From bf432a37bb24e37b709794b0c6ff26b85b60eb6d Mon Sep 17 00:00:00 2001
From: Yury Delendik <ydelendik@mozilla.com>
Date: Sat, 25 Jan 2014 12:18:22 -0600
Subject: [PATCH] Refactors shared/pattern.js into core/ and display/

---
 examples/acroforms/index.html  |   2 +-
 examples/helloworld/index.html |   2 +-
 make.js                        |   3 +-
 src/core/evaluator.js          |   4 +-
 src/core/pattern.js            | 241 +++++++++++++++++++
 src/display/canvas.js          |   8 +-
 src/display/pattern_helper.js  | 210 ++++++++++++++++
 src/shared/pattern.js          | 424 ---------------------------------
 src/worker_loader.js           |   2 +-
 test/font/font_test.html       |   3 +-
 test/test_slave.html           |   2 +-
 test/unit/unit_test.html       |   3 +-
 web/viewer.html                |   2 +-
 13 files changed, 468 insertions(+), 438 deletions(-)
 create mode 100644 src/core/pattern.js
 create mode 100644 src/display/pattern_helper.js
 delete mode 100644 src/shared/pattern.js

diff --git a/examples/acroforms/index.html b/examples/acroforms/index.html
index 91094f390..45916d23c 100644
--- a/examples/acroforms/index.html
+++ b/examples/acroforms/index.html
@@ -6,12 +6,12 @@
   <!-- In production, change the content of PDFJS.workerSrc below -->
   <script type="text/javascript" src="../../src/shared/util.js"></script>
   <script type="text/javascript" src="../../src/shared/colorspace.js"></script>
-  <script type="text/javascript" src="../../src/shared/pattern.js"></script>
   <script type="text/javascript" src="../../src/shared/function.js"></script>
   <script type="text/javascript" src="../../src/shared/annotation.js"></script>
   <script type="text/javascript" src="../../src/display/api.js"></script>
   <script type="text/javascript" src="../../src/display/metadata.js"></script>
   <script type="text/javascript" src="../../src/display/canvas.js"></script>
+  <script type="text/javascript" src="../../src/display/pattern_helper.js"></script>
   <script type="text/javascript" src="../../src/display/font_loader.js"></script>
 
   <script type="text/javascript">
diff --git a/examples/helloworld/index.html b/examples/helloworld/index.html
index 35ddf2838..2d9b2ab0e 100644
--- a/examples/helloworld/index.html
+++ b/examples/helloworld/index.html
@@ -6,12 +6,12 @@
   <!-- In production, change the content of PDFJS.workerSrc below -->
   <script type="text/javascript" src="../../src/shared/util.js"></script>
   <script type="text/javascript" src="../../src/shared/colorspace.js"></script>
-  <script type="text/javascript" src="../../src/shared/pattern.js"></script>
   <script type="text/javascript" src="../../src/shared/function.js"></script>
   <script type="text/javascript" src="../../src/shared/annotation.js"></script>
   <script type="text/javascript" src="../../src/display/api.js"></script>
   <script type="text/javascript" src="../../src/display/metadata.js"></script>
   <script type="text/javascript" src="../../src/display/canvas.js"></script>
+  <script type="text/javascript" src="../../src/display/pattern_helper.js"></script>
   <script type="text/javascript" src="../../src/display/font_loader.js"></script>
 
   <script type="text/javascript">
diff --git a/make.js b/make.js
index 44f8e5878..063045fca 100644
--- a/make.js
+++ b/make.js
@@ -277,7 +277,6 @@ target.bundle = function(args) {
   var SHARED_SRC_FILES = [
     'shared/util.js',
     'shared/colorspace.js',
-    'shared/pattern.js',
     'shared/function.js',
     'shared/annotation.js',
   ];
@@ -286,6 +285,7 @@ target.bundle = function(args) {
     'display/api.js',
     'display/metadata.js',
     'display/canvas.js',
+    'display/pattern_helper.js',
     'display/font_loader.js'
   ]);
 
@@ -298,6 +298,7 @@ target.bundle = function(args) {
     'core/charsets.js',
     'core/cidmaps.js',
     'core/crypto.js',
+    'core/pattern.js',
     'core/evaluator.js',
     'core/fonts.js',
     'core/font_renderer.js',
diff --git a/src/core/evaluator.js b/src/core/evaluator.js
index 5d0ccb69e..d88c76fb1 100644
--- a/src/core/evaluator.js
+++ b/src/core/evaluator.js
@@ -19,7 +19,7 @@
            info, isArray, isCmd, isDict, isEOF, isName, isNum,
            isStream, isString, JpegStream, Lexer, Metrics, Name, Parser,
            Pattern, PDFImage, PDFJS, serifFonts, stdFontMap, symbolsFonts,
-           TilingPattern, warn, Util, Promise, LegacyPromise,
+           getTilingPatternIR, warn, Util, Promise, LegacyPromise,
            RefSetCache, isRef, TextRenderingMode, CMapFactory, OPS,
            UNSUPPORTED_FEATURES, UnsupportedManager */
 
@@ -218,7 +218,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
       // Add the dependencies to the parent operator list so they are resolved
       // before sub operator list is executed synchronously.
