ips.inc

IPSPRGOFFSET = 16-$8000

; Generates an IPS hunk header for named segment, which specifes the location
; and length where an IPS tool will place the segment in the modded file.
;
; The code:
;       ips_hunkhdr "HUNK1"
; Is equivalent to:
;	.import __HUNK1_LOAD__, __HUNK1_SIZE__
;	.byte 0
;	.dbyt __HUNK1_LOAD__+IPSPRGOFFSET
;	.dbyt __HUNK1_SIZE__
.macro ips_hunkhdr name
	.import .ident(.concat("__", name, "_LOAD__"))
	.import .ident(.concat("__", name, "_SIZE__"))
	.byte 0
	; Dunno why -(-x) is necessary. But otherwise get a range error
	.dbyt .ident(.concat("__", name, "_LOAD__"))-(-IPSPRGOFFSET)
	.dbyt .ident(.concat("__", name, "_SIZE__"))
.endmacro

.ifndef IPSCHROFFSET
IPSCHROFFSET = 16+$8000
.endif
CHR00 = $0000
CHR01 = $2000
CHR_LEFT = $0000
CHR_RIGHT = $1000
TILE_SIZE = $10

; Generates an IPS hunk header for tiles, which specifes the location and
; length where an IPS tool will place the tiles in the modded file.
;
; For example, to replace a tile in the "left" (first) section of CHR01 in at
; row 0 and column 3:
;       ips_tilehdr CHR01+CHR_LEFT,$03
.macro ips_tilehdr mapper_addr,tile
	.byte 0
	.dbyt (mapper_addr)+((tile)*TILE_SIZE)+IPSCHROFFSET
	.dbyt TILE_SIZE
.endmacro


; Declares the IPS segment hunk with name starts at addr, and optional size.
; The segment should be defined elsewhere. Only useful when combined with
; auto-generation of linker config.
.macro ips_segment name,addr,size
	.if .paramcount = 3
	.fileopt    comment, .sprintf("ips: %d %s %d", addr, name, size)
	.else
	.fileopt    comment, .sprintf("ips: %d %s", addr, name)
	.endif

	.pushseg
	.segment    .concat(name, "_HDR")
	ips_hunkhdr name
	.popseg
.endmacro

; Declares the IPS segment hunk with name starts at mapper_addr+start_tile. The
; segment should be defined elsewhere. Only useful when combined with
; auto-generation of linker config.
.macro ips_tile_segment name,mapper_addr,start_tile
        .fileopt    comment, .sprintf("ips: %d00000 %s %d", (mapper_addr)+((start_tile)*TILE_SIZE), name, 4096-((start_tile)*TILE_SIZE))

	.pushseg
	.segment    .concat(name, "_HDR")

	.import .ident(.concat("__", name, "_SIZE__"))
	.byte   0
	.dbyt   (mapper_addr)+((start_tile)*TILE_SIZE)+IPSCHROFFSET
	.dbyt   .ident(.concat("__", name, "_SIZE__"))

	.popseg
.endmacro