mode7.mac

linux下的任天堂模拟器代码。供大家参考。

    mov edx,[.mode7yadd2]
    sub bh,[.mode7yinc]
    add dword[.mode7yrpos],edx
%%noaddstuff2
    and ebx,07FFFh
    xor ecx,ecx
    mov cl,[vrama+ebx]
    shl ecx,7
    lea edi,[ecx+vrama]
    jmp %%nextposy

%%finishmode7
    xor eax,eax
    mov dh,[curmosaicsz]
    cmp dh,1
    jne near %2
    ret

;**********************************************************
; Mode 7, no repetition mode
;**********************************************************

%%norep2
    test byte[mode7set],40h
    jnz %%tilerep2
    jmp %%nextvalb2
    ALIGN16
%%nextvalb2
    cmp byte[.mode7ypos+2],3
    ja %%offscr2
    cmp byte[.mode7xpos+2],3
    jbe near %%offscr3
%%offscr2
    mov eax,[.mode7xadder]
    mov ebx,[.mode7yadder]
    add [.mode7xpos],eax
    sub [.mode7ypos],ebx
    add esi,%3
    dec dword[.temp]
    jnz near %%nextvalb2
    mov dword[.temp],256
    add esi,75036*2-256
    dec dword[.temp2]
    jnz near %%nextvalb2
    jmp %%finishmode7
%%tilerep2
%%nextvalb3
    cmp byte[.mode7ypos+2],3
    ja %%offscr2b
    cmp byte[.mode7xpos+2],3
    jbe near %%offscr3
%%offscr2b
    mov ch,[.mode7xpos+1]
    mov eax,[.mode7xadder]
    mov cl,[.mode7ypos+1]
    mov ebx,[.mode7yadder]
    mov dl,[mode7tab+ecx]
    add [.mode7xpos],eax
    mov dl,[vrama+edx]
    sub [.mode7ypos],ebx
    %1
    dec dword[.temp]
    jnz near %%nextvalb3
    mov dword[.temp],256
    add esi,75036*2-256
    dec dword[.temp2]
    jnz near %%nextvalb3
    jmp %%finishmode7
%%offscr3
    mov eax,[.mode7xpos]
    and eax,7FFh
    mov [.mode7xrpos],eax
    mov eax,[.mode7ypos]
    and eax,7FFh
    mov [.mode7yrpos],eax

    ; get tile data offset into edi
    mov ebx,[.mode7ypos+1]
    mov eax,[.mode7xpos+1]
    shl ebx,5
    shr eax,3
    and ebx,07FF8h
    shl al,1
    mov bl,al
    mov edi,[vram]
    xor ch,ch
    mov [.mode7ptr],ebx
    mov cl,[edi+ebx]
    shl ecx,7
    add edi,ecx

