I have implemented a picking in my application, using the GLCanvas, and calling display.
I try to change with a GLJPanel, but the picking doesn’t wotk any more.
The problem seem to be, calling display on GLJPanel, doesn’t call the display of the listener.
What’s the solution ?
Could be a bug in the GLJPanel implementation. Could you post some code or file a bug and attach a test case?
Hi,
I just use the Picking code, and update it.
The problem is calling display on GLJPanel, will call asyncronously display.
Using GLCanvas we have:
call display before
in display
in display out
call display after
With GLJPanel we have:
call display before
call display after
in display
in display out
The sample code:
package com.type3.osg.render.jogl.test;
//=================================================================================
// Picking 0.2 (Thomas Bladh)
//=================================================================================
// A simple picking example using java/jogl. This is far from a complete solution
// but it should give you an idea of how to include picking in your assigment
// solutions.
//
// Notes: * Based on example 13-3 (p 542) in the “OpenGL Programming Guide”
// * This version should handle overlapping objects correctly.
//---------------------------------------------------------------------------------
import java.awt.;
import java.awt.event.;
import java.awt.Canvas.;
import java.util.;
import net.java.games.jogl.*;
import java.nio.ByteOrder;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
public class Picking
{
// Change to GLCanvas, GLJPanel...
// boolean mbUseGLJPanel = false;
boolean mbUseGLJPanel = true;
public static void main(String[] args)
{
new Picking();
}
public static GLDrawable drawable = null;
Picking()
{
Frame frame = new Frame("Picking Example");
GLDrawableFactory factory = GLDrawableFactory.getFactory();
GLCapabilities capabilities = new GLCapabilities();
if (mbUseGLJPanel)
drawable = factory.createGLJPanel(capabilities);
else drawable = factory.createGLCanvas(capabilities);
drawable.addGLEventListener(new Renderer());
drawable.setNoAutoRedrawMode(false);
frame.add( (Component)drawable);
frame.setSize(400, 400);
// final Animator animator = new Animator(drawable);
frame.addWindowListener(new WindowAdapter()
{
public void windowClosing(WindowEvent e)
{
// animator.stop();
System.exit(0);
}
});
frame.show();
// animator.start();
}
static class Renderer implements GLEventListener, MouseListener, MouseMotionListener
{
static final int NOTHING = 0, UPDATE = 1, SELECT = 2;
int cmd = UPDATE;
int mouse_x, mouse_y;
private GL gl;
private GLU glu;
private GLDrawable gldrawable;
public void init(GLDrawable drawable)
{
gl = drawable.getGL();
glu = drawable.getGLU();
this.gldrawable = drawable;
gl.glEnable(GL.GL_CULL_FACE);
gl.glEnable(GL.GL_DEPTH_TEST);
gl.glEnable(GL.GL_NORMALIZE);
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
drawable.addMouseListener(this);
drawable.addMouseMotionListener(this);
}
public void reshape(GLDrawable drawable, int x, int y, int width, int height)
{
float h = (float)height / (float)width;
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glLoadIdentity();
glu.gluOrtho2D(0.0f, 1.0f, 0.0f, 1.0f);
}
public void display(GLDrawable drawable)
{
System.err.println(“in display”);
switch (cmd)
{
case UPDATE:
drawScene();
break;
case SELECT:
int buffsize = 512;
double x = (double)mouse_x, y = (double)mouse_y;
int[] viewPort = new int[4];
int hits = 0;
IntBuffer selectBuffer = null;
ByteBuffer myBB = ByteBuffer.allocateDirect(buffsize*4);
myBB.order(ByteOrder.nativeOrder());
selectBuffer = myBB.asIntBuffer();
gl.glGetIntegerv(GL.GL_VIEWPORT, viewPort);
gl.glSelectBuffer(buffsize, selectBuffer);
gl.glRenderMode(GL.GL_SELECT);
gl.glInitNames();
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glPushMatrix();
gl.glLoadIdentity();
