added fixture test

.gitignore

@@ -1,3 +1,4 @@
 doc/
 node_modules/
 v8.log
+fixture-test-*

index.js

@@ -34,6 +34,8 @@ try {
   __cvs = null;
 }
 
+var createCanvas  = require('./lib/util/create_canvas.js');
+
 var ResizerJS     = require('./lib/resizer_js');
 var ResizerJSWW   = require('./lib/resizer_js_ww');
 var ResizerWebgl  = require('./lib/resizer_webgl');
@@ -146,8 +148,8 @@ function resizeTiled (from, to, options, resizer, callback) {
 
   for (i = 0; i < resizer.concurrency; i++) {
     tileData = {
-      src: document.createElement('canvas'),
-      dest: document.createElement('canvas')
+      src: createCanvas(),
+      dest: createCanvas()
     };
     tileData.src.width = SRC_TILE_SIZE;
     tileData.src.height = SRC_TILE_SIZE;

lib/util/create_canvas.js

@@ -0,0 +1,7 @@
+'use strict';
+
+var Canvas = require('canvas');
+
+module.exports = function () {
+  return new Canvas();
+};

lib/util/create_canvas_browser.js

@@ -0,0 +1,7 @@
+'use strict';
+
+/* global document */
+
+module.exports = function () {
+  return document.createElement('canvas');
+};

package.json

@@ -29,8 +29,10 @@
       "brfs"
     ]
   },
+  "browser": {
+    "./lib/util/create_canvas.js": "./lib/util/create_canvas_browser.js"
+  },
   "dependencies": {
-    "async": "^1.5.2",
     "glur": "^1.1.1",
     "webworkify": "1.0.2"
   },
@@ -43,6 +45,7 @@
     "eslint": "0.10.1",
     "eslint-plugin-nodeca": "^1.0.3",
     "mocha": "^2.3.3",
+    "node-resemble": "^1.1.3",
     "uglify-js": "*"
   }
 }

test/fixture.js

@@ -0,0 +1,87 @@
+'use strict';
+/* global it, describe */
+
+var Canvas  = require('canvas');
+var Image   = Canvas.Image;
+var fs      = require('fs');
+var path    = require('path');
+var pica    = require('../');
+var resemble = require('node-resemble');
+
+var FIXTURES_DIRECTORY = path.join(__dirname, 'fixtures');
+var OUTPUT_DIRECTORY = path.join(__dirname, '..');
+
+function saveDataUrlToFile(dataUrl, fileName) {
+  var image, canvas;
+
+  image = new Image();
+  image.src = dataUrl;
+  canvas = new Canvas();
+  canvas.width = image.width;
+  canvas.height = image.height;
+  canvas.getContext('2d').drawImage(image, 0, 0);
+
+  canvas
+    .pngStream()
+    .pipe(fs.createWriteStream(path.join(OUTPUT_DIRECTORY, fileName)));
+}
+
+describe('Fixtures', function () {
+  it('algorithm should be correct for the given fixture', function (done) {
+    var srcImage, srcCanvas, srcCtx,
+        fixtureImage, fixtureCanvas, fixtureCtx,
+        destCanvas;
+
+    this.timeout(3000);
+
+    srcImage = new Image();
+    srcImage.src = fs.readFileSync(path.join(FIXTURES_DIRECTORY, 'original.jpg'));
+
+    srcCanvas = new Canvas();
+    srcCanvas.width = srcImage.width;
+    srcCanvas.height = srcImage.height;
+    srcCtx = srcCanvas.getContext('2d');
+    srcCtx.drawImage(srcImage, 0, 0);
+
+    fixtureImage = new Image();
+    fixtureImage.src = fs.readFileSync(path.join(FIXTURES_DIRECTORY, 'resized.png'));
+    fixtureCanvas = new Canvas();
+    fixtureCanvas.width = fixtureImage.width;
+    fixtureCanvas.height = fixtureImage.height;
+    fixtureCtx = fixtureCanvas.getContext('2d');
+    fixtureCtx.drawImage(fixtureImage, 0, 0);
+
+    destCanvas = new Canvas();
+    destCanvas.width = fixtureImage.width;
+    destCanvas.height = fixtureImage.height;
+
+    pica.WEBGL = false;
+    pica.WW = false;
+
+    pica.resizeCanvas(srcCanvas, destCanvas, {
+      quality: 3,
+      unsharpAmount: 0
+    }, function (err) {
+      if (err) {
+        throw err;
+      }
+
+      resemble(destCanvas.toDataURL())
+        .compareTo(fixtureCanvas.toDataURL())
+        .onComplete(function (data) {
+          if (data.misMatchPercentage !== '0.00') {
+            saveDataUrlToFile(data.getImageDataUrl(), 'fixture-test-diff.png');
+            destCanvas
+              .pngStream()
+              .pipe(fs.createWriteStream(path.join(OUTPUT_DIRECTORY, 'fixture-test-output.png')));
+            fixtureCanvas
+              .pngStream()
+              .pipe(fs.createWriteStream(path.join(OUTPUT_DIRECTORY, 'fixture-test-expected.png')));
+            done(new Error('Images mismatch in ' + data.misMatchPercentage + '% of pixels'));
+          } else {
+            done();
+          }
+        });
+    });
+  });
+});