- Fixed mvlineasm1 and mvlineasm4 so that they can be used with textures

taller than 256 pixels. There was a very slight performance hit for this,
  but I was able to tweak mvlineasm4 to make it approximately as fast as
  before. Interestingly, maskwallscan manages to be nearly as fast as
  wallscan despite having to check every pixel for transparency. I'm
  tempted to dump all the old masked rendering code and use
  (trans)maskwallscan for everything for the sake of simplicity: Only
  two functions to maintain for each render style, and much less
  complicated supporting code. Currently, I need five different functions
  for each rendering style: One traditional column-at-a-time style like
  Doom did it originally, two for rt_draw4cols, and two for transmaskwallscan.
  (Right now, I have cheated, and just done the ones that can be used
  by walls for transmaskwallscan, so the actual number of different functions
  isn't quite so high.) For small textures, such as font characters and
  far-away sprites, I'm sure maskwallscan is faster than the current code.
  For large textures, it's probably still competitive even if it isn't faster.
  But considering how similar wallscan and maskwallscan perform, the
  difference is probably pretty minimal, and maskwallscan still might come
  out ahead due to its simpler overhead.


SVN r105 (trunk)

docs/rh-log.txt

@@ -1,3 +1,24 @@
+May 10, 2006
+- Fixed mvlineasm1 and mvlineasm4 so that they can be used with textures
+  taller than 256 pixels. There was a very slight performance hit for this,
+  but I was able to tweak mvlineasm4 to make it approximately as fast as
+  before. Interestingly, maskwallscan manages to be nearly as fast as
+  wallscan despite having to check every pixel for transparency. I'm
+  tempted to dump all the old masked rendering code and use
+  (trans)maskwallscan for everything for the sake of simplicity: Only
+  two functions to maintain for each render style, and much less
+  complicated supporting code. Currently, I need five different functions
+  for each rendering style: One traditional column-at-a-time style like
+  Doom did it originally, two for rt_draw4cols, and two for transmaskwallscan.
+  (Right now, I have cheated, and just done the ones that can be used
+  by walls for transmaskwallscan, so the actual number of different functions
+  isn't quite so high.) For small textures, such as font characters and
+  far-away sprites, I'm sure maskwallscan is faster than the current code.
+  For large textures, it's probably still competitive even if it isn't faster.
+  But considering how similar wallscan and maskwallscan perform, the
+  difference is probably pretty minimal, and maskwallscan still might come
+  out ahead due to its simpler overhead.
+
 May 10, 2006 (Changes by Graf Zahl)
 - Fixed: PClass::CreateNew didn't check whether the class had valid
   defaults and tried to copy data from a NULL pointer.

src/a.nas

@@ -341,8 +341,8 @@ mvlineasm1:
 beginmvline:
 		mov ebx, edx
 maskmach3a:	shr ebx, 32
-		mov bl, byte [esi+ebx]
+		movzx ebx, byte [esi+ebx]
-		cmp bl, 0
+		cmp ebx, 0
 		je short skipmask1
 maskmach3c:	mov bl, byte [ebp+ebx]
 		mov [edi], bl
@@ -371,12 +371,12 @@ mvlineasm4:
 
 		mov eax, [bufplce+0]
 		mov ebx, [bufplce+4]
-		mov [machmv1+2], eax
+		mov [machmv1+3], eax
-		mov [machmv4+2], ebx
+		mov [machmv4+3], ebx
 		mov eax, [bufplce+8]
 		mov ebx, [bufplce+12]
-		mov [machmv7+2], eax
+		mov [machmv7+3], eax
-		mov [machmv10+2], ebx
+		mov [machmv10+3], ebx
 
 		mov eax, [palookupoffse]
 		mov ebx, [palookupoffse+4]
@@ -389,7 +389,6 @@ mvlineasm4:
 
 		mov eax, [vince]	;vince
 		mov ebx, [vince+4]
-		xor al, al
 		xor bl, bl
 		mov [machmv3+2], eax
 		mov [machmv6+2], ebx
@@ -415,37 +414,37 @@ beginmvlineasm4:
 		mov eax, ebp
 		mov ebx, esi
 machmv16:	shr eax, 32
-machmv15:	shr ebx, 32
 machmv12:	add ebp, 0x88888888		;vince[3]
+machmv15:	shr ebx, 32
 machmv9:	add esi, 0x88888888		;vince[2]
-machmv10:	mov al, [eax+0x88888888]	;bufplce[3]
+machmv10:	movzx eax, byte [eax+0x88888888];bufplce[3]
-machmv7:	mov bl, [ebx+0x88888888]	;bufplce[2]
+machmv7:	movzx ebx, byte [ebx+0x88888888];bufplce[2]
-		cmp al, 1
+		cmp eax, 1
 		adc dl, dl
-		cmp bl, 1
+		cmp ebx, 1
 		adc dl, dl
 machmv8:	mov bl, [ebx+0x88888888]	;palookupoffs[2]
 machmv11:	mov bh, [eax+0x88888888]	;palookupoffs[3]
 
 		mov eax, edx
+machmv6:	add edx, 0x88888888		;vince[1]
 machmv14:	shr eax, 32
 		shl ebx, 16
-machmv4:	mov al, [eax+0x88888888]	;bufplce[1]
+machmv4:	movzx eax, byte [eax+0x88888888];bufplce[1]
-		cmp al, 1
+		cmp eax, 1
 		adc dl, dl
-machmv6:	add edx, 0x88888888		;vince[1]
 machmv5:	mov bh, [eax+0x88888888]	;palookupoffs[1]
 
 		mov eax, ecx
-machmv13:	shr eax, 32
 machmv3:	add ecx, 0x88888888		;vince[0]
-machmv1:	mov al, [eax+0x88888888]	;bufplce[0]
+machmv13:	shr eax, 32
-		cmp al, 1
+machmv1:	movzx eax, byte [eax+0x88888888];bufplce[0]
+		cmp eax, 1
 		adc dl, dl
 machmv2:	mov bl, [eax+0x88888888]	;palookupoffs[0]
 
-		shl dl, 4
 		xor eax, eax
+		shl dl, 4
 fixchain2mb:	add edi, 320
 		mov al, dl
 		add eax, mvcase15