qt-everywhere-src-5.14.1/qtscript/examples/script/context2d/scripts/stroke1.js

var ctx = document.getElementById('tutorial').getContext('2d');
    for (i=0;i<6;i++){
      for (j=0;j<6;j++){
        ctx.strokeStyle = 'rgb(0,' + Math.floor(255-42.5*i) + ',' + 
                         Math.floor(255-42.5*j) + ')';
        ctx.beginPath();
        ctx.arc(12.5+j*25,12.5+i*25,10,0,Math.PI*2,true);
        ctx.stroke();
      }
    }