       operatorList.addDependencies(tilingOpList.dependencies);
-      operatorList.addOp(fn, TilingPattern.getIR({
+      operatorList.addOp(fn, getTilingPatternIR({
                                fnArray: tilingOpList.fnArray,
                                argsArray: tilingOpList.argsArray
                               }, patternDict, args));
diff --git a/src/core/pattern.js b/src/core/pattern.js
new file mode 100644
index 000000000..5a1535ba9
--- /dev/null
+++ b/src/core/pattern.js
@@ -0,0 +1,241 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+/* Copyright 2012 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/* globals ColorSpace, PDFFunction, Util, error, warn, info, isArray, isStream,
+           isPDFFunction, UnsupportedManager, UNSUPPORTED_FEATURES */
+
+'use strict';
+
+var PatternType = {
+  AXIAL: 2,
+  RADIAL: 3
+};
+
+var Pattern = (function PatternClosure() {
+  // Constructor should define this.getPattern
+  function Pattern() {
+    error('should not call Pattern constructor');
+  }
+
+  Pattern.prototype = {
+    // Input: current Canvas context
+    // Output: the appropriate fillStyle or strokeStyle
+    getPattern: function Pattern_getPattern(ctx) {
+      error('Should not call Pattern.getStyle: ' + ctx);
+    }
+  };
+
+  Pattern.parseShading = function Pattern_parseShading(shading, matrix, xref,
+                                                       res) {
+
+    var dict = isStream(shading) ? shading.dict : shading;
+    var type = dict.get('ShadingType');
+
+    switch (type) {
+      case PatternType.AXIAL:
+      case PatternType.RADIAL:
+        // Both radial and axial shadings are handled by RadialAxial shading.
+        return new Shadings.RadialAxial(dict, matrix, xref, res);
+      default:
+        UnsupportedManager.notify(UNSUPPORTED_FEATURES.shadingPattern);
+        return new Shadings.Dummy();
+    }
+  };
+  return Pattern;
+})();
+
+var Shadings = {};
+
+// A small number to offset the first/last color stops so we can insert ones to
+// support extend.  Number.MIN_VALUE appears to be too small and breaks the
+// extend. 1e-7 works in FF but chrome seems to use an even smaller sized number
+// internally so we have to go bigger.
+Shadings.SMALL_NUMBER = 1e-2;
+
+// Radial and axial shading have very similar implementations
+// If needed, the implementations can be broken into two classes
+Shadings.RadialAxial = (function RadialAxialClosure() {
+  function RadialAxial(dict, matrix, xref, res) {
+    this.matrix = matrix;
+    this.coordsArr = dict.get('Coords');
+    this.shadingType = dict.get('ShadingType');
+    this.type = 'Pattern';
+    var cs = dict.get('ColorSpace', 'CS');
+    cs = ColorSpace.parse(cs, xref, res);
+    this.cs = cs;
+
+    var t0 = 0.0, t1 = 1.0;
+    if (dict.has('Domain')) {
+      var domainArr = dict.get('Domain');
+      t0 = domainArr[0];
+      t1 = domainArr[1];
+    }
+
+    var extendStart = false, extendEnd = false;
+    if (dict.has('Extend')) {
+      var extendArr = dict.get('Extend');
+      extendStart = extendArr[0];
+      extendEnd = extendArr[1];
+    }
+
+    if (this.shadingType === PatternType.RADIAL &&
+       (!extendStart || !extendEnd)) {
+      // Radial gradient only currently works if either circle is fully within
+      // the other circle.
+      var x1 = this.coordsArr[0];
+      var y1 = this.coordsArr[1];
+      var r1 = this.coordsArr[2];
+      var x2 = this.coordsArr[3];
+      var y2 = this.coordsArr[4];
+      var r2 = this.coordsArr[5];
+      var distance = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
+      if (r1 <= r2 + distance &&
+          r2 <= r1 + distance) {
+        warn('Unsupported radial gradient.');
+      }
+    }
+
+    this.extendStart = extendStart;
+    this.extendEnd = extendEnd;
+
+    var fnObj = dict.get('Function');
+    var fn;
+    if (isArray(fnObj)) {
+      var fnArray = [];
+      for (var j = 0, jj = fnObj.length; j < jj; j++) {
+        var obj = xref.fetchIfRef(fnObj[j]);
+        if (!isPDFFunction(obj)) {
+          error('Invalid function');
+        }
+        fnArray.push(PDFFunction.parse(xref, obj));
+      }
+      fn = function radialAxialColorFunction(arg) {
+        var out = [];
+        for (var i = 0, ii = fnArray.length; i < ii; i++) {
+          out.push(fnArray[i](arg)[0]);
+        }
+        return out;
+      };
+    } else {
+      if (!isPDFFunction(fnObj)) {
+        error('Invalid function');
+      }
+      fn = PDFFunction.parse(xref, fnObj);
+    }
+
+    // 10 samples seems good enough for now, but probably won't work
+    // if there are sharp color changes. Ideally, we would implement
+    // the spec faithfully and add lossless optimizations.
+    var diff = t1 - t0;
+    var step = diff / 10;
+
+    var colorStops = this.colorStops = [];
+
+    // Protect against bad domains so we don't end up in an infinte loop below.
+    if (t0 >= t1 || step <= 0) {
+      // Acrobat doesn't seem to handle these cases so we'll ignore for
+      // now.
