Used by the routine at REDRAW_OBJECT.

Called by REDRAW_OBJECT for each object record but the one being redrawn (THIS_RECORD), with IX at the record and D, E, C the redrawn object's far corner and floor (FAR_CORNER). The region is the rectangle of screen being rebuilt, the redrawn object's own box with three rows more above and below it: its x at IY+$64, its top row at IY+$65 (y counts up the screen), its width in pixels at IY+$66 and its height at IY+$67. An object that does not overlap the region, or has no sprite, is left out. One that overlaps it and stands in front of the redrawn object (IS_IN_FRONT) has its cover drawn at once into page $D8 (DRAW_SPRITE, mode 0), which tells the compositor (COMPOSITE_TO_SCREEN) to leave the screen as it is there. One behind goes onto the list at page $DA for SORT_AND_DRAW_BEHIND to sort and draw. Krumlinde's name for it is Cull_TestObject.

What counts depends on the pass. Normally (bit 4 of IY+$17 clear) scenery -- an object whose +$10 has bits 0-4 clear, drawn once as the room was entered and so already in the clean copy of the screen (LOADING_TUNE) -- goes on the list but does not by itself ask for the list to be drawn: only a live object behind sets bit 1 of IY+$71. In the scenery pass as a room is entered (bit 4 set, ROOMST) live objects are left out altogether, since they are drawn later, and anything behind asks for the list. A door (type 1 in +$0C) skips both tests; anything taken out of the room (bit 5 of +$10: carried, or destroyed) is never drawn.