ref: 8701ef4d61a6a55ee71aa1a964d4f7d10eded87e
dir: /home/print_num.asm/
PrintNumber:: ; Print the c-digit, b-byte value at de. ; Allows 2 to 7 digits. For 1-digit numbers, add ; the value to char "0" instead of calling PrintNumber. ; Flags LEADING_ZEROES and LEFT_ALIGN can be given ; in bits 7 and 6 of b respectively. push bc xor a ldh [hPastLeadingZeros], a ldh [hNumToPrint], a ldh [hNumToPrint + 1], a ld a, b and $f cp 1 jr z, .byte cp 2 jr z, .word .long ld a, [de] ldh [hNumToPrint], a inc de ld a, [de] ldh [hNumToPrint + 1], a inc de ld a, [de] ldh [hNumToPrint + 2], a jr .start .word ld a, [de] ldh [hNumToPrint + 1], a inc de ld a, [de] ldh [hNumToPrint + 2], a jr .start .byte ld a, [de] ldh [hNumToPrint + 2], a .start push de ld d, b ld a, c ld b, a xor a ld c, a ld a, b cp 2 jr z, .tens cp 3 jr z, .hundreds cp 4 jr z, .thousands cp 5 jr z, .ten_thousands cp 6 jr z, .hundred_thousands print_digit: MACRO IF (\1) / $10000 ld a, \1 / $10000 % $100 ELSE xor a ENDC ldh [hPowerOf10 + 0], a IF (\1) / $100 ld a, \1 / $100 % $100 ELSE xor a ENDC ldh [hPowerOf10 + 1], a ld a, \1 / $1 % $100 ldh [hPowerOf10 + 2], a call .PrintDigit call .NextDigit ENDM .millions print_digit 1000000 .hundred_thousands print_digit 100000 .ten_thousands print_digit 10000 .thousands print_digit 1000 .hundreds print_digit 100 .tens ld c, 0 ldh a, [hNumToPrint + 2] .mod cp 10 jr c, .ok sub 10 inc c jr .mod .ok ld b, a ldh a, [hPastLeadingZeros] or c ldh [hPastLeadingZeros], a jr nz, .past call .PrintLeadingZero jr .next .past ld a, "0" add c ld [hl], a .next call .NextDigit .ones ld a, "0" add b ld [hli], a pop de dec de pop bc ret .PrintDigit: ; Divide by the current decimal place. ; Print the quotient, and keep the modulus. ld c, 0 .loop ldh a, [hPowerOf10] ld b, a ldh a, [hNumToPrint] ldh [hSavedNumToPrint], a cp b jr c, .underflow0 sub b ldh [hNumToPrint], a ldh a, [hPowerOf10 + 1] ld b, a ldh a, [hNumToPrint + 1] ldh [hSavedNumToPrint + 1], a cp b jr nc, .noborrow1 ldh a, [hNumToPrint] or 0 jr z, .underflow1 dec a ldh [hNumToPrint], a ldh a, [hNumToPrint + 1] .noborrow1 sub b ldh [hNumToPrint + 1], a ldh a, [hPowerOf10 + 2] ld b, a ldh a, [hNumToPrint + 2] ldh [hSavedNumToPrint + 2], a cp b jr nc, .noborrow2 ldh a, [hNumToPrint + 1] and a jr nz, .borrowed ldh a, [hNumToPrint] and a jr z, .underflow2 dec a ldh [hNumToPrint], a xor a .borrowed dec a ldh [hNumToPrint + 1], a ldh a, [hNumToPrint + 2] .noborrow2 sub b ldh [hNumToPrint + 2], a inc c jr .loop .underflow2 ldh a, [hSavedNumToPrint + 1] ldh [hNumToPrint + 1], a .underflow1 ldh a, [hSavedNumToPrint] ldh [hNumToPrint], a .underflow0 ldh a, [hPastLeadingZeros] or c jr z, .PrintLeadingZero ld a, "0" add c ld [hl], a ldh [hPastLeadingZeros], a ret .PrintLeadingZero: bit BIT_LEADING_ZEROES, d ret z ld [hl], "0" ret .NextDigit: ; Increment unless the number is left-aligned, ; leading zeroes are not printed, and no digits ; have been printed yet. bit BIT_LEADING_ZEROES, d jr nz, .inc bit BIT_LEFT_ALIGN, d jr z, .inc ldh a, [hPastLeadingZeros] and a ret z .inc inc hl ret