yetangitu/pdf.js
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Use the built-in widths to calculate glyphs metrics

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This commit is contained in:
Vivien Nicolas 2011-09-09 01:35:37 +02:00
parent f759e56a02
commit d4fb9c786c
4 changed files with 3040 additions and 60 deletions
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pdf.js
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@ -4197,8 +4197,31 @@ var PartialEvaluator = (function() {
extractEncoding: function(dict, xref, properties) {
var type = properties.type;
if (properties.composite) {
// XXX only CIDFontType2 supported for now
if (type == 'CIDFontType2') {
var defaultWidth = xref.fetchIfRef(dict.get('DW')) || 1000;
properties.defaultWidth = defaultWidth;
var glyphsWidths = {};
var widths = xref.fetchIfRef(dict.get('W'));
if (widths) {
var start = 0, end = 0;
for (var i = 0; i < widths.length; i++) {
var code = widths[i];
if (IsArray(code)) {
for (var j = 0; j < code.length; j++)
glyphsWidths[start++] = code[j];
start = 0;
} else if (start) {
for (var j = start; j <= code; j++)
glyphsWidths[j] = widths[++i];
start = 0;
} else {
start = code;
}
}
}
properties.widths = glyphsWidths;
var cidToGidMap = dict.get('CIDToGIDMap');
if (!cidToGidMap || !IsRef(cidToGidMap))
return GlyphsUnicode;
@ -4211,15 +4234,16 @@ var PartialEvaluator = (function() {
var encoding = properties.encoding;
// Set encoding 0 to later verify the font has an encoding
encoding[0] = { unicode: 0 };
encoding[0] = { unicode: 0, width: 0 };
for (var j = 0; j < glyphsData.length; j++) {
var glyphID = (glyphsData[j++] << 8) | glyphsData[j];
if (glyphID == 0)
continue;
encoding[j >> 1] = {
var code = j >> 1;
encoding[code] = {
unicode: glyphID,
width: 0
width: glyphsWidths[code] || defaultWidth
};
}
} else if (type == 'CIDFontType0') {
@ -4287,22 +4311,24 @@ var PartialEvaluator = (function() {
var glyphs = {};
for (var i = firstChar; i <= lastChar; i++) {
var glyph = differences[i] || baseEncoding[i];
if (glyph) {
var index = GlyphsUnicode[glyph] || i;
glyphs[glyph] = map[i] = {
unicode: index,
width: properties.widths[i - firstChar] || properties.defaultWidth
};
var index = GlyphsUnicode[glyph] || i;
var width = properties.widths[i] || properties.widths[glyph];
map[i] = {
unicode: index,
width: width || properties.defaultWidth
};
// If there is no file, the character mapping can't be modified
// but this is unlikely that there is any standard encoding with
// chars below 0x1f, so that's fine.
if (!properties.file)
continue;
if (glyph)
glyphs[glyph] = map[i];
if (index <= 0x1f || (index >= 127 && index <= 255))
map[i].unicode += kCmapGlyphOffset;
}
// If there is no file, the character mapping can't be modified
// but this is unlikely that there is any standard encoding with
// chars below 0x1f, so that's fine.
if (!properties.file)
continue;
if (index <= 0x1f || (index >= 127 && index <= 255))
map[i].unicode += kCmapGlyphOffset;
}
if (type == 'TrueType' && dict.has('ToUnicode') && differences) {
@ -4339,10 +4365,9 @@ var PartialEvaluator = (function() {
var endRange = tokens[j + 1];
var code = tokens[j + 2];
while (startRange < endRange) {
map[startRange] = {
unicode: code++,
width: 0
}
var mapping = map[startRange] || {};
mapping.unicode = code++;
map[startRange] = mapping;
++startRange;
}
}
@ -4353,10 +4378,9 @@ var PartialEvaluator = (function() {
for (var j = 0; j < tokens.length; j += 2) {
var index = tokens[j];
var code = tokens[j + 1];
map[index] = {
unicode: code,
width: 0
};
var mapping = map[index] || {};
mapping.unicode = code;
map[index] = mapping;
}
break;
@ -4425,7 +4449,8 @@ var PartialEvaluator = (function() {
}
// Before PDF 1.5 if the font was one of the base 14 fonts, having a
// FontDescriptor was not required. This case is here for compatibility.
// FontDescriptor was not required.
// This case is here for compatibility.
var descriptor = xref.fetchIfRef(dict.get('FontDescriptor'));
if (!descriptor) {
var baseFontName = dict.get('BaseFont');
@ -4445,11 +4470,18 @@ var PartialEvaluator = (function() {
}
}
var defaultWidth = 0;
var widths = Metrics[stdFontMap[baseFontName] || baseFontName];
if (IsNum(widths)) {
defaultWidth = widths;
widths = null;
}
var properties = {
type: type.name,
encoding: map,
differences: [],
widths: {},
widths: widths,
defaultWidth: defaultWidth,
firstChar: 0,
lastChar: 256
};
@ -4508,13 +4540,13 @@ var PartialEvaluator = (function() {
descent: descriptor.get('Descent'),
xHeight: descriptor.get('XHeight'),
capHeight: descriptor.get('CapHeight'),
defaultWidth: descriptor.get('MissingWidth') || 0,
defaultWidth: parseFloat(descriptor.get('MissingWidth')) || 0,
flags: descriptor.get('Flags'),
italicAngle: descriptor.get('ItalicAngle'),
differences: [],
widths: (function() {
var glyphWidths = {};
for (var i = 0; i <= widths.length; i++)
for (var i = 0; i < widths.length; i++)
glyphWidths[firstChar++] = widths[i];
return glyphWidths;
})(),
@ -4903,6 +4935,7 @@ var CanvasGraphics = (function() {
showText: function(text) {
var ctx = this.ctx;
var current = this.current;
var originalText = text;
ctx.save();
ctx.transform.apply(ctx, current.textMatrix);
@ -4921,26 +4954,21 @@ var CanvasGraphics = (function() {
text = font.charsToUnicode(text);
}
var size = current.fontSize;
var charSpacing = current.charSpacing;
var wordSpacing = current.wordSpacing;
var textHScale = current.textHScale;
// This is a poor simulation for Arial Narrow while font-stretch
// is not implemented (bug 3512)
if (current.font.narrow) {
textHScale += 0.2;
charSpacing -= (0.09 * current.fontSize);
}
if (charSpacing != 0 || wordSpacing != 0 || textHScale != 1) {
scaleFactorX *= textHScale;
ctx.scale(1 / textHScale, 1);
var width = 0;
for (var i = 0, ii = text.length; i < ii; ++i) {
var c = text.charAt(i);
ctx.fillText(c, 0, 0);
var charWidth = FontMeasure.measureText(c) + charSpacing;
ctx.fillText(text.charAt(i), 0, 0);
var c = originalText.charAt(i);
var charWidth = FontMeasure.measureText(c, font, size);
charWidth += charSpacing;
if (c.charCodeAt(0) == 32)
charWidth += wordSpacing;
ctx.translate(charWidth * scaleFactorX, 0);
@ -4949,7 +4977,7 @@ var CanvasGraphics = (function() {
current.x += width;
} else {
ctx.fillText(text, 0, 0);
current.x += FontMeasure.measureText(text);
current.x += FontMeasure.measureText(originalText, font, size);
}
this.ctx.restore();