From 107dd8aa8081e90cc91c88af9cf9bba3cd351bd7 Mon Sep 17 00:00:00 2001
From: pagefault <>
Date: Thu, 13 Jun 2002 22:45:47 +0000
Subject: [PATCH] Rewrote mode 4 fix

---
 zsnes/src/video/newgfx.mac   | 42 ++++++------------------------------
 zsnes/src/video/newgfx16.mac | 15 +++++++------
 2 files changed, 15 insertions(+), 42 deletions(-)

diff --git a/zsnes/src/video/newgfx.mac b/zsnes/src/video/newgfx.mac
index 98199332..673c58dd 100644
--- a/zsnes/src/video/newgfx.mac
+++ b/zsnes/src/video/newgfx.mac
@@ -2887,11 +2887,11 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     shr edx,3
     shl edx,6
     xor eax,eax
-    cmp byte[BGMA+ebx],4
-    je .offsetmode4
     mov ax,[BGPT3+ebx*2]
-.offsetmode4
+    cmp dx,0
+    jl .isneg
     add ax,dx
+.isneg
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -2955,21 +2955,6 @@ 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]
@@ -3254,11 +3239,11 @@ EXTSYM drawmode7ngextbg,drawmode7ngextbg2
     shr edx,3
     shl edx,6
     xor eax,eax
-    cmp byte[BGMA+ebx],4
-    je .offsetmode4
     mov ax,[BGPT3+ebx*2]
-.offsetmode4
+    cmp dx,0
+    jl .isneg
     add ax,dx
+.isneg
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -3290,21 +3275,6 @@ 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
diff --git a/zsnes/src/video/newgfx16.mac b/zsnes/src/video/newgfx16.mac
index 26d49169..a6c62527 100644
--- a/zsnes/src/video/newgfx16.mac
+++ b/zsnes/src/video/newgfx16.mac
@@ -3131,7 +3131,10 @@ 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
@@ -3299,11 +3302,11 @@ EXTSYM osm2dis
     shr edx,3
     shl edx,6
     xor eax,eax
-    cmp byte[BGMA+ebx],4
-    je .offsetmode4
     mov ax,[BGPT3+ebx*2]
-.offsetmode4
+    cmp dx,0
+    jl .isneg2
     add ax,dx
+.isneg2
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h
@@ -3705,11 +3708,11 @@ EXTSYM osm2dis
     shr edx,3
     shl edx,6
     xor eax,eax
-    cmp byte[BGMA+ebx],4
-    je .offsetmode4
     mov ax,[BGPT3+ebx*2]
-.offsetmode4
+    cmp dx,0
+    jl .isneg3
     add ax,dx
+.isneg3
     xor edx,edx
     mov dx,[BG3SXl+ebx*2]
     and dx,0F8h