Accessing font kerning information in Java2D

Question

Little background ..

I am developing an OpenGL game using Java and LWJGL . I wrote a class TextRendererthat displays text using cached glyph pages. Glyphs themselves are displayed in Java2D before BufferedImageand packaged into texture pages along with glyph dimensions. TextRendererdraws symbols like textured quads using cached information.

All of this works well, with one exception: the lack of kerning. Of course, there is no need to have it, because the text looks the way it is, but it would improve the quality if I had access to information on kerning fonts.

And the question is ..

Is it possible to get kerning information using simple Java so that it is portable on Windows, Linux, and MacOS X? When I returned when I wrote TextRenderer, I looked around briefly, but could not find such a way.

One possible solution

If in pure Java there is no way to do this, I was thinking of writing a separate tool using Freetype . As indicated on the page of their functions:

FreeType 2 provides information that is often inaccessible from other similar font mechanisms, such as distance kerning , glyph names, vertical metrics, etc.

, . , , , , , , .:)

Answer 1

, , "somwhat": iText FOP Apache.

http://www.1t3xt.info/api/com/lowagie/text/pdf/BaseFont.html http://svn.apache.org/viewvc/xmlgraphics/fop/tags/fop-0_95/src/java/org/apache/fop/fonts/ ( svn, , , -)

Answer 2

Java SE 6, Java , . :

Map<TextAttribute, Object> textAttributes = new HashMap<TextAttribute, Object>();  

textAttributes.put(TextAttribute.FAMILY, "Arial");  
textAttributes.put(TextAttribute.SIZE, 25f);  
textAttributes.put(TextAttribute.KERNING, TextAttribute.KERNING_ON);  

Font font = Font.getFont(textAttributes);  

:

http://forums.sun.com/thread.jspa?threadID=5359127

Answer 3

javaScript, , , , :

javascript, :

GLYPHS = {};
KERNS  = {};

:

// GLYPHS[ unicode ] = [ "name", width ];
// KERNS [ unicode ] = { "nextGlyphName"        : horizontalAdjustment };
//                   = { GLYPHS[ unicode ][ 0 ] : horizontalAdjustment };

, "", :

glUnicode = "Text".charCodeAt( strIndex );            // "T" == 84
glName    = GLYPHS[ glUnicode ][ 0 ];
glWidth   = GLYPHS[ glUnicode ][ 1 ];

, unicode , :

nextGlyphUnicode = "Text".charCodeAt( strIndex + 1 ); // "e" == 101

, ( :

if ( !( KERNS[ glUnicode ] == undefined ) ) {
  if ( !( KERNS[ glUnicode ][ GLYPHS[ nextGlyphUnicode ][ 0 ] ] == undefined ) ) {
  ...

):

kernWidth = KERNS[ glUnicode ][ GLYPHS[ nextGlyphUnicode ][ 0 ] ];

kernWidth "e", "T",

kernWidth == -143

, , , ? unicode unicode . .

, , :

// Family Name
// 'Times New Roman'
// EM size
// '2048'
// is_quadratic
// '1'
//
// GLYPHS[ unicode ] = [ "name", width ];
// KERNS [ unicode ] = { "nextGlyphName"        : horizontalAdjustment };
//                   = { GLYPHS[ unicode ][ 0 ] : horizontalAdjustment };
GLYPHS = {};
KERNS  = {};

