libimg: 1bpp (monochrome) images support,

pcx.asm now uses 1bpp functions too, pcx code optimization


git-svn-id: svn://kolibrios.org@1593 a494cfbc-eb01-0410-851d-a64ba20cac60

programs/develop/libraries/libs-dev/libimg/libimg.asm

@@ -503,6 +503,46 @@ align 16
     @@:
     ret
 
+align 16
+.bpp1:
+    push ebx edx
+    mov ebx, esi
+    mov esi, [ebx + Image.Data]
+    mov ecx, [ebx + Image.Height]
+  .bpp1.pre:
+    mov edx, [ebx + Image.Width]
+    mov eax, 7
+  .bpp1.begin:
+    push ecx esi
+    xor cx, cx
+    bt [esi], eax
+    setc cl
+    mov esi, [ebx + Image.Palette]
+     jcxz @f
+    add esi, 4
+  @@:
+    mov ecx, 3
+    cld
+    rep movsb
+    pop esi ecx
+    dec edx
+     jz .bpp1.end_line
+    dec eax
+     jns .bpp1.begin
+    mov eax, 7
+    inc esi
+     jmp .bpp1.begin
+
+  .bpp1.end_line:
+    dec ecx
+     jz .bpp1.quit
+    inc esi
+     jmp .bpp1.pre
+
+  .bpp1.quit:
+    pop edx ebx
+    ret
+
 endp
 
 ;;================================================================================================;;
@@ -891,6 +931,61 @@ endl
     add edi, [scanline_len]
     dec ecx
     jnz .next_line_horz24
+    jmp .exit
+
+.bpp1_horz:
+    push eax edx
+    mov edi, [scanline_len]
+    mov edx, [ebx+Image.Width]
+    and edx,  0x07
+    neg dl
+    add dl, 8
+    and dl, 0x07                                        ; clear if cl=8
+.bpp1_horz.begin:
+    push ebx ecx edx esi
+    mov eax, 7
+    add edi, esi
+    sub edi, 1
+    mov ebx, [ebx+Image.Width]
+    shr ebx, 1
+.bpp1_horz.flip_line:
+    xor ecx, ecx
+    bt  [esi], eax
+    setc cl
+    bt  [edi], edx
+     jc .bpp1_horz.one
+  .bpp1_horz.zero:
+    btr [esi], eax
+     jmp @f
+  .bpp1_horz.one:
+    bts [esi], eax
+  @@:
+     jecxz .bpp1_horz.reset
+  .bpp1_horz.set:
+    bts [edi], edx
+     jmp @f
+  .bpp1_horz.reset:
+    btr [edi], edx
+  @@:
+    inc edx
+    and edx, 0x07
+     jnz @f
+    dec edi
+  @@:
+    dec eax
+     jns @f
+    mov eax, 7
+    inc esi
+  @@:
+    dec ebx
+     jnz .bpp1_horz.flip_line
+
+    pop esi edx ecx ebx
+    add esi, [scanline_len]
+    mov edi, [scanline_len]
+    dec ecx
+     jnz .bpp1_horz.begin
+    pop edx eax
 
   .exit:
     xor eax, eax
@@ -990,6 +1085,8 @@ endl
     add eax, [ebx + Image.Data]
     mov [pixels_ptr], eax
 
+    cmp [ebx + Image.Type], Image.bpp1
+    jz  .rotate_ccw1
     cmp [ebx + Image.Type], Image.bpp8
     jz  .rotate_ccw8
     cmp [ebx + Image.Type], Image.bpp24
@@ -1182,6 +1279,83 @@ endl
     pop ecx
     jmp .next_column_ccw_low24
 
