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page ,132;----------------------------Module-Header------------------------------;; Module Name: DITH775.ASM;; code to dither 16 or 24 bit DIBs to a 8bit DIB with a fixed palette;; NOTES:; this is a ASM version of the code found in dith775.c;;-----------------------------------------------------------------------;?PLM=1?WIN=0 .xlist include cmacro32.inc include windows.inc .list
externA __AHINCR externA __AHSHIFT
sBegin Data externB _lookup775 ; in look775.h externB _rdith775 ; in dtab775.h externB _gdith775 ; in dtab775.hsEnd Data
; The following structure should be used to access high and low; words of a DWORD. This means that "word ptr foo[2]" -> "foo.hi".
LONG struclo dw ?hi dw ?LONG ends
FARPOINTER strucoff dw ?sel dw ?FARPOINTER ends
ifndef SEGNAME SEGNAME equ <_TEXT>endif
createSeg %SEGNAME, CodeSeg, word, public, CODE
sBegin CodeSeg .386 assumes cs,CodeSeg assumes ds,nothing assumes es,nothing
;--------------------------------------------------------------------------;;; GET16 - read a RGB555 from the input;; INPUT:; fs:[esi] rgb555 DIB;; OUTPUT:; bx rgb555;;--------------------------------------------------------------------------;
GET16 macro colif col and 1 shr ebx,16 ; get pel from last timeelse mov ebx, dword ptr fs:[esi] ; grab two pels add esi,4endif endm
;--------------------------------------------------------------------------;;; DITH m1, m2, row, col;; grab a 16 bit pel and dither it.;; m1 and m2 are the magic dither table offsets.;; here is the 'C' code we are emulating;; w = *((WORD huge *)pbS)++;; r = (int)((w >> 7) & 0xF8);; g = (int)((w >> 2) & 0xF8);; b = (int)((w << 3) & 0xF8);;; *pbD++ = (BYTE)lookup775[ rdith775[r + m1] + gdith775[g + m1] + ((b + m2) >> 6) ];;; the 'magic' values vary over a 4x4 block;; m1: 1 17 25 41 m2: 2 26 38 62; 31 36 7 12 46 54 19 18; 20 4 39 23 30 6 58 34; 33 28 15 9 50 42 22 14;;; for a 2x2 dither use the following numbers:;; m1: 5 27 m2: 8 40; 38 16 56 24;; m1: 1 41 m2: 2 62; 33 9 50 14;; NOTE:; !!! the lookup tables should be BYTEs not INTs !!!;; Entry:; m1, m2 - magic values; fs:esi - 16bit pel to dither; ds - data segment;; Returns:; al - dithered pel (rotated into eax);; Uses:; eax, ebx, edx, ebp, esi, edi, flags;; Saves:; ecx, edi, es,ds,fs,gs,ss;;--------------------------------------------------------------------------;
DITH16 macro m1, m2, row, col
GET16 col
mov al, bl ; get blue and al, 1Fh add al, (m2 shr 3) shr al, 3
shr bx, 2 ; get green mov dl, bl and dx, 0F8h
shr bx, 5 ; get red and bx, 0F8h
add al, _rdith775[bx + m1] mov bl, dl add al, _gdith775[bx + m1] mov bl, al
if col and 1 mov al, byte ptr _lookup775[bx] xchg al, ah ror eax,16 ; rotate pixel into eaxelse mov ah, byte ptr _lookup775[bx]endif endm
;--------------------------------------------------------------------------;;; Dither16();; Entry:; Stack based parameters as described below.;; Returns:; none;; Registers Preserved:; DS,ES,ESI,EDI,EBP;;--------------------------------------------------------------------------; assumes ds,Data assumes es,nothing
Dither16TJumpTable label dword dd Dither16Scan0 dd Dither16Scan3 dd Dither16Scan2 dd Dither16Scan1
cProc Dither16T,<FAR,PUBLIC,PASCAL>,<> parmD biDst ;--> BITMAPINFO of dest parmD lpDst ;--> to destination bits parmW DstX ;Destination origin - x coordinate parmW DstY ;Destination origin - y coordinate parmW DstXE ;x extent of the BLT parmW DstYE ;y extent of the BLT parmD biSrc ;--> BITMAPINFO of source parmD lpSrc ;--> to source bits parmW SrcX ;Source origin - x coordinate parmW SrcY ;Source origin - y coordinate parmD lpDitherTable ;not used (for 8->4 bit dither)
localD SrcWidth ;width of source in bytes localD DstWidth ;width of dest in bytes
localD SrcInc localD DstInccBegin push esi push edi; push ds
