Constructs a new glyph
Gets advance (how much to offset position after rendering this character)
Gets the bearing (offset from origin)
Gets the stored buffer of the glyph
Gets the size in byte of the stored glyph pixel buffer
Gets the size of the glyph in bytes on each axis
Get number of gray levels used
Gets the pixel mode of the glyph.
Gets the size of the glyph in pixels
A glyph is a single character