Redone mode 4 fix

zsnes/src/video/newgfx.mac

@@ -2625,6 +2625,8 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     mov eax,[BGPT1+ebx*2+%1*512]
     test ecx,100h
     jz .noyinc
+    cmp byte[BGMA+ebx],4
+    je near .offsetm
     add eax,[BGPT1Y+ebx*2+%1*512]
 .noyinc
     lea ecx,[ecx*8]
@@ -2888,10 +2890,7 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     shl edx,6
     xor eax,eax
     mov ax,[BGPT3+ebx*2]
-    cmp dx,0
-    jl .isneg
     add ax,dx
-.isneg
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -2955,6 +2954,21 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     add eax,ecx
     add [ofsmtptr],ecx
     mov [ofsmmptr],eax
+
+    mov word[bgtxadd2],0
+    cmp word[BGPT3X+ebx*2],0
+    je .yesoverfl
+    mov cx,word[BG3SXl+ebx*2]
+    add cx,16
+    test cx,100h
+    jz .notoverfl
+    add dword[ofsmcptr],800h
+    sub word[bgtxadd2],800h
+    jmp .yesoverfl
+.notoverfl
+    add word[bgtxadd2],800h
+.yesoverfl
+
     mov dword[ofshvaladd],0
     mov ecx,[BGOPT1+ebx*2+%1*512]
     mov edx,[BGMA+ebx]
@@ -3240,10 +3254,7 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     shl edx,6
     xor eax,eax
     mov ax,[BGPT3+ebx*2]
-    cmp dx,0
-    jl .isneg
     add ax,dx
-.isneg
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -3275,6 +3286,21 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     mov eax,[BGPT1+ebx*2+%1*512]
     mov [ofsmtptr],eax
     mov [ofsmtptrs],eax
+
+    mov word[bgtxadd2],0
+    cmp word[BGPT3X+ebx*2],0
+    je .yesoverfl
+    mov cx,word[BG3SXl+ebx*2]
+    add cx,16
+    test cx,100h
+    jz .notoverfl
+    add dword[ofsmcptr],800h
+    sub word[bgtxadd2],800h
+    jmp .yesoverfl
+.notoverfl
+    add word[bgtxadd2],800h
+.yesoverfl
+
     mov ecx,[BG1SXl+ebx*2+%1*512]
     mov edx,[BGPT1X+ebx*2+%1*512]
     test ecx,100h

zsnes/src/video/newgfx16.mac

@@ -2832,12 +2832,15 @@ EXTSYM osm2dis
     je near .offsetm
     cmp byte[t16x161+ebx+%1*256],1
     je near .tiles16x16
-    cmp byte[BGMA+ebx],4
-    je near .offsetm
 .nooffsetm
     mov eax,[BGPT1+ebx*2+%1*512]
     test ecx,100h
     jz .noyinc
+    cmp byte[osm2dis],1
+    je .nooffsetm2
+    cmp byte[BGMA+ebx],4
+    je near .offsetm
+.nooffsetm2
     add eax,[BGPT1Y+ebx*2+%1*512]
 .noyinc
     lea ecx,[ecx*8]
@@ -3131,10 +3134,7 @@ EXTSYM osm2dis
     shl edx,6
     xor eax,eax
     mov ax,[BGPT3+ebx*2]
-    cmp dx,0
-    jl .isneg1
     add ax,dx
-.isneg1
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -3303,10 +3303,7 @@ EXTSYM osm2dis
     shl edx,6
     xor eax,eax
     mov ax,[BGPT3+ebx*2]
-    cmp dx,0
-    jl .isneg2
     add ax,dx
-.isneg2
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -3709,10 +3706,7 @@ EXTSYM osm2dis
     shl edx,6
     xor eax,eax
     mov ax,[BGPT3+ebx*2]
-    cmp dx,0
-    jl .isneg3
     add ax,dx
-.isneg3
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h