<!DOCTYPE html>
<meta charset="utf-8">
<title>Canvas's ImageBitmapRenderingContext test</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<link rel="help" href="https://html.spec.whatwg.org/multipage/scripting.html#the-imagebitmap-rendering-context">
<script>
var width = 10;
var height = 10;
function testCanvas(bitmapCanvas, r, g, b, a)
{
var myCanvas = document.createElement('canvas');
myCanvas.width = width;
myCanvas.height = height;
var myCtx = myCanvas.getContext('2d');
myCtx.drawImage(bitmapCanvas, 0, 0);
var color = myCtx.getImageData(5, 5, 1, 1).data;
assert_array_equals(color, [r, g, b, a]);
}
promise_test(function() {
function testTransferFromImageBitmapNullability(greenImage) {
var bitmapCanvas = document.createElement('canvas');
bitmapCanvas.width = width;
bitmapCanvas.height = height;
var offscreenCanvas = bitmapCanvas.transferControlToOffscreen();
var bitmapCtx = offscreenCanvas.getContext('bitmaprenderer');
bitmapCtx.transferFromImageBitmap(greenImage);
// Make sure the bitmap renderer canvas is filled correctly.
var myCanvas = document.createElement('canvas');
var myCtx = myCanvas.getContext('bitmaprenderer');
myCtx.transferFromImageBitmap(offscreenCanvas.transferToImageBitmap());
testCanvas(myCanvas, 0, 255, 0, 255);
// Test that after transfering for second time to ImageBitmap produces
// a black bitmap of the same size
var myCanvas2 = document.createElement('canvas');
var myCtx2 = myCanvas2.getContext('bitmaprenderer');
myCtx2.transferFromImageBitmap(offscreenCanvas.transferToImageBitmap());
testCanvas(myCanvas2, 0, 0, 0, 0);
}
var greenCanvas = document.createElement('canvas');
greenCanvas.width = width;
greenCanvas.height = height;
var greenCtx = greenCanvas.getContext('2d');
greenCtx.fillStyle = '#0f0';
greenCtx.fillRect(0, 0, width, height);
return Promise.all([
createImageBitmap(greenCanvas),
]).then(([greenImage]) => {
testTransferFromImageBitmapNullability(greenImage);
});
},'Test that transferToImageBitmap works and that resets the imagebitmap to black');
</script>