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Merge pull request #139 from andreasgal/staging

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cache font measurements
This commit is contained in:
Chris Jones 2011-06-30 01:10:35 -07:00
commit be6397fca7
1 changed files with 79 additions and 66 deletions
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145
fonts.js
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@ -34,65 +34,89 @@ var kDisableFonts = false;
* http://cgit.freedesktop.org/poppler/poppler/tree/poppler/GfxFont.cc#n65
*/
var kScalePrecision = 40;
var Fonts = {
_active: null,
var Fonts = (function () {
var kScalePrecision = 40;
var fonts = Object.create(null);
var ctx = document.createElement("canvas").getContext("2d");
ctx.scale(1 / kScalePrecision, 1);
get active() {
return this._active;
},
function Font(name, data, properties) {
this.name = name;
this.data = data;
this.properties = properties;
this.loading = true;
this.charsCache = Object.create(null);
this.sizes = [];
}
setActive: function fonts_setActive(name, size) {
this._active = this[name];
this.ctx.font = (size * kScalePrecision) + 'px "' + name + '"';
},
var current;
var charsCache;
var measureCache;
charsToUnicode: function fonts_chars2Unicode(chars) {
var active = this._active;
if (!active)
return chars;
return {
registerFont: function fonts_registerFont(fontName, data, properties) {
fonts[fontName] = new Font(fontName, data, properties);
},
blacklistFont: function fonts_blacklistFont(fontName) {
registerFont(fontName, null, {});
markLoaded(fontName);
},
lookup: function fonts_lookup(fontName) {
return fonts[fontName];
},
setActive: function fonts_setActive(fontName, size) {
current = fonts[fontName];
charsCache = current.charsCache;
var sizes = current.sizes;
if (!(measureCache = sizes[size]))
measureCache = sizes[size] = Object.create(null);
ctx.font = (size * kScalePrecision) + 'px "' + fontName + '"';
},
charsToUnicode: function fonts_chars2Unicode(chars) {
if (!charsCache)
return chars;
// if we translated this string before, just grab it from the cache
var str = active.cache[chars];
if (str)
return str;
// if we translated this string before, just grab it from the cache
var str = charsCache[chars];
if (str)
return str;
// translate the string using the font's encoding
var encoding = active.properties.encoding;
if (!encoding)
return chars;
// translate the string using the font's encoding
var encoding = current.properties.encoding;
if (!encoding)
return chars;
str = "";
for (var i = 0; i < chars.length; ++i) {
var charcode = chars.charCodeAt(i);
var unicode = encoding[charcode];
str = "";
for (var i = 0; i < chars.length; ++i) {
var charcode = chars.charCodeAt(i);
var unicode = encoding[charcode];
// Check if the glyph has already been converted
if (!IsNum(unicode))
// Check if the glyph has already been converted
if (!IsNum(unicode))
unicode = encoding[unicode] = GlyphsUnicode[unicode.name];
// Handle surrogate pairs
if (unicode > 0xFFFF) {
str += String.fromCharCode(unicode & 0xFFFF);
unicode >>= 16;
// Handle surrogate pairs
if (unicode > 0xFFFF) {
str += String.fromCharCode(unicode & 0xFFFF);
unicode >>= 16;
}
str += String.fromCharCode(unicode);
}
str += String.fromCharCode(unicode);
// Enter the translated string into the cache
return charsCache[chars] = str;
},
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;
}
// Enter the translated string into the cache
return active.cache[chars] = str;
},
get ctx() {
var ctx = document.createElement("canvas").getContext("2d");
ctx.scale(1 / kScalePrecision, 1);
return shadow(this, "ctx", ctx);
},
measureText: function fonts_measureText(text) {
return this.ctx.measureText(text).width / kScalePrecision;
}
};
})();
var FontLoader = {
bind: function(fonts) {
@ -101,8 +125,8 @@ var FontLoader = {
for (var i = 0; i < fonts.length; i++) {
var font = fonts[i];
if (Fonts[font.name]) {
ready = ready && !Fonts[font.name].loading;
if (Fonts.lookup(font.name)) {
ready = ready && !Fonts.lookup(font.name).loading;
continue;
}
@ -111,7 +135,7 @@ var FontLoader = {
var obj = new Font(font.name, font.file, font.properties);
var str = "";
var data = Fonts[font.name].data;
var data = Fonts.lookup(font.name).data;
var length = data.length;
for (var j = 0; j < length; j++)
str += String.fromCharCode(data[j]);
@ -138,8 +162,8 @@ var Font = (function () {
this.encoding = properties.encoding;
// If the font has already been decoded simply return it
if (Fonts[name]) {
this.font = Fonts[name].data;
if (Fonts.lookup(name)) {
this.font = Fonts.lookup(name).data;
return;
}
fontCount++;
@ -148,12 +172,7 @@ var Font = (function () {
// If the font is to be ignored, register it like an already loaded font
// to avoid the cost of waiting for it be be loaded by the platform.
if (properties.ignore || kDisableFonts) {
Fonts[name] = {
data: file,
loading: false,
properties: {},
cache: Object.create(null)
}
Fonts.blacklistFont(name);
return;
}
@ -180,13 +199,7 @@ var Font = (function () {
break;
}
this.data = data;
Fonts[name] = {
data: data,
properties: properties,
loading: true,
cache: Object.create(null)
};
Fonts.registerFont(name, data, properties);
};
function stringToArray(str) {
@ -833,7 +846,7 @@ var Font = (function () {
}
window.clearInterval(interval);
Fonts[fontName].loading = false;
Fonts.lookup(fontName).loading = false;
this.start = 0;
if (callback) {
callback();