| <!DOCTYPE html> |
| <!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. --> |
| <title>OffscreenCanvas test: 2d.filter.canvasFilterObject.componentTransfer.discrete.tentative</title> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/html/canvas/resources/canvas-tests.js"></script> |
| |
| <h1>2d.filter.canvasFilterObject.componentTransfer.discrete.tentative</h1> |
| <p class="desc">Test pixels on CanvasFilter() componentTransfer with discrete type</p> |
| |
| |
| <script> |
| var t = async_test("Test pixels on CanvasFilter() componentTransfer with discrete type"); |
| var t_pass = t.done.bind(t); |
| var t_fail = t.step_func(function(reason) { |
| throw reason; |
| }); |
| t.step(function() { |
| |
| var canvas = new OffscreenCanvas(100, 50); |
| var ctx = canvas.getContext('2d'); |
| |
| // From https://www.w3.org/TR/SVG11/filters.html#feComponentTransferElement |
| function getTransformedValue(C, V) { |
| // Get the right interval |
| const n = V.length; |
| const k = C == 1 ? n - 1 : Math.floor(C * n); |
| return V[k]; |
| } |
| |
| function getColor(inputColor, tableValues) { |
| const result = [0, 0, 0]; |
| for (const i in inputColor) { |
| const C = inputColor[i]/255; |
| const Cprime = getTransformedValue(C, tableValues[i]); |
| result[i] = Math.max(0, Math.min(1, Cprime)) * 255; |
| } |
| return result; |
| } |
| |
| tableValuesR = [0, 0, 1, 1]; |
| tableValuesG = [2, 0, 0.5, 3]; |
| tableValuesB = [1, -1, 5, 0]; |
| ctx.filter = new CanvasFilter({filter: 'componentTransfer', |
| funcR: {type: 'discrete', tableValues: tableValuesR}, |
| funcG: {type: 'discrete', tableValues: tableValuesG}, |
| funcB: {type: 'discrete', tableValues: tableValuesB}, |
| }); |
| |
| const inputColors = [ |
| [255, 255, 255], |
| [0, 0, 0], |
| [127, 0, 34], |
| [252, 186, 3], |
| [50, 68, 87], |
| ]; |
| |
| for (const color of inputColors) { |
| let outputColor = getColor(color, [tableValuesR, tableValuesG, tableValuesB]); |
| ctx.fillStyle = `rgb(${color[0]}, ${color[1]}, ${color[2]})`; |
| ctx.fillRect(0, 0, 10, 10); |
| _assertPixelApprox(canvas, 5, 5, outputColor[0],outputColor[1],outputColor[2],255, 2); |
| } |
| t.done(); |
| |
| }); |
| </script> |