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; We only handle (DstXE % 4) == 0 or 3. If it's == 1 or 2, then we; round down, because otherwise we'd have to deal with half of a; dither cell on the end. ; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; inc DstXE ; Make the == 3 mod 4 case work and DstXE, not 011b; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;
mov eax,16 mov ebx,8 call dither_init ; init all the frame variables jc Dither16Exit
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; movzx ecx, DstYE ; divide by 4 mov ebx, ecx
add ecx, 3 ; be sure to round up shr ecx, 2 jz Dither16Exit mov DstYE, cx
movzx ecx, DstXE ; divide by 4 shr ecx,2 jz Dither16Exit mov DstXE,cx
and ebx, 011b ; Get height mod 4 jmp Dither16TJumpTable[ebx*4]
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; align 4Dither16OuterLoop:
movzx ecx, DstXE align 4Dither16Scan0: DITH16 1 2 0 0 ; DITH16 1 2 0 0 DITH16 17 26 0 1 ; DITH16 41 62 0 1 DITH16 25 38 0 2 ; DITH16 1 2 0 2 DITH16 41 62 0 3 ; DITH16 41 62 0 3 stos dword ptr es:[edi] dec ecx jnz Dither16Scan0 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither16Scan1: DITH16 31 46 1 0 ; DITH16 33 50 1 0 DITH16 36 54 1 1 ; DITH16 9 14 1 1 DITH16 7 19 1 2 ; DITH16 33 50 1 2 DITH16 12 18 1 3 ; DITH16 9 14 1 3 stos dword ptr es:[edi] dec ecx jnz Dither16Scan1 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither16Scan2: DITH16 20 30 2 0 ; DITH16 1 2 2 0 DITH16 4 6 2 1 ; DITH16 41 62 2 1 DITH16 39 58 2 2 ; DITH16 1 2 2 2 DITH16 23 34 2 3 ; DITH16 41 62 2 3 stos dword ptr es:[edi] dec ecx jnz Dither16Scan2 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither16Scan3: DITH16 33 50 3 0 ; DITH16 33 50 3 0 DITH16 28 42 3 1 ; DITH16 9 14 3 1 DITH16 15 22 3 2 ; DITH16 33 50 3 2 DITH16 9 14 3 3 ; DITH16 9 14 3 3 stos dword ptr es:[edi] dec ecx jnz Dither16Scan3 add esi, SrcInc add edi, DstInc
dec DstYE jnz Dither16OuterLoop
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;Dither16Exit: xor ax,ax mov fs,ax ; to make KRNL286.EXE and DOSX happy; pop ds pop edi pop esicEnd
;--------------------------------------------------------------------------;;; Dither16L() - dither using lookup table(s);; using dither matrix:;; 0 2 2 4; 3 4 0 1 [or possibly 3 3 1 1 -- see which looks better]; 2 0 4 2; 3 3 1 1;; the dither matrix determines which lookup table to use.;; Entry:; Stack based parameters as described below.;; Returns:; none;; Registers Preserved:; DS,ES,ESI,EDI,EBP;;--------------------------------------------------------------------------; assumes ds,Data assumes es,nothing
FOO macro reg, errif err eq 0 mov reg, ds:[ebx]elseif err eq 1 mov reg, ds:[ebx + edx]elseif err eq 2 mov reg, ds:[ebx + 2*edx]elseif err eq 3 or bh,80h mov reg, ds:[ebx + 2*edx]elseif err eq 4 mov reg, ds:[ebx + 4*edx]else barkendif endm
DITH16L macro m1, m2, m3, m4 mov bx, fs:[esi + 4] and bh, ch FOO al, m3
mov bx, fs:[esi + 6] and bh, ch FOO ah, m4
shl eax,16
mov bx, fs:[esi + 0] and bh, ch FOO al, m1
mov bx, fs:[esi + 2] and bh, ch FOO ah, m2
mov dword ptr es:[edi], eax
add edi, 4 add esi, 8 endm
Dither16LJumpTable label dword dd Dither16lScan0 dd Dither16lScan3 dd Dither16lScan2 dd Dither16lScan1
cProc Dither16L,<FAR,PUBLIC,PASCAL>,<> parmD biDst ;--> BITMAPINFO of dest parmD lpDst ;--> to destination bits parmW DstX ;Destination origin - x coordinate parmW DstY ;Destination origin - y coordinate parmW DstXE ;x extent of the BLT parmW DstYE ;y extent of the BLT parmD biSrc ;--> BITMAPINFO of source parmD lpSrc ;--> to source bits parmW SrcX ;Source origin - x coordinate parmW SrcY ;Source origin - y coordinate parmD lpDitherTable ;196k dither table
localD SrcWidth ;width of source in bytes localD DstWidth ;width of dest in bytes
localD SrcInc localD DstInccBegin push esi push edi push ds
