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717 mikedld 1 
;;================================================================================================;;
2 
;;//// gif.asm //// (c) mike.dld, 2007-2008 //////////////////////////////////////////////////////;;
3 
;;================================================================================================;;
4 
;;//// Partial (c) by Willow, Diamond and HidnPlayr //////////////////////////////////////////////;;
5 
;;================================================================================================;;
6 
;;                                                                                                ;;
7 
;; This file is part of Common development libraries (Libs-Dev).                                  ;;
8 
;;                                                                                                ;;
9 
;; Libs-Dev is free software: you can redistribute it and/or modify it under the terms of the GNU ;;
999 diamond 10 
;; Lesser General Public License as published by the Free Software Foundation, either version 2.1 ;;
11 
;; of the License, or (at your option) any later version.                                         ;;
717 mikedld 12 
;;                                                                                                ;;
13 
;; Libs-Dev is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without  ;;
14 
;; even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU  ;;
999 diamond 15 
;; Lesser General Public License for more details.                                                ;;
717 mikedld 16 
;;                                                                                                ;;
999 diamond 17 
;; You should have received a copy of the GNU Lesser General Public License along with Libs-Dev.  ;;
18 
;; If not, see .                                                    ;;
717 mikedld 19 
;;                                                                                                ;;
20 
;;================================================================================================;;
21 
;;                                                                                                ;;
22 
;; References:                                                                                    ;;
23 
;;   1. GIF LITE v3.0 (2004-2007)                                                                 ;;
24 
;;      by Willow and Diamond                                                                     ;;
25 
;;      svn://kolibrios.org/programs/media/gifview/trunk/gif_lite.inc                             ;;
26 
;;   2. "GIF File Format Summary"                                                                 ;;
27 
;;      from "Encyclopedia of Graphics File Formats" by O'Reilly                                  ;;
28 
;;      http://www.fileformat.info/format/gif/                                                    ;;
29 
;;   3. "LZW and GIF explained" (1987)                                                            ;;
30 
;;      by Steve Blackstock, IEEE                                                                 ;;
31 
;;      http://www.cis.udel.edu/~amer/CISC651/lzw.and.gif.explained.html                          ;;
32 
;;   4. "Graphics Interchange Format (tm)" (June 15, 1987)                                        ;;
33 
;;      by CompuServe Incorporated                                                                ;;
34 
;;      http://examples.oreilly.de/english_examples/gff/CDROM/GFF/VENDSPEC/GIF/GIF87A.TXT         ;;
35 
;;   5. "Graphics Interchange Format (sm)" (July 31, 1990)                                        ;;
36 
;;      by CompuServe Incorporated                                                                ;;
37 
;;      http://examples.oreilly.de/english_examples/gff/CDROM/GFF/VENDSPEC/GIF/GIF89A.TXT         ;;
38 
;;                                                                                                ;;
39 
;;================================================================================================;;
40 
 
41 
 
42 
include 'gif.inc'
43 
 
44 
;;================================================================================================;;
45 
proc img.is.gif _data, _length ;//////////////////////////////////////////////////////////////////;;
46 
;;------------------------------------------------------------------------------------------------;;
47 
;? Determine if raw data could be decoded (is in GIF format)                                      ;;
48 
;;------------------------------------------------------------------------------------------------;;
49 
;> _data = raw data as read from file/stream                                                      ;;
50 
;> _length = data length                                                                          ;;
51 
;;------------------------------------------------------------------------------------------------;;
52 
;< eax = false / true                                                                             ;;
53 
;;================================================================================================;;
1079 diamond 54 
	cmp	[_length], sizeof.gif.Header
717 mikedld 55 
	jb	.nope
56 
	mov	eax, [_data]
57 
	cmp	dword[eax], 'GIF8'
58 
	jne	.nope
59 
	cmp	word[eax + 4], '7a'
60 
	je	.yep
61 
	cmp	word[eax + 4], '9a'
62 
	je	.yep
63 
 
64 
  .nope:
65 
	xor	eax, eax
66 
	ret
67 
 
68 
  .yep:
69 
	xor	eax, eax
70 
	inc	eax
71 
	ret
72 
endp
73 
 
74 
;;================================================================================================;;
75 
proc img.decode.gif _data, _length ;//////////////////////////////////////////////////////////////;;
76 
;;------------------------------------------------------------------------------------------------;;
77 
;? Decode data into image if it contains correctly formed raw data in GIF format                  ;;
78 
;;------------------------------------------------------------------------------------------------;;
79 
;> _data = raw data as read from file/stream                                                      ;;
80 
;> _length = data length                                                                          ;;
81 
;;------------------------------------------------------------------------------------------------;;
82 
;< eax = 0 (error) or pointer to image                                                            ;;
83 
;;================================================================================================;;
84 
locals
1079 diamond 85 
  max_color          dd ?
86 
  cur_color_table_size dd ?
87 
  transparent_color  dd ?
88 
  background_color   dd ?
89 
  prev_palette       dd ?
90 
  aux_palette        dd ?
717 mikedld 91 
  img		     dd ?
1079 diamond 92 
  prev_img_data      dd ?
93 
  aux_img_data       dd ?
94 
  aux_img_type       dd ?
95 
  prev_num_colors    dd ?
96 
  main_img           dd ?
717 mikedld 97 
  global_color_table dd ?
999 diamond 98 
  global_color_table_size dd ?
717 mikedld 99 
endl
100 
 
1079 diamond 101 
img.decode.gif.main_img equ main_img
102 
img.decode.gif.prev_img_data equ prev_img_data
103 
img.decode.gif.transparent_color equ transparent_color
104 
img.decode.gif.background_color equ background_color
105 
img.decode.gif._length equ _length
106 
img.decode.gif.prev_num_colors equ prev_num_colors
107 
img.decode.gif.prev_palette equ prev_palette
108 
img.decode.gif.max_color equ max_color
109 
img.decode.gif._data equ _data
110 
img.decode.gif.aux_img_data equ aux_img_data
111 
img.decode.gif.aux_img_type equ aux_img_type
112 
img.decode.gif.aux_palette equ aux_palette
113 
; offset of _length parameter for child functions with ebp-based frame
114 
; child saved ebp, return address, 3 saved registers, 14 local variables
115 
img.decode.gif._length_child equ _length + 4 + 4 + 4*3 + 4*14
116 
img.decode.gif.max_color_child equ ebp + 4 + 4 + 4*3
117 
img.decode.gif.cur_color_table_size_child equ ebp + 4 + 4 + 4*3 + 4
717 mikedld 118 
 
1079 diamond 119 
	push	ebx esi edi
120 
	xor	eax, eax
121 
	mov	[img], eax
122 
	mov	[main_img], eax
123 
	mov	[prev_img_data], eax
124 
	mov	[aux_img_data], eax
125 
	mov	[aux_img_type], eax
126 
	mov	[prev_palette], eax
127 
	mov	[aux_palette], eax
128 
; when no previous image is available, use background fill with 1-entry palette
129 
	inc	eax
130 
	mov	[prev_num_colors], eax
131 
	lea	eax, [background_color]
132 
	mov	[prev_palette], eax
133 
; guard against incorrect gif files, which use Restore-To-Background disposal method, but do not define bgr color
134 
	mov	dword [eax], 0xFFFFFF
135 
; guard against incorrect gif files without any color tables
136 
; "If no color table is available at
137 
; all, the decoder is free to use a system color table or a table of its own. In
138 
; that case, the decoder may use a color table with as many colors as its
139 
; hardware is able to support; it is recommended that such a table have black and
140 
; white as its first two entries, so that monochrome images can be rendered
141 
; adequately." (c) official gif documentation
142 
	mov	[global_color_table], gif_default_palette
143 
	mov	[global_color_table_size], 2
144 
 
999 diamond 145 
; img.is.gif is called by caller (img.decode)
146 
;	stdcall img.is.gif, [_data], [_length]
147 
;	or	eax, eax
148 
;	jz	.error
717 mikedld 149 
 
150 
	mov	ebx, [_data]
1079 diamond 151 
	sub	[_length], sizeof.gif.Header
717 mikedld 152 
 