    jmp %%nextvalr
    ALIGN16
%%nodr2
    add esi,%3
    dec dword[.temp]
    jz near %%fin2
%%nextvalr
    test byte[.mode7xrpos+1],0F8h
    jnz near %%rposoffxr
%%nextposxr
    test byte[.mode7yrpos+1],0F8h
    jnz near %%rposoffyr
%%nextposyr
    mov cl,[.mode7yrpos+1]
    mov edx,[.mode7xadder]
    mov ch,[.mode7xrpos+1]
    add dword[.mode7xrpos],edx
    mov edx,[.mode7yadder]
    sub dword[.mode7yrpos],edx
    xor edx,edx
    mov dl,[mode7tab+ecx]
    mov dl,[edi+edx]
    %1
    dec dword[.temp]
    jnz near %%nextvalr
%%fin2
    mov dword[.temp],256
    add esi,75036*2-256
    dec dword[.temp2]
    jnz near %%nextvalr
    jmp %%finishmode7
%%rposoffxr
    mov al,[.mode7xinc]
    mov edi,[vram]
    add [.mode7ptr],al
    mov cl,[.mode7xincc]
    cmp byte[.mode7ptr],cl
    je %%roff
%%roffxretb
    mov ebx,[.mode7ptr]
    xor ecx,ecx
    mov cl,[edi+ebx]
    mov eax,[.mode7xadd2]
    shl ecx,7
    sub [.mode7xrpos],eax
    add edi,ecx
    jmp %%nextvalr
%%rposoffyr
    mov al,[.mode7yinc]
    mov edi,[vram]
    sub [.mode7ptr+1],al
    js %%roff
%%roffyretb
    mov ebx,[.mode7ptr]
    xor ecx,ecx
    mov cl,[edi+ebx]
    mov eax,[.mode7yadd2]
    shl ecx,7
    add [.mode7yrpos],eax
    add edi,ecx
    jmp %%nextposxr
%%roff
    test byte[mode7set],40h
    jnz %%tilerep3
    jmp %%finishmode7
%%tilerep3
    and byte[.mode7yrpos+1],07h
    and byte[.mode7xrpos+1],07h
    mov cl,[.mode7yrpos+1]
    mov eax,[.mode7xadder]
    mov ch,[.mode7xrpos+1]
    add [.mode7xrpos],eax
    mov dl,[mode7tab+ecx]
    mov eax,[.mode7yadder]
    mov dl,[vrama+edx]
    sub [.mode7yrpos],eax
    %1
    dec dword[.temp]
    jnz near %%tilerep3
    mov dword[.temp],256
    add esi,75036*2-256
    dec dword[.temp2]
    jnz near %%tilerep3
    jmp %%finishmode7
%endmacro

%macro ProcessBuildWindow 1
    mov dword[ngwinen],0
    test byte[winbg1enval+ebx+%1*256],0Ah
    jz %%nowindowing
    push eax
    push ebx
    mov al,[winlogicaval+ebx*2]
    shr al,%1*2
    and al,03h
    mov [nglogicval],al
    mov eax,ebx
    add ebx,%1*256
    call BuildWindow
    cmp dword[ngwintable],0
    je %%zero
    dec dword[ngwintable]
    jmp %%notzero
%%zero
    dec dword[ngwintable+4]
%%notzero
    pop ebx
    pop eax
    mov dword[ngcwinptr],ngwintable
%%nowindowing
%endmacro

;************************************

%macro Mode7Processngw 3
    mov dword[ngwleftb],256
    mov dword[ngwleft],256
    test byte[mode7set],80h
    jnz near %%norep2

    mov eax,[.mode7xpos]
    and eax,7FFh
    mov [mode7xrpos],eax
    mov eax,[.mode7ypos]
    and eax,7FFh
    mov [mode7yrpos],eax

    ; get tile data offset into edi
    mov ebx,[.mode7ypos+1]
    mov eax,[.mode7xpos+1]
    shl ebx,5
    shr eax,3
    and ebx,07FF8h
    shl al,1
    mov bl,al
    mov edi,[vram]
    xor ch,ch
    mov [.mode7ptr],ebx
    mov cl,[edi+ebx]
    shl ecx,7
    add edi,ecx

    xor dl,dl
    xor ecx,ecx
    mov ebx,[.mode7xadder]
    test ebx,80000000h
    jz %%nexta
    neg ebx
%%nexta
    cmp ebx,0800h
    jl %%skipx
    sub ebx,800h
    add ecx,[.mode7xadd2]
    add dl,[.mode7xinc]
    jmp %%nexta
%%skipx
    mov [.m7xaddofa],ecx
    mov [.m7xaddof2a],dl

    xor dl,dl
    xor ecx,ecx
    mov ebx,[.mode7yadder]
    test ebx,80000000h
    jz %%nextay
    neg ebx
%%nextay
    cmp ebx,0800h
    jl %%skipy
    sub ebx,800h
    add ecx,[.mode7yadd2]
    add dl,[.mode7yinc]
    jmp %%nextay
%%skipy
    mov [.m7yaddofa],ecx
    mov [.m7yaddof2a],dl

