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;;
;; Alternate Yoshi Coin Counter, by imamelia
;;
;; This patch installs a numerical Yoshi coin counter on the status bar that replaces
;; the normal one.  It is 3 digits, so it can go up to 999.  The coins also save to SRAM,
;; so each coin can be collected only once.  But please read the readme.
;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

header
lorom

!Freespace = $1A8000

!RAM_TotalYCoins = $7F9C80		; the total number of Yoshi coins that have been collected (16-bit)
!SRAM_TotalYCoins = $7003FA	; SRAM for the total number of Yoshi coins that have been collected (6 bytes)
!RAM_CoinFlags = $7FB600		; flags for each individual coin, 0x600 bytes' worth of free RAM
!SRAM_CoinFlags = $700E00		; SRAM for the coin flags, 0x600 bytes per file (0x1200 bytes total)
!OWLevel = $13BF		; the current overworld level
			; (should be changed only if you are using the Extra Overworld Level RAM patch)
!Points = $0A		; the points/lives to give for each Yoshi coin before the last
!Points2 = $0D		; the points/lives to give for the last Yoshi coin
; 00 = 0, 01 = 10, 02 = 20, 03 = 40, 04 = 80, 05 = 100, 06 = 200, 07 = 400, 08 = 800, 09 = 1000,
; 0A = 2000, 0B = 4000, 0C = 8000, 0D = 1-Up, 0E = 2-Up, 0F = 3-Up, 10 = 5-Up (may glitch)
!SBDigit1 = $0F01		; the position of the ones digit on the status bar (can be 24-bit)
!SBDigit10 = $0F00		; the position of the tens digit on the status bar (can be 24-bit)
!SBDigit100 = $0EFF	; the position of the hundreds digit on the status bar (can be 24-bit)
!SBCoin = $0EFE		; the position of the coin symbol on the status bar (can be 24-bit)

org $008FD8	; the routine that draws Yoshi coins onto the status bar
JML YCoinStatusBar	;

org $00F343	; the routine that increments the Yoshi coin counter and resets it if necessary
JML YCoinNumber	;

org $00F377	; the routine that gives you an extra life when you have enough Yoshi coins
JML YCoinLives	;

org $0DB2CA	; the routine that creates the Yoshi coin object in the first place
JML YCoinObject	;

org $009D22	; part of the load game routine
JML LoadCoinFlags	;

org $009BD2	; part of the save game routine
JML SaveCoinFlags	;

org $00A5F3
JML ClearSRAM	; clear the coin flags in SRAM
NOP #2		;

org $00FFD8	; SRAM size
db $08		; expand the SRAM to $700000-$701FFF

org !Freespace

reset bytes

db "STAR"
dw EndCode-StartCode-$01
dw EndCode-StartCode-$01^$FFFF

StartCode:

YCoinStatusBar:

REP #$20			; set A to 16-bit mode
LDA !RAM_TotalYCoins	; take the total number of Yoshi coins collected
PHX			;
PHY			;
JSR HexToDecLong		; and convert it to decimal
STA !SBDigit1		; store the ones digit
CPX #$00			; if the hundreds digit is 0...
BNE NotZero		;
LDX #$FC			; make it a space instead
CPY #$00			; if the tens digit is 0...
BNE NotZero		;
LDY #$FC			; make it a space instead
NotZero:			;
TYA			;
STA !SBDigit10		; store the tens digit
TXA			;
STA !SBDigit100		; store the hundreds digit
PLY			;
PLX			;
LDA #$2E			; store the coin symbol
STA !SBCoin		; (you can comment out these two lines if you don't want it there)
JML $008FF9		;

YCoinLives:		;

PHX			; preserve the contents of X
PHY			; and Y
PHB			;
PHK			;
PLB			;
LDY #!Points		; default point value
LDX !OWLevel		; load the overworld level
LDA $1422		; check the current number of Yoshi coins collected
CMP TotalNumber,x		; if it has not reached the total number in the level...
BCC LessThanTotal		; use the default point value
LDY #!Points2		; if all of them have been collected, use the other point value
LessThanTotal:		;
CPY #$00			; if the point value is 0...
BEQ NoPoints		; don't give any points
TYA			;
PLB
PLY
PLX
JML $00F38A		; jump back to the rest of the normal routine
NoPoints:			;
PLY
PLX
PLB			;
JML $00F3B1		;

YCoinNumber:		;

INC $1422		; increment the coins collected in the current level
REP #$20			; set A to 16-bit mode
LDA !RAM_TotalYCoins	; check the total number of coins collected
CMP #$03E7		; if it has reached 999...
BEQ NoIncTotal		; don't let it go any higher
INC			;
STA !RAM_TotalYCoins	;
NoIncTotal:		;
SEP #$20			;

PHX			;
LDA $9A			; X position of contact with the block
AND #$70		; in terms of 8 tiles
LSR #4			;
STA $06			; X position on the screen = *bit* index (00-07)
LDA $5B			; check whether the level is vertical or horizontal
LSR			; if bit 0 of $5B is set...
BCS Vertical		; then the level is vertical
LDA $9B			; base the high byte on the player's X position
BRA StoreHighByte		;
Vertical:			; if the level is vertical...
LDA $99			; base the high byte on the player's Y position
StoreHighByte:		;
AND #$0F		; 4 bits for the screen number (the 5th bit is cleared)
STA $07			;
STZ $08			; clear the next byte
LDA !OWLevel		; overworld level
REP #$20			;
AND.w #$00FF		; clear the high byte of A
ASL #4			;
ORA $07			; overworld level + low 4 bits of screen number
STA $07			; = resulting *byte* index
SEP #$20			;
LDX $06			; load the index from the player's X position
LDA $028000,x		; set a particular coin flag (bitwise)
REP #$10			; set X to 16-bit as well
LDX $07			; get an index from 0-600 based on the level number and screen number
ORA !RAM_CoinFlags,x	;
STA !RAM_CoinFlags,x	;
SEP #$10			;
PLX			;
JML $00F358		; finish up with the regular code