153 
	mov	cl, [ebx + gif.Header.lsd.Packed]
1079 diamond 154 
	add	ebx, sizeof.gif.Header
155 
; gif.LSD.Packed.GlobalColorTableFlag = 80h
156 
;	test	cl, gif.LSD.Packed.GlobalColorTableFlag
157 
;	jz	@f
158 
	test	cl, cl
159 
	jns	@f
160 
	mov	[global_color_table], ebx
717 mikedld 161 
	and	cl, gif.LSD.Packed.SizeOfGlobalColorTableMask
1079 diamond 162 
;	shr	cl, gif.LSD.Packed.SizeOfGlobalColorTableShift	; here Shift = 0
163 
	push	2
164 
	pop	eax
717 mikedld 165 
	shl	eax, cl
999 diamond 166 
	mov	[global_color_table_size], eax
717 mikedld 167 
	lea	eax, [eax * 3]
1079 diamond 168 
	sub	[_length], eax
169 
	jbe	.error	; there must be at least 1 additional byte after color table
170 
	movzx	ecx, byte [ebx - sizeof.gif.Header + gif.Header.lsd.BackgroundColor]
171 
	lea	ecx, [ecx*3]
172 
	mov	ecx, [ebx + ecx]	; eax = xxBBGGRR, convert to Kolibri color
173 
	bswap	ecx
174 
	shr	ecx, 8
175 
	mov	[background_color], ecx
717 mikedld 176 
	add	ebx, eax
1079 diamond 177 
    @@:
717 mikedld 178 
 
179 
;   @@: cmp     byte[ebx + gif.Block.Introducer], gif.Block.Introducer.Extension
180 
;       jne     .next_image
181 
;       cmp     byte[ebx + gif.Extension.Label], gif.Extension.Label.Comment
182 
;       jne     .error
183 
;       add     ebx, sizeof.gif.Extension
184 
;       stdcall ._.skip_data
185 
;       mov     ebx, eax
186 
;       jmp     @b
187 
 
188 
  .next_image:
189 
	stdcall img._.new
190 
	or	eax, eax
191 
	jz	.error
192 
	mov	edx, [img]
193 
	mov	[eax + Image.Previous], edx
1079 diamond 194 
	push	sizeof.gif.LogicalScreenDescriptor
195 
	pop	ecx
999 diamond 196 
	test	edx, edx
197 
	jz	@f
198 
	mov	[edx + Image.Next], eax
1079 diamond 199 
	xor	ecx, ecx
200 
  @@:
201 
	push	eax
999 diamond 202 
	mov	[eax + Image.Type], Image.bpp8
717 mikedld 203 
 
1079 diamond 204 
	add	ecx, sizeof.gif.Image
205 
	invoke	mem.alloc, ecx
206 
	pop	edx
717 mikedld 207 
	or	eax, eax
1079 diamond 208 
	jz	.error2
717 mikedld 209 
	mov	[edx + Image.Extended], eax
1079 diamond 210 
	xor	ecx, ecx
211 
	cmp	[img], ecx
212 
	jnz	@f
213 
	mov	esi, [_data]
214 
	add	esi, gif.Header.lsd
215 
	lea	edi, [eax + sizeof.gif.Image]
216 
	mov	cl, sizeof.gif.LogicalScreenDescriptor
217 
	rep	movsb
218 
	mov	[main_img], edx
219 
  @@:
220 
	mov	[img], edx
717 mikedld 221 
 
222 
	stdcall ._.process_extensions
223 
 
1079 diamond 224 
	cmp	al, gif.Block.Introducer.ImageDescriptor
717 mikedld 225 
	jne	.error
1079 diamond 226 
	sub	[_length], sizeof.gif.ImageDescriptor
227 
	jc	.error
717 mikedld 228 
	movzx	eax, [ebx + gif.ImageDescriptor.Width]
229 
	movzx	ecx, [ebx + gif.ImageDescriptor.Height]
1079 diamond 230 
	push	edx
783 mikedld 231 
	stdcall img._.resize_data, [img], eax, ecx
1079 diamond 232 
	pop	edx
717 mikedld 233 
	or	eax, eax
234 
	jz	.error
235 
 
999 diamond 236 
	mov	esi, ebx
237 
	mov	edi, [edx + Image.Extended]
238 
	mov	ecx, sizeof.gif.ImageDescriptor
239 
	rep	movsb
240 
 
241 
	mov	edi, [edx + Image.Palette]
242 
	mov	esi, [global_color_table]
243 
	mov	ecx, [global_color_table_size]
717 mikedld 244 
	test	[ebx + gif.ImageDescriptor.Packed], gif.ID.Packed.LocalColorTableFlag
245 
	jz	@f
999 diamond 246 
	lea	esi, [ebx + sizeof.gif.ImageDescriptor]
717 mikedld 247 
	mov	cl, [ebx + gif.ImageDescriptor.Packed]
248 
	and	cl, gif.ID.Packed.SizeOfLocalColorTableMask
1079 diamond 249 
; here Shift = 0
250 
;	shr	cl, gif.ID.Packed.SizeOfLocalColorTableShift
251 
	push	2
252 
	pop	eax
717 mikedld 253 
	shl	eax, cl
999 diamond 254 
	mov	ecx, eax
255 
	lea	eax, [eax*3]
256 
	add	ebx, eax
1079 diamond 257 
	sub	[_length], eax
258 
	jbe	.error	; because we load additional byte, check is 'jbe', not 'jc'
999 diamond 259 
@@:
1079 diamond 260 
	mov	[cur_color_table_size], ecx
261 
	dec	[cur_color_table_size]
262 
@@:
999 diamond 263 
	lodsd
264 
	dec	esi
265 
	bswap	eax
266 
	shr	eax, 8
267 
	stosd
268 
	loop	@b
269 
	add	ebx, sizeof.gif.ImageDescriptor
270 
	stdcall ._.process_image
1079 diamond 271 
	push	ebx
272 
	mov	edx, [img]
273 
	push	edx
274 
	stdcall	._.superimpose
275 
	pop	edx
276 
	push	edx
277 
	stdcall	._.dispose
278 
	pop	edx
279 
	mov	edx, [edx + Image.Previous]
280 
	test	edx, edx
281 
	jz	.nofreeprev
282 
	mov	ebx, [edx + Image.Extended]
283 
	cmp	[ebx + gif.Image.gce.DelayTime], 0
284 
	jnz	.nofreeprev
285 
	mov	esi, [prev_palette]
286 
	cmp	esi, [edx + Image.Palette]
287 
	jnz	@f
288 
	mov	ecx, [prev_num_colors]
289 
	stdcall	._.alloc_aux_palette
290 
	test	eax, eax
291 
	jz	.nofreeprev
292 
	mov	[prev_palette], eax
293 
    @@:
294 
	mov	esi, [prev_img_data]
295 
	cmp	esi, [edx + Image.Data]
296 
	jnz	.noprevdata
297 
	push	1
298 
	pop	eax
299 
	cmp	[edx + Image.Type], Image.bpp8
717 mikedld 300 
	jz	@f
1079 diamond 301 
	mov	al, 3
302 
    @@:
303 
	cmp	[aux_img_type], eax
304 
	jb	.resetaux
305 
	mov	edi, [aux_img_data]
306 
	imul	eax, [edx + Image.Width]
307 
	imul	eax, [edx + Image.Height]
308 
	xchg	eax, ecx
309 
	rep	movsb
310 
	jmp	.noprevdata
311 
    .resetaux:
312 
	mov	[aux_img_type], eax
313 
	mov	eax, [aux_img_data]
314 
	test	eax, eax
315 
	jz	@f
316 
	invoke	mem.free, eax
317 
    @@:
318 
	xor	eax, eax
319 
	xchg	eax, [edx + Image.Data]
320 
	mov	[aux_img_data], eax
321 
    .noprevdata:
322 
	cmp	edx, [main_img]
323 
	jnz	@f
324 
	mov	eax, [edx + Image.Next]
325 
	mov	[main_img], eax
326 
	mov	esi, [eax + Image.Extended]
327 
	mov	edi, [edx + Image.Extended]
328 
	mov	[edx + Image.Extended], esi
329 
	mov	[eax + Image.Extended], edi
330 
	push	sizeof.gif.Image
331 
	pop	ecx
332 
	rep	movsb
333 
    @@:
334 
	stdcall	img.destroy.layer, edx
335 
  .nofreeprev:
336 
	pop	ebx
337 
	test	ebx, ebx
338 
	jz	.ret
339 
	jmp	.next_image
717 mikedld 340 
 