    xor ecx,ecx

    mov eax,[mode7xrpos]
    mov ebx,[.mode7ptr]

    call ProcessMode7ngwin
    cmp dword[ngwleftb],0
    jne near %%nextval
    jmp %%finishmode7
    ALIGN16
%%nextval
    test ah,0F8h
    jnz near %%rposoffx
%%nextposx
    test byte[mode7yrpos+1],0F8h
    jnz near %%rposoffy
%%nextposy
    mov ch,ah
    mov cl,[mode7yrpos+1]
    mov edx,[mode7yadder]
    sub dword[mode7yrpos],edx
    xor edx,edx
    mov dl,[mode7tab+ecx]
    add eax,[mode7xadder]
    mov dl,[edi+edx]
    %1
    dec dword[ngwleftb]
    jnz near %%nextval
    mov [mode7xrpos],eax
    cmp dword[ngwleft],0
    je %%notskipvalues
    call ProcessMode7ngwinB
    cmp dword[ngwleftb],0
    jne near %%nextval
%%notskipvalues
    jmp %%finishmode7

%%rposoffx
    sub eax,[.m7xaddofa]
    add bl,[.m7xaddof2a]
    test ah,0F8h
    jz %%noaddstuff
    add bl,[.mode7xinc]
    sub eax,[.mode7xadd2]
%%noaddstuff
    xor ecx,ecx
    mov cl,[vrama+ebx]
    shl ecx,7
    lea edi,[ecx+vrama]
    jmp %%nextposx

%%rposoffy
    mov edx,[.m7yaddofa]
    sub bh,[.m7yaddof2a]
    add dword[mode7yrpos],edx
    test byte[mode7yrpos+1],0F8h
    jz %%noaddstuff2
    mov edx,[.mode7yadd2]
    sub bh,[.mode7yinc]
    add dword[mode7yrpos],edx
%%noaddstuff2
    and ebx,07FFFh
    xor ecx,ecx
    mov cl,[vrama+ebx]
    shl ecx,7
    lea edi,[ecx+vrama]
    jmp %%nextposy

%%finishmode7
    xor eax,eax
    mov dh,[curmosaicsz]
    cmp dh,1
    jne near %2
    ret

;**********************************************************
; Mode 7, no repetition mode
;**********************************************************

%%norep2
    call ProcessMode7ngwinC
    cmp dword[ngwleftb],0
    jne near %%nextvald
    jmp %%finishmode7
%%nextvald
    mov dword[ngwleft],0

    test byte[mode7set],40h
    jnz near %%tilerep2
    jmp %%nextvalb2
    ALIGN16
%%nextvalb2
    cmp byte[mode7ypos+2],3
    ja %%offscr2
    cmp byte[mode7xpos+2],3
    jbe near %%offscr3
%%offscr2
    mov eax,[mode7xadder]
    mov ebx,[mode7yadder]
    add [mode7xpos],eax
    sub [mode7ypos],ebx
    add esi,%3
    dec dword[ngwleftb]
    jnz near %%nextvalb2

    cmp dword[ngwleft],0
    je %%notskipvalues3b
    call ProcessMode7ngwinD
    cmp dword[ngwleftb],0
    jne near %%nextvalb2
%%notskipvalues3b

    jmp %%finishmode7
%%tilerep2
%%nextvalb3
    cmp byte[mode7ypos+2],3
    ja %%offscr2b
    cmp byte[mode7xpos+2],3
    jbe near %%offscr3
%%offscr2b
    mov ch,[mode7xpos+1]
    mov eax,[mode7xadder]
    mov cl,[mode7ypos+1]
    mov ebx,[mode7yadder]
    mov dl,[mode7tab+ecx]
    add [mode7xpos],eax
    mov dl,[vrama+edx]
    sub [mode7ypos],ebx
    %1
    dec dword[ngwleftb]
    jnz near %%nextvalb3

    cmp dword[ngwleft],0
    je %%notskipvalues3
    call ProcessMode7ngwinD
    cmp dword[ngwleftb],0
    jne near %%nextvalb3
%%notskipvalues3

    jmp %%finishmode7
%%offscr3
    mov eax,[mode7xpos]
    and eax,7FFh
    mov [mode7xrpos],eax
    mov eax,[mode7ypos]
    and eax,7FFh
    mov [mode7yrpos],eax

