Avalon: Routine at 54782

54782: Prepare data for any creatures that are entering Maroc's room


For a creature entering the room - sets up graphics and determines its speed/direction of movement.
54782	LD A,(60343)	Creature type (see 60230)
54785	CP 0	Creature type (see 60230)
54787	JR Z,54842	If no creature, skip to the next routine
54789	CALL 57706	This routine sets up data for creatures/warlocks appearing in Maroc's room (the A register normally contains creature type/number from 60230)
54792	LD A,(60344)	Creature's horizontal position (in 4 pixel steps) in room, after entering through a door
54795	LD (60232),A	Copy to graphic data buffer
54798	LD C,A	Copy to graphic data buffer
54799	LD A,(60345)	Creature's vertical pixel position in room, after entering through a door
54802	SUB 14	Adjust slightly by moving vertical position up 14 pixels. This puts the creatures in the doorway itself when they appear, rather than looking as if they've appeared a couple of feet into the room
54804	LD (60234),A	Copy to graphic data buffer
Calculate which area of the room (left, right or back wall door) the creature is entering from, and set their speed/direction accordingly:
54807	LD DE,4	If the forthcoming checks don't hit a match, the creature is between the room floor/wall connectors, so entering through a BACK WALL DOOR
54810	LD A,C	(Superfluous instruction, as this value is immediately overwritten in next one)
54811	LD A,(60155)	Left room corner section - floor/wall connector - graphic's horizontal position, in half character squares (4 pixel steps)
54814	CP C	Compare with creature's horizontal position (also in 4 pixel steps)
54815	JR C,54822
54817	LD DE,1024	Creature is to the left of the room's left connector, so entering through a LEFT WALL DOOR
54820	JR 54831
54822	LD A,(60156)	Right wall corner section - floor/wall connector - graphic's horizontal position, in half character squares (4 pixel steps)
54825	CP C	Compare with creature's horizontal position (also in 4 pixel steps) in room
54826	JR NC,54831
54828	LD DE,64512	Creature is to the right or the room's right (wall/floor) connector graphics - so entering through a RIGHT WALL DOOR
The result in the DE registers is used to set the creature's horizontal (60236) and vertical (60237) speed/direction Back wall door: E (vertical) = +4, D (horizontal) = 0 Left wall door: E (vertical) = 0, D (horizontal) = +4 Right wall door: E (vertical) = 0, D (horizontal) = -4 (252)
54831	LD A,D
54832	LD (60236),A	Horizontal speed/direction
54835	LD A,E	Horizontal speed/direction
54836	LD (60237),A	Vertical speed/direction
54839	JP 54983	Vertical speed/direction