+.rotate_ccw1:
+    push ecx edx
+
+    mov eax, [ebx+Image.Height]
+    add eax, 7
+    shr eax, 3
+    mul word[ebx+Image.Width]
+    shl eax, 16
+    shrd eax, edx, 16
+    push eax                                            ; save new data size
+
+    invoke  mem.alloc, eax
+    or  eax, eax
+    jz  .error
+    push eax                                            ; save pointer to new data
+
+    mov ecx, [ebx+Image.Width]
+    and ecx,  0x07
+    neg cl
+    add cl, 8
+    and cl, 0x07                                        ; clear if cl=8
+
+    mov esi, eax
+    mov edi, [ebx+Image.Data]
+    mov eax, 7
+    mov edx, [scanline_len_old]
+    dec edx
+    add edi, edx
+
+  .rotate_ccw1.begin:
+    bt  [edi], ecx
+     jc .rotate_ccw1.one
+  .rotate_ccw1.zero:
+    btr [esi], eax
+     jmp @f
+  .rotate_ccw1.one:
+    bts [esi], eax
+  @@:
+    add edi, [scanline_len_old]
+    dec [scanline_pixels_new]
+     jz .rotate_ccw1.end_of_line
+    dec eax
+     jns .rotate_ccw1.begin
+    mov eax, 7
+    inc esi
+     jmp .rotate_ccw1.begin
+
+  .rotate_ccw1.end_of_line:
+    inc esi
+    mov eax, 7
+    mov edi, [ebx+Image.Height]
+    mov [scanline_pixels_new],  edi
+    inc ecx
+    and cl, 0x07
+     jz @f
+    mov edi, [ebx+Image.Data]
+    add edi, edx
+     jmp .rotate_ccw1.begin 
+  @@:
+    dec edx
+     js .rotate_ccw1.quit
+    mov edi, [ebx+Image.Data]
+    add edi, edx
+     jmp .rotate_ccw1.begin
+
+  .rotate_ccw1.quit:
+    pop eax                                             ; get pointer to new data
+    mov esi, eax
+    mov edi, [ebx + Image.Data]
+    pop ecx                                             ; get new data size
+    rep movsb
+
+    invoke  mem.free, eax
+
+    pop edx ecx
+     jmp .exchange_dims
+
   .rotate_cw_low:
     mov eax, [ebx + Image.Height]
     mov [scanline_pixels_new], eax
@@ -1203,6 +1377,8 @@ endl
     add eax, [ebx + Image.Data]
     mov [pixels_ptr], eax
 
+    cmp [ebx + Image.Type], Image.bpp1
+    jz  .rotate_cw1
     cmp [ebx + Image.Type], Image.bpp8
     jz  .rotate_cw8
     cmp [ebx + Image.Type], Image.bpp24
@@ -1405,6 +1581,93 @@ endl
     pop ecx
     jmp .next_column_cw_low24
 
+.rotate_cw1:
+    push ecx edx
+
+    mov eax, [ebx+Image.Height]
+    add eax, 7
+    shr eax, 3
+    mul word[ebx+Image.Width]
+    shl eax, 16
+    shrd eax, edx, 16
+
+    push eax                                            ; save new data size
+
+    invoke  mem.alloc, eax
+    or  eax, eax
+    jz  .error
+    push eax                                            ; save pointer to new data
+
+    mov ecx, 7
+
+    mov edx, [ebx+Image.Width]
+    mov [pixels_ptr],   edx                             ; we don't use pixels_ptr as it do other procedures, we save there [ebx+Image.Width]
+    mov esi, eax
+    mov edi, [ebx+Image.Data]
+    mov eax, [ebx+Image.Height]
+    dec eax
+    mul [scanline_len_old]
+    add edi, eax
+    mov eax, 7
+    mov edx, 0
+
+  .rotate_cw1.begin:
+    bt  [edi], ecx
+     jc .rotate_cw1.one
+  .rotate_cw1.zero:
+    btr [esi], eax
+     jmp @f
+  .rotate_cw1.one:
+    bts [esi], eax
+  @@:
+    sub edi, [scanline_len_old]
+    dec [scanline_pixels_new]
+     jz .rotate_cw1.end_of_line
+    dec eax
+     jns .rotate_cw1.begin
+    mov eax, 7
+    inc esi
+     jmp .rotate_cw1.begin
+
+  .rotate_cw1.end_of_line:
+    dec [pixels_ptr]
+     jz .rotate_cw1.quit
+    inc esi
+    mov eax, [ebx+Image.Height]
+    mov [scanline_pixels_new],   eax
+    mov eax, 7
+    dec ecx
+     js @f
+    mov edi, [ebx+Image.Height]
+    dec edi
+    imul edi, [scanline_len_old]
+    add edi, [ebx+Image.Data]
+    add edi, edx
+     jmp .rotate_cw1.begin
+  @@:
+    mov ecx, 7
+    inc edx
+    cmp edx, [scanline_len_old]
+     je .rotate_cw1.quit
+    mov edi, [ebx+Image.Height]
+    dec edi
+    imul edi, [scanline_len_old]
+    add edi, [ebx+Image.Data]
+    add edi, edx
+     jmp .rotate_cw1.begin
+
+  .rotate_cw1.quit:
+    pop eax                                             ; get pointer to new data
+    mov esi, eax
+    mov edi, [ebx + Image.Data]
+    pop ecx                                             ; get new data size
+    rep movsb
+
+    invoke  mem.free, eax
+
+    pop edx ecx
+     jmp .exchange_dims
+
   .flip:
     jmp .exit
 