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; We only handle (DstXE % 4) == 0 or 3. If it's == 1 or 2, then we; round down, because otherwise we'd have to deal with half of a; dither cell on the end. ; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; inc DstXE ; Make the == 3 mod 4 case work and DstXE, not 011b; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;
mov eax,16 mov ebx,8 call dither_init ; init all the frame variables jc Dither16lExit
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; movzx ecx, DstYE ; divide by 4 mov ebx, ecx
add ecx, 3 ; be sure to round up shr ecx, 2 jz Dither16lExit mov DstYE, cx
movzx ecx, DstXE ; divide by 4 shr ecx,2 jz Dither16lExit mov DstXE,cx
mov ds, lpDitherTable.sel ; DS --> dither table mov ax, ds add ax, __AHINCR mov gs, ax
xor ebx, ebx mov edx, 32768 mov ch,7Fh
and ebx, 011b ; Get height mod 4 jmp Dither16LJumpTable[ebx*4]
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; align 4Dither16lOuterLoop:
mov cl, byte ptr DstXE align 4Dither16lScan0: DITH16L 0 2 2 4 dec cl jnz short Dither16lScan0 add esi, SrcInc add edi, DstInc
mov cl, byte ptr DstXE align 4Dither16lScan1: DITH16L 3 4 0 1 dec cl jnz short Dither16lScan1 add esi, SrcInc add edi, DstInc
mov cl, byte ptr DstXE align 4Dither16lScan2: DITH16L 2 0 4 2 dec cl jnz short Dither16lScan2 add esi, SrcInc add edi, DstInc
mov cl, byte ptr DstXE align 4Dither16lScan3: DITH16L 3 3 1 1 dec cl jnz short Dither16lScan3 add esi, SrcInc add edi, DstInc
dec DstYE jnz Dither16lOuterLoop
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;Dither16lExit: xor ax,ax mov fs,ax ; to make KRNL286.EXE and DOSX happy mov gs,ax pop ds pop edi pop esicEnd
;--------------------------------------------------------------------------;;; Dither16S() - dither using scale table(s);; pel8 = lookup[scale[rgb555] + error];; using error matrix:;; 0 3283 4924 8207; 6565 6566 1641 1642; 3283 0 8207 4924; 6566 4925 3282 1641;; Entry:; Stack based parameters as described below.;; Returns:; none;; Registers Preserved:; DS,ES,ESI,EDI,EBP;;--------------------------------------------------------------------------; assumes ds,Data assumes es,nothing
DITH16S macro m1, m2, m3, m4 mov ebx, fs:[esi + 4] ; grab rgb555 add bx, bx mov bx, ds:[bx] ; scale it mov al, gs:[bx + m3] ; dither it with error
shr ebx,16; mov bx, fs:[esi + 6] ; grab rgb555 add bx, bx mov bx, ds:[bx] ; scale it mov ah, gs:[bx + m4] ; dither it with error
shl eax,16
mov ebx, fs:[esi + 0] ; grab rgb555 add bx, bx mov bx, ds:[bx] ; scale it mov al, gs:[bx + m1] ; dither it with error
shr ebx,16; mov bx, fs:[esi + 2] ; grab rgb555 add bx, bx mov bx, ds:[bx] ; scale it mov ah, gs:[bx + m2] ; dither it with error
mov dword ptr es:[edi], eax
add edi, 4 add esi, 8 endm
Dither16SJumpTable label dword dd Dither16sScan0 dd Dither16sScan3 dd Dither16sScan2 dd Dither16sScan1
cProc Dither16S,<FAR,PUBLIC,PASCAL>,<> parmD biDst ;--> BITMAPINFO of dest parmD lpDst ;--> to destination bits parmW DstX ;Destination origin - x coordinate parmW DstY ;Destination origin - y coordinate parmW DstXE ;x extent of the BLT parmW DstYE ;y extent of the BLT parmD biSrc ;--> BITMAPINFO of source parmD lpSrc ;--> to source bits parmW SrcX ;Source origin - x coordinate parmW SrcY ;Source origin - y coordinate parmD lpDitherTable ;196k dither table
localD SrcWidth ;width of source in bytes localD DstWidth ;width of dest in bytes
localD SrcInc localD DstInccBegin push esi push edi push ds
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; align everything on four pixel boundries, we realy should; not do this but should handle the general case instead,; but hey we are hackers.; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; inc DstXE ; Make the == 3 mod 4 case work and DstXE, not 011b; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;
