User Defined Charactersand SVG Fonts

August 4, 2010

Jun Fujisawafujisawa.jun@canon.co.jp

User Defined Characters EGLS Requirements

EGLS_TK_01 Unicode 6.0 should be used for IVS and Emoji EGLS_TK_02 SVG font format should be supported EGLS_CHANG_R1 Characters outside of BMP can be EUDC EGLS_CHANG_R2 EUDC can be embedded inside EPUB file EGLS_CHANG_R3 Mechanism to assign resource for each font EGLS_CHANG_R4 Embed mapping information in EPUB file

Additional Requirements JF_01 Must be compatible with major scalable font formats JF_02 Must be applicable to XHTML/HTML5/SVG documents JF_03 Should support the use of glyphs without code points JF_04 Should be applicable to vertical oriented text as well JF_05 Each glyph should optionally be defined separately

Web Fonts Overview Web Fonts Specification

Introduced in CSS Level 2www.w3.org/TR/2008/REC-CSS2-20080411

Enhanced in CSS Fonts Module Level 3dev.w3.org/csswg/css3-fonts

Major Features Supports downloadable fonts, local fonts, and system fonts Font properties ('font-family', 'font-weight', 'font-stretch',

'font-style', 'font-variant', 'font-size', 'font-size-adjust', 'font') Font reference rules (@font-face, 'src', 'unicode-range') Font matching algorithm

Referencing Web Fonts Multi Weights Example

One rule for each weight Use 'local' to use local

fonts if available Use 'url' to reference

downloadable fonts

Composite Font Example One rule for each language

specific font subset file Use "-" to specify range Use "?" for any digit value Download smaller subset

file if the text contains onlyLatin characters

@font-face { font-family: Helvetica; src: local(Helvetica), url(fonts/Helvetica.ttf);}

@font-face { font-family: Helvetica; font-weight: bold; src: local("Helvetica Bold"), url(fonts/HelveticaBold.ttf);}

@font-face { font-family: DroidSans; src: url(DroidSansJp.woff); unicode-range: U+3000-9FFF, U+FF??;}

@font-face { font-family: DroidSans; src: url(DroidSans.woff); unicode-range: U+000-5FF, U+1E00-1FFF, U+2000-2300;}

New in CSS Fonts Level 3 Renewed Font Format List

"truetype", "truetype-aat" : TrueType Font (.ttf) "opentype": OpenType Font (.ttf, .otf) "embedded-opentype": Embedded OpenType Font (.eot) "woff": WOFF Font (.woff) "svg": SVG Font (.svg)

OpenType Features Support Kerning ('font-kerning') and ligatures ('font-variant-ligatures') Subscript and superscript ('character-transform') Alternates and swashes ('font-variant-alternates') Capitalization ('font-variant-caps') Numerical formatting ('font-variant-numeric')

Same-origin Restriction Cross-Origin Resource Sharing (CORS) should be supported as well

Handling Variations East Asian Text

The editor's draft of CSS Fonts Level 3 introduced 'font-variant-east-asian' property

Supports OpenType Feature Tags (hojo-kanji, jis78, jis83, jis90, jis04, nlckanji, simplified, traditional, fwid, pwid)

OpenType UVS Subtable should be supported as well?

Example of Variations JIS78 Forms (jis78) ■ Traditional Forms (traditional)

Proportionally Spaced Variants (pwid)

WOFF Font Format WOFF Font Specification

WOFF File Format 1.0www.w3.org/TR/2010/WD-WOFF-20100727

WOFF stands for Web Open Font Format

Progress WebFonts Working Group launched in March 2010 W3C Submission from Microsoft, Mozilla, and Opera in April Already implemented on Firefox 3.6, Google Chrome 5, and

IE9 Platform Preview 3

Major Features A GZIP compressed repackaging of TrueType/OpenType fonts Added XML based extended metadata block No DRM (WOFF fonts may not be reused as system fonts) Same-origin restriction as well as CORS is supported

SVG Fonts Overview SVG Fonts Specification

Introduced in SVG 1.0www.w3.org/TR/2001/REC-SVG-20010904

Reduced the features in SVG Tiny 1.2www.w3.org/TR/2008/REC-SVGTiny12-20081222

Mandatory feature in SVG 1.1/2.0 (required for ACID3)

Major Features Embedded within HTML/SVG documents or saved as a

separate SVG file (GZIP compressed .svgz file is supported) Define font with 'font' ('horiz-origin-x', 'horiz-adv-x') and 'font-

face' elements ('font-family', 'font-weight', etc.) Define each glyph with 'glyph' element ('unicode', 'glyph-

name', 'd', 'arabic-form', 'lang', 'horiz-adv-x') Hinted outline fonts is not supported