YCoinObject:

LDA $1BA1		; the current screen the loading routine is on
AND #$0F		;
STA $06			;
STZ $07			;
LDA !OWLevel		;
REP #$30			;
AND.w #$00FF		;
ASL #4			; get the overworld level x16
ORA $06			; add in the screen bits
TAX			;
SEP #$20			;
LDA !RAM_CoinFlags,x	; check a particular byte of coin flags
SEP #$10			;
PHA			;
LDA $57			; check the object's position within the subscreen
AND #$07		;
TAX			;
PLA			;
AND $028000,x		; check a single flag to see if it is set or not
BNE YCoinCollected		; if set, the coin has already been collected
LDY $57			;
LDA #$2D		;
STA [$6B],y		;
LDA #$00			;
STA [$6E],y		;
TYA			;
CLC			;
ADC #$10		;
TAY			;
LDA #$2E			;
STA [$6B],y		;
LDA #$00			;
STA [$6E],y		;
YCoinCollected:		;
JML $0DB335		;          

SaveCoinFlags:

XBA				;
LDA $009CCE,x			; restore hijacked code
PHA				; preserve this to prevent it getting overwritten
PHX				;
PHY				;
PHP				;
REP #$30				;
PHX				;
TXA				;
ASL				;
TAX				;
LDA !RAM_TotalYCoins		;
STA !SRAM_TotalYCoins,x		;
PLX				;
LDA.w #$05FE			;
DEX				;
BMI $06				;
CLC				;
ADC #$0600			;
BRA $F7				;

TAX				;
LDA.w #!RAM_CoinFlags		;
STA $00				;
LDA.w #!RAM_CoinFlags/$10000	; set up a pointer
STA $02				;
LDY #$05FE			;
SaveLoop:				;
LDA [$00],y			;
STA !SRAM_CoinFlags,x		;
DEX				;
DEX				;
DEY				;
DEY				;
BPL SaveLoop

PLP				;
PLY				;
PLX				;
PLA				;
JML $009BD6			;

LoadCoinFlags:			;

SEP #$10				;
LDY #$12				; restore hijacked code
PHY
PHP				;
REP #$30				;
LDA $010A			;
AND.w #$00FF			;
PHA				;
ASL				;
TAX				;
LDA !SRAM_TotalYCoins,x		;
STA !RAM_TotalYCoins		;
PLA				;
TAX				;
LDA #$05FE			;
DEX				;
BMI $06				;
CLC				;
ADC #$0600			;
BRA $F7				;

TAX				;
LDA.w #!RAM_CoinFlags		;
STA $00				;
LDA.w #!RAM_CoinFlags/$10000	; set up a pointer
STA $02				;
LDY #$05FE			;
LoadLoop:			;
LDA !SRAM_CoinFlags,x		;
STA [$00],y			;
DEX				;
DEX				;
DEY				;
DEY				;
BPL LoadLoop

PLP				;
PLY				;
JML $009D26			;

ClearSRAM:

PHP			;
SEP #$30			;
LDA $0109		;
CMP #$E9			;
BNE NoClear		;
PHX			; preserve the value of X
PHY			; and Y
LDA $010A		; save file number
ASL			; x2
STA $00			; into scratch
ASL			; x4
CLC			;
ADC $00			; x6
XBA			;
REP #$30			;
AND #$FF00		; save file x600
CLC			;
ADC #$05FE		;
TAX			;
LDA.w #!RAM_CoinFlags		;
STA $00				;
LDA.w #!RAM_CoinFlags/$10000	; set up a pointer
STA $02				;
LDY #$05FE		; 0x600 bytes to clear
LDA.w #$0000		;
SRAMClearLoop:		;
STA !SRAM_CoinFlags,x	; set the coin flags to zero
STA [$00],y		;
DEX			;
DEX			;
DEY			;
DEY			;
BPL SRAMClearLoop		; loop if Y hasn't dropped below zero
STA !RAM_TotalYCoins	;
SEP #$30			;
PLY			;
PLX			;
NoClear:			;
PLP			;
PEA $93F3		;
JML $008494		;

HexToDecLong:		;

LDX #$00
LDY #$00

HexDecLoop1:

CMP.w #$0064
BCC HexDecLoop2
SBC.w #$0064
INX
BRA HexDecLoop1

HexDecLoop2:

CMP.w #$000A
BCC EndHexDec
SBC.w #$000A
INY
BRA HexDecLoop2

EndHexDec:

SEP #$20
RTS

TotalNumber:		; the total number of Yoshi coins in each level

db $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04	; levels 0-F
db $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04	; levels 10-1F
db $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04	; levels 20-24 and 101-10B
db $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04	; levels 10C-11B
db $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04	; levels 11C-12B
db $04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04,$04	; levels 12C-13B

print "This patch uses ",bytes," bytes."

EndCode: