1 files changed, 62 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/canvas/offscreen/filters/2d.filter.canvasFilterObject.componentTransfer.discrete.tentative.worker.js b/testing/web-platform/tests/html/canvas/offscreen/filters/2d.filter.canvasFilterObject.componentTransfer.discrete.tentative.worker.js
new file mode 100644
index 0000000000..0e68f4899f
--- /dev/null
+++ b/testing/web-platform/tests/html/canvas/offscreen/filters/2d.filter.canvasFilterObject.componentTransfer.discrete.tentative.worker.js
@@ -0,0 +1,62 @@
+// DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py.
+// OffscreenCanvas test in a worker:2d.filter.canvasFilterObject.componentTransfer.discrete.tentative
+// Description:Test pixels on CanvasFilter() componentTransfer with discrete type
+// Note:
+
+importScripts("/resources/testharness.js");
+importScripts("/html/canvas/resources/canvas-tests.js");
+
+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({name: '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();
+});
+done();