Rotating cube

< Rotating cube

InitGraph();
ScaleWindow(-2.7, -2, 2.7, 2);
Colour("red");
Label("a, A, s, S, d, D to rotate",-2,2);

v=new Array(7);

v[0]=new Array(-1,-1,-1);
v[1]=new Array(-1,-1, 1);
v[2]=new Array(-1, 1, 1);
v[3]=new Array(-1, 1,-1);
v[4]=new Array( 1, 1,-1);
v[5]=new Array( 1, 1, 1);
v[6]=new Array( 1,-1, 1);
v[7]=new Array( 1,-1,-1);

theta = .05;                //the unit of rotation, theta
var cth = Math.cos(theta);  //saves calculating them
var sth = Math.sin(theta);  //each time

var r=10;                   //distance of viewpoint

function pline (i, j, c){

//draw projected line from vertex i to vertex j

var si = 5 / (r - v[i][2]);
var sj = 5 / (r - v[j][2]);
Colour(c);
LineStart(v[i][0] * si, v[i][1] * si)
LineTo(v[j][0] * sj, v[j][1] * sj)
}

function rotate (i, j){
   for(k = 0;k<=7;k++){
      t = v[k][i] * cth + v[k][j] * sth;
      v[k][j] = v[k][j] * cth - v[k][i] * sth;
      v[k][i] = t;
   }
}

function showcube (c){
 i = 7;
 for(j = 0;j<=7;j++){
   pline (i, j, c);
   i = j;
 }
 pline (0, 3, c);
 pline (1, 6, c);
 pline (2, 5, c);
 pline (4, 7, c);
}

showcube("black");     //draw cube in black

StepModel();         //Start the model running