mov eax,16 mov ebx,8 call dither_init ; init all the frame variables jc Dither16sExit
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; movzx ecx, DstYE ; divide by 4 mov ebx, ecx
add ecx, 3 ; be sure to round up shr ecx, 2 jz Dither16sExit mov DstYE, cx
movzx ecx, DstXE ; divide by 4 shr ecx,2 jz Dither16sExit mov DstXE,cx
mov ds, lpDitherTable.sel ; DS --> dither table mov ax, ds add ax, __AHINCR mov gs, ax
and ebx, 011b ; Get height mod 4 jmp Dither16SJumpTable[ebx*4]
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; align 4Dither16sOuterLoop:
movzx ecx, DstXE align 4Dither16sScan0: DITH16S 0 3283 4924 8207 dec ecx jnz short Dither16sScan0 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither16sScan1: DITH16S 6565 6566 1641 1642 dec ecx jnz short Dither16sScan1 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither16sScan2: DITH16S 3283 0 8207 4924 dec ecx jnz short Dither16sScan2 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither16sScan3: DITH16S 6566 4925 3282 1641 dec ecx jnz short Dither16sScan3 add esi, SrcInc add edi, DstInc
dec DstYE jnz Dither16sOuterLoop
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;Dither16sExit: xor ax,ax mov fs,ax ; to make KRNL286.EXE and DOSX happy mov gs,ax pop ds pop edi pop esicEnd
;--------------------------------------------------------------------------;;; LODSB32 - get a byte, every four times doing a LODSD;;--------------------------------------------------------------------------;
LODSB32_N = 0
LODSB32 macro if (LODSB32_N mod 4) eq 0;; lods dword ptr ds:[esi] mov eax,dword ptr fs:[esi] add esi,4 else ror eax,8 endif
LODSB32_N = LODSB32_N + 1
endm
;--------------------------------------------------------------------------;;; Dither24S() - dither using scale table(s);; pel8 = lookup[scale[rgb555] + error];; using error matrix:;; 0 3283 4924 8207; 6565 6566 1641 1642; 3283 0 8207 4924; 6566 4925 3282 1641;; Entry:; Stack based parameters as described below.;; Returns:; none;; Registers Preserved:; DS,ES,ESI,EDI,EBP;;--------------------------------------------------------------------------; assumes ds,Data assumes es,nothing
GET24 macro LODSB32 ; get BLUE and al,0F8h mov bl,al LODSB32 ; get GREEN mov bh,al shr bh,3 shr ebx,2 LODSB32 ; get RED and al,0F8h or bh,al endm
DITH24S macro m1, m2, m3, m4
GET24 ; grab rgb555*2 movzx ebx, word ptr ds:[ebx] ; scale it mov dl, ds:[ebx + m1 + 65536] ; dither it with error
GET24 ; grab rgb555*2 movzx ebx, word ptr ds:[ebx] ; scale it mov dh, ds:[ebx + m2 + 65536] ; dither it with error
ror edx,16 ; save ax
GET24 ; grab rgb555 movzx ebx, word ptr ds:[ebx] ; scale it mov dl, ds:[ebx + m3 + 65536] ; dither it with error
GET24 ; grab rgb555 movzx ebx, word ptr ds:[ebx] ; scale it mov dh, ds:[ebx + m4 + 65536] ; dither it with error
ror edx,16 ; get eax right mov dword ptr es:[edi], edx ; store four pixels add edi, 4 endm
Dither24SJumpTable label dword dd Dither24sScan0 dd Dither24sScan3 dd Dither24sScan2 dd Dither24sScan1
cProc Dither24S,<FAR,PUBLIC,PASCAL>,<> parmD biDst ;--> BITMAPINFO of dest parmD lpDst ;--> to destination bits parmW DstX ;Destination origin - x coordinate parmW DstY ;Destination origin - y coordinate parmW DstXE ;x extent of the BLT parmW DstYE ;y extent of the BLT parmD biSrc ;--> BITMAPINFO of source parmD lpSrc ;--> to source bits parmW SrcX ;Source origin - x coordinate parmW SrcY ;Source origin - y coordinate parmD lpDitherTable ;196k dither table
localD SrcWidth ;width of source in bytes localD DstWidth ;width of dest in bytes
localD SrcInc localD DstInccBegin push esi push edi push ds
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; align everything on four pixel boundries, we realy should; not do this but should handle the general case instead,; but hey we are hackers.; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; inc DstXE ; Make the == 3 mod 4 case work and DstXE, not 011b; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;
