Knight Lore: Routine at CDEF

Used by the routine at upd_player_top.

Copies the legs' position, size and flags into the head -- so the head inherits the legs' redraw, wipe and flip bits and is wiped and redrawn with them -- then gives the head a height of zero and sets its bit 1, which takes it out of every collision test. The legs' record carries the whole body's height, so the head never needs to collide with anything.

Then the choice of head sprite. The low nibble of +$0D is a countdown: while it is running the head keeps the sprite it has.

Used by the routine at upd_player_top. Copies the legs' position, size and flags into the head -- so the head inherits the legs' redraw, wipe and flip bits and is wiped and redrawn with them -- then gives the head a height of zero and sets its bit 1, which takes it out of every collision test. The legs' record carries the whole body's height, so the head never needs to collide with anything. Then the choice of head sprite. The low nibble of +$0D is a countdown: while it is running the head keeps the sprite it has.
head_follows_legs	CDEF	PUSH IX	DE = the head; IY = HL = the legs, one record below
	CDF1	POP DE
	CDF2	LD HL,$FFE0
	CDF5	ADD HL,DE
	CDF6	PUSH HL
	CDF7	POP IY
	CDF9	INC DE	copy +$01 to +$07: X, Y, Z, the three half-sizes, flags
	CDFA	INC HL
	CDFB	LD BC,$0007
	CDFE	LDIR
	CE00	LD (IX+$06),$00	height 0
	CE04	SET 1,(IX+$07)	bit 1: ignored by collision tests
	CE08	LD A,(IX+$0D)	countdown running?
	CE0B	AND $0F
	CE0D	JR Z,choose_head_sprite	yes: count it down and keep the current head
	CE0F	DEC (IX+$0D)
	CE12	JR head_on_shoulders