translate.js Example File | Qt Script

- Qt 5.5
- Qt Script
- Context2D Example
- translate.js Example File
- Qt 5.5.1 Reference Documentation

# translate.js Example File

script/context2d/scripts/translate.js

      var ctx = document.getElementById('tutorial').getContext('2d');
      ctx.fillRect(0,0,300,300);
      for (var i=0;i<3;i++) {
        for (var j=0;j<3;j++) {
          ctx.save();
          ctx.strokeStyle = "#9CFF00";
          ctx.translate(50+j*100,50+i*100);
          drawSpirograph(ctx,20*(j+2)/(j+1),-8*(i+3)/(i+1),10);
          ctx.restore();
        }
      }

    function drawSpirograph(ctx,R,r,O){
      var x1 = R-O;
      var y1 = 0;
      var i  = 1;
      ctx.beginPath();
      ctx.moveTo(x1,y1);
      do {
        if (i>20000) break;
        var x2 = (R+r)*Math.cos(i*Math.PI/72) - (r+O)*Math.cos(((R+r)/r)*(i*Math.PI/72))
        var y2 = (R+r)*Math.sin(i*Math.PI/72) - (r+O)*Math.sin(((R+r)/r)*(i*Math.PI/72))
        ctx.lineTo(x2,y2);
        x1 = x2;
        y1 = y2;
        i++;
      } while (x2 != R-O && y2 != 0 );
      ctx.stroke();
    }