1079 diamond 341 
  .error2:
342 
	mov	[img], edx
343 
 
717 mikedld 344 
  .error:
999 diamond 345 
	mov	eax, [img]
346 
	test	eax, eax
1079 diamond 347 
	jz	.ret
348 
	cmp	[main_img], eax
349 
	jnz	@f
350 
	and	[main_img], 0
351 
  @@:
352 
	stdcall	img.destroy.layer, eax
353 
  .ret:
354 
	mov	eax, [aux_img_data]
355 
	test	eax, eax
999 diamond 356 
	jz	@f
1079 diamond 357 
	invoke	mem.free, eax
358 
  @@:
359 
	mov	eax, [aux_palette]
360 
	test	eax, eax
361 
	jz	@f
362 
	invoke	mem.free, eax
363 
  @@:
364 
	mov	eax, [main_img]
365 
	cmp	[eax + Image.Next], 0
366 
	jz	@f
367 
	or	[eax + Image.Flags], Image.IsAnimated
368 
  @@:
369 
	pop	edi esi ebx
717 mikedld 370 
	ret
371 
endp
372 
 
373 
;;================================================================================================;;
374 
proc img.encode.gif _img, _p_length ;/////////////////////////////////////////////////////////////;;
375 
;;------------------------------------------------------------------------------------------------;;
376 
;? Encode image into raw data in GIF format                                                       ;;
377 
;;------------------------------------------------------------------------------------------------;;
378 
;> _img = pointer to image                                                                        ;;
379 
;;------------------------------------------------------------------------------------------------;;
380 
;< eax = 0 (error) or pointer to encoded data                                                     ;;
381 
;< _p_length = encoded data length                                                                ;;
382 
;;================================================================================================;;
383 
	xor	eax, eax
384 
	ret
385 
endp
386 
 
387 
 
388 
;;================================================================================================;;
389 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
390 
;;================================================================================================;;
391 
;! Below are private procs you should never call directly from your code                          ;;
392 
;;================================================================================================;;
393 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
394 
;;================================================================================================;;
395 
 
396 
 
397 
;;================================================================================================;;
398 
proc img.decode.gif._.process_extensions ;////////////////////////////////////////////////////////;;
399 
;;------------------------------------------------------------------------------------------------;;
400 
;? --- TBD ---                                                                                    ;;
401 
;;------------------------------------------------------------------------------------------------;;
402 
;> ebx = raw image data                                                                           ;;
403 
;> edx = image data                                                                               ;;
404 
;;------------------------------------------------------------------------------------------------;;
405 
;< --- TBD ---                                                                                    ;;
406 
;;================================================================================================;;
407 
	mov	esi, ebx
1079 diamond 408 
	xor	eax, eax
409 
	mov	[edx + Image.Delay], eax
717 mikedld 410 
 
411 
  .next_block:
1079 diamond 412 
	dec	[img.decode.gif._length]
413 
	js	.exit_err
414 
	lodsb	; load gif.Block.Introducer
717 mikedld 415 
	cmp	al, gif.Block.Introducer.Extension
1079 diamond 416 
	jne	.exit
717 mikedld 417 
 
418 
  .ext_block:
1079 diamond 419 
	dec	[img.decode.gif._length]
420 
	js	.exit_err
421 
	lodsb	; load gif.Extension.Label
717 mikedld 422 
	cmp	al, gif.Extension.Label.GraphicsControl
423 
	je	.graphics_control_ext
1079 diamond 424 
;	cmp	al, gif.Extension.Label.PlainText
425 
;	je	.plain_text_ext
426 
;	cmp	al, gif.Extension.Label.Comment
427 
;	je	.comment_ext
428 
;	cmp	al, gif.Extension.Label.Application
429 
;	je	.application_ext
430 
; skip all other extensions
431 
  .skip_ext:
432 
	dec	[img.decode.gif._length]
433 
	js	.exit_err
434 
	lodsb	; load BlockSize
435 
  .1:
436 
	test	al, al
437 
	jz	.next_block
438 
	sub	[img.decode.gif._length], eax
439 
	jc	.exit_err
440 
	add	esi, eax
441 
	jmp	.skip_ext
717 mikedld 442 
 
443 
  .graphics_control_ext:
1079 diamond 444 
	dec	[img.decode.gif._length]
445 
	js	.exit_err
446 
	lodsb	; load BlockSize; must be sizeof.gif.GraphicsControlExtension
447 
	cmp	al, sizeof.gif.GraphicsControlExtension
448 
	jnz	.1
449 
	sub	[img.decode.gif._length], eax
450 
	jc	.exit_err
717 mikedld 451 
	push	edi
1079 diamond 452 
	movzx	edi, [esi + gif.GraphicsControlExtension.DelayTime]
453 
	mov	[edx + Image.Delay], edi
717 mikedld 454 
	mov	edi, [edx + Image.Extended]
455 
	add	edi, gif.Image.gce
1079 diamond 456 
	mov	ecx, eax
717 mikedld 457 
	rep	movsb
458 
	pop	edi
1079 diamond 459 
	jmp	.skip_ext
717 mikedld 460 
 
1079 diamond 461 
  .exit_err:
462 
	xor	eax, eax
717 mikedld 463 
 
464 
  .exit:
465 
	mov	ebx, esi
466 
	ret
467 
endp
468 
 
469 
;;================================================================================================;;
999 diamond 470 
proc img.decode.gif._.process_image ;/////////////////////////////////////////////////////////////;;
717 mikedld 471 
;;------------------------------------------------------------------------------------------------;;
472 
;? --- TBD ---                                                                                    ;;
473 
;;------------------------------------------------------------------------------------------------;;
474 
;> ebx = raw image data                                                                           ;;
475 
;> edx = image data                                                                               ;;
476 
;;------------------------------------------------------------------------------------------------;;
477 
;< --- TBD ---                                                                                    ;;
478 
;;================================================================================================;;
479 
locals
480 
  width      dd ?
481 
  img_start  dd ?
482 
  img_end    dd ?
483 
  row_end    dd ?
484 
  pass	     dd ?
485 
  codesize   dd ?
486 
  compsize   dd ?
487 
  workarea   dd ?
488 
  block_ofs  dd ?
489 
  bit_count  dd ?
490 
  CC	     dd ?
491 
  EOI	     dd ?
492 
endl
493 
 
494 
	invoke	mem.alloc, 16 * 1024
495 
	mov	[workarea], eax
496 
	or	eax, eax
497 
	jz	.error
498 
 
499 
	mov	ecx, [edx + Image.Width]
500 
	mov	[width], ecx
501 
	mov	eax, [edx + Image.Height]
502 
	imul	eax, ecx
503 
	mov	[img_end], eax
504 
	inc	eax
505 
	mov	[row_end], eax
506 
	and	[pass], 0
1079 diamond 507 
	and	dword [img.decode.gif.max_color_child], 0
717 mikedld 508 
	mov	eax, [edx + Image.Extended]
509 
	test	[eax + gif.Image.info.Packed], gif.ID.Packed.InterleaceFlag
510 
	jz	@f
511 
	mov	[row_end], ecx
512 
 
