Fairlight: Routine at EC75

Used by the routines at SHOW_THING_IN_USE, CREATURE_UPDATE and MAIN_LOOP.

The author's INFO0 (named by its calls in the leftover source text). The panel shows the thing in use in a box 24 pixels wide and 32 high at x 20, row 40 down, and the number of its carried place (1-5) above it at x 10, y 50. The box is put back as the clean copy of the screen (LOADING_TUNE) has it: the compositor (COMPOSITE_TO_SCREEN) is given its second plane all set, which takes every pixel from the clean copy, so whatever sprite it finds does not matter. Then the digit is printed, from SELECTED. Called on its own when a thing is dropped (CREATURE_UPDATE) or an empty place is chosen (MAIN_LOOP), and by SHOW_THING_IN_USE.

Used by the routines at SHOW_THING_IN_USE, CREATURE_UPDATE and MAIN_LOOP. The author's INFO0 (named by its calls in the leftover source text). The panel shows the thing in use in a box 24 pixels wide and 32 high at x 20, row 40 down, and the number of its carried place (1-5) above it at x 10, y 50. The box is put back as the clean copy of the screen (LOADING_TUNE) has it: the compositor (COMPOSITE_TO_SCREEN) is given its second plane all set, which takes every pixel from the clean copy, so whatever sprite it finds does not matter. Then the digit is printed, from SELECTED. Called on its own when a thing is dropped (CREATURE_UPDATE) or an empty place is chosen (MAIN_LOOP), and by SHOW_THING_IN_USE.
CLEAR_THING_BOX	EC75	LD B,$20	the second plane all set: every pixel from the clean copy
	EC77	LD HL,BUFFER_DA00
	EC7A	LD DE,$FFFF
	EC7D	CALL FILL_BELOW
	EC80	LD HL,BUFFER_D900	the first plane clear
	EC83	LD B,$20
	EC85	CALL CLEAR_BELOW
	EC88	LD HL,$2814	the box: x 20, row 40, 24 by 32
	EC8B	LD (POINT),HL
	EC8E	LD HL,$2018
	EC91	LD (SECOND_POINT),HL
	EC94	LD HL,BUFFER_D800	not used: COMPOSITE_TO_SCREEN loads HL itself
	EC97	LD (IY+WORK_DIRECTION-V),$00	nothing else to merge; 4 bytes wide
	EC9B	LD A,$04
	EC9D	LD (DRAW_WIDTH),A
	ECA0	CALL COMPOSITE_TO_SCREEN	put the box back
	ECA3	LD A,(SELECTED)	the place in use ($9F-$A7 in twos) as a digit 1-5, into the string
	ECA6	SUB $9E
	ECA8	RRA
	ECA9	ADD A,$1C
	ECAB	LD ($ECB4),A
	ECAE	CALL PRINT	print it (the string follows the CALL, laid out by the data generator)
	ECB1	DEFB $C8,$0A,$32	Print at x 10, y 50
	ECB4	DEFB $00	" "
	ECB5	DEFB $A4	End of the string
	ECB6	LD HL,$2814
	ECB9	LD (POINT),HL
	ECBC	RET