| <!DOCTYPE html> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/common/canvas-tests.js"></script> |
| <link rel="help" href="https://html.spec.whatwg.org/#dom-offscreencanvas-getcontext"> |
| <script> |
| |
| test(function() { |
| var offscreenCanvas = new OffscreenCanvas(1, 1); |
| assert_throws(new TypeError(), function() { offscreenCanvas.getContext('3d'); }); |
| }, "Test that getContext with un-supported string throws a TypeError."); |
| |
| test(function() { |
| var offscreenCanvas1 = new OffscreenCanvas(1, 1); |
| var ctx1 = offscreenCanvas1.getContext('2d'); |
| assert_true(ctx1 instanceof OffscreenCanvasRenderingContext2D); |
| |
| var offscreenCanvas2 = new OffscreenCanvas(1, 1); |
| var ctx2 = offscreenCanvas2.getContext('webgl'); |
| assert_true(ctx2 instanceof WebGLRenderingContext); |
| |
| var offscreenCanvas3 = new OffscreenCanvas(1, 1); |
| var ctx3 = offscreenCanvas3.getContext('webgl2'); |
| assert_true(ctx3 instanceof WebGL2RenderingContext); |
| }, "Test that getContext with supported string returns correct results"); |
| |
| test(function() { |
| var offscreenCanvas1 = new OffscreenCanvas(1, 1); |
| var ctx1 = offscreenCanvas1.getContext('2d'); |
| var ctx2 = offscreenCanvas1.getContext('webgl'); |
| assert_equals(ctx2, null); |
| |
| var offscreenCanvas2 = new OffscreenCanvas(1, 1); |
| var ctx3 = offscreenCanvas2.getContext('webgl'); |
| var ctx4 = offscreenCanvas2.getContext('2d'); |
| assert_equals(ctx4, null); |
| }, "Test that getContext twice with different context type returns null the second time"); |
| |
| test(function() { |
| var offscreenCanvas = new OffscreenCanvas(1, 2); |
| var ctx = offscreenCanvas.getContext('2d'); |
| var dstCanvas = ctx.canvas; |
| assert_equals(dstCanvas.width, 1); |
| assert_equals(dstCanvas.height, 2); |
| }, "Test that 2dcontext.canvas should return the original OffscreenCanvas"); |
| |
| test(function() { |
| var offscreenCanvas = new OffscreenCanvas(1, 2); |
| var ctx = offscreenCanvas.getContext('webgl'); |
| var dstCanvas = ctx.canvas; |
| assert_equals(dstCanvas.width, 1); |
| assert_equals(dstCanvas.height, 2); |
| }, "Test that webglcontext.canvas should return the original OffscreenCanvas"); |
| |
| test(function() { |
| var offscreenCanvas = new OffscreenCanvas(10, 10); |
| var ctx = offscreenCanvas.getContext('2d', {alpha: false}); |
| ctx.fillStyle = 'rgba(0, 255, 0, 0.5)'; |
| ctx.fillRect(0, 0, 10, 10); |
| _assertPixelApprox(offscreenCanvas, 5,5, 0,127,0,255, "5,5", "0,127,0,255", 2); |
| }, "Test that OffscreenCanvasRenderingContext2D with alpha disabled makes the OffscreenCanvas opaque"); |
| |
| test(function() { |
| var offscreenCanvas = new OffscreenCanvas(10, 10); |
| var ctx = offscreenCanvas.getContext('2d', {alpha: true}); |
| ctx.fillStyle = 'rgba(0, 255, 0, 0.5)'; |
| ctx.fillRect(0, 0, 10, 10); |
| _assertPixelApprox(offscreenCanvas, 5,5, 0,255,0,127, "5,5", "0,255,0,127", 2); |
| }, "Test that OffscreenCanvasRenderingContext2D with alpha enabled preserves the alpha"); |
| |
| test(function() { |
| var offscreenCanvas = new OffscreenCanvas(10, 10); |
| var ctx = offscreenCanvas.getContext('2d'); |
| ctx.fillStyle = 'rgba(0, 255, 0, 0.5)'; |
| ctx.fillRect(0, 0, 10, 10); |
| _assertPixelApprox(offscreenCanvas, 5,5, 0,255,0,127, "5,5", "0,255,0,127", 2); |
| }, "Test that 'alpha' context creation attribute is true by default"); |
| |
| </script> |
| |
