| <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"> |
| <html> |
| <head> |
| <script src="../../resources/js-test-pre.js"></script> |
| </head> |
| <body> |
| <script> |
| description("Ensure correct behavior of canvas with path stroke using a strokeStyle color with alpha and a shadow"); |
| |
| function print(message, color) |
| { |
| var paragraph = document.createElement("div"); |
| paragraph.appendChild(document.createTextNode(message)); |
| paragraph.style.fontFamily = "monospace"; |
| if (color) |
| paragraph.style.color = color; |
| document.getElementById("console").appendChild(paragraph); |
| } |
| |
| function shouldBeAround(a, b) |
| { |
| var evalA; |
| try { |
| evalA = eval(a); |
| } catch(e) { |
| evalA = e; |
| } |
| |
| if (Math.abs(evalA - b) < 15) |
| print("PASS " + a + " is around " + b , "green") |
| else |
| print("FAIL " + a + " is not around " + b + " (actual: " + evalA + ")", "red"); |
| } |
| |
| var canvas = document.createElement('canvas'); |
| document.body.appendChild(canvas); |
| canvas.setAttribute('width', '600'); |
| canvas.setAttribute('height', '1100'); |
| var ctx = canvas.getContext('2d'); |
| |
| ctx.save(); |
| ctx.strokeStyle = 'rgba(0, 0, 255, 0.5)'; |
| ctx.shadowColor = 'rgba(255, 0, 0, 0.5)'; |
| ctx.shadowOffsetX = 250; |
| ctx.lineWidth = 50; |
| |
| function strokePath(x, y) { |
| ctx.beginPath(); |
| ctx.arc(x, y, 75, 0, Math.PI*2, true); |
| ctx.stroke(); |
| } |
| |
| // Alpha shadow. |
| ctx.shadowBlur = 0; |
| strokePath(150, 150); |
| |
| // Blurry shadow. |
| ctx.shadowBlur = 10; |
| strokePath(150, 400); |
| |
| ctx.rotate(Math.PI/2); |
| |
| // Rotated alpha shadow. |
| ctx.shadowBlur = 0; |
| strokePath(650, -150); |
| |
| // Rotated blurry shadow. |
| ctx.shadowBlur = 10; |
| strokePath(900, -150); |
| |
| ctx.restore(); |
| |
| var imageData, data; |
| ctx.fillStyle = 'black'; |
| |
| function test(alphaTestFunction, x, y, r, g, b, a) { |
| // Get pixel. |
| imageData = ctx.getImageData(x, y, 1, 1); |
| data = imageData.data; |
| // Test pixel color components. |
| shouldBe('data[0]', r+''); |
| shouldBe('data[1]', g+''); |
| shouldBe('data[2]', b+''); |
| alphaTestFunction('data[3]', a+''); |
| // Plot test point. |
| ctx.fillRect(x, y, 3, 3); |
| } |
| |
| print('Verifying alpha shadow...'); |
| test(shouldBe, 400, 150, 0, 0, 0, 0); |
| test(shouldBeAround, 400, 75, 255, 0, 0, 64); |
| test(shouldBeAround, 400, 225, 255, 0, 0, 64); |
| test(shouldBeAround, 325, 150, 255, 0, 0, 64); |
| test(shouldBeAround, 475, 150, 255, 0, 0, 64); |
| |
| print(' '); |
| print('Verifying blurry shadow...'); |
| test(shouldBe, 400, 400, 0, 0, 0, 0); |
| test(shouldBeAround, 400, 300, 255, 0, 0, 31); |
| test(shouldBeAround, 400, 500, 255, 0, 0, 31); |
| test(shouldBeAround, 300, 400, 255, 0, 0, 31); |
| test(shouldBeAround, 500, 400, 255, 0, 0, 31); |
| |
| print(' '); |
| print('Verifying rotated alpha shadow...'); |
| test(shouldBe, 400, 650, 0, 0, 0, 0); |
| test(shouldBeAround, 400, 575, 255, 0, 0, 64); |
| test(shouldBeAround, 400, 725, 255, 0, 0, 64); |
| test(shouldBeAround, 325, 650, 255, 0, 0, 64); |
| test(shouldBeAround, 475, 650, 255, 0, 0, 64); |
| |
| print(' '); |
| print('Verifying rotated blurry shadow...'); |
| test(shouldBe, 400, 900, 0, 0, 0, 0); |
| test(shouldBeAround, 400, 800, 255, 0, 0, 31); |
| test(shouldBeAround, 400, 1000, 255, 0, 0, 31); |
| test(shouldBeAround, 300, 900, 255, 0, 0, 31); |
| test(shouldBeAround, 500, 900, 255, 0, 0, 31); |
| |
| print(' '); |
| </script> |
| <script src="../../resources/js-test-post.js"></script> |
| </body> |
| </html> |
