I attach the original quiz with graphic output sample for your perusal.

thanks very much

bernie

--eager noob

This original from my c++ code was an inclass quiz...the java version I'm doing just for the heck of it.  Not for a grade. Can someone point out what I need to do to
get display draw Triangle in a loop - should print the # of triangles specified by the variable "num"

thanks..Bernie


import javax.media.opengl.*;
import javax.swing.*;

public class Quiz1{

  public static void main (String []args){
final int num = 1;     
      JFrame.setDefaultLookAndFeelDecorated(true);
      JFrame jframe = new JFrame(Quiz1.class.getSimpleName());
      jframe.setSize(500,500);
      jframe.setLocationRelativeTo(null);//center of screen
     
      GLCanvas canvas = new GLCanvas();
     
      canvas.addGLEventListener(new GLEventListener(){
          public void init(GLAutoDrawable drawable){}
         
          public void display(GLAutoDrawable drawable){
              GL gl = drawable.getGL();
             
              for (int i = 0; i< num; i++){
                  gl.glPushMatrix();
                  gl.glScalef(1/num,1/num,1);
                  gl.glTranslatef((1/num*i), 0, 0);
                 
                  drawTriangle();
                  gl.glPopMatrix();
                 
                }
            }
            public void drawTriangle(){
                gl.glClearColor(0.0f,0.0f,0.0f,0.0f);
                gl.glClear(GL.GL_COLOR_BUFFER_BIT);
                gl.glColor3f(1.0f,1.0f,0.0f);
                gl.glMatrixMode(GL.GL_PROJECTION);
                gl.glLoadIsentity();
                gl.glOrtho2D(0,1,0,1);
                gl.glBegin(GL.GL_POLYGON);
                gl.glVertex2f(0.0,0.0);
                gl.glVertex2f(.5,1.0);
                gl.glVertex2f(1.0,0.0);
                gl.glEnd();
                gl.glFlush();
            }
       
       
        public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {}
       
        public void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged){}
       
    });
    jframe.add(canvas);
    jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    jframe.setVisible(true);
}
}


       

thank you for your efforts,

bernie

Hi all, what do I need to change not to get this error?

@hum301-09 ~]$ javac Lesson01.java
Lesson01.java:10: cannot find symbol
symbol  : class GLDisplay
location: class Lesson01
        GLDisplay neheGLDisplay = GLDisplay.createGLDisplay("Lesson 01: An OpenGL Window");
        ^
Lesson01.java:10: cannot find symbol
symbol  : variable GLDisplay
location: class Lesson01
        GLDisplay neheGLDisplay = GLDisplay.createGLDisplay("Lesson 01: An OpenGL Window");
                                  ^

Hi folks,

what import statements do I use to get access to:

Animator

drawable.setGL()
drawable.getGL()

thanks,
bernie

hi all..
having recently installed the JOGL libraries on Ubuntu, I still dont have it working. I get a lot of
"depreciated" this and that when trying NEHE tutorials. Are they in fact out of date with the current standard?

thanks,
bernie

Thank you both..I'm working on it...

bernie

hi folks...question: this program doesnt work yet, what's wrong with it...
this is my first Java program with JOGL (i've only been programming for 6months in my life, so I'm new at this. any advice will be appreciated.)



import java.awt.*;
import java.awt.event.*;
import net.java.games.jogl.*;
import javax.*;
public class Simple {
  public static void main (Strng args []){

   Frame simpleFrame = new Frame ("simple"); //awt window
   GLCapabilities glc = new GLCapabilities();//config OPen GL
   glc.setDoubleBuffered(false);
   GLCanvas drawable = GLDrawableFactory.getFactory().createGLCanvas(glc);
   drawable.addGLEventListener(new simpleRnderer());
   simpleFrame.add(drawable);

    simpleFrame.setLocation(100,100);
   simpleFrame.setSize(500,500);
   simpleFrame.show();}

   public void init(GLDrawable drawable){
   GL gl = drawable.getGL();
   GLU glu = drawable.getGLU();

   gl.glClearColor(0f,0f,0f,0f);
        glglColor3f(1.0f,1.0f,1.0f,1.0f);

   gl.glMatrixMode(GL.GL_PROJECTION);
   gl.glLoadIdentity();
   gl.glOrtho(-1.0,1.0,-1.0,1.0,1.0);
   }

   static class SimpleRenderer implements GLEventListener{
   public void display(GlDrawable drawable){
      GL gl = drawable.getGL();
      GLU glu = drawable.getGLU();
          gl.glClear(GL.GL_COLOR_BUFFER_BIT);
     gl.glBegin(GL.GL_POLYGON);
          gl.glVertex2f(-0.5f,-0.5f);
          gl.glVertex2f(-0.5f,0.5f);
          gl.glVertex2f(0.5f,0.5f);
       gl.glEnd();
gl.glFlush();
}
}
}

