TTF Specification :
The 'head' table contains global information about the font.

@author Johann Sorel

int : set by font manufacturer */

uint32 : To compute: set it to 0, calculate the checksum for the
'head' table and put it in the table directory, sum the entire
font as uint32, then store B1B0AFBA - sum. The checksum for the
'head' table will not be wrong. That is OK.*/

uint32 : set to 0x5F0F3CF5*/

uint16 :
bit 0 - y value of 0 specifies baseline
bit 1 - x position of left most black bit is LSB
bit 2 - scaled point size and actual point size will differ (i.e. 24 point glyph differs from 12 point glyph scaled by factor of 2)
bit 3 - use integer scaling instead of fractional
bit 4 - (used by the Microsoft implementation of the TrueType scaler)
bit 5 - This bit should be set in fonts that are intended to e laid out vertically, and in which the glyphs have been drawn such that an x-coordinate of 0 corresponds to the desired vertical baseline.
bit 6 - This bit must be set to zero.
bit 7 - This bit should be set if the font requires layout for correct linguistic rendering (e.g. Arabic fonts).
bit 8 - This bit should be set for a GX font which has one or more metamorphosis effects designated as happening by default.
bit 9 - This bit should be set if the font contains any strong right-to-left glyphs.
bit 10 - This bit should be set if the font contains Indic-style rearrangement effects.
bits 11-12 - Defined by Adobe.

uint16 : range from 64 to 16384*/

longDateTime : international date*/

FWord : for all glyph bounding boxes */

uint16 :
bit 0 bold
bit 1 italic
bit 2 underline
bit 3 outline
bit 4 shadow
bit 5 condensed (narrow)
bit 6 extended

uint16 : smallest readable size in pixels */

uint16 :
0 Mixed directional glyphs
1 Only strongly left to right glyphs
2 Like 1 but also contains neutrals
-1 Only strongly right to left glyphs
-2 Like -1 but also contains neutrals

uint16 : 0 for short offsets, 1 for long */

uint16 : 0 for current format */