1 files changed, 67 insertions, 0 deletions
diff --git a/examples/script/context2d/scripts/scale.js b/examples/script/context2d/scripts/scale.js
new file mode 100644
index 0000000000..75ef8650c0
--- /dev/null
+++ b/examples/script/context2d/scripts/scale.js
@@ -0,0 +1,67 @@
+var ctx = document.getElementById('tutorial').getContext('2d');
+  ctx.strokeStyle = "#fc0";
+  ctx.lineWidth = 1.5;
+  ctx.fillRect(0,0,300,300);
+
+  // Uniform scaling
+  ctx.save()
+  ctx.translate(50,50);
+  drawSpirograph(ctx,22,6,5);  // no scaling
+
+  ctx.translate(100,0);
+  ctx.scale(0.75,0.75);
+  drawSpirograph(ctx,22,6,5);
+
+  ctx.translate(133.333,0);
+  ctx.scale(0.75,0.75);
+  drawSpirograph(ctx,22,6,5);
+  ctx.restore();
+
+  // Non uniform scaling (y direction)
+  ctx.strokeStyle = "#0cf";
+  ctx.save()
+  ctx.translate(50,150);
+  ctx.scale(1,0.75);
+  drawSpirograph(ctx,22,6,5);
+
+  ctx.translate(100,0);
+  ctx.scale(1,0.75);
+  drawSpirograph(ctx,22,6,5);
+
+  ctx.translate(100,0);
+  ctx.scale(1,0.75);
+  drawSpirograph(ctx,22,6,5);
+  ctx.restore();
+
+  // Non uniform scaling (x direction)
+  ctx.strokeStyle = "#cf0";
+  ctx.save()
+  ctx.translate(50,250);
+  ctx.scale(0.75,1);
+  drawSpirograph(ctx,22,6,5);
+
+  ctx.translate(133.333,0);
+  ctx.scale(0.75,1);
+  drawSpirograph(ctx,22,6,5);
+
+  ctx.translate(177.777,0);
+  ctx.scale(0.75,1);
+  drawSpirograph(ctx,22,6,5);
+  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();
+}