| 1 | /** |
| 2 | * @fileoverview Tests for fastCanvasProxy, which drops superfluous segments. |
| 3 | * |
| 4 | * @author danvdk@gmail.com (Dan Vanderkam) |
| 5 | */ |
| 6 | describe("fast-canvas-proxy", function() { |
| 7 | |
| 8 | beforeEach(function() { |
| 9 | }); |
| 10 | |
| 11 | afterEach(function() { |
| 12 | }); |
| 13 | |
| 14 | var fakeCanvasContext = { |
| 15 | moveTo: function() {}, |
| 16 | lineTo: function() {}, |
| 17 | beginPath: function() {}, |
| 18 | closePath: function() {}, |
| 19 | fill: function() {}, |
| 20 | stroke: function() {} |
| 21 | } |
| 22 | |
| 23 | function extractMoveToAndLineToCalls(proxy) { |
| 24 | var calls = proxy.calls__; |
| 25 | var out = []; |
| 26 | for (var i = 0; i < calls.length; i++) { |
| 27 | var c = calls[i]; |
| 28 | if (c.name == 'moveTo' || c.name == 'lineTo') { |
| 29 | out.push([c.name, c.args[0], c.args[1]]); |
| 30 | } |
| 31 | } |
| 32 | return out; |
| 33 | } |
| 34 | |
| 35 | it('testExtraMoveTosElided', function() { |
| 36 | var htx = new Proxy(fakeCanvasContext); |
| 37 | var fastProxy = DygraphCanvasRenderer._fastCanvasProxy(htx); |
| 38 | |
| 39 | fastProxy.moveTo(1, 1); |
| 40 | fastProxy.lineTo(2, 1); |
| 41 | fastProxy.moveTo(2, 1); |
| 42 | fastProxy.lineTo(3, 1); |
| 43 | fastProxy.moveTo(3, 1); |
| 44 | fastProxy.stroke(); |
| 45 | |
| 46 | assert.deepEqual([['moveTo', 1, 1], |
| 47 | ['lineTo', 2, 1], |
| 48 | ['lineTo', 3, 1]], extractMoveToAndLineToCalls(htx)); |
| 49 | }); |
| 50 | |
| 51 | it('testConsecutiveMoveTosElided', function() { |
| 52 | var htx = new Proxy(fakeCanvasContext); |
| 53 | var fastProxy = DygraphCanvasRenderer._fastCanvasProxy(htx); |
| 54 | |
| 55 | fastProxy.moveTo(1, 1); |
| 56 | fastProxy.lineTo(2, 1); |
| 57 | fastProxy.moveTo(3, 1); |
| 58 | fastProxy.moveTo(3.1, 2); |
| 59 | fastProxy.moveTo(3.2, 3); |
| 60 | fastProxy.stroke(); |
| 61 | |
| 62 | assert.deepEqual([['moveTo', 1, 1], |
| 63 | ['lineTo', 2, 1], |
| 64 | ['moveTo', 3.2, 3]], extractMoveToAndLineToCalls(htx)); |
| 65 | }); |
| 66 | |
| 67 | it('testSuperfluousSegmentsElided', function() { |
| 68 | var htx = new Proxy(fakeCanvasContext); |
| 69 | var fastProxy = DygraphCanvasRenderer._fastCanvasProxy(htx); |
| 70 | |
| 71 | fastProxy.moveTo(0.6, 1); |
| 72 | fastProxy.lineTo(0.7, 2); |
| 73 | fastProxy.lineTo(0.8, 3); |
| 74 | fastProxy.lineTo(0.9, 4); |
| 75 | fastProxy.lineTo(1.0, 5); // max for Math.round(x) == 1 |
| 76 | fastProxy.lineTo(1.1, 3); |
| 77 | fastProxy.lineTo(1.2, 0); // min for Math.round(x) == 1 |
| 78 | fastProxy.lineTo(1.3, 1); |
| 79 | fastProxy.lineTo(1.4, 2); |
| 80 | fastProxy.moveTo(1.4, 2); |
| 81 | fastProxy.lineTo(1.5, 2); // rounding up to 2 |
| 82 | fastProxy.moveTo(1.5, 2); |
| 83 | fastProxy.lineTo(1.6, 3); |
| 84 | fastProxy.moveTo(1.6, 3); |
| 85 | fastProxy.lineTo(1.7, 30); // max for Math.round(x) == 2 |
| 86 | fastProxy.moveTo(1.7, 30); |
| 87 | fastProxy.lineTo(1.8, -30); // min for Math.round(x) == 2 |
| 88 | fastProxy.moveTo(1.8, -30); |
| 89 | fastProxy.lineTo(1.9, 0); |
| 90 | fastProxy.moveTo(3, 0); // dodge the "don't touch the last pixel" rule. |
| 91 | fastProxy.stroke(); |
| 92 | |
| 93 | assert.deepEqual([['moveTo', 0.6, 1], |
| 94 | ['lineTo', 1.0, 5], |
| 95 | ['lineTo', 1.2, 0], |
| 96 | ['lineTo', 1.7, 30], |
| 97 | ['lineTo', 1.8, -30], |
| 98 | ['moveTo', 3, 0]], extractMoveToAndLineToCalls(htx)); |
| 99 | }); |
| 100 | |
| 101 | }); |