+      info('Bad shading domain.');
+      return;
+    }
+
+    for (var i = t0; i <= t1; i += step) {
+      var rgbColor = cs.getRgb(fn([i]), 0);
+      var cssColor = Util.makeCssRgb(rgbColor);
+      colorStops.push([(i - t0) / diff, cssColor]);
+    }
+
+    var background = 'transparent';
+    if (dict.has('Background')) {
+      var rgbColor = cs.getRgb(dict.get('Background'), 0);
+      background = Util.makeCssRgb(rgbColor);
+    }
+
+    if (!extendStart) {
+      // Insert a color stop at the front and offset the first real color stop
+      // so it doesn't conflict with the one we insert.
+      colorStops.unshift([0, background]);
+      colorStops[1][0] += Shadings.SMALL_NUMBER;
+    }
+    if (!extendEnd) {
+      // Same idea as above in extendStart but for the end.
+      colorStops[colorStops.length - 1][0] -= Shadings.SMALL_NUMBER;
+      colorStops.push([1, background]);
+    }
+
+    this.colorStops = colorStops;
+  }
+
+  RadialAxial.prototype = {
+    getIR: function RadialAxial_getIR() {
+      var coordsArr = this.coordsArr;
+      var shadingType = this.shadingType;
+      var type, p0, p1, r0, r1;
+      if (shadingType == PatternType.AXIAL) {
+        p0 = [coordsArr[0], coordsArr[1]];
+        p1 = [coordsArr[2], coordsArr[3]];
+        r0 = null;
+        r1 = null;
+        type = 'axial';
+      } else if (shadingType == PatternType.RADIAL) {
+        p0 = [coordsArr[0], coordsArr[1]];
+        p1 = [coordsArr[3], coordsArr[4]];
+        r0 = coordsArr[2];
+        r1 = coordsArr[5];
+        type = 'radial';
+      } else {
+        error('getPattern type unknown: ' + shadingType);
+      }
+
+      var matrix = this.matrix;
+      if (matrix) {
+        p0 = Util.applyTransform(p0, matrix);
+        p1 = Util.applyTransform(p1, matrix);
+      }
+
+      return ['RadialAxial', type, this.colorStops, p0, p1, r0, r1];
+    }
+  };
+
+  return RadialAxial;
+})();
+
+Shadings.Dummy = (function DummyClosure() {
+  function Dummy() {
+    this.type = 'Pattern';
+  }
+
+  Dummy.prototype = {
+    getIR: function Dummy_getIR() {
+      return ['Dummy'];
+    }
+  };
+  return Dummy;
+})();
+
+function getTilingPatternIR(operatorList, dict, args) {
+  var matrix = dict.get('Matrix');
+  var bbox = dict.get('BBox');
+  var xstep = dict.get('XStep');
+  var ystep = dict.get('YStep');
+  var paintType = dict.get('PaintType');
+  var tilingType = dict.get('TilingType');
+
+  return [
+    'TilingPattern', args, operatorList, matrix, bbox, xstep, ystep,
+    paintType, tilingType
+  ];
+}
diff --git a/src/display/canvas.js b/src/display/canvas.js
index a2dee78a6..776cb0222 100644
--- a/src/display/canvas.js
+++ b/src/display/canvas.js
@@ -16,8 +16,8 @@
  */
 /* globals ColorSpace, DeviceCmykCS, DeviceGrayCS, DeviceRgbCS, error,
            FONT_IDENTITY_MATRIX, IDENTITY_MATRIX, ImageData, isArray, isNum,
-           Pattern, TilingPattern, Util, warn, assert, info, shadow,
-           TextRenderingMode, OPS, Promise */
+           TilingPattern, OPS, Promise, Util, warn, assert, info, shadow,
+           TextRenderingMode, getShadingPatternFromIR */
 
 'use strict';
 
@@ -1500,7 +1500,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
         var pattern = new TilingPattern(IR, color, this.ctx, this.objs,
                                         this.commonObjs, this.baseTransform);
       } else if (IR[0] == 'RadialAxial' || IR[0] == 'Dummy') {
-        var pattern = Pattern.shadingFromIR(IR);
+        var pattern = getShadingPatternFromIR(IR);
       } else {
         error('Unkown IR type ' + IR[0]);
       }
@@ -1582,7 +1582,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       var ctx = this.ctx;
 
       this.save();
-      var pattern = Pattern.shadingFromIR(patternIR);
+      var pattern = getShadingPatternFromIR(patternIR);
       ctx.fillStyle = pattern.getPattern(ctx, this);
 
       var inv = ctx.mozCurrentTransformInverse;
diff --git a/src/display/pattern_helper.js b/src/display/pattern_helper.js
new file mode 100644
index 000000000..ee20fa130
--- /dev/null
+++ b/src/display/pattern_helper.js
@@ -0,0 +1,210 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+/* Copyright 2014 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+/* globals CanvasGraphics, CachedCanvases, ColorSpace, Util, error, info,
+           isArray */
+
+'use strict';
+
+var ShadingIRs = {};
+
+ShadingIRs.RadialAxial = {
+  fromIR: function RadialAxial_fromIR(raw) {
+    var type = raw[1];
+    var colorStops = raw[2];
+    var p0 = raw[3];
+    var p1 = raw[4];
+    var r0 = raw[5];
+    var r1 = raw[6];
+    return {
+      type: 'Pattern',
+      getPattern: function RadialAxial_getPattern(ctx) {
+        var grad;
+        if (type === 'axial') {
+          grad = ctx.createLinearGradient(p0[0], p0[1], p1[0], p1[1]);
+        } else if (type === 'radial') {
+          grad = ctx.createRadialGradient(p0[0], p0[1], r0, p1[0], p1[1], r1);
+        }
+
+        for (var i = 0, ii = colorStops.length; i < ii; ++i) {