513 
    @@: mov	esi, ebx
514 
	mov	edi, [edx + Image.Data]
515 
 
1079 diamond 516 
	sub	dword [img.decode.gif._length_child], 2
517 
	jc	.error
717 mikedld 518 
	movzx	ecx, byte[esi]
519 
	inc	esi
1079 diamond 520 
	cmp	cl, 12
521 
	jae	.error
717 mikedld 522 
	mov	[codesize], ecx
523 
	inc	[codesize]
524 
	xor	eax, eax
525 
	lodsb				; eax - block_count
1079 diamond 526 
	sub	[img.decode.gif._length_child], eax
527 
	jc	.error
717 mikedld 528 
	add	eax, esi
1079 diamond 529 
	push	edi
530 
	mov	edi, [workarea]
717 mikedld 531 
	mov	[block_ofs], eax
532 
	mov	[bit_count], 8
533 
	mov	eax, 1
534 
	shl	eax, cl
535 
	mov	[CC], eax
536 
	mov	ecx, eax
537 
	inc	eax
538 
	mov	[EOI], eax
539 
	mov	eax, gif.Null shl 16
540 
  .filltable:
541 
	stosd
542 
	inc	eax
543 
	loop	.filltable
544 
	pop	edi
545 
	mov	[img_start], edi
546 
	add	[img_end], edi
547 
	add	[row_end], edi
548 
  .reinit:
549 
	mov	edx, [EOI]
550 
	inc	edx
551 
	push	[codesize]
552 
	pop	[compsize]
553 
	call	.get_symbol
554 
	cmp	eax, [CC]
555 
	je	.reinit
556 
	call	.output
557 
  .cycle:
558 
	movzx	ebx, ax
559 
	call	.get_symbol
1079 diamond 560 
	cmp	eax, [EOI]
561 
	je	.end
717 mikedld 562 
	cmp	eax, edx
1079 diamond 563 
	ja	.error
564 
	je	.notintable
717 mikedld 565 
	cmp	eax, [CC]
566 
	je	.reinit
567 
	call	.output
568 
  .add:
1079 diamond 569 
	cmp	edx, 0x00001000
570 
	jae	.cycle
717 mikedld 571 
	mov	ecx, [workarea]
572 
	mov	[ecx + edx * 4], ebx
573 
	inc	edx
1079 diamond 574 
	cmp	edx, 0x1000
575 
	je	.noinc
717 mikedld 576 
	bsr	ebx, edx
577 
	cmp	ebx, [compsize]
578 
	jne	.noinc
579 
	inc	[compsize]
580 
  .noinc:
581 
	jmp	.cycle
582 
  .notintable:
583 
	push	eax
584 
	mov	eax, ebx
585 
	call	.output
586 
	push	ebx
587 
	movzx	eax, bx
588 
	call	.output
589 
	pop	ebx eax
590 
	jmp	.add
591 
  .end:
592 
	mov	edi, [img_end]
593 
	xor	eax, eax
594 
 
595 
  .exit:
596 
	cmp	[workarea], 0
597 
	je	@f
598 
	invoke	mem.free, [workarea]
1079 diamond 599 
    @@:
600 
	mov	ebx, [block_ofs]
601 
    @@:
602 
	dec	[img.decode.gif._length_child]
603 
	js	@f
604 
	movzx	eax, byte [ebx]
605 
	inc	ebx
606 
	test	eax, eax
607 
	jz	.ret
608 
	sub	[img.decode.gif._length_child], eax
609 
	jc	@f
610 
	add	ebx, eax
611 
	jmp	@b
717 mikedld 612 
 
613 
  .error:
614 
	cmp	[workarea], 0
615 
	je	@f
616 
	invoke	mem.free, [workarea]
1079 diamond 617 
    @@: xor	ebx, ebx
618 
  .ret:
717 mikedld 619 
	ret
620 
 
621 
;;------------------------------------------------------------------------------------------------;;
622 
 
623 
img.decode.gif._.process_image.get_symbol:
624 
	mov	ecx, [compsize]
625 
	push	ecx
626 
	xor	eax, eax
627 
 
628 
  .shift:
629 
	dec	[bit_count]
1079 diamond 630 
	jns	.loop1
717 mikedld 631 
	inc	esi
632 
	cmp	esi, [block_ofs]
633 
	jb	.noblock
634 
	push	eax
635 
	xor	eax, eax
1079 diamond 636 
	sub	[img.decode.gif._length_child], 1
637 
	jc	.error_eof
717 mikedld 638 
	lodsb
639 
	test	eax, eax
640 
	jnz	.nextbl
1079 diamond 641 
  .error_eof:
642 
	add	esp, 12
643 
	jmp	img.decode.gif._.process_image.error
717 mikedld 644 
 
645 
  .nextbl:
1079 diamond 646 
	sub	[img.decode.gif._length_child], eax
647 
	jc	.error_eof
717 mikedld 648 
	add	eax, esi
649 
	mov	[block_ofs], eax
650 
	pop	eax
651 
 
652 
  .noblock:
1079 diamond 653 
	mov	[bit_count], 7
717 mikedld 654 
 
655 
  .loop1:
1079 diamond 656 
	ror	byte[esi], 1
657 
	rcr	eax,1
717 mikedld 658 
	loop	.shift
659 
	pop	ecx
660 
	rol	eax, cl
661 
 
662 
  .exit:
663 
	xor	ecx, ecx
664 
	retn
665 
 
666 
;;------------------------------------------------------------------------------------------------;;
667 
 
668 
img.decode.gif._.process_image.output:
669 
	push	esi eax edx
670 
	mov	edx, [workarea]
671 
 
672 
  .next:
673 
	pushw	[edx + eax * 4]
674 
	mov	ax, [edx + eax * 4 + 2]
675 
	inc	ecx
676 
	cmp	ax, gif.Null
677 
	jnz	.next
678 
	shl	ebx, 16
679 
	mov	bx, [esp]
680 
 
681 
  .loop2:
682 
	pop	ax
1079 diamond 683 
	cmp	al, byte [img.decode.gif.cur_color_table_size_child]
684 
	jbe	@f	; guard against incorrect GIFs
685 
	mov	al, 0
686 
    @@: cmp	al, byte [img.decode.gif.max_color_child]
687 
	jbe	@f
688 
	mov	[img.decode.gif.max_color_child], al
689 
    @@:	stosb
717 mikedld 690 
 
1079 diamond 691 
	cmp	edi, [img_end]
692 
	jz	.done
717 mikedld 693 
	cmp	edi, [row_end]
694 
	jb	.norowend
695 
	mov	eax, [width]
696 
	push	eax
697 
	sub	edi, eax
698 
	add	eax, eax
699 
	cmp	[pass], 3
700 
	je	@f
701 
	add	eax, eax
702 
	cmp	[pass], 2
703 
	je	@f
704 
	add	eax, eax
705 
    @@: add	edi, eax
706 
	pop	eax
707 
	cmp	edi, [img_end]
708 
	jb	.nextrow
709 
	mov	edi, [img_start]
710 
	inc	[pass]
711 
	add	edi, eax
712 
	cmp	[pass], 3
713 
	je	@f
714 
	add	edi, eax
715 
	cmp	[pass], 2
716 
	je	@f
717 
	add	edi, eax
718 
	add	edi, eax
719 
    @@:
720 
 
721 
  .nextrow:
722 
	add	eax, edi
723 
	mov	[row_end], eax
724 
	xor	eax, eax
725 
 
726 
  .norowend:
727 
	loop	.loop2
728 
	pop	edx eax esi
729 
	retn
730 
 
1079 diamond 731 
  .done:
732 
	lea	esp, [esp+(ecx-1)*2]
733 
	pop	edx eax esi eax
734 
	jmp	img.decode.gif._.process_image.exit
735 
 
717 mikedld 736 
endp
737 
 
1079 diamond 738 
;;================================================================================================;;
739 
proc img.decode.gif._.is_logical_screen ;/////////////////////////////////////////////////////////;;
740 
;;------------------------------------------------------------------------------------------------;;
741 
;? Determines whether GIF image occupies the whole logical screen                                 ;;
742 
;;------------------------------------------------------------------------------------------------;;
743 
;> eax = extended image data                                                                      ;;
744 
;> ebx = main image                                                                               ;;
745 
;;------------------------------------------------------------------------------------------------;;
746 
;< ZF set <=> image area equals logical screen                                                    ;;
747 
;;================================================================================================;;
748 
	mov	ebx, [ebx + Image.Extended]
749 
	cmp	[eax + gif.Image.info.Left], 0
750 
	jnz	@f
751 
	cmp	[eax + gif.Image.info.Top], 0
752 
	jnz	@f
753 
	mov	cx, [eax + gif.Image.info.Width]
754 
	cmp	cx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenWidth]
755 
	jnz	@f
756 
	mov	cx, [eax + gif.Image.info.Height]
757 
	cmp	cx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenHeight]
758 
@@:	retn
759 
endp
717 mikedld 760 
 