glu.gluPickMatrix(x, (double)viewPort[3] - y, 5.0d, 5.0d, viewPort);
glu.gluOrtho2D(0.0d, 1.0d, 0.0d, 1.0d);
drawScene();
gl.glMatrixMode(GL.GL_PROJECTION);
gl.glPopMatrix();
gl.glFlush();
hits = gl.glRenderMode(GL.GL_RENDER);
processHits(hits, selectBuffer);
cmd = UPDATE;
break;
}
System.err.println(“in display out”);
}
public void processHits(int hits, IntBuffer buffer)
{
System.out.println("---------------------------------");
System.out.println(" HITS: " + hits);
int offset = 0;
int names;
float z1, z2;
for (int i = 0; i < hits; i++)
{
System.out.println("- - - - - - - - - - - -");
System.out.println(" hit: " + (i + 1));
names = buffer.get(offset);
offset++;
z1 = (float)buffer.get(offset) / 0x7fffffff;
offset++;
z2 = (float)buffer.get(offset) / 0x7fffffff;
offset++;
System.out.println(" number of names: " + names);
System.out.println(" z1: " + z1);
System.out.println(" z2: " + z2);
System.out.println(" names: ");
for (int j = 0; j < names; j++)
{
System.out.print(" " + buffer.get(offset));
if (j == (names - 1))
{
System.out.println("<-");
}
else
{
System.out.println();
}
offset++;
}
System.out.println("- - - - - - - - - - - -");
}
System.out.println("---------------------------------");
}
public int viewPortWidth()
{
int[] viewPort = new int[4];
gl.glGetIntegerv(GL.GL_VIEWPORT, viewPort);
return viewPort[2];
}
public int viewPortHeight()
{
int[] viewPort = new int[4];
gl.glGetIntegerv(GL.GL_VIEWPORT, viewPort);
return viewPort[3];
}
public void drawScene()
{
gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
// Colors
float red[] =
{
1.0f, 0.0f, 0.0f, 1.0f};
float green[] =
{
0.0f, 1.0f, 0.0f, 1.0f};
float blue[] =
{
0.0f, 0.0f, 1.0f, 1.0f};
// Red rectangle
GLRectangleEntity r1 = new GLRectangleEntity(gl, glu);
r1.x = 0.15f;
r1.y = 0.25f;
r1.w = 0.4f;
r1.h = 0.4f;
r1.c = red;
r1.id = 10;
r1.draw();
// Green rectangle
GLRectangleEntity r2 = new GLRectangleEntity(gl, glu);
r2.x = 0.35f;
r2.y = 0.45f;
r2.w = 0.4f;
r2.h = 0.4f;
r2.c = green;
r2.id = 20;
r2.draw();
// Blue rectangle
GLRectangleEntity r3 = new GLRectangleEntity(gl, glu);
r3.x = 0.45f;
r3.y = 0.15f;
r3.w = 0.4f;
r3.h = 0.4f;
r3.c = blue;
r3.id = 30;
r3.draw();
gl.glFlush();
}
public void displayChanged(GLDrawable drawable, boolean modeChanged, boolean deviceChanged)
{}
public void mousePressed(MouseEvent e)
{
cmd = SELECT;
mouse_x = e.getX();
mouse_y = e.getY();
// call to do the pick
System.err.println("call display before");
drawable.display();
System.err.println("call display after");
}
public void mouseEntered(MouseEvent e)
{}
public void mouseExited(MouseEvent e)
{}
public void mouseReleased(MouseEvent e)
{}
public void mouseClicked(MouseEvent e)
{}
public void mouseDragged(MouseEvent e)
{}
public void mouseMoved(MouseEvent e)
{}
public abstract class GLEntity
{
float x, y, z;
float[] c;
int id = 0;
boolean outline = false;
GL gl;
GLU glu;
public GLEntity(GL gl, GLU glu)
{
this.gl = gl;
this.glu = glu;
}
public void draw()
{
gl.glPushName(id);
_draw();
}
public abstract void _draw();
}
public class GLRectangleEntity extends GLEntity
{
float w = 0.1f;
float h = 0.1f;
public GLRectangleEntity(GL gl, GLU glu)
{
super(gl, glu);
}
public void _draw()
{
if (outline)
{
gl.glPolygonMode(GL.GL_FRONT, GL.GL_LINE);
}
else
{
gl.glPolygonMode(GL.GL_FRONT, GL.GL_FILL);
}
gl.glColor4fv(c);
gl.glBegin(GL.GL_POLYGON);
gl.glVertex3f(x, y, z);
gl.glVertex3f(x + w, y, z);
gl.glVertex3f(x + w, y + h, z);
gl.glVertex3f(x, y + h, z);
gl.glEnd();
}
}
}
}
You’re right, the GLJPanel display() implementation wasn’t obeying its specification. When called from the AWT event queue thread, it was scheduling a repaint rather than performing the work immediately; I hadn’t known until now how to do this correctly. I’ve checked a change to JOGL’s CVS repository to fix this; it will be present in the next JOGL beta, or you can take an update and rebuild your own source tree. Thanks for pointing out this problem.