+          var c = colorStops[i];
+          grad.addColorStop(c[0], c[1]);
+        }
+        return grad;
+      }
+    };
+  }
+};
+
+ShadingIRs.Dummy = {
+  fromIR: function Dummy_fromIR() {
+    return {
+      type: 'Pattern',
+      getPattern: function Dummy_fromIR_getPattern() {
+        return 'hotpink';
+      }
+    };
+  }
+};
+
+function getShadingPatternFromIR(raw) {
+  return ShadingIRs[raw[0]].fromIR(raw);
+}
+
+var TilingPattern = (function TilingPatternClosure() {
+  var PaintType = {
+    COLORED: 1,
+    UNCOLORED: 2
+  };
+
+  var MAX_PATTERN_SIZE = 3000; // 10in @ 300dpi shall be enough
+
+  function TilingPattern(IR, color, ctx, objs, commonObjs, baseTransform) {
+    this.name = IR[1][0].name;
+    this.operatorList = IR[2];
+    this.matrix = IR[3] || [1, 0, 0, 1, 0, 0];
+    this.bbox = IR[4];
+    this.xstep = IR[5];
+    this.ystep = IR[6];
+    this.paintType = IR[7];
+    this.tilingType = IR[8];
+    this.color = color;
+    this.objs = objs;
+    this.commonObjs = commonObjs;
+    this.baseTransform = baseTransform;
+    this.type = 'Pattern';
+    this.ctx = ctx;
+  }
+
+  TilingPattern.prototype = {
+    createPatternCanvas: function TilinPattern_createPatternCanvas(owner) {
+      var operatorList = this.operatorList;
+      var bbox = this.bbox;
+      var xstep = this.xstep;
+      var ystep = this.ystep;
+      var paintType = this.paintType;
+      var tilingType = this.tilingType;
+      var color = this.color;
+      var objs = this.objs;
+      var commonObjs = this.commonObjs;
+      var ctx = this.ctx;
+
+      info('TilingType: ' + tilingType);
+
+      var x0 = bbox[0], y0 = bbox[1], x1 = bbox[2], y1 = bbox[3];
+
+      var topLeft = [x0, y0];
+      // we want the canvas to be as large as the step size
+      var botRight = [x0 + xstep, y0 + ystep];
+
+      var width = botRight[0] - topLeft[0];
+      var height = botRight[1] - topLeft[1];
+
+      // Obtain scale from matrix and current transformation matrix.
+      var matrixScale = Util.singularValueDecompose2dScale(this.matrix);
+      var curMatrixScale = Util.singularValueDecompose2dScale(
+        this.baseTransform);
+      var combinedScale = [matrixScale[0] * curMatrixScale[0],
+        matrixScale[1] * curMatrixScale[1]];
+
+      // MAX_PATTERN_SIZE is used to avoid OOM situation.
+      // Use width and height values that are as close as possible to the end
+      // result when the pattern is used. Too low value makes the pattern look
+      // blurry. Too large value makes it look too crispy.
+      width = Math.min(Math.ceil(Math.abs(width * combinedScale[0])),
+        MAX_PATTERN_SIZE);
+
+      height = Math.min(Math.ceil(Math.abs(height * combinedScale[1])),
+        MAX_PATTERN_SIZE);
+
+      var tmpCanvas = CachedCanvases.getCanvas('pattern', width, height, true);
+      var tmpCtx = tmpCanvas.context;
+      var graphics = new CanvasGraphics(tmpCtx, commonObjs, objs);
+      graphics.groupLevel = owner.groupLevel;
+
+      this.setFillAndStrokeStyleToContext(tmpCtx, paintType, color);
+
+      this.setScale(width, height, xstep, ystep);
+      this.transformToScale(graphics);
+
+      // transform coordinates to pattern space
+      var tmpTranslate = [1, 0, 0, 1, -topLeft[0], -topLeft[1]];
+      graphics.transform.apply(graphics, tmpTranslate);
+
+      this.clipBbox(graphics, bbox, x0, y0, x1, y1);
+
+      graphics.executeOperatorList(operatorList);
+      return tmpCanvas.canvas;
+    },
+
+    setScale: function TilingPattern_setScale(width, height, xstep, ystep) {
+      this.scale = [width / xstep, height / ystep];
+    },
+
+    transformToScale: function TilingPattern_transformToScale(graphics) {
+      var scale = this.scale;
+      var tmpScale = [scale[0], 0, 0, scale[1], 0, 0];
+      graphics.transform.apply(graphics, tmpScale);
+    },
+
+    scaleToContext: function TilingPattern_scaleToContext() {
+      var scale = this.scale;
+      this.ctx.scale(1 / scale[0], 1 / scale[1]);
+    },
+
+    clipBbox: function clipBbox(graphics, bbox, x0, y0, x1, y1) {
+      if (bbox && isArray(bbox) && 4 == bbox.length) {
+        var bboxWidth = x1 - x0;
+        var bboxHeight = y1 - y0;
+        graphics.rectangle(x0, y0, bboxWidth, bboxHeight);
+        graphics.clip();
+        graphics.endPath();
+      }
+    },
+
+    setFillAndStrokeStyleToContext:
+      function setFillAndStrokeStyleToContext(context, paintType, color) {
+        switch (paintType) {
+          case PaintType.COLORED:
+            var ctx = this.ctx;
+            context.fillStyle = ctx.fillStyle;
+            context.strokeStyle = ctx.strokeStyle;
+            break;
+          case PaintType.UNCOLORED:
+            var rgbColor = ColorSpace.singletons.rgb.getRgb(color, 0);
+            var cssColor = Util.makeCssRgb(rgbColor);
+            context.fillStyle = cssColor;
+            context.strokeStyle = cssColor;
+            break;
+          default:
+            error('Unsupported paint type: ' + paintType);
+        }
+      },