1079 diamond 761 
main_img equ img.decode.gif.main_img
762 
transparent_color equ img.decode.gif.transparent_color
763 
background_color equ img.decode.gif.background_color
764 
prev_num_colors equ img.decode.gif.prev_num_colors
765 
prev_palette equ img.decode.gif.prev_palette
766 
max_color equ img.decode.gif.max_color
767 
prev_img_data equ img.decode.gif.prev_img_data
768 
_data equ img.decode.gif._data
769 
aux_img_data equ img.decode.gif.aux_img_data
770 
aux_img_type equ img.decode.gif.aux_img_type
771 
aux_palette equ img.decode.gif.aux_palette
772 
 
717 mikedld 773 
;;================================================================================================;;
1079 diamond 774 
proc img.decode.gif._.superimpose ;///////////////////////////////////////////////////////////////;;
775 
;;------------------------------------------------------------------------------------------------;;
776 
;? --- TBD ---                                                                                    ;;
777 
;;------------------------------------------------------------------------------------------------;;
778 
;> edx = image data                                                                               ;;
779 
;;------------------------------------------------------------------------------------------------;;
780 
;< --- TBD ---                                                                                    ;;
781 
;;================================================================================================;;
782 
	mov	ebx, [main_img]
783 
	mov	eax, [edx + Image.Extended]
784 
	or	[transparent_color], -1		; no transparent color
785 
	test	byte [eax + gif.Image.gce.Packed], 1
786 
	jz	@f
787 
	movzx	ecx, byte [eax + gif.Image.gce.ColorIndex]
788 
	mov	[transparent_color], ecx
789 
	cmp	edx, ebx
790 
	jnz	.has_transparency
791 
	shl	ecx, 2
792 
	add	ecx, [edx + Image.Palette]
793 
	mov	dword [background_color], 0xFFFFFF	; white background
794 
	mov	dword [ecx], 0xFFFFFF
795 
;	mov	esi, [_data]
796 
;	test	[esi+gif.Header.lsd.Packed], gif.LSD.Packed.GlobalColorTableFlag
797 
;	jz	@f
798 
;	movzx	ecx, [esi+gif.Header.lsd.BackgroundColor]
799 
;	push	ecx
800 
;	shl	ecx, 2
801 
;	add	ecx, [edx + Image.Palette]
802 
;	mov	dword [ecx], 0xFFFFFF
803 
;	pop	ecx
804 
;	lea	ecx, [ecx*3]
805 
;	add	esi, ecx
806 
;	mov	byte [esi+sizeof.gif.Header+0], 0xFF
807 
;	mov	byte [esi+sizeof.gif.Header+1], 0xFF
808 
;	mov	byte [esi+sizeof.gif.Header+2], 0xFF
809 
@@:
810 
	call	img.decode.gif._.is_logical_screen
811 
	jnz	.has_transparency
812 
; image is not transparent, so keep it as is
813 
	retn
814 
 
815 
.has_transparency:
816 
; image has transparent areas, we must superimpose it on the previous
817 
	mov	ecx, [prev_num_colors]
818 
	cmp	ecx, 0x100
819 
	ja	.superimpose_on_rgb
820 
; create common palette
821 
	sub	esp, 3FCh
822 
	push	eax
823 
	mov	edi, esp
824 
	push	ecx
825 
	mov	esi, [prev_palette]
826 
	rep	movsd
827 
	pop	ecx
828 
	mov	esi, [edx + Image.Palette]
829 
	xor	ebx, ebx
830 
	mov	edi, esp
831 
	sub	esp, 100h
832 
.create_palette_loop:
833 
	push	ecx
834 
	lodsd
835 
	cmp	ebx, [transparent_color]
836 
	jz	.nochange
837 
	cmp	ebx, ecx
838 
	jae	@f
839 
	cmp	eax, [edi+ebx*4]
840 
	jz	.nochange
841 
@@:
842 
	push	edi
843 
	repnz	scasd
844 
	pop	edi
845 
	jnz	.increase_palette
846 
	sub	ecx, [esp]
847 
	not	ecx	; cl = index of new color in current palette
848 
	jmp	.palette_common
849 
.increase_palette:
850 
	mov	ecx, [esp]
851 
	test	ch, ch
852 
	jnz	.output_to_rgb
853 
	inc	dword [esp]
854 
	mov	[edi+ecx*4], eax
855 
	jmp	.palette_common
856 
.nochange:
857 
	mov	ecx, ebx
858 
.palette_common:
859 
	mov	[ebx+esp+4], cl
860 
	pop	ecx
861 
	inc	ebx
862 
	cmp	ebx, [max_color]
863 
	jbe	.create_palette_loop
864 
	mov	[max_color], ecx
865 
; if image occupies only part of logical screen, allocate memory for full logical screen
866 
	mov	ebx, [main_img]
867 
	mov	eax, [edx + Image.Extended]
868 
	mov	esi, [edx + Image.Data]
869 
	call	img.decode.gif._.is_logical_screen
870 
	jz	@f
871 
	and	[edx + Image.Data], 0
872 
	push	edx
873 
	movzx	eax, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenHeight]
874 
	push	eax
875 
	movzx	eax, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenWidth]
876 
	stdcall	img._.resize_data, edx, eax
877 
	pop	edx
878 
	test	eax, eax
879 
	jz	.palette_nomem
880 
@@:
881 
; copy final palette to Image.Palette
882 
	push	esi esi
883 
	mov	esi, edi
884 
	mov	edi, [edx + Image.Palette]
885 
	mov	ecx, [max_color]
886 
	dec	[max_color]
887 
	rep	movsd
888 
	mov	esi, [prev_img_data]
889 
	mov	edi, [edx + Image.Data]
890 
; do superimpose, [esp] -> source data, esi -> prev image data
891 
;   (NULL if previous image is filled with background color), esp+8 -> correspondence between
892 
;   used palette and final palette, edi -> destination data
893 
	mov	ebx, [edx + Image.Extended]
894 
; first Top rows are copied from [prev_img_data] or filled with bgr
895 
	movzx	ecx, [ebx + gif.Image.info.Top]
896 
	cmp	ecx, [edx + Image.Height]
897 
	jb	@f
898 
	mov	ecx, [edx + Image.Height]
899 
@@:
900 
	push	ecx
901 
	imul	ecx, [edx + Image.Width]
902 
	call	.rep_movsb_or_stosb
903 
	pop	ecx
904 
; convert rows
905 
	sub	ecx, [edx + Image.Height]
906 
	neg	ecx
907 
	push	ecx
908 
	cmp	cx, [ebx + gif.Image.info.Height]
909 
	jbe	@f
910 
	mov	cx, [ebx + gif.Image.info.Height]
911 
@@:
912 
	jecxz	.norows
913 
.convert_rows:
914 
	push	ecx
915 
	movzx	ecx, [ebx + gif.Image.info.Left]
916 
	cmp	ecx, [edx + Image.Width]
917 
	jb	@f
918 
	mov	ecx, [edx + Image.Width]
919 
@@:
920 
	push	ecx
921 
	call	.rep_movsb_or_stosb
922 
	pop	ecx
923 
	sub	ecx, [edx + Image.Width]
924 
	neg	ecx
925 
	push	ecx edx
926 
	mov	edx, [esp+16]	; source data
927 
	cmp	cx, [ebx + gif.Image.info.Width]
928 
	jbe	@f
929 
	mov	cx, [ebx + gif.Image.info.Width]
930 
@@:
931 
	jecxz	.norowsi
932 
.rowsloop:
933 
	movzx	eax, byte [edx]
934 
	inc	edx
935 
	cmp	eax, [transparent_color]
936 
	jz	.rows_transparent
937 
	mov	al, [eax+esp+24]
938 
	stosb
939 
	call	.lodsb
940 
	jmp	@f
941 
.rows_transparent:
942 
	call	.lodsb
943 
	stosb
944 
@@:
945 
	loop	.rowsloop
946 
.norowsi:
947 
	pop	edx ecx
948 
	sub	cx, [ebx + gif.Image.info.Width]
949 
	jbe	@f
950 
	call	.rep_movsb_or_stosb
951 
@@:
952 
	movzx	eax, [ebx + gif.Image.info.Width]
953 
	add	[esp+8], eax
954 
	pop	ecx
955 
	loop	.convert_rows
956 
.norows:
957 
	pop	ecx
958 
	sub	cx, [ebx + gif.Image.info.Height]
959 
	jbe	@f
960 
	imul	ecx, [edx + Image.Width]
961 
	call	.rep_movsb_or_stosb
962 
@@:
963 
; free old image data if we have allocated new copy
964 
	pop	esi esi
965 
	cmp	esi, [edx + Image.Data]
966 
	jz	@f
967 
	invoke	mem.free, esi
968 
@@:
969 
; cleanup stack and return
970 
	add	esp, 500h
971 
	retn
972 
.palette_nomem:
973 
	mov	[edx + Image.Data], esi
974 
	jmp	@b
975 
 
