regs.mac

著名SFC模拟器Snes9x的源代码。

; Snes9x - Portable Super Nintendo Entertainment System (TM) emulator.
;
; Super FX assembler emulator code
; (c) Copyright 1998, 1999 zsKnight and _Demo_.
;
; Permission to use, copy, modify and distribute Snes9x in both binary and
; source form, for non-commercial purposes, is hereby granted without fee,
; providing that this license information and copyright notice appear with
; all copies and any derived work.
;
; This software is provided 'as-is', without any express or implied
; warranty. In no event shall the authors be held liable for any damages
; arising from the use of this software.
;
; Snes9x is freeware for PERSONAL USE only. Commercial users should
; seek permission of the copyright holders first. Commercial use includes
; charging money for Snes9x or software derived from Snes9x.
;
; The copyright holders request that bug fixes and improvements to the code
; should be forwarded to them so everyone can benefit from the modifications
; in future versions.
;
; Super NES and Super Nintendo Entertainment System are trademarks of
; Nintendo Co., Limited and its subsidiary companies.
;
;*******************************************************
; InitReg                          Initializes Registers
;*******************************************************

%macro setreg 2
    mov edi,%1
    add edi,[regptr]
    mov eax,%2
    mov [edi],eax
%endmacro

;*******************************************************
; Registers     Note : Remember to restore AH, ECX, & DX
;*******************************************************

%macro checkmultchange 0
    ; execute multiplication
    cmp byte[multchange],0
    je .nomult
    push edx
    push eax
    xor bh,bh
    mov bl,[mode7B+1]
    mov ax,[mode7A]
    test bl,80h
    jz .noneg
    mov bh,0FFh
.noneg
    imul bx
    mov [compmult],ax
    mov [compmult+2],dl
    pop eax
    pop edx
    mov byte[multchange],0
.nomult
%endmacro

%macro mouse4016doxA 2
    cmp byte[JoyAPos],%1
    jne .nx7
    mov bx,[mousexpos]
    shr bx,%2
    and bx,1
    mov al,bl
.nx7
%endmacro

%macro mouse4016doyA 2
    cmp byte[JoyAPos],%1
    jne .ny7
    mov bx,[mouseypos]
    shr bx,%2
    and bx,1
    mov al,bl
.ny7
%endmacro

%macro mouse4017dox 2
    cmp byte[JoyBPos],%1
    jne .nx7
    mov bx,[mousexpos]
    shr bx,%2
    and bx,1
    mov al,bl
.nx7
%endmacro

%macro mouse4017doy 2
    cmp byte[JoyBPos],%1
    jne .ny7
    mov bx,[mouseypos]
    shr bx,%2
    and bx,1
    mov al,bl
.ny7
%endmacro