back out bad font measurement changes

fonts.js

@@ -22,7 +22,14 @@ var kMaxWaitForFontFace = 1000;
  */
 
 var Fonts = (function Fonts() {
+  var kScalePrecision = 40;
   var fonts = [];
+
+  if (!isWorker) {
+    var ctx = document.createElement('canvas').getContext('2d');
+    ctx.scale(1 / kScalePrecision, 1);
+  }
+
   var fontCount = 0;
   
   function FontInfo(name, data, properties) {
@@ -35,6 +42,7 @@ var Fonts = (function Fonts() {
   }
 
   var current;
+  var measureCache;
 
   return {
     registerFont: function fonts_registerFont(fontName, data, properties) {
@@ -49,6 +57,28 @@ var Fonts = (function Fonts() {
     },
     lookupById: function fonts_lookupById(id) {
       return fonts[id];
+    },
+    setActive: function fonts_setActive(fontName, fontObj, size) {
+      // |current| can be null is fontName is a built-in font
+      // (e.g. "sans-serif")
+      if (fontObj && (current = fonts[fontObj.id])) {
+        var sizes = current.sizes;
+        if (!(measureCache = sizes[size]))
+          measureCache = sizes[size] = Object.create(null);
+      } else {
+        measureCache = null
+      }
+
+      ctx.font = (size * kScalePrecision) + 'px "' + fontName + '"';
+    },
+    measureText: function fonts_measureText(text) {
+      var width;
+      if (measureCache && (width = measureCache[text]))
+        return width;
+      width = ctx.measureText(text).width / kScalePrecision;
+      if (measureCache)
+        measureCache[text] = width;
+      return width;
     }
   };
 })();
@@ -1080,7 +1110,7 @@ var Font = (function() {
       return rule;
     },
 
-    charsToUnicode: function fonts_charsToUnicode(chars) {
+    charsToUnicode: function fonts_chars2Unicode(chars) {
       var charsCache = this.charsCache;
 
       // if we translated this string before, just grab it from the cache

pdf.js

@@ -3972,6 +3972,7 @@ var CanvasGraphics = (function() {
         this.ctx.$setFont(fontName, size);
       } else {
         this.ctx.font = size + 'px "' + fontName + '"';
+        Fonts.setActive(fontName, fontObj, size);
       }
     },
     setTextRenderingMode: function(mode) {
@@ -4009,25 +4010,24 @@ var CanvasGraphics = (function() {
       var ctx = this.ctx;
       var current = this.current;
 
+      ctx.save();
+      ctx.transform.apply(ctx, current.textMatrix);
+      ctx.scale(1, -1);
+
       if (this.ctx.$showText) {
         ctx.$showText(current.y, text);
       } else {
-        ctx.save();
-
-        ctx.transform.apply(ctx, current.textMatrix);
-        ctx.scale(1, -1);
         ctx.translate(current.x, -1 * current.y);
-
+        var font = this.current.font;
-        var font = current.font;
+        if (font) {
-        ctx.transform.apply(ctx, font.textMatrix);
+          ctx.transform.apply(ctx, font.textMatrix);
-
+          text = font.charsToUnicode(text);
-        text = font.charsToUnicode(text);
+        }
-
         ctx.fillText(text, 0, 0);
-        current.x += ctx.measureText(text).width;
+        current.x += Fonts.measureText(text);
-
-        ctx.restore();
       }
+
+      this.ctx.restore();
     },
     showSpacedText: function(arr) {
       for (var i = 0; i < arr.length; ++i) {