976 
.output_to_rgb:
977 
	pop	ecx
978 
	add	esp, 500h
979 
; compose two palette-based images to one RGB image
980 
	xor	esi, esi
981 
	xchg	esi, [edx + Image.Data]
982 
	push	esi
983 
	mov	ebx, [_data]
984 
	push	[edx + Image.Palette]
985 
	mov	byte [edx + Image.Type], Image.bpp24
986 
	push	edx
987 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
988 
	push	eax
989 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
990 
	stdcall	img._.resize_data, edx, eax
991 
	pop	edx
992 
	test	eax, eax
993 
	jz	.convrgb_nomem
994 
	push	esi
995 
	mov	edi, [edx + Image.Data]
996 
	mov	esi, [prev_img_data]
997 
	mov	ebx, [edx + Image.Extended]
998 
; first Top rows are copied from [prev_img_data] or filled with bgr
999 
	movzx	ecx, [ebx + gif.Image.info.Top]
1000 
	cmp	ecx, [edx + Image.Height]
1001 
	jb	@f
1002 
	mov	ecx, [edx + Image.Height]
1003 
@@:
1004 
	push	ecx
1005 
	imul	ecx, [edx + Image.Width]
1006 
	call	.convrgb_prev
1007 
	pop	ecx
1008 
; convert rows
1009 
	sub	ecx, [edx + Image.Height]
1010 
	neg	ecx
1011 
	push	ecx
1012 
	cmp	cx, [ebx + gif.Image.info.Height]
1013 
	jbe	@f
1014 
	mov	cx, [ebx + gif.Image.info.Height]
1015 
@@:
1016 
	jecxz	.convrgb_norows
1017 
.convrgb_convert_rows:
1018 
	push	ecx
1019 
	movzx	ecx, [ebx + gif.Image.info.Left]
1020 
	cmp	ecx, [edx + Image.Width]
1021 
	jb	@f
1022 
	mov	ecx, [edx + Image.Width]
1023 
@@:
1024 
	push	ecx
1025 
	call	.convrgb_prev
1026 
	pop	ecx
1027 
	sub	ecx, [edx + Image.Width]
1028 
	neg	ecx
1029 
	push	ecx edx
1030 
	mov	edx, [esp+16]	; source data
1031 
	cmp	cx, [ebx + gif.Image.info.Width]
1032 
	jbe	@f
1033 
	mov	cx, [ebx + gif.Image.info.Width]
1034 
@@:
1035 
	jecxz	.convrgb_norowsi
1036 
.convrgb_rowsloop:
1037 
	movzx	eax, byte [edx]
1038 
	inc	edx
1039 
	cmp	eax, [transparent_color]
1040 
	jz	.convrgb_rows_transparent
1041 
	shl	eax, 2
1042 
	add	eax, [esp+20]	; source palette
1043 
	mov	eax, [eax]
1044 
	stosw
1045 
	shr	eax, 16
1046 
	stosb
1047 
	call	.convrgb_lodsb
1048 
	jmp	@f
1049 
.convrgb_rows_transparent:
1050 
	call	.convrgb_lodsb
1051 
	stosw
1052 
	shr	eax, 16
1053 
	stosb
1054 
@@:
1055 
	loop	.convrgb_rowsloop
1056 
.convrgb_norowsi:
1057 
	pop	edx ecx
1058 
	sub	cx, [ebx + gif.Image.info.Width]
1059 
	jbe	@f
1060 
	call	.convrgb_prev
1061 
@@:
1062 
	movzx	eax, [ebx + gif.Image.info.Width]
1063 
	add	[esp+8], eax
1064 
	pop	ecx
1065 
	loop	.convrgb_convert_rows
1066 
.convrgb_norows:
1067 
	pop	ecx
1068 
	sub	cx, [ebx + gif.Image.info.Height]
1069 
	jbe	@f
1070 
	imul	ecx, [edx + Image.Width]
1071 
	call	.convrgb_prev
1072 
@@:
1073 
; free old image data
1074 
	pop	esi esi ;esi
1075 
	invoke	mem.free;, esi
1076 
	retn
1077 
.convrgb_nomem:
1078 
	pop	esi esi
1079 
	retn
1080 
 
1081 
.superimpose_on_rgb:
1082 
; previous image is RGB, new image has transparent areas
1083 
	xor	esi, esi
1084 
	xchg	esi, [edx + Image.Data]
1085 
	push	esi
1086 
	mov	ebx, [_data]
1087 
	push	[edx + Image.Palette]
1088 
	mov	byte [edx + Image.Type], Image.bpp24
1089 
	push	edx
1090 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
1091 
	push	eax
1092 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1093 
	stdcall	img._.resize_data, edx, eax
1094 
	pop	edx
1095 
	test	eax, eax
1096 
	jz	.rgb_nomem
1097 
	push	esi
1098 
	mov	edi, [edx + Image.Data]
1099 
	mov	esi, [prev_img_data]
1100 
	mov	ebx, [edx + Image.Extended]
1101 
; first Top rows are copied from [prev_img_data] or filled with bgr
1102 
	movzx	ecx, [ebx + gif.Image.info.Top]
1103 
	cmp	ecx, [edx + Image.Height]
1104 
	jb	@f
1105 
	mov	ecx, [edx + Image.Height]
1106 
@@:
1107 
	push	ecx
1108 
	lea	ecx, [ecx*3]
1109 
	imul	ecx, [edx + Image.Width]
1110 
	rep	movsb
1111 
	pop	ecx
1112 
; convert rows
1113 
	sub	ecx, [edx + Image.Height]
1114 
	neg	ecx
1115 
	push	ecx
1116 
	cmp	cx, [ebx + gif.Image.info.Height]
1117 
	jbe	@f
1118 
	mov	cx, [ebx + gif.Image.info.Height]
1119 
@@:
1120 
	jecxz	.rgb_norows
1121 
.rgb_convert_rows:
1122 
	push	ecx
1123 
	movzx	ecx, [ebx + gif.Image.info.Left]
1124 
	cmp	ecx, [edx + Image.Width]
1125 
	jb	@f
1126 
	mov	ecx, [edx + Image.Width]
1127 
@@:
1128 
	push	ecx
1129 
	lea	ecx, [ecx*3]
1130 
	rep	movsb
1131 
	pop	ecx
1132 
	sub	ecx, [edx + Image.Width]
1133 
	neg	ecx
1134 
	push	ecx edx
1135 
	mov	edx, [esp+16]	; source data
1136 
	cmp	cx, [ebx + gif.Image.info.Width]
1137 
	jbe	@f
1138 
	mov	cx, [ebx + gif.Image.info.Width]
1139 
@@:
1140 
	jecxz	.rgb_norowsi
1141 
.rgb_rowsloop:
1142 
	movzx	eax, byte [edx]
1143 
	inc	edx
1144 
	cmp	eax, [transparent_color]
1145 
	jz	.rgb_rows_transparent
1146 
	shl	eax, 2
1147 
	add	eax, [esp+20]	; source palette
1148 
	mov	eax, [eax]
1149 
	stosw
1150 
	shr	eax, 16
1151 
	stosb
1152 
	add	esi, 3
1153 
	jmp	@f
1154 
.rgb_rows_transparent:
1155 
	movsb
1156 
	movsb
1157 
	movsb
1158 
@@:
1159 
	loop	.rgb_rowsloop
1160 
.rgb_norowsi:
1161 
	pop	edx ecx
1162 
	sub	cx, [ebx + gif.Image.info.Width]
1163 
	jbe	@f
1164 
	lea	ecx, [ecx*3]
1165 
	rep	movsb
1166 
@@:
1167 
	movzx	eax, [ebx + gif.Image.info.Width]
1168 
	add	[esp+8], eax
1169 
	pop	ecx
1170 
	loop	.rgb_convert_rows
1171 
.rgb_norows:
1172 
	pop	ecx
1173 
	sub	cx, [ebx + gif.Image.info.Height]
1174 
	jbe	@f
1175 
	imul	ecx, [edx + Image.Width]
1176 
	lea	ecx, [ecx*3]
1177 
	rep	movsb
1178 
@@:
1179 
; free old image data
1180 
	pop	esi esi ;esi
1181 
	invoke	mem.free;, esi
1182 
	retn
1183 
.rgb_nomem:
1184 
	pop	esi esi
1185 
	retn
1186 
 
