description("Series of tests to ensure correct behaviour of canvas.setTransform()");
var ctx = document.createElement('canvas').getContext('2d');

debug("Reset the CTM to the initial matrix");
ctx.beginPath();
ctx.scale(0.5, 0.5);
ctx.setTransform(1, 0, 0, 1, 0, 0);
ctx.fillStyle = 'green';
ctx.fillRect(0, 0, 100, 100);

var imageData = ctx.getImageData(1, 1, 98, 98);
var imgdata = imageData.data;
shouldBe("imgdata[4]", "0");
shouldBe("imgdata[5]", "128");
shouldBe("imgdata[6]", "0");

debug("setTransform should not affect the current path");
ctx.beginPath();
ctx.rect(0,0,100,100);
ctx.save();
ctx.setTransform(0.5, 0, 0, 0.5, 10, 10);
ctx.fillStyle = 'red';
ctx.fillRect(0, 0, 100, 100);
ctx.restore();
ctx.fillStyle = 'green';
ctx.fillRect(0, 0, 100, 100);

imageData = ctx.getImageData(1, 1, 98, 98);
imgdata = imageData.data;
shouldBe("imgdata[4]", "0");
shouldBe("imgdata[5]", "128");
shouldBe("imgdata[6]", "0");

debug("setTransform should not affect the CTM outside of save() and restore()");
ctx.beginPath();
ctx.fillStyle = 'green';
ctx.save();
ctx.setTransform(0.5, 0, 0, 0.5, 0, 0);
ctx.fillStyle = 'red';
ctx.fillRect(0, 0, 100, 100);
ctx.restore();
ctx.fillRect(0, 0, 100, 100);

imageData = ctx.getImageData(1, 1, 98, 98);
imgdata = imageData.data;
shouldBe("imgdata[4]", "0");
shouldBe("imgdata[5]", "128");
shouldBe("imgdata[6]", "0");


debug("stop drawing on not-invertible CTM");
ctx.beginPath();
ctx.fillStyle = 'green';
ctx.fillRect(0, 0, 100, 100);
ctx.setTransform(0, 0, 0, 0, 0, 0);
ctx.fillStyle = 'red';
ctx.fillRect(0, 0, 100, 100);

imageData = ctx.getImageData(1, 1, 98, 98);
imgdata = imageData.data;
shouldBe("imgdata[4]", "0");
shouldBe("imgdata[5]", "128");
shouldBe("imgdata[6]", "0");

debug("setTransform with a not-invertible matrix should only stop the drawing up to the next restore()");
ctx.beginPath();
ctx.resetTransform();
ctx.save();
ctx.setTransform(0, 0, 0, 0, 0, 0);
ctx.fillStyle = 'red';
ctx.fillRect(0, 0, 100, 100);
ctx.restore();
ctx.fillStyle = 'blue';
ctx.fillRect(0, 0, 100, 100);

imageData = ctx.getImageData(1, 1, 98, 98);
imgdata = imageData.data;
shouldBe("imgdata[4]", "0");
shouldBe("imgdata[5]", "0");
shouldBe("imgdata[6]", "255");

debug("setTransform should set transform although CTM is not-invertible");
ctx.beginPath();
ctx.fillStyle = 'red';
ctx.fillRect(0, 0, 100, 100);
ctx.setTransform(0, 0, 0, 0, 0, 0);
ctx.fillStyle = 'green';
ctx.fillRect(0, 0, 100, 100);
ctx.setTransform(1, 0, 0, 1, 0, 0);
ctx.fillStyle = 'blue';
ctx.fillRect(0, 0, 100, 100);

imageData = ctx.getImageData(1, 1, 98, 98);
imgdata = imageData.data;
shouldBe("imgdata[4]", "0");
shouldBe("imgdata[5]", "0");
shouldBe("imgdata[6]", "255");