    ; get tile data offset into edi
    mov ebx,[mode7ypos+1]
    mov eax,[mode7xpos+1]
    shl ebx,5
    shr eax,3
    and ebx,07FF8h
    shl al,1
    mov bl,al
    mov edi,[vram]
    xor ch,ch
    mov [.mode7ptr],ebx
    mov cl,[edi+ebx]
    shl ecx,7
    add edi,ecx


    jmp %%nextvalr
    ALIGN16
%%nodr2
    add esi,%3
    dec dword[ngwleftb]
    jz near %%fin2
%%nextvalr
    test byte[mode7xrpos+1],0F8h
    jnz near %%rposoffxr
%%nextposxr
    test byte[mode7yrpos+1],0F8h
    jnz near %%rposoffyr
%%nextposyr
    mov cl,[mode7yrpos+1]
    mov ch,[mode7xrpos+1]
    mov edx,[mode7xadder]
    add dword[mode7xrpos],edx
    mov edx,[mode7yadder]
    sub dword[mode7yrpos],edx
    xor edx,edx
    mov dl,[mode7tab+ecx]
    mov dl,[edi+edx]
    %1
    dec dword[ngwleftb]
    jnz near %%nextvalr
%%fin2

    cmp dword[ngwleft],0
    je %%notskipvalues4
    call ProcessMode7ngwinB
    cmp dword[ngwleftb],0
    jne near %%nextvalr
%%notskipvalues4

    jmp %%finishmode7
%%rposoffxr
    mov al,[.mode7xinc]
    mov edi,[vram]
    add [.mode7ptr],al
    mov cl,[.mode7xincc]
    cmp byte[.mode7ptr],cl
    je %%roff
%%roffxretb
    mov ebx,[.mode7ptr]
    xor ecx,ecx
    mov cl,[edi+ebx]
    mov eax,[.mode7xadd2]
    shl ecx,7
    sub [mode7xrpos],eax
    add edi,ecx
    jmp %%nextvalr
%%rposoffyr
    mov al,[.mode7yinc]
    mov edi,[vram]
    sub [.mode7ptr+1],al
    js %%roff
%%roffyretb
    mov ebx,[.mode7ptr]
    xor ecx,ecx
    mov cl,[edi+ebx]
    mov eax,[.mode7yadd2]
    shl ecx,7
    add [mode7yrpos],eax
    add edi,ecx
    jmp %%nextposxr
%%roff
    test byte[mode7set],40h
    jnz %%tilerep3
    jmp %%finishmode7
%%tilerep3
    and byte[mode7yrpos+1],07h
    and byte[mode7xrpos+1],07h
    mov cl,[mode7yrpos+1]
    mov eax,[mode7xadder]
    mov ch,[mode7xrpos+1]
    add [mode7xrpos],eax
    mov dl,[mode7tab+ecx]
    mov eax,[mode7yadder]
    mov dl,[vrama+edx]
    sub [mode7yrpos],eax
    %1
    dec dword[ngwleftb]
    jnz near %%tilerep3

    mov [mode7xrpos],eax
    cmp dword[ngwleft],0
    je %%notskipvalues5
    call ProcessMode7ngwinB
    cmp dword[ngwleftb],0
    jne near %%tilerep3
%%notskipvalues5

    jmp %%finishmode7
%endmacro

;************************************