@@ -1613,6 +1876,8 @@ proc img._.resize_data _img, _width, _height ;//////////////////////////////////
 ; do not allow images which require too many memory
     cmp eax, 4000000h
     jae .error
+    cmp [ebx + Image.Type], Image.bpp1
+    jz  .bpp1
     cmp [ebx + Image.Type], Image.bpp8
     jz  .bpp8
     cmp [ebx + Image.Type], Image.bpp24
@@ -1625,6 +1890,34 @@ proc img._.resize_data _img, _width, _height ;//////////////////////////////////
     jmp @f
 .bpp8:
     add eax, 256*4  ; for palette
+    jmp @f
+.bpp1:
+    mov eax, [_width]
+    add eax, 7
+    shr eax, 3
+    mul word[_height]
+    shl eax, 16
+    mov ax,  dx
+    ror eax, 16
+
+    push ebx
+    mov ebx, eax
+
+    mov eax, [_height]
+    add eax, 7
+    shr eax, 3
+    mul word[_width]
+    shl eax, 16
+    mov ax,  dx
+    ror eax, 16
+
+    cmp eax, ebx
+     jge .bpp1.skip
+    mov eax, ebx
+  .bpp1.skip:
+    pop ebx
+
+    add eax, 2*4    ; for palette
 @@:
     mov esi, eax
     invoke  mem.realloc, [ebx + Image.Data], eax
@@ -1637,10 +1930,16 @@ proc img._.resize_data _img, _width, _height ;//////////////////////////////////
     push    [_height]
     pop [ebx + Image.Height]
     cmp [ebx + Image.Type], Image.bpp8
-    jnz .ret
+    jnz @f
     lea esi, [eax + esi - 256*4]
     mov [ebx + Image.Palette], esi
     jmp .ret
+@@:
+    cmp [ebx + Image.Type], Image.bpp1
+    jnz .ret
+    lea esi, [eax + esi - 2*4]
+    mov [ebx + Image.Palette], esi
+    jmp .ret
 
   .error:
     xor eax, eax
@@ -1658,19 +1957,25 @@ img._.get_scanline_len: ;///////////////////////////////////////////////////////
 ;;------------------------------------------------------------------------------------------------;;
 ;< --- TBD ---                                                                                    ;;
 ;;================================================================================================;;
+    cmp [ebx + Image.Type], Image.bpp1
+    jz  .bpp1.1
     cmp [ebx + Image.Type], Image.bpp8
     jz  .bpp8.1
     cmp [ebx + Image.Type], Image.bpp24
     jz  .bpp24.1
     add eax, eax
     cmp [ebx + Image.Type], Image.bpp32
-    jnz @f
+    jnz .quit
     add eax, eax
-    jmp @f
+    jmp .quit
 .bpp24.1:
     lea eax, [eax*3]
+    jmp .quit
+.bpp1.1:
+    add eax, 7
+    shr eax, 3
 .bpp8.1:
-@@:
+.quit:
     ret
 
