嗯，猜猜我可能需要一些帮助。我是JOGL的新手，我试图在3D画布上画任何东西，但重点是使用鼠标拖动事件。知道我怎么能这样做？
我尝试下面的东西，但没有成功。 而且在下面的代码中，我不明白为什么display（）方法在被调用之前被调用了。
提前多多感谢..
package Testing.Drawing;
import java.awt.event.*;
import java.awt.*;
import javax.swing.JFrame;
import javax.media.opengl.*;
import javax.media.opengl.glu.*;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.universe.*;
public class TestDraw2
extends JFrame
implements GLEventListener, KeyListener,MouseListener, MouseMotionListener
{
private GLCapabilities caps;
private GLCanvas canvas;
private float rotAngle = 0f;
private boolean rotate = false;
public TestDraw2()
{
super("TestDraw2");
caps = new GLCapabilities();
canvas = new GLCanvas(caps);
canvas.addGLEventListener(this);
canvas.addKeyListener(this);
// canvas.addMouseListener(this);
//canvas.addMouseMotionListener(this);
setVisible(true);
//this.getContentPane().add(canvas);
}
public void run()
{
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(512, 512);
setLocationRelativeTo(null);
this.getContentPane().add(canvas);
canvas.requestFocusInWindow();
}
float mouse_x = 0.0f;
float mouse_y = 0.0f;
public static void main(String[] args)
{
new TestDraw2().run();
}
final double PI = Math.PI;
final double PI_2 = PI / 2;
final double sin(double i) {
return Math.sin(i);
}
final double cos(double i) {
return Math.cos(i);
}
public void init(GLAutoDrawable drawable)
{
GL gl = drawable.getGL();
drawable.addKeyListener(this);
drawable.addMouseListener(this);
drawable.addMouseMotionListener(this);
//
float values[] = new float[2];
gl.glGetFloatv(GL.GL_LINE_WIDTH_GRANULARITY, values, 0);
System.out.println("GL.GL_LINE_WIDTH_GRANULARITY value is " + values[0]);
gl.glGetFloatv(GL.GL_LINE_WIDTH_RANGE, values, 0);
System.out.println("GL.GL_LINE_WIDTH_RANGE values are " + values[0] + ", "
+ values[1]);
gl.glEnable(GL.GL_LINE_SMOOTH);
gl.glEnable(GL.GL_BLEND);
gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE_MINUS_SRC_ALPHA);
gl.glHint(GL.GL_LINE_SMOOTH_HINT, GL.GL_DONT_CARE);
gl.glLineWidth(1.5f);
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
}
public void display(GLAutoDrawable drawable)
{
//draw(drawable);
/*GL gl = drawable.getGL();
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glColor3f(0.0f, 1.0f, 0.0f);
gl.glPushMatrix();
gl.glRotatef(-rotAngle, 0.0f, 0.0f, 0.1f);
gl.glBegin(GL.GL_LINES);
gl.glVertex2f(-0.5f, 0.5f);
gl.glVertex2f(0.5f, -0.5f);
gl.glEnd();
gl.glPopMatrix();
gl.glColor3f(0.0f, 0.0f, 1.0f);
gl.glPushMatrix();
gl.glRotatef(rotAngle, 0.0f, 0.0f, 0.1f);
gl.glBegin(GL.GL_LINES);
gl.glVertex2f(0.5f, 0.5f);
gl.glVertex2f(-0.5f, -0.5f);
gl.glEnd();
gl.glPopMatrix();
gl.glFlush();
if (rotate) rotAngle += 1f;
if (rotAngle >= 360f) rotAngle = 0f;*/
GL gl = drawable.getGL();
//gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glColor3f(0.0f, 1.0f, 0.0f);
gl.glPushMatrix();
//gl.glRotatef(-rotAngle, 0.0f, 0.0f, 0.1f)
gl.glTranslatef(mouse_x, mouse_y,0.1f);
// gl.glRasterPos2f(mouse_x, mouse_y);
//gl.glDrawPixels(gl.GL_CURRENT_RASTER_POSITION);
gl.glBegin(GL.GL_POINTS);
System.out.println("start values of x,y are: "+mouse_x+", "+mouse_y);
gl.glVertex2f(mouse_x, mouse_y);
//gl.glVertex2f(0.5f, -0.5f);
gl.glEnd();
gl.glPopMatrix();
gl.glFlush();
}
public void draw(){
canvas.display();
}
public void reshape(GLAutoDrawable drawable, int x, int y, int w, int h)
{
GL gl = drawable.getGL();
GLU glu = new GLU();
gl.glViewport(0, 0, w, h);
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();
if (w <= h) //
glu.gluOrtho2D(-1.0, 1.0, -1.0 * (float) h / (float) w, //
1.0 * (float) h / (float) w);
else glu.gluOrtho2D(-1.0 * (float) w / (float) h, //
1.0 * (float) w / (float) h, -1.0, 1.0);
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.getKeyCode()) {
case KeyEvent.VK_ESCAPE:
System.exit(0);
case KeyEvent.VK_R:
rotate = !rotate;
canvas.display();
default:
break;
}
}
public void keyReleased(KeyEvent key)
{
}
//////////////////////////////////////////////////////////////////////
// Mouse events
// Do-nothing methods, but required nonetheless
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
public void mousePressed(MouseEvent e) {
}
public void mouseReleased(MouseEvent e) {
}
public void mouseClicked(MouseEvent e) {
}
// Mouse event called when mouse button is pressed and moved
public void mouseDragged(MouseEvent e) {
// float x = e.getX();
// float y = e.getY();
// Button 1 pressed
if ((e.getModifiers() & e.BUTTON1_MASK) != 0){
mouse_x = e.getX();
mouse_y = e.getY();
draw();
}
/* if ((e.getModifiers() & e.BUTTON1_MASK) != 0) {
camera_yaw += angle_sensitivity * (double) (mouse_x - x);
if (camera_yaw > PI) {
camera_yaw -= 2.0 * PI;
} else if (camera_yaw < -PI) {
camera_yaw += 2.0 * PI;
}
camera_pitch += angle_sensitivity * (double) (y - mouse_y);
if (camera_pitch > PI_2) {
camera_pitch = PI_2;
} else if (camera_pitch < -PI_2) {
camera_pitch = -PI_2;
}
}*/
// Button 2 pressed: change position
/*if ((e.getModifiers() & e.BUTTON2_MASK) != 0) {
camera_x += dist_sensitivity * (double) (y - mouse_y)
* cos (camera_yaw) * cos (camera_pitch);
camera_y += dist_sensitivity * (double) (y - mouse_y)
* sin (camera_yaw) * cos (camera_pitch);
camera_z += dist_sensitivity * (double) (y - mouse_y)
* sin (camera_pitch);
}/*
// Button 3 pressed: rotate scene
/* if ((e.getModifiers() & e.BUTTON3_MASK) != 0) {
scene_yaw += angle_sensitivity * (double) (x - mouse_x);
if (scene_yaw > PI) {
scene_yaw -= 2.0 * PI;
} else if (scene_yaw < -PI) {
scene_yaw += 2.0 * PI;
}
scene_pitch += angle_sensitivity * (double) (y - mouse_y);
if (scene_pitch > PI) {
scene_pitch -= 2.0 * PI;
} else if (scene_pitch < -PI) {
scene_pitch += 2.0 * PI;
}
}*/
}
// Passive motion callback to capture mouse movements while buttons
// are not pressed
public void mouseMoved(MouseEvent e) {
// Update mouse position
// mouse_x = e.getX();
//mouse_y = e.getY();
}
}