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[gl4java-usergroup] Trivial selection problem.
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From: R.M. L. <u8...@cs...> - 2002-02-27 17:01:21
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After having another attempt at picking i noticed something strange in
my applet. When you move the spheres with the arrow keys ( y
translation) and (x translation) or use the mouse zoom (z translation)
you are still able to click on the spheres and the crosshair will appear
as a test.
However, when you use the rotation and camera rotation feature the
program appears to lose track of the objects.
If anyone can help, they're welcome to try it out...
Left mouse button-pick, crosshair should appear on an object
Hold right mouse button, camera movements
Hold both buttons, y direction to zoom, x to rotate spheres.
PS, it uses MatrixFuncs.class from the jausoft demos
Thanks,
Mark.
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import java.applet.*;
import java.awt.*;
import java.awt.event.*;
//Gl4Java classes.
import gl4java.GLContext;
import gl4java.awt.GLAnimCanvas;//Constantly redraws canvas
import gl4java.utils.textures.*;
public class Windowt extends Applet {
renderCanvas canvas = null;
//Initialise applet
public void init() {
setLayout(new BorderLayout());//lays applet components out
canvas = new renderCanvas(getSize().width, getSize().height);
canvas.requestFocus();
add("Center", canvas);
}
//Begin the applet
public void start() {
canvas.start(); //Begins canvas animation
}
public void stop() {
canvas.stop();//stops the canvas
}
public void destroy() {
canvas.stop();
canvas.destroy();//destroys canvas
}
//NB put commas here
private class renderCanvas extends GLAnimCanvas implements
KeyListener,MouseListener, MouseMotionListener {
//Keys initially
//Putting in mouse
float xrot = 0.0f;//rotation for x and y
float yrot = 0.0f;
//Think about mouse x and y and the out of window calculations
//Make sure this works
private MatrixFuncs mFun = null;
private float rotation[] = {1.0f, 0.0f, 0.0f, 0.0f,
0.0f, 1.0f, 0.0f, 0.0f,
0.0f, 0.0f, 1.0f, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f};
float moveX = 0.0f;//For mouse movements, try as ints
float moveY = 0.0f;
float x = 0.0f;
float y = 0.0f;
float z = -8.0f;
public renderCanvas(int w, int h) {
super(w, h);
addKeyListener(this);//Key listener back in
addMouseListener(this);//Alter, will for mouse
addMouseMotionListener(this);
mFun = new MatrixFuncs();
}
public void preInit() {
//Understand this
doubleBuffer = true;
stereoView = false;
}
public void init() {
/*float[] ambient = {0.5f, 0.5f, 0.5f, 1.0f};
float[] diffuse = {1.0f, 1.0f, 1.0f, 1.0f};
float[] position = {0.0f, 0.0f, 2.0f, 1.0f};
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);//Clears colour, change
background
gl.glClearDepth(1.0);//Clear depth buffer
gl.glDepthFunc(GL_LESS);//Depth test
gl.glEnable(GL_DEPTH_TEST);//enable test of depth
gl.glShadeModel(GL_SMOOTH);//Smooth colour shading
gl.glMatrixMode(GL_PROJECTION);//Projection matrix
gl.glLoadIdentity();//Resets matrix
glu.gluPerspective(45.0f,
(float)getSize().width/(float)getSize().height, 0.1f, 100f);//Calculate
window aspect ratio
gl.glMatrixMode(GL_MODELVIEW);//Model view matrix
/*gl.glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
gl.glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
gl.glLightfv(GL_LIGHT0, GL_POSITION, position);//Put in later
gl.glEnable(GL_LIGHT0);
gl.glEnable(GL_LIGHTING);*/
}
public void destroy() {
cvsDispose();//Destroys GL context
}
public void reshape(int width, int height)
{
//Might need to change viewport for object selection???
gl.glViewport(0, 0 , width, height);//Reset viewport & perspective
gl.glMatrixMode(GL_PROJECTION);//select proj matrix
gl.glLoadIdentity();//reset proj matrix
glu.gluPerspective(45.0f,
(float)getSize().width/(float)getSize().height,0.1f, 100.0f);//Aspect
ratio of window
gl.glMatrixMode(GL_MODELVIEW);
gl.glLoadIdentity();
}
public void display() {//Draw to the canvas
//Changing to implement true camera...
