Merge pull request #241 from cgjones/workers

#123, part 1: create PartialEvaluator

pdf.js

@@ -3385,18 +3385,13 @@ var Encodings = {
 
 var IDENTITY_MATRIX = [1, 0, 0, 1, 0, 0];
 
-// <canvas> contexts store most of the state we need natively.
+var EvalState = (function() {
-// However, PDF needs a bit more state, which we store here.
-var CanvasExtraState = (function() {
   function constructor() {
     // Are soft masks and alpha values shapes or opacities?
     this.alphaIsShape = false;
     this.fontSize = 0;
     this.textMatrix = IDENTITY_MATRIX;
     this.leading = 0;
-    // Current point (in user coordinates)
-    this.x = 0;
-    this.y = 0;
     // Start of text line (in text coordinates)
     this.lineX = 0;
     this.lineY = 0;
@@ -3413,34 +3408,13 @@ var CanvasExtraState = (function() {
   return constructor;
 })();
 
-function ScratchCanvas(width, height) {
+var PartialEvaluator = (function() {
-  var canvas = document.createElement('canvas');
+  function constructor() {
-  canvas.width = width;
+    this.state = new EvalState();
-  canvas.height = height;
+    this.stateStack = [ ];
-  return canvas;
-}
-
-var CanvasGraphics = (function() {
-  function constructor(canvasCtx, imageCanvas) {
-    this.ctx = canvasCtx;
-    this.current = new CanvasExtraState();
-    this.stateStack = [];
-    this.pendingClip = null;
-    this.res = null;
-    this.xobjs = null;
-    this.ScratchCanvas = imageCanvas || ScratchCanvas;
   }
 
-  var LINE_CAP_STYLES = ['butt', 'round', 'square'];
+  var OP_MAP = {
-  var LINE_JOIN_STYLES = ['miter', 'round', 'bevel'];
-  var NORMAL_CLIP = {};
-  var EO_CLIP = {};
-
-  // Used for tiling patterns
-  var PAINT_TYPE_COLORED = 1, PAINT_TYPE_UNCOLORED = 2;
-
-  constructor.prototype = {
-    map: {
     // Graphics state
     w: 'setLineWidth',
     J: 'setLineCap',
@@ -3533,6 +3507,88 @@ var CanvasGraphics = (function() {
     // Compatibility
     BX: 'beginCompat',
     EX: 'endCompat'
+  };
+
+  constructor.prototype = {
+    eval: function(stream, xref, resources, fonts) {
+      resources = xref.fetchIfRef(resources) || new Dict();
+      var xobjs = xref.fetchIfRef(resources.get('XObject')) || new Dict();
+
+      var parser = new Parser(new Lexer(stream), false);
+      var objpool = [];
+
+      function emitArg(arg) {
+        if (typeof arg == 'object' || typeof arg == 'string') {
+          var index = objpool.length;
+          objpool[index] = arg;
+          return 'objpool[' + index + ']';
+        }
+        return arg;
+      }
+
+      var src = '';
+
+      var args = [];
+      var obj;
+      while (!IsEOF(obj = parser.getObj())) {
+        if (IsCmd(obj)) {
+          var cmd = obj.cmd;
+          var fn = OP_MAP[cmd];
+          assertWellFormed(fn, "Unknown command '" + cmd + "'");
+          // TODO figure out how to type-check vararg functions
+
+          if (cmd == 'Do' && !args[0].code) { // eagerly compile XForm objects
+            var name = args[0].name;
+            var xobj = xobjs.get(name);
+            if (xobj) {
+              xobj = xref.fetchIfRef(xobj);
+              assertWellFormed(IsStream(xobj), 'XObject should be a stream');
+
+              var type = xobj.dict.get('Subtype');
+              assertWellFormed(
+                IsName(type),
+                'XObject should have a Name subtype'
+              );
+
+              if ('Form' == type.name) {
+                args[0].code = this.eval(xobj,
+                                         xref,
+                                         xobj.dict.get('Resources'),
+                                         fonts);
+              }
+            }
+          } else if (cmd == 'Tf') { // eagerly collect all fonts
+            var fontRes = resources.get('Font');
+            if (fontRes) {
+              fontRes = xref.fetchIfRef(fontRes);
+              var font = xref.fetchIfRef(fontRes.get(args[0].name));
+              assertWellFormed(IsDict(font));
+              if (!font.translated) {
+                font.translated = this.translateFont(font, xref, resources);
+                if (fonts && font.translated) {
+                  // keep track of each font we translated so the caller can
+                  // load them asynchronously before calling display on a page
+                  fonts.push(font.translated);
+                }
+              }
+            }
+          }
+
+          src += 'this.';
+          src += fn;
+          src += '(';
+          src += args.map(emitArg).join(',');
+          src += ');\n';
+
+          args.length = 0;
+        } else {
+          assertWellFormed(args.length <= 33, 'Too many arguments');
+          args.push(obj);
+        }
+      }
+
+      var fn = Function('objpool', src);
+      return function(gfx) { fn.call(gfx, objpool); };
     },
 
