Refactors font matrix operations

src/canvas.js

@@ -159,7 +159,7 @@ var CanvasExtraState = (function CanvasExtraStateClosure() {
     this.fontSize = 0;
     this.fontSizeScale = 1;
     this.textMatrix = IDENTITY_MATRIX;
-    this.fontMatrix = IDENTITY_MATRIX;
+    this.fontMatrix = FONT_IDENTITY_MATRIX;
     this.leading = 0;
     // Current point (in user coordinates)
     this.x = 0;
@@ -716,11 +716,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       if (!fontObj)
         error('Can\'t find font for ' + fontRefName);
 
-      // Slice-clone matrix so we can manipulate it without affecting original
-      if (fontObj.fontMatrix)
-        current.fontMatrix = fontObj.fontMatrix.slice(0);
-      else
-        current.fontMatrix = IDENTITY_MATRIX.slice(0);
+      current.fontMatrix = fontObj.fontMatrix ? fontObj.fontMatrix :
+                                                FONT_IDENTITY_MATRIX;
 
       // A valid matrix needs all main diagonal elements to be non-zero
       // This also ensures we bypass FF bugzilla bug #719844.
@@ -731,11 +728,11 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
 
       // The spec for Tf (setFont) says that 'size' specifies the font 'scale',
       // and in some docs this can be negative (inverted x-y axes).
-      // We implement this condition with fontMatrix.
       if (size < 0) {
         size = -size;
-        current.fontMatrix[0] *= -1;
-        current.fontMatrix[3] *= -1;
+        current.fontDirection = -1;
+      } else {
+        current.fontDirection = 1;
       }
 
       this.current.font = fontObj;
@@ -788,14 +785,13 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
     applyTextTransforms: function CanvasGraphics_applyTextTransforms() {
       var ctx = this.ctx;
       var current = this.current;
-      var textHScale = current.textHScale;
-      var fontMatrix = current.fontMatrix || IDENTITY_MATRIX;
-
       ctx.transform.apply(ctx, current.textMatrix);
-      ctx.scale(1, -1);
-      ctx.translate(current.x, -current.y - current.textRise);
-      ctx.transform.apply(ctx, fontMatrix);
-      ctx.scale(textHScale, 1);
+      ctx.translate(current.x, current.y + current.textRise);
+      if (current.fontDirection > 0) {
+        ctx.scale(current.textHScale, -1);
+      } else {
+        ctx.scale(-current.textHScale, 1);
+      }
     },
     createTextGeometry: function CanvasGraphics_createTextGeometry() {
       var geometry = {};
@@ -826,9 +822,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       var fontSizeScale = current.fontSizeScale;
       var charSpacing = current.charSpacing;
       var wordSpacing = current.wordSpacing;
-      var textHScale = current.textHScale;
-      var fontMatrix = current.fontMatrix || IDENTITY_MATRIX;
-      var textHScale2 = textHScale * fontMatrix[0];
+      var textHScale = current.textHScale * current.fontDirection;
+      var fontMatrix = current.fontMatrix || FONT_IDENTITY_MATRIX;
       var glyphsLength = glyphs.length;
       var textLayer = this.textLayer;
       var geom;
@@ -867,8 +862,8 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
           this.restore();
 
           var transformed = Util.applyTransform([glyph.width, 0], fontMatrix);
-          var width = transformed[0] * fontSize +
-              Util.sign(current.fontMatrix[0]) * charSpacing;
+          var width = (transformed[0] * fontSize + charSpacing) *
+                      current.fontDirection;
 
           ctx.translate(width, 0);
           current.x += width * textHScale;
@@ -882,8 +877,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
 