if (glj.gljMakeCurrent(true)==false)
return;//Is GL initialised properly
gl.glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);//Clears
//screen & depth buffer
gl.glLoadIdentity();//Reset view
gl.glMultMatrixf(rotation);
gl.glTranslatef(0.0f, 0.0f, z);//Move into environment
gl.glTranslatef(x, 0.0f, 0.0f);//Strafe
gl.glTranslatef(0.0f, y, 0.0f);//Strafe
gl.glRotatef(xrot,0.0f,1.0f,0.0f);//Rotate on x axis
gl.glRotatef(yrot,1.0f,0.0f,0.0f);//Rotate y..swapped
drawLayout(GL_RENDER);
gl.glFlush();//Might not be necessary
gl.glEnd();
glj.gljSwap();//Swap buffers
glj.gljFree();
}
private void renderSphereRed(float x, float y, float z) {//Create
sphere
gl.glPushMatrix();
gl.glTranslatef(x,y,z);
long qobj = glu.gluNewQuadric();
glu.gluQuadricOrientation(qobj , GLU_OUTSIDE);
glu.gluQuadricNormals(qobj, GLU_SMOOTH);
gl.glColor3f(1.0f,0.0f,0.0f);//Red
glu.gluQuadricTexture(qobj, false);
glu.gluSphere(qobj, 0.4f, 16, 16);
glu.gluDeleteQuadric(qobj);
gl.glPopMatrix();
}
private void renderSphereYellow(float x, float y, float z)
{//Create sphere
gl.glPushMatrix();
gl.glTranslatef(x,y,z);
long qobj = glu.gluNewQuadric();
glu.gluQuadricOrientation(qobj , GLU_OUTSIDE);
glu.gluQuadricNormals(qobj, GLU_SMOOTH);
gl.glColor3f(1.0f, 1.0f, 0.0f);//Yellow
glu.gluQuadricTexture(qobj, false);
glu.gluSphere(qobj, 0.4f, 16, 16);
glu.gluDeleteQuadric(qobj);
gl.glPopMatrix();
}
private void renderSphereBlue(float x, float y, float z) {//Create
sphere
gl.glPushMatrix();
gl.glTranslatef(x,y,z);
long qobj = glu.gluNewQuadric();
glu.gluQuadricOrientation(qobj , GLU_OUTSIDE);
glu.gluQuadricNormals(qobj, GLU_SMOOTH);
gl.glColor3f(0.0f, 0.0f, 1.0f);//Blue
glu.gluQuadricTexture(qobj, false);
glu.gluSphere(qobj, 0.4f, 16, 16);
glu.gluDeleteQuadric(qobj);
gl.glPopMatrix();
}
void drawLayout(int mode) {//Check syntax
if (mode == GL_SELECT){
//Might put in draw methods
gl.glLoadName(1);
}
renderSphereRed(-2.0f, 1.0f, -1.0f);//Wrap bitmaps around
renderSphereBlue(2.0f, 2.0f, 2.0f);//Need morphing
operation
renderSphereYellow(2.0f, 4.0f, 5.0f);//?Name convertor
needed
gl.glEnd();
}
void processSelection(float moveX, float moveY) {
int BUFSIZE = 512;//May change size
int[] selectBuf = new int[BUFSIZE];
int hits;
int[] viewport = new int[4];
gl.glGetIntegerv(GL_VIEWPORT, viewport);
gl.glSelectBuffer(BUFSIZE, selectBuf);
gl.glRenderMode(GL_SELECT);//Select mode
gl.glInitNames();
gl.glPushName(-1);//Check implementation of stack
names
gl.glMatrixMode(GL_PROJECTION);
gl.glPushMatrix();
gl.glLoadIdentity();
glu.gluPickMatrix((float) moveX, (float) (viewport[3] -
moveY),5.0,5.0, viewport);//Size of pick cube, may change
//Check perspective matrix
glu.gluPerspective(45.0f,
(float)getSize().width/(float)getSize().height,0.1f, 100.0f);//Aspect
ratio of window
//Need drawLayout method
drawLayout(GL_SELECT);
gl.glPopMatrix();
gl.glFlush();
hits = gl.glRenderMode(GL_RENDER);
gl.glMatrixMode(GL_MODELVIEW);
if (hits > 0)
//Need process hits method
processHits(hits, selectBuf);
}
void processHits (int hits, int buffer[]) {
//Will have zoom and menu here
setCursor(
Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
/*glu.gluLookAt(0.0f, 0.0f, 0.0f);*/
/*objectZoom(moveX, moveY);*/
}
/*public void objectZoom(float moveX, float moveY) {
//Another picking operation, need reverse
//Zoom to where clicked..first attempt, see red book
//Check viewpoint
gl.glPushMatrix();
gl.glGetIntegerv(GL_VIEWPORT, viewport);
gl.glMatrixMode(GL_PROJECTION);
gl.glLoadIdentity();
glu.gluPickMatrix((double) moveX, (double) (viewport[3] -
moveY),5.0,5.0, viewport);
gl.glScalef(zoom, zoom, zoom);
display(GL_RENDER);
gl.glPopMatrix();
//Look in book
}*///no
//Required for implementation of mouselistener etc...