+
+    getPattern: function TilingPattern_getPattern(ctx, owner) {
+      var temporaryPatternCanvas = this.createPatternCanvas(owner);
+
+      var ctx = this.ctx;
+      ctx.setTransform.apply(ctx, this.baseTransform);
+      ctx.transform.apply(ctx, this.matrix);
+      this.scaleToContext();
+
+      return ctx.createPattern(temporaryPatternCanvas, 'repeat');
+    }
+  };
+
+  return TilingPattern;
+})();
diff --git a/src/shared/pattern.js b/src/shared/pattern.js
deleted file mode 100644
index f0fa153a8..000000000
--- a/src/shared/pattern.js
+++ /dev/null
@@ -1,424 +0,0 @@
-/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
-/* Copyright 2012 Mozilla Foundation
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-/* globals CanvasGraphics, ColorSpace, DeviceRgbCS, error,
-           info, isArray, isPDFFunction, isStream, PDFFunction, Util,
-           warn, CachedCanvases, UnsupportedManager, UNSUPPORTED_FEATURES */
-
-'use strict';
-
-var PatternType = {
-  AXIAL: 2,
-  RADIAL: 3
-};
-
-var Pattern = (function PatternClosure() {
-  // Constructor should define this.getPattern
-  function Pattern() {
-    error('should not call Pattern constructor');
-  }
-
-  Pattern.prototype = {
-    // Input: current Canvas context
-    // Output: the appropriate fillStyle or strokeStyle
-    getPattern: function Pattern_getPattern(ctx) {
-      error('Should not call Pattern.getStyle: ' + ctx);
-    }
-  };
-
-  Pattern.shadingFromIR = function Pattern_shadingFromIR(raw) {
-    return Shadings[raw[0]].fromIR(raw);
-  };
-
-  Pattern.parseShading = function Pattern_parseShading(shading, matrix, xref,
-                                                       res) {
-
-    var dict = isStream(shading) ? shading.dict : shading;
-    var type = dict.get('ShadingType');
-
-    switch (type) {
-      case PatternType.AXIAL:
-      case PatternType.RADIAL:
-        // Both radial and axial shadings are handled by RadialAxial shading.
-        return new Shadings.RadialAxial(dict, matrix, xref, res);
-      default:
-        UnsupportedManager.notify(UNSUPPORTED_FEATURES.shadingPattern);
-        return new Shadings.Dummy();
-    }
-  };
-  return Pattern;
-})();
-
-var Shadings = {};
-
-// A small number to offset the first/last color stops so we can insert ones to
-// support extend.  Number.MIN_VALUE appears to be too small and breaks the
-// extend. 1e-7 works in FF but chrome seems to use an even smaller sized number
-// internally so we have to go bigger.
-Shadings.SMALL_NUMBER = 1e-2;
-
-// Radial and axial shading have very similar implementations
-// If needed, the implementations can be broken into two classes
-Shadings.RadialAxial = (function RadialAxialClosure() {
-  function RadialAxial(dict, matrix, xref, res, ctx) {
-    this.matrix = matrix;
-    this.coordsArr = dict.get('Coords');
-    this.shadingType = dict.get('ShadingType');
-    this.type = 'Pattern';
-    this.ctx = ctx;
-    var cs = dict.get('ColorSpace', 'CS');
-    cs = ColorSpace.parse(cs, xref, res);
-    this.cs = cs;
-
-    var t0 = 0.0, t1 = 1.0;
-    if (dict.has('Domain')) {
-      var domainArr = dict.get('Domain');
-      t0 = domainArr[0];
-      t1 = domainArr[1];
-    }
-
-    var extendStart = false, extendEnd = false;
-    if (dict.has('Extend')) {
-      var extendArr = dict.get('Extend');
-      extendStart = extendArr[0];
-      extendEnd = extendArr[1];
-    }
-
-    if (this.shadingType === PatternType.RADIAL &&
-       (!extendStart || !extendEnd)) {
-      // Radial gradient only currently works if either circle is fully within
-      // the other circle.
-      var x1 = this.coordsArr[0];
-      var y1 = this.coordsArr[1];
-      var r1 = this.coordsArr[2];
-      var x2 = this.coordsArr[3];
-      var y2 = this.coordsArr[4];
-      var r2 = this.coordsArr[5];
-      var distance = Math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
-      if (r1 <= r2 + distance &&
-          r2 <= r1 + distance) {
-        warn('Unsupported radial gradient.');
-      }
-    }
-
-    this.extendStart = extendStart;
-    this.extendEnd = extendEnd;
-
-    var fnObj = dict.get('Function');
-    var fn;
-    if (isArray(fnObj)) {
-      var fnArray = [];
-      for (var j = 0, jj = fnObj.length; j < jj; j++) {
-        var obj = xref.fetchIfRef(fnObj[j]);
-        if (!isPDFFunction(obj)) {
-          error('Invalid function');
-        }
-        fnArray.push(PDFFunction.parse(xref, obj));
-      }
-      fn = function radialAxialColorFunction(arg) {
-        var out = [];
-        for (var i = 0, ii = fnArray.length; i < ii; i++) {
-          out.push(fnArray[i](arg)[0]);
-        }
-        return out;
-      };
-    } else {
-      if (!isPDFFunction(fnObj)) {
-        error('Invalid function');
-      }
-      fn = PDFFunction.parse(xref, fnObj);
-    }
-
-    // 10 samples seems good enough for now, but probably won't work
-    // if there are sharp color changes. Ideally, we would implement
-    // the spec faithfully and add lossless optimizations.
