Simple rotation transformation
<!DOCTYPE html> <html> <head> <style> #canvas { /*w w w . j a v a 2s . c o m*/ border:1px solid #03F; background:#CFC; } </style> </head> <body> <canvas id="canvas" width="640" height="480"></canvas> <script> let context = document.getElementById('canvas').getContext('2d'); //now draw a red square context.setTransform(1,0,0,1,0,0); let angleInRadians = 45 * Math.PI / 180; context.rotate(angleInRadians); context.fillStyle = "red"; context.fillRect(100,100,50,50); </script> </body> </html>