Knight Lore: Routine at BC10

Used by the routine at GameOver.

Works out how much of the quest has been completed and prints the percentage in the screen buffer. Each room that has been visited counts for one point and each charm that has been put in the cauldron counts for two. The most that can be scored is 9C points (80 rooms and 0E charms counted twice), so each point is worth about 0.64 percent. The percentage is worked out as a BCD number and is printed with the hundreds digit only if the quest has been completed in full.

Used by the routine at GameOver. Works out how much of the quest has been completed and prints the percentage in the screen buffer. Each room that has been visited counts for one point and each charm that has been put in the cauldron counts for two. The most that can be scored is 9C points (80 rooms and 0E charms counted twice), so each point is worth about 0.64 percent. The percentage is worked out as a BCD number and is printed with the hundreds digit only if the quest has been completed in full.
PrintPercentageComplete	BC10	LD E,$00	Set the count of rooms to zero.
	BC12	LD BC,$0820	Set B to the number of bits in a byte and C to the number of bytes of flags.
	BC15	LD HL,$5BE8	Point HL at the flags for the rooms that have been visited, RoomsVisitedBitmap.
PrintPercentageComplete_CountByte	BC18	PUSH BC	Stash the counters on the stack.
	BC19	LD A,(HL)	Fetch a byte of flags.
	BC1A	INC HL	Move on to the next byte.
PrintPercentageComplete_CountBit	BC1B	RRCA	Move a flag into the carry flag.
	BC1C	JR NC,PrintPercentageComplete_NextBit	Jump to PrintPercentageComplete_NextBit if the room has not been visited.
	BC1E	INC E	Count the room.
PrintPercentageComplete_NextBit	BC1F	DJNZ PrintPercentageComplete_CountBit	Jump to PrintPercentageComplete_CountBit until the whole byte has been counted.
	BC21	POP BC	Restore the counters from the stack.
	BC22	DEC C	Decrease the number of bytes left.
	BC23	JR NZ,PrintPercentageComplete_CountByte	Jump to PrintPercentageComplete_CountByte until all of the bytes have been counted.
Keep the number of rooms visited for the rating, and work out the number of points.
	BC25	LD A,E	Fetch the number of rooms visited.
	BC26	DEC A	Take off one, so that the first room does not count towards the rating.
	BC27	LD ($5BC6),A	Store it for the rating at RoomsVisited.
	BC2A	LD A,($5BBB)	Fetch the number of charms collected from Charms.
	BC2D	SLA A	Double it.
	BC2F	ADD A,E	Add the number of rooms visited.
	BC30	LD E,A	Stash the number of points in E.
Add up the percentage as a BCD number. The percentage that each point is worth is the 16-bit fraction A41A (about 0.64 percent).
	BC31	LD BC,$A41A	Set BC to the percentage that each point is worth.
	BC34	LD HL,$0000	Clear the fraction of the percentage.
	BC37	XOR A	Clear the whole percentage.
PrintPercentageComplete_AddPoint	BC38	ADD HL,BC	Add the percentage for a point to the fraction.
	BC39	ADC A,$00	Carry into the whole percentage.
	BC3B	DAA	Keep the whole percentage as a BCD number.
	BC3C	DEC E	Decrease the number of points left.
	BC3D	JR NZ,PrintPercentageComplete_AddPoint	Jump to PrintPercentageComplete_AddPoint until every point has been added.
	BC3F	LD BC,$0028	Set BC to the amount that makes up for the rounding. The 24-bit total for all of the points is 63FF in the high word and D8 in the low byte, and this takes it up to 6400 in the high word.
	BC42	ADD HL,BC	Add it to the fraction.
	BC43	ADC A,$00	Carry into the whole percentage.
	BC45	DAA	Keep the whole percentage as a BCD number.
	BC46	LD ($5BCA),A	Store the lowest two digits of the percentage.
	BC49	LD A,$00	Clear A without changing the carry flag.
	BC4B	ADC A,$00	Carry into the hundreds digit.
	BC4D	DAA	Keep the hundreds digit as a BCD number.
	BC4E	LD ($5BC9),A	Store the hundreds digit at PercentComplete.
Print the digits.
	BC51	LD HL,$E4E6	Point HL at ScreenBuffer_ResultsPercentage.
	BC54	LD DE,$5BC9	Point DE at PercentComplete.
	BC57	LD B,$01	Set the number of bytes to print to 01.
	BC59	LD A,(DE)	Fetch the hundreds digit.
	BC5A	AND A	Test whether it is zero.
	BC5B	JR Z,PrintPercentageComplete_TwoDigits	Jump to PrintPercentageComplete_TwoDigits if the quest is not complete.
	BC5D	INC B	Set the number of bytes to print to 02.
	BC5E	JP PrintBCDNumber_SecondDigit	Jump to PrintBCDNumber_SecondDigit to print the hundreds digit and then the rest.
PrintPercentageComplete_TwoDigits	BC61	INC HL	Move the position past the space for the hundreds digit.
	BC62	INC DE	Move on to the lowest two digits.
	BC63	JP PrintBCDNumber	Jump to PrintBCDNumber to print them.