 
@@ -1697,13 +2002,14 @@ img._.formats_table:
        dd 0
 
 align 4
-type2bpp    dd  8, 24, 32, 15, 16
+type2bpp    dd  8, 24, 32, 15, 16, 1
 img._.do_rgb.handlers:
     dd  img._.do_rgb.bpp8
     dd  img._.do_rgb.bpp24
     dd  img._.do_rgb.bpp32
     dd  img._.do_rgb.bpp15.amd  ; can be overwritten in lib_init
     dd  img._.do_rgb.bpp16.amd  ; can be overwritten in lib_init
+    dd  img._.do_rgb.bpp1
 
 img.flip.layer.handlers_horz:
     dd  img.flip.layer.bpp8_horz
@@ -1711,6 +2017,7 @@ img.flip.layer.handlers_horz:
     dd  img.flip.layer.bpp32_horz
     dd  img.flip.layer.bpp1x_horz
     dd  img.flip.layer.bpp1x_horz
+    dd  img.flip.layer.bpp1_horz
 
 ;;================================================================================================;;
 ;;////////////////////////////////////////////////////////////////////////////////////////////////;;

programs/develop/libraries/libs-dev/libimg/libimg.inc

@@ -19,7 +19,7 @@
 
 
 struct FormatsTableEntry
-  Is	 dd ?
+  Is     dd ?
   Decode dd ?
   Encode dd ?
 ends
@@ -28,10 +28,10 @@ struct Image
   Checksum dd ? ; ((Width ROL 16) OR Height) XOR Data[0]
   Width    dd ?
   Height   dd ?
-  Next	   dd ?
+  Next     dd ?
   Previous dd ?
   Type     dd ? ; one of Image.bppN
-  Data	   dd ?
+  Data     dd ?
   Palette  dd ? ; used iff Type eq Image.bpp8
   Extended dd ?
   Flags    dd ? ; bitfield
@@ -45,6 +45,7 @@ Image.bpp24 = 2
 Image.bpp32 = 3
 Image.bpp15 = 4
 Image.bpp16 = 5
+Image.bpp1  = 6
 
 ; bits in Image.Flags
 Image.IsAnimated = 1
@@ -54,9 +55,9 @@ struct ImageDecodeOptions
   BackgroundColor dd ? ; used for transparent images as background
 ends
 
-FLIP_VERTICAL	= 0x01
+FLIP_VERTICAL   = 0x01
 FLIP_HORIZONTAL = 0x02
-FLIP_BOTH	= FLIP_VERTICAL or FLIP_HORIZONTAL
+FLIP_BOTH   = FLIP_VERTICAL or FLIP_HORIZONTAL
 
 ROTATE_90_CW   = 0x01
 ROTATE_180     = 0x02

programs/develop/libraries/libs-dev/libimg/pcx/pcx.asm

@@ -73,38 +73,26 @@ proc img.decode.pcx _data, _length, _options ;//////////////////////////////////
 ;< eax = 0 (error) or pointer to image                                                            ;;
 ;;================================================================================================;;
 locals
-;  IMGwidth      dd ?
-;  IMGheight     dd ?
-;  IMGbpp        dd ?
-buf                 rb      1
 nplanes             rd      1
 xsize               rw      1
 ysize               rw      1
-stxsize             rw      1
+bpl                 rw      1
-stysize             rw      1
 total_bpl           rd      1
-total_bpl_tmp       rd      1
 line_begin          rd      1
-retvalue            rd      1
+retvalue            rd      1                       ; 0 (error) or pointer to image 
-
 endl
 
     pusha
 
     mov     esi,    [_data]
-
+    movzx   eax,    byte[esi+pcx_header.nplanes]
-    cmp     [esi+pcx_header.bpp],   1
-     jz     monochrome
-    cmp     byte[esi+pcx_header.nplanes],   3
-     jnz    indexed
-
-
-
-  _24bit:
-    xor     eax,   eax
-    mov     al,    byte[esi+pcx_header.nplanes]
     mov     [nplanes],  eax
-    mul     word[esi+pcx_header.bpl]
+    mov     bx,  word[esi+pcx_header.bpl]
+    mov     [bpl],  bx
+    mul     bx
+    shl     eax,    16
+    mov     ax,     dx
+    ror     eax,    16
     mov     [total_bpl],    eax
 
     movzx   eax,    word[esi+pcx_header.xmax]
@@ -117,6 +105,15 @@ endl
     sub     bx,     word[esi+pcx_header.ymin]
     mov     [ysize],    bx
 