     translateFont: function(fontDict, xref, resources) {
@@ -3697,7 +3753,66 @@ var CanvasGraphics = (function() {
         properties: properties
       };
     },
+  };
+
+  return constructor;
+})();
+
+// <canvas> contexts store most of the state we need natively.
+// However, PDF needs a bit more state, which we store here.
+var CanvasExtraState = (function() {
+  function constructor() {
+    // Are soft masks and alpha values shapes or opacities?
+    this.alphaIsShape = false;
+    this.fontSize = 0;
+    this.textMatrix = IDENTITY_MATRIX;
+    this.leading = 0;
+    // Current point (in user coordinates)
+    this.x = 0;
+    this.y = 0;
+    // Start of text line (in text coordinates)
+    this.lineX = 0;
+    this.lineY = 0;
+    // Character and word spacing
+    this.charSpace = 0;
+    this.wordSpace = 0;
+    this.textHScale = 100;
+    // Color spaces
+    this.fillColorSpace = null;
+    this.strokeColorSpace = null;
+  }
+  constructor.prototype = {
+  };
+  return constructor;
+})();
+
+function ScratchCanvas(width, height) {
+  var canvas = document.createElement('canvas');
+  canvas.width = width;
+  canvas.height = height;
+  return canvas;
+}
 
+var CanvasGraphics = (function() {
+  function constructor(canvasCtx, imageCanvas) {
+    this.ctx = canvasCtx;
+    this.current = new CanvasExtraState();
+    this.stateStack = [];
+    this.pendingClip = null;
+    this.res = null;
+    this.xobjs = null;
+    this.ScratchCanvas = imageCanvas || ScratchCanvas;
+  }
+
+  var LINE_CAP_STYLES = ['butt', 'round', 'square'];
+  var LINE_JOIN_STYLES = ['miter', 'round', 'bevel'];
+  var NORMAL_CLIP = {};
+  var EO_CLIP = {};
+
+  // Used for tiling patterns
+  var PAINT_TYPE_COLORED = 1, PAINT_TYPE_UNCOLORED = 2;
+
+  constructor.prototype = {
     beginDrawing: function(mediaBox) {
       var cw = this.ctx.canvas.width, ch = this.ctx.canvas.height;
       this.ctx.save();
@@ -3705,6 +3820,11 @@ var CanvasGraphics = (function() {
       this.ctx.translate(0, -mediaBox.height);
     },
 
+    compile: function(stream, xref, resources, fonts) {
+      var pe = new PartialEvaluator();
+      return pe.eval(stream, xref, resources, fonts);
+    },
+
     execute: function(code, xref, resources) {
       resources = xref.fetchIfRef(resources) || new Dict();
       var savedXref = this.xref, savedRes = this.res, savedXobjs = this.xobjs;
@@ -3719,88 +3839,6 @@ var CanvasGraphics = (function() {
       this.xref = savedXref;
     },
 
-    compile: function(stream, xref, resources, fonts) {
-      resources = xref.fetchIfRef(resources) || new Dict();
-      var xobjs = xref.fetchIfRef(resources.get('XObject')) || new Dict();
-
-      var parser = new Parser(new Lexer(stream), false);
-      var objpool = [];
-
-      function emitArg(arg) {
-        if (typeof arg == 'object' || typeof arg == 'string') {
-          var index = objpool.length;
-          objpool[index] = arg;
-          return 'objpool[' + index + ']';
-        }
-        return arg;
-      }
-
-      var src = '';
-
-      var args = [];
-      var map = this.map;
-      var obj;
-      while (!IsEOF(obj = parser.getObj())) {
-        if (IsCmd(obj)) {
-          var cmd = obj.cmd;
-          var fn = map[cmd];
-          assertWellFormed(fn, "Unknown command '" + cmd + "'");
-          // TODO figure out how to type-check vararg functions
-
-          if (cmd == 'Do' && !args[0].code) { // eagerly compile XForm objects
-            var name = args[0].name;
-            var xobj = xobjs.get(name);
-            if (xobj) {
-              xobj = xref.fetchIfRef(xobj);
-              assertWellFormed(IsStream(xobj), 'XObject should be a stream');
-
-              var type = xobj.dict.get('Subtype');
-              assertWellFormed(
-                IsName(type),
-                'XObject should have a Name subtype'
-              );
-
-              if ('Form' == type.name) {
-                args[0].code = this.compile(xobj,
-                                            xref,
-                                            xobj.dict.get('Resources'),
-                                            fonts);
-              }
-            }
-          } else if (cmd == 'Tf') { // eagerly collect all fonts
-            var fontRes = resources.get('Font');
-            if (fontRes) {
-              fontRes = xref.fetchIfRef(fontRes);
-              var font = xref.fetchIfRef(fontRes.get(args[0].name));
-              assertWellFormed(IsDict(font));
-              if (!font.translated) {
-                font.translated = this.translateFont(font, xref, resources);
-                if (fonts && font.translated) {
-                  // keep track of each font we translated so the caller can
-                  // load them asynchronously before calling display on a page
-                  fonts.push(font.translated);
-                }
-              }
-            }
-          }
-
-          src += 'this.';
-          src += fn;
-          src += '(';
-          src += args.map(emitArg).join(',');
-          src += ');\n';
-
-          args.length = 0;
-        } else {
-          assertWellFormed(args.length <= 33, 'Too many arguments');
-          args.push(obj);
-        }
-      }
-
-      var fn = Function('objpool', src);
-      return function(gfx) { fn.call(gfx, objpool); };
-    },
-
     endDrawing: function() {
       this.ctx.restore();
     },