A rectangle that defines the position of a glyph within an atlas texture.
| zero | A GlyphRect with all values set to zero. Shorthand for writing GlyphRect(0, 0, 0, 0). | 
| height | The height of the glyph. | 
| width | The width of the glyph. | 
| x | The x position of the glyph in the font atlas texture. | 
| y | The y position of the glyph in the font atlas texture. | 
| GlyphRect | Constructor for a new GlyphRect. |