Latest posts of: ankitmcgill

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1	Java Game APIs & Engines / Java Sound & OpenAL / Installing JOAL with netbeans IDE	on: 2008-11-23 10:21:26
Hi all, quick question. How do i go about installing joal libraries to use them in my project in netbeans under windows ? Did a lot of googling but could not find any definite answer. thanks -ankit

2	Game Development / Newbie & Debugging Questions / Re: OpenGl transformation question newbie	on: 2008-11-23 10:19:11
lhkbob, thank you for the advice ... i think i understand it now -ankit

3	Game Development / Newbie & Debugging Questions / Re: OpenGl transformation question newbie	on: 2008-11-18 06:39:27
hmm .. .i am not sure if i follow ur advice completely. so i use init() for 1-time stuff. now you said that in the keylistener i should set a boolean to recompute the projection matrix .. assuming i do that , how would the display() function of opengl get called ? wont i need to explicitly call it from my keylistener ? thanks -ankit

Game Development / Newbie & Debugging Questions / Re: OpenGl transformation question newbie

on: 2008-11-18 01:00:54

lhkbob,

thank you so much ! fixing the camera project did the trick Grin

have another noob question.

i added code so that every time the user presses the right key i change the camera rotate angle to rotate the final projection. it works fine except that right now what i do is (pseudocode)

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void keypressed(....)
{
       if key(==right key)
       {
               angle+=2.0f;
               init();
               display();
        }
}

so i am calling the display() and init() every time => redrawing the whole scene. i am wondering since opengl is a state machine there should be a way to just recompute the projection according to the new angle instead of drawing the whole thing again ... any ideas how would i do that ?

thanks
-ankit

5	Game Development / Newbie & Debugging Questions / Re: OpenGl transformation question newbie	on: 2008-11-17 01:22:05
Quote from: lhkbob on 2008-11-17 00:32:27 Not exactly sure what you mean by -ve, can you elaborate? the code is supposed to draw all the axes between the limits [-0.5,0.5] however if you look at the attached picture of the output all i see is the positive half of the axis lines. -ankit

Game Development / Newbie & Debugging Questions / Re: OpenGl transformation question newbie

on: 2008-11-16 08:57:23

ok ..makes sense .. so i modified my code and now i can see the axis with the desired view however there is a small problem in the code

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 final GL gl = drawable.getGL();
        final GLU glu = new GLU();
        gl.glClear(GL.GL_COLOR_BUFFER_BIT|GL.GL_DEPTH_BUFFER_BIT);
        gl.glMatrixMode(GL.GL_MODELVIEW);
        gl.glLoadIdentity();
        gl.glTranslatef(0.0f, 0.0f, -1.0f);
        gl.glRotatef(45.0f, 1.0f, 0.0f, 0.0f);
        gl.glRotatef(45.0f, 0.0f, 1.0f, 0.0f);
        //gl.glRotatef(xy_angle0 , xz_angle, xy_angle, xz_angle);
        
 

        gl.glColor3f(0.0f, 0.0f, 0.0f);
        
        //gl.glRotatef(xz_angle, 0.0f, 0.0f, 1.0f);
        gl.glBegin(GL.GL_LINES);
        
            
            //x axis = green
            gl.glColor3f(0.0f, 1.0f, 0.0f);
            gl.glVertex3f( -1.5f, 0.0f, 0.0f );
            gl.glVertex3f( 1.5f, 0.0f, 0.0f );
            
            //y axis = red
            gl.glColor3f(1.0f, 0.0f, 0.0f);
            gl.glVertex3f( 0.0f, -1.5f, 0.0f );
            gl.glVertex3f( 0.0f, 1.5f, 0.0f );
            
            //z axis = blue
            gl.glColor3f(0.0f, 0.0f, 1.0f);
            gl.glVertex3f( 0.0f, 0.0f, -1.5f );
            gl.glVertex3f( 0.0f, 0.0f, 1.5f );
            
                     
            
        gl.glEnd();
        gl.glFlush();

the output that i get is :

my question .. why cant i see the -ve part of the axis ?

thanks again
-ankit

Game Development / Newbie & Debugging Questions / OpenGl transformation question newbie

on: 2008-11-15 23:13:05

Hi all,

i am a complete newbie to opengl taking a computer graphics course this semester. we just did transformations so i am playing around with some code to make sure i understand them. however there seems to be some basic flaw in my understanding as i always get output different that what i predicted.

I have posted a sample code below and hoping someone would be kind enough to walk me through it to point what i am not getting right.

the code below is supposed to draw x,y and z axis with the viewpoint situated at (1,1,1) so that i can see all the axis.

what i want to see is all 3 axes in something like

* *
* *
* *
* *
*******************
**
* *
* *
* *

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gl.glClear(GL.GL_COLOR_BUFFER_BIT|gl.GL_DEPTH_BUFFER_BIT);   //clear gl buffers
gl.glMatrixMode(GL.GL_MODELVIEW); //set the current matrix as modelview
gl.glLoadIdentity(); //load identity matrix => locate viewpoint at (0,0,0)

gl.glClearColor(1.0f,1.0f,1.0f,0); //clear window with white
gl.glClear(GL.GL_COLOR_BUFFER_BIT);
gl.glColor3f(0.0f, 0.0f, 0.0f); //set drawing color as black
        
gl.glBegin(GL.GL_LINES);  //draw all three axis within -0.5 to +0.5 with viewer at (0,0,0). this when rendered will show a
     gl.glVertex3f( -0.5f, 0.0f, 0.0f ); // a plus sign since z axis would be 'hidden'
     gl.glVertex3f( 0.5f, 0.0f, 0.0f );
         
     gl.glVertex3f( 0.0f, -0.5f, 0.0f );
     gl.glVertex3f( 0.0f, 0.5f, 0.0f );
            
     gl.glVertex3f( 0.0f, 0.0f, -0.5f );
     gl.glVertex3f( 0.0f, 0.0f, 0.5f );
            
gl.glEnd();
gl.glTranslatef(1.0f, 1.0f, 1.0f); //finally move the viewer to (1,1,1) to get the desired view

when i run this all i see is half a part of of the plus sign drawn at the top right corner of the gl canvas.

thank you for all the help
-ankit

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