Optimize drawing invisibles
Optimize drawing invisibles

glyphAtIndex:isValidIndex: is more efficent thant normal glyphAtIndex:

angi2/CotEditor,eric-seekas/CotEditor,onevcat/CotEditor,angi2/CotEditor,uchuugaka/CotEditor,uchuugaka/CotEditor,onevcat/CotEditor,yangchenghu/CotEditor,uchuugaka/CotEditor,eric-seekas/CotEditor,yangchenghu/CotEditor,angi2/CotEditor,angi2/CotEditor,angi2/CotEditor,yangchenghu/CotEditor,eric-seekas/CotEditor,eric-seekas/CotEditor,eric-seekas/CotEditor,uchuugaka/CotEditor,uchuugaka/CotEditor,eric-seekas/CotEditor,onevcat/CotEditor,uchuugaka/CotEditor,eric-seekas/CotEditor,angi2/CotEditor,yangchenghu/CotEditor,uchuugaka/CotEditor,yangchenghu/CotEditor,eric-seekas/CotEditor,angi2/CotEditor,uchuugaka/CotEditor