| OCR Text |
Show 235 it he ra;hic ;rccessor input functions. ,:r.e fi re::- of "pc i n t ' te a pictwre e l erne n t ' i th the c:.:rser. Pa=aiieers 6escibig the type ad location ef ttis ictre e:errent in the data strcture are returneo to the user rs;ra. The ty?e of tte draing attribute which cause te hit ana either the index of the point (for direct tves) or the adreses ef the point attributes (for list. types) are retured as aruments to the pointing routines. ·-::-.e =c;:hic c r o c e s s c r s l so builds a "hit stack" which cotains the address of the objects, GHAs, and drawing attributes which are the "context" at the time of the hit. By pC9ping addresses off this hit stack, the user program car. back track as far as it needs to. For example, if the ;::;=se of the pointing is to delete an otject, the hi- CALL PTPKT (ITYPE,ICl,ID2,ISTAT) r c rc t i o n : test each e r.c pc i r.t (lir:es are not tested) fer the first hit r:YFE--type code of the drawins attribute which caused the hit ID1--index of point ( c i r e c t ty?€'s) or address of t h e c i r. t 2 t t r i :: !J t e (1 i s tty? e 5) .,." hie h c a u sed |