+
+    cmp     [esi+pcx_header.bpp],   1
+     jz     .monochrome
+    cmp     byte[esi+pcx_header.nplanes],   3
+     jnz    .indexed
+
+
+  ._24bit:
+
       stdcall   img.create, eax, ebx, Image.bpp24
     mov     [retvalue], eax
     test    eax,    eax
@@ -134,107 +131,107 @@ endl
 
     mov     esi,    [_data]
     add     esi,    128
-    mov     edi,    [retvalue]
+;    mov     edi,    [retvalue]
-    mov     edi,    [edi+Image.Data]
+    mov     edi,    [eax+Image.Data]
     add     edi,    2
     mov     [line_begin],   edi
     mov     ebx,    [total_bpl]
 
-  .begin:
+  ._24bit.begin:
-    mov     eax,    [_data]
+    mov     ax,     word[bpl]
-    mov     ax,     word[eax+pcx_header.bpl]
+  ._24bit.decode:
-  .decode:
+      call      get_byte
-    mov     dl,     byte[esi]
+  ._24bit.write_sequence:
-    inc     esi
+    mov     [edi],  dl
-    mov     [buf],  dl
-    and     dl,     0xC0
-    cmp     dl,     0xC0
-     jne    @f
-    mov     dl,     byte[buf]
-    and     dl,     0x3F
-    mov     dh,     [esi]
-    inc     esi
-
-  .write_sequence:
-    mov     [edi], dh
     dec     ax
-    dec     ebx
     add     edi,    [nplanes]
-    dec     dl
+    dec     dh
-    test    dl,     dl
+     jnz    ._24bit.write_sequence
-     jnz    .write_sequence
 
     test    ax,     ax
-     jz     .end_color_line
+     jz     ._24bit.end_color_line
-     jmp    .decode
+     jmp    ._24bit.decode
-  @@:
-    mov     dl,     byte[buf]
-    mov     [edi],  dl
-    add     edi, [nplanes]
-    dec     ebx
-    dec     ax
-     jz     .end_color_line
-     jmp    .decode
 
- .end_color_line:
+ ._24bit.end_color_line:
     test    ebx,    ebx
-     jz     .end_full_line
+     jz     ._24bit.end_full_line
     dec     [line_begin]
     mov     edi,    [line_begin]
-     jmp    .begin
+     jmp    ._24bit.begin
 
-  .end_full_line:
+  ._24bit.end_full_line:
     dec     word[ysize]
      jz     .quit
     mov     ebx,    [total_bpl]
     add     edi,    2
     mov     [line_begin],   edi
-     jmp    .begin
+     jmp    ._24bit.begin
 
-  .quit:
-    popa
-    mov     eax,    [retvalue]
-    ret
 
-  indexed:
+  .indexed:
-
-    xor     eax,   eax
-    mov     al,    byte[esi+pcx_header.nplanes]
-    mov     [nplanes],  eax
-    mul     word[esi+pcx_header.bpl]
-    mov     [total_bpl],    eax
-
-    movzx   eax,    word[esi+pcx_header.xmax]
-    inc     ax
-    sub     ax,     word[esi+pcx_header.xmin]
-    mov     [xsize],    ax
-
-    movzx   ebx,    word[esi+pcx_header.ymax]
-    inc     bx
-    sub     bx,     word[esi+pcx_header.ymin]
-    mov     [ysize],    bx
 
       stdcall   img.create, eax, ebx, Image.bpp8
     mov     [retvalue], eax
     test    eax,    eax
      jz     .quit
 