GLYPHS[    32 ] = [ "space",  512 ];
KERNS [    32 ] = {
  "Upsilondieresis" :   -76,
  "Upsilon"         :   -76,
  "Tau"             :   -37,
  "Lambda"          :  -113,
  "Delta"           :  -113,
  "Alpha"           :  -113,
  "Alphatonos"      :  -113,
  "Y"               :   -76,
  "W"               :   -37,
  "V"               :   -37,
  "T"               :   -37,
  "A"               :  -113
};
GLYPHS[    33 ] = [ "exclam",  682 ];
GLYPHS[    34 ] = [ "quotedbl",  836 ];
GLYPHS[    35 ] = [ "numbersign", 1024 ];
GLYPHS[    36 ] = [ "dollar", 1024 ];
GLYPHS[    37 ] = [ "percent", 1706 ];
GLYPHS[    38 ] = [ "ampersand", 1593 ];
GLYPHS[    39 ] = [ "quotesingle",  369 ];
GLYPHS[    40 ] = [ "parenleft",  682 ];
GLYPHS[    41 ] = [ "parenright",  682 ];
GLYPHS[    42 ] = [ "asterisk", 1024 ];
GLYPHS[    43 ] = [ "plus", 1155 ];
GLYPHS[    44 ] = [ "comma",  512 ];
GLYPHS[    45 ] = [ "hyphen",  682 ];
GLYPHS[    46 ] = [ "period",  512 ];
GLYPHS[    47 ] = [ "slash",  569 ];
GLYPHS[    48 ] = [ "zero", 1024 ];
GLYPHS[    49 ] = [ "one", 1024 ];
KERNS [    49 ] = {
  "one"             :   -76
};
GLYPHS[    50 ] = [ "two", 1024 ];
GLYPHS[    51 ] = [ "three", 1024 ];
GLYPHS[    52 ] = [ "four", 1024 ];
GLYPHS[    53 ] = [ "five", 1024 ];
GLYPHS[    54 ] = [ "six", 1024 ];
GLYPHS[    55 ] = [ "seven", 1024 ];
GLYPHS[    56 ] = [ "eight", 1024 ];
GLYPHS[    57 ] = [ "nine", 1024 ];
GLYPHS[    58 ] = [ "colon",  569 ];
GLYPHS[    59 ] = [ "semicolon",  569 ];
GLYPHS[    60 ] = [ "less", 1155 ];
GLYPHS[    61 ] = [ "equal", 1155 ];
GLYPHS[    62 ] = [ "greater", 1155 ];
GLYPHS[    63 ] = [ "question",  909 ];
GLYPHS[    64 ] = [ "at", 1886 ];
GLYPHS[    65 ] = [ "A", 1479 ];
KERNS [    65 ] = {
  "quoteright"      :  -227,
  "y"               :  -188,
  "w"               :  -188,
  "v"               :  -152,
  "Y"               :  -188,
  "W"               :  -164,
  "V"               :  -264,
  "T"               :  -227,
  "space"           :  -113
};
GLYPHS[    66 ] = [ "B", 1366 ];
GLYPHS[    67 ] = [ "C", 1366 ];

, , , .

script, fontforge "" python 2.7. script , !

#
# run these two commands in the fontforge "embedded" python interpreter (ffpython.exe)
# >>> script = open( "Scripts\\Kernings.py", "r" )
# >>> exec script

import fontforge

fontFilenames = [
  "arial.ttf",
  "arialbd.ttf",
  "ariali.ttf",
  "arialbi.ttf",
  "ARIALN.TTF",
  "ARIALNB.TTF",
  "ARIALNI.TTF",
  "ARIALNBI.TTF",
  "calibri.ttf",
  "calibrib.ttf",
  "calibrii.ttf",
  "calibriz.ttf",
  "cambria.ttc",
  "cambriab.ttf",
  "cambriai.ttf",
  "cambriaz.ttf",
  "times.ttf",
  "timesbd.ttf",
  "timesi.ttf",
  "timesbi.ttf",
  "verdana.ttf",
  "verdanab.ttf",
  "verdanai.ttf",
  "verdanaz.ttf"
  ]

for actFontFile in fontFilenames :
  print( "c:\\windows\\fonts\\" + actFontFile )
  out  = open( "Scripts\\Kern_" + actFontFile[ : len( actFontFile ) - 4 ] + "_json.txt", "w" )
  font = fontforge.open( "c:\\windows\\fonts\\" + actFontFile )
  out.write(
      "// Family Name\n// '"  + font.familyname          + "'\n"
    + "// EM size\n// '"      + str( font.em )           + "'\n"
    + "// is_quadratic\n// '" + str( font.is_quadratic ) + "'\n"
    + "//\n"
    + '// GLYPHS[ unicode ] = [ "name", width ];\n'
    + '// KERNS [ unicode ] = { "nextGlyphName"        : horizontalAdjustment };\n'
    + "//                   = { GLYPHS[ unicode ][ 0 ] : horizontalAdjustment };\n"
    + "GLYPHS = {};\n"
    + "KERNS  = {};\n\n"
    )
  glyphIdIterator = font.__iter__()
  for glyphName in glyphIdIterator :
    if font[ glyphName ].unicode >=0 :
      kerningStrings = []
      outstring = ( "GLYPHS[ "
        + str( font[ glyphName ].unicode ).rjust( 5 ) + " ] = [ \""
        + glyphName + "\"," 
        + str( font[ glyphName ].width ).rjust( 5 ) + " ];\n"
        )
      subs = font[ glyphName ].getPosSub("*")
      if len( subs ):
        for sub in subs:
          if len( sub ):
            for subsub in sub:
              if str( subsub ).lower().find( "'kern'" ) >=0:
                kerningStrings.append(
                  ("  \"" + str( sub[ 2 ] ) + "\"").ljust( 20 )
                + ":"     + str( sub[ 5 ] ).rjust( 6 )
                )
                break
      krnStrLen = len( kerningStrings )
      if ( krnStrLen ) :
        outstring = outstring + ( "KERNS [ "
          + str( font[ glyphName ].unicode ).rjust( 5 ) + " ] = {" )
        for kerningString in kerningStrings :
          outstring = outstring + "\n" + kerningString + ","
        outstring = outstring.rstrip( "," )
        outstring = outstring + "\n};\n"
      out.write( outstring )
  out.close()
  font.close()

Hope this can help. Thank you so much for your attention,

Richard