1187 
.lodsb:
1188 
	xor	eax, eax
1189 
	test	esi, esi
1190 
	jz	@f
1191 
	lodsb
1192 
@@:	retn
1193 
 
1194 
.rep_movsb_or_stosb:
1195 
	test	esi, esi
1196 
	jz	.rmos1
1197 
	rep	movsb
1198 
	jmp	.rmos2
1199 
.rmos1:	xor	eax, eax	; background index in final palette is 0 in bgr mode
1200 
	rep	stosb
1201 
.rmos2:	retn
1202 
 
1203 
.convrgb_prev:
1204 
	jecxz	.convrgb_noprev
1205 
	test	esi, esi
1206 
	jz	.convrgb_prev_bgr
1207 
@@:
1208 
	xor	eax, eax
1209 
	lodsb
1210 
	shl	eax, 2
1211 
	add	eax, [prev_palette]
1212 
	mov	eax, [eax]
1213 
	stosw
1214 
	shr	eax, 16
1215 
	stosb
1216 
	loop	@b
1217 
	retn
1218 
.convrgb_prev_bgr:
1219 
@@:
1220 
	mov	eax, [background_color]
1221 
	stosw
1222 
	shr	eax, 16
1223 
	stosb
1224 
	loop	@b
1225 
.convrgb_noprev:
1226 
	retn
1227 
.convrgb_lodsb:
1228 
	xor	eax, eax
1229 
	test	esi, esi
1230 
	jz	@f
1231 
	lodsb
1232 
	shl	eax, 2
1233 
	add	eax, [prev_palette]
1234 
	mov	eax, [eax]
1235 
	retn
1236 
@@:	mov	eax, [background_color]
1237 
	retn
1238 
 
1239 
endp
1240 
 
1241 
;;================================================================================================;;
1242 
proc img.decode.gif._.dispose ;///////////////////////////////////////////////////////////////////;;
1243 
;;------------------------------------------------------------------------------------------------;;
1244 
;? --- TBD ---                                                                                    ;;
1245 
;;------------------------------------------------------------------------------------------------;;
1246 
;> edx = image data                                                                               ;;
1247 
;;------------------------------------------------------------------------------------------------;;
1248 
;< --- TBD ---                                                                                    ;;
1249 
;;================================================================================================;;
1250 
	mov	ebx, [edx + Image.Extended]
1251 
	mov	al, [ebx + gif.Image.gce.Packed]
1252 
	shr	al, 2
1253 
	and	al, 7
1254 
	cmp	al, 2
1255 
	jz	.background
1256 
	cmp	al, 3
1257 
	jz	.previous
1258 
; don't dispose - set prev_img and related vars to current image
1259 
	mov	eax, [edx + Image.Data]
1260 
	mov	[prev_img_data], eax
1261 
	cmp	[edx + Image.Type], Image.bpp8
1262 
	jnz	@f
1263 
	mov	eax, [max_color]
1264 
	inc	eax
1265 
	mov	[prev_num_colors], eax
1266 
	mov	eax, [edx + Image.Palette]
1267 
	mov	[prev_palette], eax
1268 
	retn
1269 
@@:
1270 
	or	[prev_num_colors], -1
1271 
	and	[prev_palette], 0
1272 
.previous:
1273 
	retn
1274 
.background:
1275 
	cmp	[prev_img_data], 0
1276 
	jz	.bgr_full
1277 
	mov	ebx, [main_img]
1278 
	mov	eax, [edx + Image.Extended]
1279 
	call	img.decode.gif._.is_logical_screen
1280 
	jnz	@f
1281 
.bgr_full:
1282 
	xor	eax, eax
1283 
	mov	[prev_img_data], eax
1284 
	inc	eax
1285 
	mov	[prev_num_colors], eax
1286 
	lea	eax, [background_color]
1287 
	mov	[prev_palette], eax
1288 
	retn
1289 
@@:
1290 
	cmp	[prev_num_colors], 0x100
1291 
	ja	.rgb
1292 
	mov	eax, [background_color]
1293 
	mov	edi, [prev_palette]
1294 
	mov	ecx, [prev_num_colors]
1295 
	repnz	scasd
1296 
	jz	.palette_ok
1297 
	cmp	[prev_num_colors], 0x100
1298 
	jz	.convert_rgb
1299 
	push	1
1300 
	pop	eax
1301 
	stdcall	img.decode.gif._.alloc_aux_img
1302 
	test	eax, eax
1303 
	jz	.previous
1304 
	mov	ecx, [prev_num_colors]
1305 
	mov	esi, [prev_palette]
1306 
	call	img.decode.gif._.alloc_aux_palette
1307 
	test	eax, eax
1308 
	jz	.previous
1309 
	mov	[prev_palette], eax
1310 
	mov	eax, [background_color]
1311 
	stosd
1312 
	mov	eax, [prev_num_colors]	; eax = index of background color
1313 
	inc	[prev_num_colors]
1314 
	jmp	.bpp8_common
1315 
.palette_ok:
1316 
	push	1
1317 
	pop	eax
1318 
	stdcall	img.decode.gif._.alloc_aux_img
1319 
	test	eax, eax
1320 
	jz	.previous
1321 
	sub	edi, [prev_palette]
1322 
	shr	edi, 2
1323 
	lea	eax, [edi-1]	; eax = index of background color
1324 
.bpp8_common:
1325 
	push	eax
1326 
	mov	ebx, [_data]
1327 
	mov	esi, [prev_img_data]
1328 
	mov	edi, [aux_img_data]
1329 
	mov	[prev_img_data], edi
1330 
	cmp	esi, edi
1331 
	jz	@f
1332 
	movzx	ecx, [ebx + gif.Header.lsd.ScreenWidth]
1333 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
1334 
	imul	ecx, eax
1335 
	push	edi
1336 
	rep	movsb
1337 
	pop	edi
1338 
@@:
1339 
	movzx	esi, [ebx + gif.Header.lsd.ScreenHeight]
1340 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1341 
	mov	edx, [edx + Image.Extended]
1342 
	movzx	ecx, [edx + gif.Image.info.Top]
1343 
	sub	esi, ecx
1344 
	jbe	.bpp8_ret
1345 
	imul	ecx, eax
1346 
	add	edi, ecx
1347 
	cmp	si, [edx + gif.Image.info.Height]
1348 
	jb	@f
1349 
	mov	si, [edx + gif.Image.info.Height]
1350 
@@:
1351 
	movzx	ecx, [edx + gif.Image.info.Left]
1352 
	sub	eax, ecx
1353 
	jbe	.bpp8_ret
1354 
	add	edi, ecx
1355 
	cmp	ax, [edx + gif.Image.info.Width]
1356 
	jb	@f
1357 
	mov	ax, [edx + gif.Image.info.Width]
1358 
@@:
1359 
	xchg	eax, ecx
1360 
	movzx	edx, [ebx + gif.Header.lsd.ScreenWidth]
1361 
	sub	edx, ecx
1362 
	pop	eax
1363 
@@:
1364 
	push	ecx
1365 
	rep	stosb
1366 
	pop	ecx
1367 
	add	edi, edx
1368 
	dec	esi
1369 
	jnz	@b
1370 
	push	eax
1371 
.bpp8_ret:
1372 
	pop	eax
1373 
	retn
1374 
.convert_rgb:
1375 
	push	3
1376 
	pop	eax
1377 
	stdcall	img.decode.gif._.alloc_aux_img
1378 
	test	eax, eax
1379 
	jz	.previous
1380 
	or	[prev_num_colors], -1
1381 
	mov	ebx, [_data]
1382 
	mov	esi, [prev_img_data]
1383 
	mov	edi, [aux_img_data]
1384 
	mov	[prev_img_data], edi
1385 
	movzx	ecx, [ebx + gif.Header.lsd.ScreenWidth]
1386 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
1387 
	imul	ecx, eax
1388 
	push	edx
1389 
	xor	edx, edx
1390 
	xchg	edx, [prev_palette]
1391 
	add	edi, ecx
1392 
	add	esi, ecx
1393 
	add	edi, ecx
1394 
	add	edi, ecx
1395 
@@:
1396 
	dec	esi
1397 
	movzx	eax, byte [esi]
1398 
	mov	eax, [eax*4+edx]
1399 
	sub	edi, 3
1400 
	mov	[edi], ax
1401 
	shr	eax, 16
1402 
	mov	[edi+2], al
1403 
	loop	@b
1404 
	pop	edx
1405 
	movzx	esi, [ebx + gif.Header.lsd.ScreenHeight]
1406 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1407 
	mov	edx, [edx + Image.Extended]
1408 
	movzx	ecx, [edx + gif.Image.info.Top]
1409 
	sub	esi, ecx
1410 
	jbe	.convert_rgb_ret
1411 
	imul	ecx, eax
1412 
	lea	ecx, [ecx*3]
1413 
	add	edi, ecx
1414 
	cmp	si, [edx + gif.Image.info.Height]
1415 
	jb	@f
1416 
	mov	si, [edx + gif.Image.info.Height]
1417 
@@:
1418 
	movzx	ecx, [edx + gif.Image.info.Left]
1419 
	sub	eax, ecx
1420 
	jbe	.convert_rgb_ret
1421 
	lea	ecx, [ecx*3]
1422 
	add	edi, ecx
1423 
	cmp	ax, [edx + gif.Image.info.Width]
1424 
	jb	@f
1425 
	mov	ax, [edx + gif.Image.info.Width]
1426 
@@:
1427 
	xchg	eax, ecx
1428 
	movzx	edx, [ebx + gif.Header.lsd.ScreenWidth]
1429 
	sub	edx, ecx
1430 
	mov	eax, [background_color]
1431 
	lea	edx, [edx*3]
1432 
.convert_rgb_loop:
1433 
	push	ecx
1434 
@@:
1435 
	stosw
1436 
	shr	eax, 16
1437 
	stosb
1438 
	loop	@b
1439 
	pop	ecx
1440 
	add	edi, edx
1441 
	dec	esi
1442 
	jnz	.convert_rgb_loop
1443 
.convert_rgb_ret:
1444 
	retn
1445 
.rgb:
1446 
	push	3
1447 
	pop	eax
1448 
	stdcall	img.decode.gif._.alloc_aux_img
1449 
	test	eax, eax
1450 
	jz	.previous
1451 
	or	[prev_num_colors], -1
1452 
	and	[prev_palette], 0
1453 
	mov	ebx, [_data]
1454 
	mov	esi, [prev_img_data]
1455 
	mov	edi, [aux_img_data]
1456 
	mov	[prev_img_data], edi
1457 
	cmp	esi, edi
1458 
	jz	@f
1459 
	movzx	ecx, [ebx + gif.Header.lsd.ScreenHeight]
1460 
	push	ecx
1461 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1462 
	imul	ecx, eax
1463 
	lea	ecx, [ecx*3]
1464 
	push	edi
1465 
	rep	movsb
1466 
	pop	edi
1467 
	pop	esi
1468 
	mov	edx, [edx + Image.Extended]
1469 
	movzx	ecx, [edx + gif.Image.info.Top]
1470 
	sub	esi, ecx
1471 
	jbe	.rgb_ret
1472 
	imul	ecx, eax
1473 
	lea	ecx, [ecx*3]
1474 
	add	edi, ecx
1475 
	cmp	si, [edx + gif.Image.info.Height]
1476 
	jb	@f
1477 
	mov	si, [edx + gif.Image.info.Height]
1478 
@@:
1479 
	movzx	ecx, [edx + gif.Image.info.Left]
1480 
	sub	eax, ecx
1481 
	jbe	.rgb_ret
1482 
	lea	ecx, [ecx*3]
1483 
	add	edi, ecx
1484 
	cmp	ax, [edx + gif.Image.info.Width]
1485 
	jb	@f
1486 
	mov	ax, [edx + gif.Image.info.Width]
1487 
@@:
1488 
	xchg	eax, ecx
1489 
	movzx	edx, [ebx + gif.Header.lsd.ScreenWidth]
1490 
	sub	edx, ecx
1491 
	mov	eax, [background_color]
1492 
	lea	edx, [edx*3]
1493 
.rgb_loop:
1494 
	push	ecx
1495 
@@:
1496 
	stosw
1497 
	shr	eax, 16
1498 
	stosb
1499 
	loop	@b
1500 
	pop	ecx
1501 
	add	edi, edx
1502 
	dec	esi
1503 
	jnz	.rgb_loop
1504 
.rgb_ret:
1505 
	retn
1506 
 