mov eax,24 mov ebx,8 call dither_init ; init all the frame variables jc Dither24sExit
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; movzx ecx, DstYE ; divide by 4 mov ebx, ecx
add ecx, 3 ; be sure to round up shr ecx, 2 jz Dither24sExit mov DstYE, cx
movzx ecx, DstXE ; divide by 4 shr ecx,2 jz Dither24sExit mov DstXE,cx
mov ds, lpDitherTable.sel ; DS --> dither table mov ax, ds add ax, __AHINCR mov gs, ax
and ebx, 011b ; Get height mod 4 jmp Dither24SJumpTable[ebx*4]
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; align 4Dither24sOuterLoop:
movzx ecx, DstXE align 4Dither24sScan0: DITH24S 0 3283 4924 8207 dec ecx jnz Dither24sScan0 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither24sScan1: DITH24S 6565 6566 1641 1642 dec ecx jnz Dither24sScan1 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither24sScan2: DITH24S 3283 0 8207 4924 dec ecx jnz Dither24sScan2 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither24sScan3: DITH24S 6566 4925 3282 1641 dec ecx jnz Dither24sScan3 add esi, SrcInc add edi, DstInc
dec DstYE jnz Dither24sOuterLoop
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;Dither24sExit: xor ax,ax mov fs,ax ; to make KRNL286.EXE and DOSX happy mov gs,ax pop ds pop edi pop esicEnd
;--------------------------------------------------------------------------;;; Dither32S() - dither using scale table(s);; pel8 = lookup[scale[rgb555] + error];; using error matrix:;; 0 3283 4924 8207; 6565 6566 1641 1642; 3283 0 8207 4924; 6566 4925 3282 1641;; Entry:; Stack based parameters as described below.;; Returns:; none;; Registers Preserved:; DS,ES,ESI,EDI,EBP;;--------------------------------------------------------------------------; assumes ds,Data assumes es,nothing
GET32 macroif 1 mov bx,fs:[esi+0] ; ebx = ????????????????GGGGGgggBBBBBbbb shr bh,3 ; ebx = 000?????????????000GGGGGBBBBBbbb shr bx,3 ; ebx = 000?????????????000000GGGGGBBBBB mov al,fs:[esi+2] ; eax = ????????????????????????RRRRRrrr and al,0F8h ; eax = ????????????????????????RRRRR000 shr al,1 ; eax = ????????????????????????0RRRRR00 or bh,al ; ebx = 000?????????????0RRRRRGGGGGBBBBB add ebx,ebx ; ebx = 00?????????????0RRRRRGGGGGBBBBB0 add esi,4else mov eax,fs:[esi] ; eax = RRRRRrrrGGGGGgggBBBBBbbb add esi,2 mov bl,al ; ebx = 00000000????????BBBBBbbb shr eax,8 ; eax = 00000000RRRRRrrrGGGGGggg shr ah,3 ; eax = 00000000000RRRRRGGGGGggg shl ax,5 ; eax = 000000RRRRRGGGGGggg00000endif endm
DITH32S macro m1, m2, m3, m4
GET32 ; grab rgb555*2 mov bx, word ptr ds:[ebx] ; scale it mov dl, ds:[ebx + m1 + 65536] ; dither it with error
GET32 ; grab rgb555*2 mov bx, word ptr ds:[ebx] ; scale it mov dh, ds:[ebx + m2 + 65536] ; dither it with error
ror edx,16 ; save ax
GET32 ; grab rgb555 mov bx, word ptr ds:[ebx] ; scale it mov dl, ds:[ebx + m3 + 65536] ; dither it with error
GET32 ; grab rgb555 movzx bx, word ptr ds:[ebx] ; scale it mov dh, ds:[ebx + m4 + 65536] ; dither it with error
ror edx,16 ; get eax right mov dword ptr es:[edi], edx ; store four pixels add edi, 4 endm
Dither32SJumpTable label dword dd Dither32sScan0 dd Dither32sScan3 dd Dither32sScan2 dd Dither32sScan1
cProc Dither32S,<FAR,PUBLIC,PASCAL>,<> parmD biDst ;--> BITMAPINFO of dest parmD lpDst ;--> to destination bits parmW DstX ;Destination origin - x coordinate parmW DstY ;Destination origin - y coordinate parmW DstXE ;x extent of the BLT parmW DstYE ;y extent of the BLT parmD biSrc ;--> BITMAPINFO of source parmD lpSrc ;--> to source bits parmW SrcX ;Source origin - x coordinate parmW SrcY ;Source origin - y coordinate parmD lpDitherTable ;196k dither table
localD SrcWidth ;width of source in bytes localD DstWidth ;width of dest in bytes