So, here's some code, but  what this does, every time I resize the window, It re calculates the origin, and moves right off the screen..
so what gives....thanks
bernie (yes, I know its c code, but you people are so nice )


#include <iostream>
#include <cstdlib>
#include <glut.h>
#include <math.h>

const float DEG2RAD = 3.1416/180;

void init(void){
   glClearColor(1.0,1.0,1.0,0.0);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluOrtho2D(0,1.0,0,1.0);
  glMatrixMode (GL_MODELVIEW);
  glLoadIdentity();

}


void disp(void){
  glClear(GL_COLOR_BUFFER_BIT);

  glColor3f(0.0,0.0,0.0);
 float xradius = 0.25;
 float yradius = 0.125;

 
  glBegin(GL_LINE_LOOP);

  for (int i = 0; i<360; i++){
       float degInRad = i*DEG2RAD;
      glVertex2f(cos(degInRad)*xradius, sin(degInRad)*yradius);
   }
  glEnd();


glRotatef (45,0,0,1);
glTranslatef(.75,.25,0);
 glBegin(GL_LINE_LOOP);

  for (int j = 0; j<360; j++){
       float degInRad = j*DEG2RAD;
      glVertex2f(cos(degInRad)*xradius, sin(degInRad)*yradius);
   }
  glEnd();
glFlush();
}
  void main(int argc, char** argv){
glutInit (&argc, argv); // Initialize GLUT.
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); // Set display mode.
glutInitWindowPosition (50, 100); // Set top-left display-window position.
glutInitWindowSize (400, 300); // Set display-window width and height.
glutCreateWindow ("ellipse"); // Create display window.
init ( ); // Execute initialization procedure.
glutDisplayFunc (disp); // Send graphics to display window.

glutMainLoop ( ); // Display everything and wait.
}
   

Hi people, please help me understand how to make the following:

I have an ellipse, centered at the origin,  defined by the parametric equation
(x (t ), y (t )) = (a cos(t), b(sin(t)),    t being from   {0, 2pi}

what is the parametric representation of the same figure translated by +2 along the x-axis, +3 along the y-axis
and then rotated by 45 degrees

I get,

x'        =   cos(pi/4)     -sin(pi/4)    |x|   + |2|
y'             sin(pi/4)      cos(pi/4)     |y|      |3|

to be read as the matrix multiplication of cos, -sin  by original coordinates
plus the vector 2, 3 yielding the new coordinates....but this is not in homogeneous
coordinates....how to make it homogeneous.....

and any additional info will be appreciated for the Math-phobic among us...

thanks,

bernie

thanks so much

Yay..small success..

Whoa...there's a ton of stuff there in the GL app you wrote...Will play with it...any other pointers to use....also what are
NBPROJECT
ORG
TEST
(including subdirectories)...

directories for?

seems like a lot of stuff...
thanks SO much

bernie

Ok,  netbeans is cool

hi there..thanks so much for the info!! I did what you suggested, and downloaded netbeans and set an auto config to your URL...yay! so, now, can you please tell me more about properly using it.. is there JOGL documentation available?


bernie

hi..For netbeans environement, I just d/l Netbeans 5.0 IDE, one file only...Or do I need anything additional? Then I add your module...

thanks for all the help.

bernie

Below, my current C++ code for this assignment (see pdf attachement earlier) ..please comment if you are willing to look at c code
thanks
bernie

ps, yes, I've pulled down the Gears demo and am getting into it. Thanks

#include<iostream>
#include <cstdlib>
#include <glut.h>
using namespace std;

class Point{
   double x;
   double y;
   Point (double x=0, double y=0){this.x=x;this.y=y;}
   //constructor connects x and y values of the calling object
   //'this'

};

class House{
private:
   double w; //width
   double h; // height
   double p; //the peak
   Point O; //House origin.  bottom left corner of the shell of
   //the house

public:
   House(double w, double h, double p, Point origin); // constructor
   //for a house