-    var diff = t1 - t0;
-    var step = diff / 10;
-
-    var colorStops = this.colorStops = [];
-
-    // Protect against bad domains so we don't end up in an infinte loop below.
-    if (t0 >= t1 || step <= 0) {
-      // Acrobat doesn't seem to handle these cases so we'll ignore for
-      // now.
-      info('Bad shading domain.');
-      return;
-    }
-
-    for (var i = t0; i <= t1; i += step) {
-      var rgbColor = cs.getRgb(fn([i]), 0);
-      var cssColor = Util.makeCssRgb(rgbColor);
-      colorStops.push([(i - t0) / diff, cssColor]);
-    }
-
-    var background = 'transparent';
-    if (dict.has('Background')) {
-      var rgbColor = cs.getRgb(dict.get('Background'), 0);
-      background = Util.makeCssRgb(rgbColor);
-    }
-
-    if (!extendStart) {
-      // Insert a color stop at the front and offset the first real color stop
-      // so it doesn't conflict with the one we insert.
-      colorStops.unshift([0, background]);
-      colorStops[1][0] += Shadings.SMALL_NUMBER;
-    }
-    if (!extendEnd) {
-      // Same idea as above in extendStart but for the end.
-      colorStops[colorStops.length - 1][0] -= Shadings.SMALL_NUMBER;
-      colorStops.push([1, background]);
-    }
-
-    this.colorStops = colorStops;
-  }
-
-  RadialAxial.fromIR = function RadialAxial_fromIR(raw) {
-    var type = raw[1];
-    var colorStops = raw[2];
-    var p0 = raw[3];
-    var p1 = raw[4];
-    var r0 = raw[5];
-    var r1 = raw[6];
-    return {
-      type: 'Pattern',
-      getPattern: function RadialAxial_getPattern(ctx) {
-        var grad;
-        if (type == PatternType.AXIAL)
-          grad = ctx.createLinearGradient(p0[0], p0[1], p1[0], p1[1]);
-        else if (type == PatternType.RADIAL)
-          grad = ctx.createRadialGradient(p0[0], p0[1], r0, p1[0], p1[1], r1);
-
-        for (var i = 0, ii = colorStops.length; i < ii; ++i) {
-          var c = colorStops[i];
-          grad.addColorStop(c[0], c[1]);
-        }
-        return grad;
-      }
-    };
-  };
-
-  RadialAxial.prototype = {
-    getIR: function RadialAxial_getIR() {
-      var coordsArr = this.coordsArr;
-      var type = this.shadingType;
-      if (type == PatternType.AXIAL) {
-        var p0 = [coordsArr[0], coordsArr[1]];
-        var p1 = [coordsArr[2], coordsArr[3]];
-        var r0 = null;
-        var r1 = null;
-      } else if (type == PatternType.RADIAL) {
-        var p0 = [coordsArr[0], coordsArr[1]];
-        var p1 = [coordsArr[3], coordsArr[4]];
-        var r0 = coordsArr[2];
-        var r1 = coordsArr[5];
-      } else {
-        error('getPattern type unknown: ' + type);
-      }
-
-      var matrix = this.matrix;
-      if (matrix) {
-        p0 = Util.applyTransform(p0, matrix);
-        p1 = Util.applyTransform(p1, matrix);
-      }
-
-      return ['RadialAxial', type, this.colorStops, p0, p1, r0, r1];
-    }
-  };
-
-  return RadialAxial;
-})();
-
-Shadings.Dummy = (function DummyClosure() {
-  function Dummy() {
-    this.type = 'Pattern';
-  }
-
-  Dummy.fromIR = function Dummy_fromIR() {
-    return {
-      type: 'Pattern',
-      getPattern: function Dummy_fromIR_getPattern() {
-        return 'hotpink';
-      }
-    };
-  };
-
-  Dummy.prototype = {
-    getIR: function Dummy_getIR() {
-      return ['Dummy'];
-    }
-  };
-  return Dummy;
-})();
-
-var TilingPattern = (function TilingPatternClosure() {
-  var PaintType = {
-    COLORED: 1,
-    UNCOLORED: 2
-  };
-
-  var MAX_PATTERN_SIZE = 3000; // 10in @ 300dpi shall be enough
-
-  function TilingPattern(IR, color, ctx, objs, commonObjs, baseTransform) {
-    this.name = IR[1][0].name;
-    this.operatorList = IR[2];
-    this.matrix = IR[3] || [1, 0, 0, 1, 0, 0];
-    this.bbox = IR[4];
-    this.xstep = IR[5];
-    this.ystep = IR[6];
-    this.paintType = IR[7];
-    this.tilingType = IR[8];
-    this.color = color;
-    this.objs = objs;
-    this.commonObjs = commonObjs;
-    this.baseTransform = baseTransform;
-    this.type = 'Pattern';
-    this.ctx = ctx;
-  }
-
-  TilingPattern.getIR = function TilingPattern_getIR(operatorList, dict, args) {
-    var matrix = dict.get('Matrix');
-    var bbox = dict.get('BBox');
-    var xstep = dict.get('XStep');
-    var ystep = dict.get('YStep');
-    var paintType = dict.get('PaintType');
-    var tilingType = dict.get('TilingType');
-
-    return [
-      'TilingPattern', args, operatorList, matrix, bbox, xstep, ystep,
-      paintType, tilingType
-    ];
-  };
-
-  TilingPattern.prototype = {
-    createPatternCanvas: function TilinPattern_createPatternCanvas(owner) {
-      var operatorList = this.operatorList;
-      var bbox = this.bbox;
-      var xstep = this.xstep;
-      var ystep = this.ystep;
-      var paintType = this.paintType;
-      var tilingType = this.tilingType;
-      var color = this.color;
-      var objs = this.objs;
-      var commonObjs = this.commonObjs;
-      var ctx = this.ctx;
-
-      info('TilingType: ' + tilingType);
-
-      var x0 = bbox[0], y0 = bbox[1], x1 = bbox[2], y1 = bbox[3];
-
-      var topLeft = [x0, y0];
-      // we want the canvas to be as large as the step size
-      var botRight = [x0 + xstep, y0 + ystep];
-
-      var width = botRight[0] - topLeft[0];
-      var height = botRight[1] - topLeft[1];
-
-      // Obtain scale from matrix and current transformation matrix.
