Nightshade: Routine at BF95

Used by the routine at NEW_GAME.

When the low byte of TURNS comes round to zero, the first monster record that is not in the knight's cell or next to it becomes the creature (graphic 136) -- empty or not: a monster further off is simply replaced. It is put in the knight's cell, at a random place 64-191 across it each way, with a half-size of 16 each way; if that place already touches him (TOUCHING_KNIGHT) it is a puff (graphic 12) instead, and harmless. If all six records are within a cell of him, the first becomes the creature wherever it is, with only its graphic changed.

Measured: in a game left to run, a monster record held the creature every time the turn counter's low byte was zero; and with all six records empty and so at cell (0,0), next to a knight in cell (1,1), the first record got graphic 136 and nothing else.

Used by the routine at NEW_GAME. When the low byte of TURNS comes round to zero, the first monster record that is not in the knight's cell or next to it becomes the creature (graphic 136) -- empty or not: a monster further off is simply replaced. It is put in the knight's cell, at a random place 64-191 across it each way, with a half-size of 16 each way; if that place already touches him (TOUCHING_KNIGHT) it is a puff (graphic 12) instead, and harmless. If all six records are within a cell of him, the first becomes the creature wherever it is, with only its graphic changed. Measured: in a game left to run, a monster record held the creature every time the turn counter's low byte was zero; and with all six records empty and so at cell (0,0), next to a knight in cell (1,1), the first record got graphic 136 and nothing else.
SPAWN_CREATURE	BF95	LD A,(TURNS)	not the 256th turn: nothing
	BF98	AND A
	BF99	RET NZ
	BF9A	LD IX,MONSTERS	the first monster record not within a cell of the knight
	BF9E	LD DE,$0010
	BFA1	LD B,$06
SPAWN_CREATURE_0	BFA3	LD C,$02
	BFA5	CALL NEAR_KNIGHT
	BFA8	JR NC,SPAWN_CREATURE_1
	BFAA	ADD IX,DE
	BFAC	DJNZ SPAWN_CREATURE_0
	BFAE	LD A,$88	all six are: the first becomes the creature where it is
	BFB0	LD (MONSTERS),A
	BFB3	RET
SPAWN_CREATURE_1	BFB4	LD A,(RANDOM)	in the knight's cell, at a random place in it
	BFB7	AND $7F
	BFB9	ADD A,$40
	BFBB	LD (IX+$01),A
	BFBE	LD A,(KNIGHT_COLUMN)
	BFC1	LD (IX+$02),A
	BFC4	LD A,($BBAB)
	BFC7	AND $7F
	BFC9	ADD A,$40
	BFCB	LD (IX+$03),A
	BFCE	LD A,(KNIGHT_ROW)
	BFD1	LD (IX+$04),A
	BFD4	LD (IX+$08),$10	half-size 16 each way; the drawing offset
	BFD8	LD (IX+$09),$10
	BFDC	LD (IX+$0C),$F4
	BFE0	LD (IX+$0D),$04
	BFE4	CALL TOUCHING_KNIGHT	touching him already? a puff (12); otherwise the creature (136)
	BFE7	LD A,$0C
	BFE9	JR C,SPAWN_CREATURE_2
	BFEB	ADD A,$7C
SPAWN_CREATURE_2	BFED	LD (IX+$00),A
	BFF0	RET