+    movzx   ebx,    [xsize]
+    movzx   ecx,    [ysize]
+    mov     edx,    [eax+Image.Data]
+
+    rol     ebx,    16
+    or      ebx,    ecx
+    xor     ebx,    [edx]
+    mov     [eax+Image.Checksum],   ebx
+
     mov     esi,    [_data]
     add     esi,    [_length]
     sub     esi,    768
     mov     edi,    [eax+Image.Palette]
-    mov     ecx,    256
+    mov      cx,    256
   @@:
     mov     ebx,    [esi]
-    and     ebx,    0x00ffffff
     bswap   ebx
     shr     ebx,    8
     mov     [edi],  ebx
     add     edi,    4
     add     esi,    3
-    dec     ecx
+    dec     cx
      jnz    @b
 
+    mov     esi,    [_data]
+    add     esi,    128
+;    mov     edi,    [retvalue]
+    mov     edi,    [eax+Image.Data]
+
+  .indexed.begin:
+    mov     ax,     word[bpl]
+  .indexed.decode:
+      call      get_byte
+  .indexed.write_sequence:
+    mov     [edi], dl
+    inc     edi
+    dec     ax
+    dec     dh
+     jnz    .indexed.write_sequence
+
+    test    ax,     ax
+     jz     .indexed.end_line
+     jmp    .indexed.decode
+
+  .indexed.end_line:
+    dec     word[ysize]
+     jz     .quit
+     jmp    .indexed.begin
+
+
+  .monochrome:
+
+      stdcall   img.create, eax, ebx, Image.bpp1
+    mov     [retvalue], eax
+    test    eax,    eax
+     jz     .quit
+
     movzx   ebx,    [xsize]
     movzx   ecx,    [ysize]
     mov     edx,    [eax+Image.Data]
@@ -244,175 +241,42 @@ endl
     xor     ebx,    [edx]
     mov     [eax+Image.Checksum],   ebx
 
-
-    mov     esi,    [_data]
-    add     esi,    128
-    mov     edi,    [retvalue]
-    mov     edi,    [edi+Image.Data]
-
-  .begin:
-    mov     eax,    [_data]
-    mov     ax,     word[eax+pcx_header.bpl]
-  .decode:
-    mov     dl,     byte[esi]
-    inc     esi
-    mov     [buf],  dl
-    and     dl,     0xC0
-    cmp     dl,     0xC0
-     jne    @f
-    mov     dl,     [buf]
-    and     dl,     0x3F
-    mov     dh,     [esi]
-    inc     esi
-
-  .write_sequence:
-    mov     [edi], dh
-    inc     edi
-    dec     ax
-    dec     dl
-     jnz    .write_sequence
-
-    test    ax,     ax
-     jz     .end_line
-     jmp    .decode
-  @@:
-    mov     dl,     byte[buf]
-    mov     [edi],  dl
-    inc     edi
-    dec     ax
-     jz     .end_line
-     jmp    .decode
-
-  .end_line:
-    dec     word[ysize]
-     jz     .quit
-     jmp    .begin
-
-  .quit:
-    popa
-    mov     eax,    [retvalue]
-    ret
-
-
-  monochrome:
-
-    xor     eax,    eax
-    mov     ax,     word[esi+pcx_header.bpl]
-    mov     [total_bpl],    eax
-
-    movzx   eax,    word[esi+pcx_header.xmax]
-    inc     ax
-    sub     ax,     word[esi+pcx_header.xmin]
-    mov     [xsize],    ax
-
-    movzx   ebx,    word[esi+pcx_header.ymax]
-    inc     bx
-    sub     bx,     word[esi+pcx_header.ymin]
-    mov     [ysize],    bx
-
-      stdcall   img.create, eax, ebx, Image.bpp8
-    mov     [retvalue], eax
-    test    eax,    eax
-     jz     .quit
-
     mov     edi,    [eax+Image.Palette]
     mov     [edi],  dword   0x00000000
     mov     [edi+4],    dword   0x00ffffff
 