-      var matrixScale = Util.singularValueDecompose2dScale(this.matrix);
-      var curMatrixScale = Util.singularValueDecompose2dScale(
-                             this.baseTransform);
-      var combinedScale = [matrixScale[0] * curMatrixScale[0],
-                           matrixScale[1] * curMatrixScale[1]];
-
-      // MAX_PATTERN_SIZE is used to avoid OOM situation.
-      // Use width and height values that are as close as possible to the end
-      // result when the pattern is used. Too low value makes the pattern look
-      // blurry. Too large value makes it look too crispy.
-      width = Math.min(Math.ceil(Math.abs(width * combinedScale[0])),
-                       MAX_PATTERN_SIZE);
-
-      height = Math.min(Math.ceil(Math.abs(height * combinedScale[1])),
-                        MAX_PATTERN_SIZE);
-
-      var tmpCanvas = CachedCanvases.getCanvas('pattern', width, height, true);
-      var tmpCtx = tmpCanvas.context;
-      var graphics = new CanvasGraphics(tmpCtx, commonObjs, objs);
-      graphics.groupLevel = owner.groupLevel;
-
-      this.setFillAndStrokeStyleToContext(tmpCtx, paintType, color);
-
-      this.setScale(width, height, xstep, ystep);
-      this.transformToScale(graphics);
-
-      // transform coordinates to pattern space
-      var tmpTranslate = [1, 0, 0, 1, -topLeft[0], -topLeft[1]];
-      graphics.transform.apply(graphics, tmpTranslate);
-
-      this.clipBbox(graphics, bbox, x0, y0, x1, y1);
-
-      graphics.executeOperatorList(operatorList);
-      return tmpCanvas.canvas;
-    },
-
-    setScale: function TilingPattern_setScale(width, height, xstep, ystep) {
-      this.scale = [width / xstep, height / ystep];
-    },
-
-    transformToScale: function TilingPattern_transformToScale(graphics) {
-      var scale = this.scale;
-      var tmpScale = [scale[0], 0, 0, scale[1], 0, 0];
-      graphics.transform.apply(graphics, tmpScale);
-    },
-
-    scaleToContext: function TilingPattern_scaleToContext() {
-      var scale = this.scale;
-      this.ctx.scale(1 / scale[0], 1 / scale[1]);
-    },
-
-    clipBbox: function clipBbox(graphics, bbox, x0, y0, x1, y1) {
-      if (bbox && isArray(bbox) && 4 == bbox.length) {
-        var bboxWidth = x1 - x0;
-        var bboxHeight = y1 - y0;
-        graphics.rectangle(x0, y0, bboxWidth, bboxHeight);
-        graphics.clip();
-        graphics.endPath();
-      }
-    },
-
-    setFillAndStrokeStyleToContext:
-      function setFillAndStrokeStyleToContext(context, paintType, color) {
-      switch (paintType) {
-        case PaintType.COLORED:
-          var ctx = this.ctx;
-          context.fillStyle = ctx.fillStyle;
-          context.strokeStyle = ctx.strokeStyle;
-          break;
-        case PaintType.UNCOLORED:
-          var rgbColor = ColorSpace.singletons.rgb.getRgb(color, 0);
-          var cssColor = Util.makeCssRgb(rgbColor);
-          context.fillStyle = cssColor;
-          context.strokeStyle = cssColor;
-          break;
-        default:
-          error('Unsupported paint type: ' + paintType);
-      }
-    },
-
-    getPattern: function TilingPattern_getPattern(ctx, owner) {
-      var temporaryPatternCanvas = this.createPatternCanvas(owner);
-
-      var ctx = this.ctx;
-      ctx.setTransform.apply(ctx, this.baseTransform);
-      ctx.transform.apply(ctx, this.matrix);
-      this.scaleToContext();
-
-      return ctx.createPattern(temporaryPatternCanvas, 'repeat');
-    }
-  };
-
-  return TilingPattern;
-})();
-
diff --git a/src/worker_loader.js b/src/worker_loader.js
index 71fa59d60..f37e02497 100644
--- a/src/worker_loader.js
+++ b/src/worker_loader.js
@@ -22,7 +22,6 @@
 var sharedFiles = [
   'shared/util.js',
   'shared/colorspace.js',
-  'shared/pattern.js',
   'shared/function.js',
   'shared/annotation.js'
 ];
@@ -37,6 +36,7 @@ var otherFiles = [
   'core/charsets.js',
   'core/cidmaps.js',
   'core/crypto.js',
+  'core/pattern.js',
   'core/evaluator.js',
   'core/cmap.js',
   'core/fonts.js',
diff --git a/test/font/font_test.html b/test/font/font_test.html
index efde2bf2e..4c781a2b3 100644
--- a/test/font/font_test.html
+++ b/test/font/font_test.html
@@ -26,13 +26,14 @@
   <script type="text/javascript" src="../../src/core/cidmaps.js"></script>
   <script type="text/javascript" src="../../src/shared/colorspace.js"></script>
   <script type="text/javascript" src="../../src/core/crypto.js"></script>
