X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=Readme;fp=Readme;h=026833055418900ea2c133ecd0a8ba38f5d2ca8c;hb=6c8c1afdbad505c04a251da05499658b7cc65825;hp=c4fc9d05cbfb2ca7fd07a412ca1c2d6000291586;hpb=63abd0338f9d71caa40f8316c95b6e38216bdcc8;p=ttf2png.git

diff --git a/Readme b/Readme
index c4fc9d0..0268330 100644
--- a/Readme
+++ b/Readme
@@ -108,23 +108,24 @@ the image and the font:
   Field 3: nominal size of the font
   Fields 4-5: ascent and descent of the font
 
-The keyword "glyph" is followed by eight fields describing a single glyph:
+The keyword "code" is followed by two fields establishing a code point to
+glyph mapping:
 
-  Field 1: the code point of the glyph
-  Fields 2-3: x and y position of the glyph in the image
-  Fields 4-5: width and height of the glyph
-  Fields 6-7: x and y offset of the glyph from its base point
-  Field 8: advance from this glyph to the next
+  Field 1: Unicode code point
+  Field 2: Glyph index
 
-The keyword "kern" is followed by three fields describing kerning between two
-glyphs:
+The keyword "metrics" is followed by six fields describing the metrics of a
+glyph:
 
-  Field 1: the code point of the left-hand glyph
-  Field 2: the code point of the right-hand glyph
-  Field 3: kerning distance between the glyphs
+  Field 1: the index of the glyph
+  Fields 2-3: width and height of the glyph
+  Fields 4-5: x and y offset of the glyph from its base point
+  Field 6: advance from this glyph to the next
 
-The following ASCII art image illustrates most of these metrics.  Note that in
-some fonts, not all of the glyphs fit completely inside the character box.
+The following ASCII art image illustrates the basic metrics.  The character
+box is a conceptual rectangle in which most of the glyphs in the font fit.
+Some fonts may contain glyphs that extend outside of the nominal character
+box.
 
                 - - - - - - - -     ^
                | character box |    |
@@ -148,6 +149,27 @@ some fonts, not all of the glyphs fit completely inside the character box.
                |--------------->
                advance
 
+The keyword "glyph" is followed by six field describing the area of the image
+used for the glyph:
+
+  Field 1: the index of the glyph
+  Fields 2-3: x and y position of the glyph in the image
+  Fields 4-5: width and height of the glyph
+  Field 6: border zone included in the image
+
+The border zone is used with distance field textures to allow the distance
+field to extend past the actual glyph.  If a glyph has a border, the origin
+point in the metrics refers to the glyph's lower left corner.  Subtract the
+border width from both coordinates to obtain the correct rendering position
+for the image.
+
+The keyword "kern" is followed by three fields describing kerning between two
+glyphs:
+
+  Field 1: the index of the left-hand glyph
+  Field 2: the index of the right-hand glyph
+  Field 3: kerning distance between the glyphs
+
 
 Changelog