0, 5.0);
else gl.glOrtho(-5.0 * (float) w / (float) h, //
5.0 * (float) w / (float) h,//
-5.0, 5.0, -5.0, 5.0);
gl.glMatrixMode(GL.GL_MODELVIEW);
gl.glLoadIdentity();
}
public void displayChanged(GLAutoDrawable drawable, boolean modeChanged,
boolean deviceChanged)
{
}
public void keyTyped(KeyEvent key)
{
}
public void keyPressed(KeyEvent key)
{
switch (key.getKeyChar()) {
case KeyEvent.VK_ESCAPE:
System.exit(0);
break;
default:
break;
}
}
public void keyReleased(KeyEvent key)
{
}
}
|
Other API Tips 
You can share your information about this topic using the form below!
Please do not post your questions with this form! Thanks.