Håvard Rast Blok

A little something

[ 3D-fonts ] [ Casteljau's algorithm ] [ Torus and sphere ]
[ A watch ] [ Rubik's Cube ] [ First try ]

3D-fonts

This program draws the letter above. Except some updates in the near future.
 

Casteljau's algorithm

For more information about this algorithm, see the pages of Børre Stenseth. (in Norwegian)

Torus and sphere

float x;
float y;
float z;

float R = 0.3f; //inner radius of torus
float r = 0.07f; //radius of torus (r*2 = thicknes)

float rings = 80.0f;
float sides = 12.0f;
float tmp;
double pi_2_s;
double pi_2_t;

float step_s = 1.0f / rings;
float step_t = 1.0f / sides;

gl.glLineWidth( 3.0f );
gl.glColor3f(0.2f, 0.1f, 0.7f);

gl.glBegin( GL.GL_LINE_STRIP );
for(double s = 0.0f; s < 1.0; s += step_s)  //rings
{
  for(double t = 0.0f; t < 1.0; t += step_t)  //divsions in each ring
  {
    pi_2_t = PI_2 * t;
    //(step_s*t) makes s spiral out of each ring
    //to remove the gap between beginning and end of two nabouring rings
    pi_2_s = PI_2 * (s + (step_s*t));  
    
    tmp = R + r*(float)Math.cos( pi_2_t );
    x = tmp*(float)Math.cos( pi_2_s );
    y = tmp*(float)Math.sin( pi_2_s );
    z = r*(float)Math.sin( pi_2_t );
        
    gl.glVertex3f( x, y, z );
  }
}
gl.glEnd();

//draw shpere moving inside the torus
GLUQuadric glpQ = new GLUQuadric();

gl.glRotatef( sphereAngle, 0.0f, 0.0f, 1.0f );
gl.glTranslatef(R, 0.0f , 0.0f );

gl.glColor3f(1.0f, 1.0f, 0.1f);
glu.gluSphere(glpQ,r*0.3f,20,20);               

glu.gluDeleteQuadric(glpQ);

//move the sphere
sphereAngle += 3.0f;

A watch

The source code also features a moving mechanism controlled by the keyboard and mouse (not optimized yet, thought).

To navigate, use these keys:
Rotate: LEFT - RIGHT (and drag mouse up/down)
Forward: UP
Back: DOWN
Strafing: Hold SHIFT while using arrow keys
Zoom: PAGE UP - PAGE DOWN
As I said, the calculations for the movements are not done yet.
 

Rubik's Cube

Finally, it works! :)
 

First try

My first, none abstract, object in OpenGL.
The code:
(parameters to glLookAt call on top of picture)

 private final double sqrt2 = Math.sqrt( 2.0 );
 private final double sqrt2_div2 = sqrt2/2;
 private final float sqrt2_div2f = (float)sqrt2_div2;

 (...)

 float r = 2.0f;

 gl.glRotatef( 90.0f, 0.0f, 0.0f, 1.0f );
 gl.glColor3f(1.0f, 0.0f, 0.0f);
 glu.sphere( glpQ, r, 2, 2 );  //draw ground sphere

 for(int i = 0; i < 4; i++)
 {
   gl.glPushMatrix();
   gl.glRotatef( -45.0f + (float)(90*i), 1.0f, 0.0f, 0.0f ); //rotate to mid (instaed of corner)
   gl.glTranslatef( 0.0f, r*sqrt2_div2f, 0.0f ); //trans to edge
   gl.glRotatef( -90.0f, 0.0f, 0.0f, 1.0f ); //rotate around edge
   gl.glTranslatef( 0.0f, r*sqrt2_div2f, 0.0f ); //trans to mid
   gl.glRotatef( 45.0f, 1.0f, 0.0f, 0.0f ); //rotate to get square instead of diamond
   gl.glColor3f(1.0f, 0.0f, 1.0f); //set color 
   glu.sphere( glpQ, r, 2, 2 ); //draw quadrat
   gl.glPopMatrix(); //go back to ground sphere
 }