Defining SVG Fonts Inline Font Example

One 'glyph' for each glyph 'd' value contains path data

defining the glyph outline 'unicode' value can be a

character or string (to defineligatures, for example)

External Font Example Font definition can be moved

to local or downloadable files Use 'font-face-uri' to point

to external SVG Font files Need to directly reference

'font' element (by using afragment identifier)

<defs><font horiz-adv-x="500"> <font-face font-family="Vera" units-per-em="1000"> <glyph unicode="S" glyph-name="S" d="…"> <glyph unicode="V" glyph-name="V" d="…"> <glyph unicode="G" glyph-name="G" d="…"> <missing-glyph d="…"> </font-face></font></defs><text font-family="Vera" font-size="100">SVG</text>

<defs><font> <font-face font-family="Vera"> <font-face-src> <font-face-uri xlink:href="Vera.svg#f"/> </font-face-src> </font-face></font></defs><text font-family="Vera" font-size="100">SVG</text>

New in SVG Tiny 1.2 No Arbitrary SVG

Specify glyph outline only by using path data (with 'd' attribute)

'glyph' element in SVG 1.0/1.1 can contain arbitrary SVG graphic elements)

No Vertical Orientation Unsupported 'font' element attributes: 'horiz-origin-y',

'vert-origin-x', 'vert-origin-y', 'vert-adv-y' Unsupported 'font-face' element attributes: 'v-ideographic', 'v-

alphabetic', 'v-mathematical', 'v-hanging' Unsupported 'glyph' element attributes: 'orientation',

'vert-origin-x', 'vert-origin-y', 'vert-adv-y'

No External Font Descriptors 'definition-src' element is not supported in SVG Tiny 1.2 and

SVG 1.1 2nd Edition

Web Fonts Implementations WOFF is going to be supported everywhere

SVG Fonts is the only choice for iPhone and iPad

Web BrowserTrueTypeOpenType

EOT WOFF SVG

IE IE9 IE9

Safari WebKit Firefox Opera Chrome

User Defined Characters EGLS Requirements

EGLS_TK_01 Unicode 6.0 should be used for IVS and Emoji EGLS_TK_02 SVG font format should be supported EGLS_CHANG_R1 Characters outside of BMP can be EUDC EGLS_CHANG_R2 EUDC can be embedded inside EPUB file EGLS_CHANG_R3 Mechanism to assign resource for each font EGLS_CHANG_R4 Embed mapping information in EPUB file

Additional Requirements JF_01 Must be compatible with major scalable font formats JF_02 Must be applicable to XHTML/HTML5/SVG documents JF_03 Should support the use of glyphs without code points JF_04 Should be applicable to vertical oriented text as well JF_05 Each glyph should optionally be defined separately

Solution Using SVG Fonts Obvious Advantages

Supported by major browsers and tools (TK_02, JF_01) Compatible and should work well with Unicode IVS (TK_01) Can be embedded directly into contents (CHANG_R2, JF_02) Can be applicable to vertical oriented text (JF_04) Each glyph can be stored in a separate file (JF_05)

Disadvantages Unable to include hinting information in SVG Fonts Size can be larger than other formats without compression

Needs Investigation Can we add characters to existing fonts? (CHANG_03) Can we support glyphs without code points? (JF_03)

Extending Existing Fonts Extended Font Example

Add @font-face rule foreach user defined character

Use 'unicode-range' tospecify the code point

Default 'unicode-range'value is U+0-10FFFF

Rules defined later takeprecedence

Referencing from HTML Just use the extended font Referencing user defined

characters is easy as log asthe code point is assigned

@font-face { font-family: Helvetica; src: local(Arial);}

@font-face { font-family: Helvetica; src: url(HelveticaEx01.svg#f); unicode-range: U+E758;}

@font-face { font-family: Helvetica; src: url(HelveticaEx02.svg#f); unicode-range: U+E759;}

body { font-family: Helvetica; }

<html> <body> <p>&#xE758;SVG&#xE759;</p> </body></html>

Glyphs without Code Points SVG Glyph Example

Use unique identifier instead of a character asthe value of 'unicode'

SVG user agent recognizesthe specific sequence ofcharacters and replace itwith user defied glyph

Referencing from HTML Use 'image' element to

display a glyph image You can directly embed

an SVG fragment into theHTML5 document

<defs><font horiz-adv-x="500"> <font-face font-family="Vera" units-per-em="1000"> <glyph unicode="&edanashi;" glyph-name="edanashi" d="…"> <missing-glyph d="…"> </font-face></font></defs><text font-family="Vera" font-size="100">&edanashi;</text>

body { font-family: Vera; }

<html> <body> <p>Edanashi in HTML: <img src="edanashi.svg#f/> </p> <svg> <text>Edanashi in SVG: &edanashi;</text> </svg> </body></html>