+  <script type="text/javascript" src="../../src/core/pattern.js"></script>
   <script type="text/javascript" src="../../src/core/evaluator.js"></script>
   <script type="text/javascript" src="../../src/core/fonts.js"></script>
   <script type="text/javascript" src="../../src/core/glyphlist.js"></script>
   <script type="text/javascript" src="../../src/core/image.js"></script>
   <script type="text/javascript" src="../../src/core/metrics.js"></script>
   <script type="text/javascript" src="../../src/core/parser.js"></script>
-  <script type="text/javascript" src="../../src/shared/pattern.js"></script>
+  <script type="text/javascript" src="../../src/display/pattern_helper.js"></script>
   <script type="text/javascript" src="../../src/core/stream.js"></script>
   <script type="text/javascript" src="../../src/core/worker.js"></script>
   <script type="text/javascript" src="../../src/display/metadata.js"></script>
diff --git a/test/test_slave.html b/test/test_slave.html
index a4864dbf9..72439ee76 100644
--- a/test/test_slave.html
+++ b/test/test_slave.html
@@ -21,12 +21,12 @@ limitations under the License.
     <style type="text/css"></style>
     <script type="text/javascript" src="/src/shared/util.js"></script>
     <script type="text/javascript" src="/src/shared/colorspace.js"></script>
-    <script type="text/javascript" src="/src/shared/pattern.js"></script>
     <script type="text/javascript" src="/src/shared/function.js"></script>
     <script type="text/javascript" src="/src/shared/annotation.js"></script>
     <script type="text/javascript" src="/src/display/api.js"></script>
     <script type="text/javascript" src="/src/display/metadata.js"></script>
     <script type="text/javascript" src="/src/display/canvas.js"></script>
+    <script type="text/javascript" src="/src/display/pattern_helper.js"></script>
     <script type="text/javascript" src="/src/display/font_loader.js"></script>
     <script type="text/javascript" src="driver.js"></script>
 
diff --git a/test/unit/unit_test.html b/test/unit/unit_test.html
index df640b66c..c5280d59b 100644
--- a/test/unit/unit_test.html
+++ b/test/unit/unit_test.html
@@ -25,6 +25,7 @@
   <script type="text/javascript" src="../../src/core/cidmaps.js"></script>
   <script type="text/javascript" src="../../src/shared/colorspace.js"></script>
   <script type="text/javascript" src="../../src/core/crypto.js"></script>
+  <script type="text/javascript" src="../../src/core/pattern.js"></script>
   <script type="text/javascript" src="../../src/core/evaluator.js"></script>
   <script type="text/javascript" src="../../src/core/cmap.js"></script>
   <script type="text/javascript" src="../../src/core/fonts.js"></script>
@@ -32,7 +33,7 @@
   <script type="text/javascript" src="../../src/core/image.js"></script>
   <script type="text/javascript" src="../../src/core/metrics.js"></script>
   <script type="text/javascript" src="../../src/core/parser.js"></script>
-  <script type="text/javascript" src="../../src/shared/pattern.js"></script>
+  <script type="text/javascript" src="../../src/display/pattern_helper.js"></script>
   <script type="text/javascript" src="../../src/core/stream.js"></script>
   <script type="text/javascript" src="../../src/core/worker.js"></script>
   <script type="text/javascript" src="../../src/display/metadata.js"></script>
diff --git a/web/viewer.html b/web/viewer.html
index 46d7109c4..116201242 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -46,12 +46,12 @@ limitations under the License.
 <!--#if !PRODUCTION-->
     <script type="text/javascript" src="../src/shared/util.js"></script>
     <script type="text/javascript" src="../src/shared/colorspace.js"></script>
-    <script type="text/javascript" src="../src/shared/pattern.js"></script>
     <script type="text/javascript" src="../src/shared/function.js"></script>
     <script type="text/javascript" src="../src/shared/annotation.js"></script>
     <script type="text/javascript" src="../src/display/api.js"></script>
     <script type="text/javascript" src="../src/display/metadata.js"></script>
     <script type="text/javascript" src="../src/display/canvas.js"></script>
+    <script type="text/javascript" src="../src/display/pattern_helper.js"></script>
     <script type="text/javascript" src="../src/display/font_loader.js"></script>
     <script type="text/javascript">PDFJS.workerSrc = '../src/worker_loader.js';</script>
 <!--#endif-->