         var lineWidth = current.lineWidth;
         var a1 = current.textMatrix[0], b1 = current.textMatrix[1];
-        var a2 = fontMatrix[0], b2 = fontMatrix[1];
-        var scale = Math.sqrt((a1 * a1 + b1 * b1) * (a2 * a2 + b2 * b2));
+        var scale = Math.sqrt(a1 * a1 + b1 * b1);
         if (scale == 0 || lineWidth == 0)
           lineWidth = this.getSinglePixelWidth();
         else
@@ -904,13 +898,13 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
           var glyph = glyphs[i];
           if (glyph === null) {
             // word break
-            x += Util.sign(current.fontMatrix[0]) * wordSpacing;
+            x += current.fontDirection * wordSpacing;
             continue;
           }
 
           var character = glyph.fontChar;
-          var charWidth = glyph.width * fontSize * 0.001 +
-              Util.sign(current.fontMatrix[0]) * charSpacing;
+          var charWidth = glyph.width * fontSize * current.fontMatrix[0] +
+                          charSpacing * current.fontDirection;
 
           if (!glyph.disabled) {
             var scaledX = x / fontSizeScale;
@@ -943,7 +937,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
 
           canvasWidth += charWidth;
         }
-        current.x += x * textHScale2;
+        current.x += x * textHScale;
         ctx.restore();
       }
 
@@ -959,9 +953,9 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       var current = this.current;
       var font = current.font;
       var fontSize = current.fontSize;
-      var textHScale = current.textHScale;
-      if (!font.coded)
-        textHScale *= (current.fontMatrix || IDENTITY_MATRIX)[0];
+      var textHScale = current.textHScale * (current.fontMatrix && !font.coded ?
+        current.fontMatrix[0] : FONT_IDENTITY_MATRIX[0]) *
+        current.fontDirection;
       var arrLength = arr.length;
       var textLayer = this.textLayer;
       var geom;
@@ -970,14 +964,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
 
       if (textSelection) {
         ctx.save();
-        // Type3 fonts - each glyph is a "mini-PDF" (see also showText)
-        if (font.coded) {
-          ctx.transform.apply(ctx, current.textMatrix);
-          ctx.scale(1, -1);
-          ctx.translate(current.x, -1 * current.y);
-          ctx.scale(textHScale, 1);
-        } else
-          this.applyTextTransforms();
+        this.applyTextTransforms();
         geom = this.createTextGeometry();
         ctx.restore();
       }
@@ -985,7 +972,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
       for (var i = 0; i < arrLength; ++i) {
         var e = arr[i];
         if (isNum(e)) {
-          var spacingLength = -e * 0.001 * fontSize * textHScale;
+          var spacingLength = -e * fontSize * textHScale;
           current.x += spacingLength;
 
           if (textSelection)

src/evaluator.js

@@ -1171,7 +1171,7 @@ var PartialEvaluator = (function PartialEvaluatorClosure() {
         composite: composite,
         wideChars: composite,
         fixedPitch: false,
-        fontMatrix: dict.get('FontMatrix') || IDENTITY_MATRIX,
+        fontMatrix: dict.get('FontMatrix') || FONT_IDENTITY_MATRIX,
         firstChar: firstChar || 0,
         lastChar: lastChar || maxCharIndex,
         bbox: descriptor.get('FontBBox'),

src/fonts.js

@@ -29,6 +29,8 @@ var PDF_GLYPH_SPACE_UNITS = 1000;
 // Until hinting is fully supported this constant can be used
 var HINTING_ENABLED = false;
 
+var FONT_IDENTITY_MATRIX = [0.001, 0, 0, 0.001, 0, 0];
+
 var FontFlags = {
   FixedPitch: 1,
   Serif: 2,
@@ -2214,6 +2216,19 @@ function fontCharsToUnicode(charCodes, font) {
   return result;
 }
 