public void mouseEntered(MouseEvent e) {
Component comp = e.getComponent();
if(comp.equals(this)) {
requestFocus();
}
}
public void mouseExited(MouseEvent e) {
}
public void mousePressed(MouseEvent e) {//Find a way to hide the
mouse pointer
moveX = e.getX();//Take new mouse reading
moveY = e.getY();
//Selection here
if ((e.getModifiers() &
InputEvent.BUTTON1_MASK)==InputEvent.BUTTON1_MASK) {
//Test for cursor hiding, hand selector
setCursor( Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
if(!glj.gljMakeCurrent(true))//See if is initialised
return;
processSelection(moveX,moveY);//Send arguements to process
selection
glj.gljSwap();
glj.gljCheckGL();
glj.gljFree();
}
}
public void mouseReleased(MouseEvent e) {
setCursor( Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
}
public void mouseClicked(MouseEvent e) {
Component comp = e.getComponent();
if(comp.equals(this)) {
requestFocus();
}
}
public void mouseMoved(MouseEvent e) {
}
public void mouseDragged(MouseEvent e) {
//Manual zoom....
if ((e.isMetaDown()) & ((e.getModifiers() &
InputEvent.BUTTON1_MASK)==InputEvent.BUTTON1_MASK)) {
setCursor( Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
//Also two button for roataion of structure
//Put in proper camera zoom.
float newMoveX = e.getX();
float newMoveY = e.getY();//Need distance for zoom
//See which feels better for user
xrot -= newMoveX - moveX;
//Might need method
z -= newMoveY - moveY;
//Update method
moveX = newMoveX;
moveY = newMoveY;
}
else if (e.isMetaDown()) {
setCursor(
Cursor.getPredefinedCursor(Cursor.MOVE_CURSOR));//Find correct method
float newMoveX = e.getX();
float newMoveY = e.getY();
float angleX = (float)(newMoveX -
moveX)*360.0f/(float)getSize().width;//Assign x angle
float angleY = (float)(newMoveY -
moveY)*360.0f/(float)getSize().height;//Assign y angle
float mBuf1[] = new float[16];
float mBuf2[] = new float[16];
moveX = newMoveX;
moveY = newMoveY;
if ((angleX != 0.0f) || (angleY != 0.0f)) {
mFun.rotateAroundY(((float)angleX), mBuf1);
mFun.rotateAroundX(((float)angleY), mBuf2);
//Accredit particle source..fair, for matrix
mFun.multiplyMatrices(mBuf2,mBuf1, mBuf1);//Look at both
mFun.multiplyMatrices(rotation, mBuf1, rotation);
}
}
}
public void keyTyped(KeyEvent e) {
}
public void keyPressed(KeyEvent e) {
//Ensure initialisation
if (glj.gljMakeCurrent(true)== false)
return;
switch(e.getKeyCode()) {
case KeyEvent.VK_PAGE_UP: {//Move back with page up
z -=0.5f;
break;
}
case KeyEvent.VK_PAGE_DOWN: {//Move forward with pd
z +=0.5f;
break;
}
//Change position, change to strafe
case KeyEvent.VK_UP:{//height
y -=0.1f;
break;
}
case KeyEvent.VK_DOWN:{//height
y +=0.1f;
break;
}//Give a camera like feel
//
case KeyEvent.VK_RIGHT:{//pan
x -=0.1f;
break;
}
case KeyEvent.VK_LEFT:{//pan
x +=0.1f;
break;
}
}
glj.gljFree();
}
public void keyReleased(KeyEvent e) {
}
}
}
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