/*   void draw_shell();
   void draw_door();
   void draw_chimney();
   void draw_window();
*/
   

   void draw_shell(){
   glClear (GL_COLOR_BUFFER_BIT);
   glColor3f (0.0, 0.0, 1.0); .
   glBegin (GL_LINES);
      glVertex2i(O.x, O.y); //vertices of shell in terms of origin(O.x, O.y)
      glVertex2i(O.x, O.y+h);
      glVertex2i(O.x+w, O.y);
      glVertex2i(O.x+(1/2)w, p);
      glVertex2i(O.x+w, O.y+h);

   glEnd ( );
   glFlush ( );
   }

   void draw_door(){
   glClear (GL_COLOR_BUFFER_BIT);
   glColor3f (0.0, 0.0, 1.0); .
   glBegin (GL_LINES);
      glVertex2i(O.x+(1/8)w, O.y);
      glVeretex2i(O.x+(1/8)w, O.y+h);
      glVertex2i(O.x+(1/4)w, O.y+h);
      glVertex2i(O.x+(1/4)w, O.y);

   glEnd ( );
   glFlush ( );
   }
   void draw_window(){
   glClear (GL_COLOR_BUFFER_BIT);
   glColor3f (0.0, 0.0, 1.0); .
   glBegin (GL_LINES);
      glVertex2i(O.x+(5/8)w, O.y+(1/2)h);
      glVertex2i(O.x+(5/8)w, O.y+(3/4)h);
      glVertex2i(O.x+(7/8)w, O.y+(3/4)h);
      glVertex2i(O.x+(7/8)w, O.y+(1/2)h);

   glEnd ( );
   glFlush ( );
   }

   void draw_chimney(){
   glClear (GL_COLOR_BUFFER_BIT);
   glColor3f (0.0, 0.0, 1.0); .
   glBegin (GL_LINES);
      glVertex2i(O.x+(1/8)w, O.y+((1/4)*(p-h)+h);
      glVertex2i(O.x+(1/8)w, O.y+p);
      glVertex2i(O.x+(3/16)w, O.y+p);
      glVertex2i(O.x+(3/16)w, O.y+((3/8)*(p-h)+h);

   glEnd ( );
   glFlush ( );
   }

   void init(){


   glClearColor (1.0, .0, .0, 0.6);
   //glMatrixMode (GL_PROJECTION);
   gluOrtho2D (0.0, 200.0, 0.0, 200.0);
}

void display_house(){
      draw_shell();
      draw_door();
      draw_window();
      draw_chimney();

   }

   void display(){
      House h1(100, 150, 200, Point (0,0) );
      House h2 (100, 200, 280, Point(150,0) );
      House h3 (50, 70, 90, Point (0, 300) );
   //some gl code

      h1.display_house();
      //maybe some more gl code
      h2.display_house();
      h3.display_house();
   }


};

void main (int argc, char** argv)
{
   Point origin(20,20);
   House h4(2, 10, 15, origin);
glutInit (&argc, argv);
glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
glutInitWindowPosition (50, 100);
glutInitWindowSize (400, 300);
glutCreateWindow ("Bernie Project 1");
//init ( ); //
glutDisplayFunc (display_house);
glutMainLoop ( );
}

Can Somone give me a consise list of all import statements that use GL...
thanks
bernie

I have one semester of programming in C++ (accelerated, with data structures)... That's it. So..newbee-ish...Any help is appreciated.

thanks to all

bernie

Most appreciated, the impression I got from my instructor was that it would be "worth it" to use Java for these things.

Does anyone suggest a book for OpenGL with Java?

bernie

PS, thank you all for replying...most appreciated

Hi, no, I havent done any Java before, thus I am more like asking, what Development environments are you using, how to install
a jogl library to said environment, and are the functions the same...you could say, in a sense I need help more with Java than with open GL.
I think that is reasonable.  Meanwhile I'm doing the assignment in C++ myself.  So, I guess if someone could just help me get an openGL for Java environment up and running, that would be good.

bernie 

Hello everyone,
I'm a student in a computer graphics course at SUNY Newpaltz, and our instructor is using C++.  He said he will give extra credit if I can learn to do it with Java, but he will provide no support, as his focus is C.   He has given me permission to use any help I can find to do it in Java, and so I come to you people.  I attach a file  of my current exercise I wish to accomplish with OpenGL for your help and viewing pleasure..Its to draw a simple house.

Most appreciatively,

bernie