1507 
endp
1508 
 
1509 
;;================================================================================================;;
1510 
proc img.decode.gif._.alloc_aux_img ;/////////////////////////////////////////////////////////////;;
1511 
;;------------------------------------------------------------------------------------------------;;
1512 
;? Allocate auxiliary memory for previous image                                                   ;;
1513 
;;------------------------------------------------------------------------------------------------;;
1514 
;> eax = image type: 1 = bpp8, 3 = bpp24                                                          ;;
1515 
;;------------------------------------------------------------------------------------------------;;
1516 
;< eax = [aux_img_data]                                                                           ;;
1517 
;;================================================================================================;;
1518 
	cmp	[aux_img_type], eax
1519 
	jae	@f
1520 
	push	edx eax
1521 
	movzx	ecx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenWidth]
1522 
	mul	ecx
1523 
	movzx	ecx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenHeight]
1524 
	mul	ecx
1525 
	invoke	mem.realloc, [aux_img_data], eax
1526 
	pop	ecx edx
1527 
	test	eax, eax
1528 
	jz	@f
1529 
	mov	[aux_img_type], ecx
1530 
	mov	[aux_img_data], eax
1531 
@@:	retn
1532 
 
1533 
endp
1534 
 
1535 
;;================================================================================================;;
1536 
proc img.decode.gif._.alloc_aux_palette ;/////////////////////////////////////////////////////////;;
1537 
;;------------------------------------------------------------------------------------------------;;
1538 
;? Allocate and fill aux_palette                                                                  ;;
1539 
;;------------------------------------------------------------------------------------------------;;
1540 
;> esi -> palette, ecx = palette size                                                             ;;
1541 
;;------------------------------------------------------------------------------------------------;;
1542 
;< [aux_palette] set                                                                              ;;
1543 
;;================================================================================================;;
1544 
	mov	eax, [aux_palette]
1545 
	test	eax, eax
1546 
	jnz	@f
1547 
	push	edx ecx
1548 
	invoke	mem.alloc, 0x400
1549 
	pop	ecx edx
1550 
	test	eax, eax
1551 
	jz	.ret
1552 
	mov	[aux_palette], eax
1553 
@@:
1554 
	mov	edi, eax
1555 
	rep	movsd
1556 
.ret:
1557 
	retn
1558 
 
1559 
endp
1560 
 
1561 
restore main_img
1562 
restore transparent_color
1563 
restore background_color
1564 
restore prev_num_colors
1565 
restore prev_palette
1566 
restore max_color
1567 
restore prev_img_data
1568 
restore _data
1569 
restore aux_img_data
1570 
restore aux_img_type
1571 
restore aux_palette
1572 
 
1573 
;;================================================================================================;;
717 mikedld 1574 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
1575 
;;================================================================================================;;
1576 
;! Below is private data you should never use directly from your code                             ;;
1577 
;;================================================================================================;;
1578 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
1579 
;;================================================================================================;;
1580 
 
1581 
 
1582 
;