-    movzx   ebx,    [xsize]
-    movzx   ecx,    [ysize]
-    mov     edx,    [eax+Image.Data]
-
-    rol     ebx,    16
-    or      ebx,    ecx
-    xor     ebx,    [edx]
-    mov     [eax+Image.Checksum],   ebx
-
-
     mov     esi,    [_data]
     add     esi,    128
-    mov     edi,    [retvalue]
+;    mov     edi,    [retvalue]
-    mov     edi,    [edi+Image.Data]
+    mov     edi,    [eax+Image.Data]
 
-  .begin:
+
-    mov     eax,    [total_bpl]
+  .monochrome.begin:
-    mov     [total_bpl_tmp],    eax
+    mov     ebx,    [total_bpl]
     mov     ax,     [xsize]
 
-  .decode:
+  .monochrome.decode:
-
+      call      get_byte
-    mov     dh,     byte[esi]
+  .monochrome.write_sequence:
-    inc     esi
+    mov     [edi],  dl
-    mov     [buf],  dh
-    and     dh,     0xC0
-    cmp     dh,     0xC0
-     je    .cycle1
-    mov     dh,     1
-    mov     dl,     [buf]
-     jmp    .exit1
-  .cycle1:
-    mov     dh,     [buf]
-    and     dh,     0x3F
-    mov     dl,     byte[esi]
-    inc     esi
-  .exit1:
-    push    eax
-    xor     eax,    eax
-    mov     al,     dh
-    sub     [total_bpl_tmp],    eax
-    pop     eax
-
-
-  .write_sequence:
-    mov     ecx,    7
-  .go:
-    bt      edx,    ecx
-     jnc    @f
-    mov     [edi],  byte    0x01
-     jmp    .later
-  @@:
-    mov     [edi],  byte    0x00
-  .later:
     inc     edi
-    dec     ax
+    cmp     ax,     8
-     jnz    .lol
+     jng    .monochrome.is_last_byte_in_line
-  @@:
+    sub     ax,     8
-    cmp     [total_bpl_tmp],    0
+    dec     dh
+     jnz    .monochrome.write_sequence
+     jmp    .monochrome.decode
+
+  .monochrome.is_last_byte_in_line:
+    test    ebx,    ebx
      jng    @f
-
+      call      get_byte
-    mov     dh,     byte[esi]
+     jmp    .monochrome.is_last_byte_in_line
-    inc     esi
-    mov     [buf],  dh
-    and     dh,     0xC0
-    cmp     dh,     0xC0
-     je    .cycle2
-    mov     dh,     1
-    mov     dl,     [buf]
-     jmp    .exit2
-  .cycle2:
-    mov     dh,     [buf]
-    and     dh,     0x3F
-    mov     dl,     byte[esi]
-    inc     esi
-  .exit2:
-    push    eax
-    xor     eax,    eax
-    mov     al,     dh
-    sub     [total_bpl_tmp],    eax
-    pop     eax
-
-     jmp    @b
   @@:
     dec     word[ysize]
-     jnz    .begin
+     jnz    .monochrome.begin
      jmp    .quit
-  .lol:
+
-    dec     ecx
-    cmp     ecx,    -1
-     jne    .go
-    dec     dh
-     jnz    .write_sequence
-     jmp    .decode
 
   .quit:
     popa
@@ -445,7 +309,25 @@ endp
 ;;================================================================================================;;
 ;;////////////////////////////////////////////////////////////////////////////////////////////////;;
 ;;================================================================================================;;
+proc get_byte
 
+    mov     dh,     byte[esi]
+    inc     esi
+    cmp     dh,     0xC0
+     jnb    .cycle1
+    mov     dl,     dh
+    mov     dh,     1
+     jmp    .exit1
+  .cycle1:
+    and     dh,     0x3F
+    mov     dl,     byte[esi]
+    inc     esi
+  .exit1:
+    movzx   ecx,     dh
+    sub     ebx,    ecx
+
+    ret
+endp
 ;;================================================================================================;;
 ;;////////////////////////////////////////////////////////////////////////////////////////////////;;
 ;;================================================================================================;;