localD SrcInc localD DstInccBegin push esi push edi push ds
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; align everything on four pixel boundries, we realy should; not do this but should handle the general case instead,; but hey we are hackers.; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; inc DstXE ; Make the == 3 mod 4 case work and DstXE, not 011b; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;
mov eax,32 mov ebx,8 call dither_init ; init all the frame variables jc Dither32sExit
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; movzx ecx, DstYE ; divide by 4 mov ebx, ecx
add ecx, 3 ; be sure to round up shr ecx, 2 jz Dither32sExit mov DstYE, cx
movzx ecx, DstXE ; divide by 4 shr ecx,2 jz Dither32sExit mov DstXE,cx
mov ds, lpDitherTable.sel ; DS --> dither table mov ax, ds add ax, __AHINCR mov gs, ax
and ebx, 011b ; Get height mod 4 jmp Dither32SJumpTable[ebx*4]
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; align 4Dither32sOuterLoop:
movzx ecx, DstXE align 4Dither32sScan0: DITH32S 0 3283 4924 8207 dec ecx jnz Dither32sScan0 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither32sScan1: DITH32S 6565 6566 1641 1642 dec ecx jnz Dither32sScan1 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither32sScan2: DITH32S 3283 0 8207 4924 dec ecx jnz Dither32sScan2 add esi, SrcInc add edi, DstInc
movzx ecx, DstXE align 4Dither32sScan3: DITH32S 6566 4925 3282 1641 dec ecx jnz Dither32sScan3 add esi, SrcInc add edi, DstInc
dec DstYE jnz Dither32sOuterLoop
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;Dither32sExit: xor ax,ax mov fs,ax ; to make KRNL286.EXE and DOSX happy mov gs,ax pop ds pop edi pop esicEnd
;--------------------------------------------------------------------------;;; dither_init;; init local frame vars for DitherDIB;; ENTRY:; AX - source bpp; BX - dest bpp; ss:bp --> ditherdib frame;; EXIT:; FS:ESI --> source DIB start x,y; ES:EDI --> dest DIB start x,y; DS: --> dither tables (in DGROUP);;--------------------------------------------------------------------------;
dither_init_error: stc ret
dither_init proc near
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; validate the DIBs; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; movzx eax,ax movzx ebx,bx movzx ecx,cx movzx edx,dx movzx edi,di movzx esi,si
lfs si, biSrc les di, biDst
mov cx, es:[di].biBitCount ; dest must be right cmp cx, bx jne dither_init_error
mov cx, fs:[si].biBitCount ; source must be right cmp cx, ax jne dither_init_error
dither_init_bit_depth_ok:
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;;; Set up the initial source pointer;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; mov eax,fs:[si].biWidth mul ecx add eax,31 and eax,not 31 shr eax,3 mov SrcWidth,eax mov SrcInc,eax
lfs si,lpSrc
movzx edx,SrcY mul edx add esi,eax
movzx eax,SrcX mul ecx shr eax,3 add esi,eax
movzx eax, DstXE ; SrcInc = SrcWidth - DstXE*bits/8 mul ecx shr eax, 3 sub SrcInc, eax
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;;; Set up the initial dest pointer;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ; mov cx, es:[di].biBitCount mov eax,es:[di].biWidth mul ecx add eax,31 and eax,not 31 shr eax,3 mov DstWidth,eax mov DstInc,eax
cmp es:[edi].biHeight,0 ; init a upside down DIB jge short @f movsx ebx,DstY add ebx,es:[edi].biHeight not ebx mov DstY,bx neg DstWidth neg DstInc@@: les di,lpDst
movsx edx,DstY mul edx add edi,eax
movsx eax,DstX mul ecx shr eax,3 add edi,eax
movzx eax, DstXE ; DstInc = DstWidth - DstXE*bits/8 mul ecx shr eax, 3 sub DstInc, eax
; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;; - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ;
dither_init_exit: clc ret
dither_init endp
sEnd CodeSeg
end
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