+function adjustWidths(properties) {
+  if (properties.fontMatrix[0] === FONT_IDENTITY_MATRIX[0]) {
+    return;
+  }
+  // adjusting width to fontMatrix scale
+  var scale = 0.001 / properties.fontMatrix[0];
+  var glyphsWidths = properties.widths;
+  for (var glyph in glyphsWidths) {
+    glyphsWidths[glyph] *= scale;
+  }
+  properties.defaultWidth *= scale;
+}
+
 /**
  * 'Font' is the class the outside world should use, it encapsulate all the font
  * decoding logics whatever type it is (assuming the font type is supported).
@@ -2260,7 +2275,6 @@ var Font = (function FontClosure() {
     this.hasEncoding = properties.hasEncoding;
 
     this.fontMatrix = properties.fontMatrix;
-    this.widthMultiplier = 1.0;
     if (properties.type == 'Type3') {
       this.encoding = properties.baseEncoding;
       return;
@@ -2318,6 +2332,8 @@ var Font = (function FontClosure() {
         var cff = (subtype == 'Type1C' || subtype == 'CIDFontType0C') ?
           new CFFFont(file, properties) : new Type1Font(name, file, properties);
 
+        adjustWidths(properties);
+
         // Wrap the CFF data inside an OTF font file
         data = this.convert(name, cff, properties);
         break;
@@ -2337,10 +2353,13 @@ var Font = (function FontClosure() {
     }
 
     this.data = data;
+
+    // Transfer some properties again that could change during font conversion
     this.fontMatrix = properties.fontMatrix;
-    this.widthMultiplier = !properties.fontMatrix ? 1.0 :
-      1.0 / properties.fontMatrix[0];
+    this.widths = properties.widths;
+    this.defaultWidth = properties.defaultWidth;
     this.encoding = properties.baseEncoding;
+
     this.loading = true;
   };
 
@@ -3931,7 +3950,7 @@ var Font = (function FontClosure() {
         }
         this.toFontChar = toFontChar;
       }
-      var unitsPerEm = properties.unitsPerEm || 1000; // defaulting to 1000
+      var unitsPerEm = 1 / (properties.fontMatrix || FONT_IDENTITY_MATRIX)[0];
 
       var fields = {
         // PostScript Font Program
@@ -4170,7 +4189,7 @@ var Font = (function FontClosure() {
         if (width)
           break; // the non-zero width found
       }
-      width = (width || this.defaultWidth) * this.widthMultiplier;
+      width = width || this.defaultWidth;
       // Do not shadow the property here. See discussion:
       // https://github.com/mozilla/pdf.js/pull/2127#discussion_r1662280
       this._shadowWidth = width;
@@ -4251,7 +4270,7 @@ var Font = (function FontClosure() {
       if (typeof unicodeChars === 'number')
         unicodeChars = String.fromCharCode(unicodeChars);
 
-      width = (isNum(width) ? width : this.defaultWidth) * this.widthMultiplier;
+      width = isNum(width) ? width : this.defaultWidth;
       disabled = this.unicodeIsEnabled ?
         !this.unicodeIsEnabled[fontCharCode] : false;
 
@@ -4902,14 +4921,6 @@ var Type1Parser = function type1Parser() {
         switch (token) {
           case '/FontMatrix':
             var matrix = readNumberArray(headerString, i + 1);
-
-            // The FontMatrix is in unitPerEm, so make it pixels
-            for (var j = 0, jj = matrix.length; j < jj; j++)
-              matrix[j] *= 1000;
-
-            // Make the angle into the right direction
-            matrix[2] *= -1;
-
             properties.fontMatrix = matrix;
             break;
           case '/Encoding':
@@ -5185,6 +5196,7 @@ Type1Font.prototype = {
     topDict.setByName('FamilyName', 3);
     topDict.setByName('Weight', 4);
     topDict.setByName('Encoding', null); // placeholder
+    topDict.setByName('FontMatrix', properties.fontMatrix);
     topDict.setByName('FontBBox', properties.bbox);
     topDict.setByName('charset', null); // placeholder
     topDict.setByName('CharStrings', null); // placeholder
@@ -5459,8 +5471,7 @@ var CFFParser = (function CFFParserClosure() {
 
       var fontMatrix = topDict.getByName('FontMatrix');
       if (fontMatrix) {
-        // estimating unitsPerEM for the font
-        properties.unitsPerEm = 1 / fontMatrix[0];
+        properties.fontMatrix = fontMatrix;
       }
 
       var fontBBox = topDict.getByName('FontBBox');