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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 
;;================================================================================================;;
1102 diamond 75 
proc img.decode.gif _data, _length, _options ;////////////////////////////////////////////////////;;
717 mikedld 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 ?
1102 diamond 89 
  options_bgr        dd ?
1079 diamond 90 
  prev_palette       dd ?
91 
  aux_palette        dd ?
717 mikedld 92 
  img		     dd ?
1079 diamond 93 
  prev_img_data      dd ?
94 
  aux_img_data       dd ?
95 
  aux_img_type       dd ?
96 
  prev_num_colors    dd ?
97 
  main_img           dd ?
717 mikedld 98 
  global_color_table dd ?
999 diamond 99 
  global_color_table_size dd ?
717 mikedld 100 
endl
101 
 
1079 diamond 102 
img.decode.gif.main_img equ main_img
103 
img.decode.gif.prev_img_data equ prev_img_data
104 
img.decode.gif.transparent_color equ transparent_color
105 
img.decode.gif.background_color equ background_color
106 
img.decode.gif._length equ _length
107 
img.decode.gif.prev_num_colors equ prev_num_colors
108 
img.decode.gif.prev_palette equ prev_palette
109 
img.decode.gif.max_color equ max_color
110 
img.decode.gif._data equ _data
111 
img.decode.gif.aux_img_data equ aux_img_data
112 
img.decode.gif.aux_img_type equ aux_img_type
113 
img.decode.gif.aux_palette equ aux_palette
1102 diamond 114 
img.decode.gif.options_bgr equ options_bgr
1079 diamond 115 
; offset of _length parameter for child functions with ebp-based frame
1118 diamond 116 
; child saved ebp, return address, 3 saved registers, 15 local variables
117 
img.decode.gif._length_child equ _length + 4 + 4 + 4*3 + 4*15
1079 diamond 118 
img.decode.gif.max_color_child equ ebp + 4 + 4 + 4*3
119 
img.decode.gif.cur_color_table_size_child equ ebp + 4 + 4 + 4*3 + 4
717 mikedld 120 
 
1079 diamond 121 
	push	ebx esi edi
122 
	xor	eax, eax
123 
	mov	[img], eax
124 
	mov	[main_img], eax
125 
	mov	[prev_img_data], eax
126 
	mov	[aux_img_data], eax
127 
	mov	[aux_img_type], eax
128 
	mov	[prev_palette], eax
129 
	mov	[aux_palette], eax
130 
; when no previous image is available, use background fill with 1-entry palette
131 
	inc	eax
132 
	mov	[prev_num_colors], eax
133 
	lea	eax, [background_color]
134 
	mov	[prev_palette], eax
1102 diamond 135 
; value for bgr color in transparent images
136 
	mov	edx, 0xFFFFFF	; white bgr if no value given
137 
	mov	ecx, [_options]
138 
	jecxz	@f
139 
	cmp	[ecx + ImageDecodeOptions.UsedSize], ImageDecodeOptions.BackgroundColor + 4
140 
	jb	@f
141 
	mov	edx, [ecx + ImageDecodeOptions.BackgroundColor]
142 
@@:
143 
	mov	[options_bgr], edx
144 
	mov	dword [eax], edx
1079 diamond 145 
; guard against incorrect gif files without any color tables
146 
; "If no color table is available at
147 
; all, the decoder is free to use a system color table or a table of its own. In
148 
; that case, the decoder may use a color table with as many colors as its
149 
; hardware is able to support; it is recommended that such a table have black and
150 
; white as its first two entries, so that monochrome images can be rendered
151 
; adequately." (c) official gif documentation
152 
	mov	[global_color_table], gif_default_palette
153 
	mov	[global_color_table_size], 2
154 
 
999 diamond 155 
; img.is.gif is called by caller (img.decode)
156 
;	stdcall img.is.gif, [_data], [_length]
157 
;	or	eax, eax
158 
;	jz	.error
717 mikedld 159 
 
160 
	mov	ebx, [_data]
1079 diamond 161 
	sub	[_length], sizeof.gif.Header
717 mikedld 162 
 
163 
	mov	cl, [ebx + gif.Header.lsd.Packed]
1079 diamond 164 
	add	ebx, sizeof.gif.Header
165 
; gif.LSD.Packed.GlobalColorTableFlag = 80h
166 
;	test	cl, gif.LSD.Packed.GlobalColorTableFlag
167 
;	jz	@f
168 
	test	cl, cl
169 
	jns	@f
170 
	mov	[global_color_table], ebx
717 mikedld 171 
	and	cl, gif.LSD.Packed.SizeOfGlobalColorTableMask
1079 diamond 172 
;	shr	cl, gif.LSD.Packed.SizeOfGlobalColorTableShift	; here Shift = 0
173 
	push	2
174 
	pop	eax
717 mikedld 175 
	shl	eax, cl
999 diamond 176 
	mov	[global_color_table_size], eax
717 mikedld 177 
	lea	eax, [eax * 3]
1079 diamond 178 
	sub	[_length], eax
179 
	jbe	.error	; there must be at least 1 additional byte after color table
180 
	movzx	ecx, byte [ebx - sizeof.gif.Header + gif.Header.lsd.BackgroundColor]
181 
	lea	ecx, [ecx*3]
182 
	mov	ecx, [ebx + ecx]	; eax = xxBBGGRR, convert to Kolibri color
183 
	bswap	ecx
184 
	shr	ecx, 8
185 
	mov	[background_color], ecx
717 mikedld 186 
	add	ebx, eax
1079 diamond 187 
    @@:
717 mikedld 188 
 
189 
;   @@: cmp     byte[ebx + gif.Block.Introducer], gif.Block.Introducer.Extension
190 
;       jne     .next_image
191 
;       cmp     byte[ebx + gif.Extension.Label], gif.Extension.Label.Comment
192 
;       jne     .error
193 
;       add     ebx, sizeof.gif.Extension
194 
;       stdcall ._.skip_data
195 
;       mov     ebx, eax
196 
;       jmp     @b
197 
 
198 
  .next_image:
199 
	stdcall img._.new
200 
	or	eax, eax
201 
	jz	.error
202 
	mov	edx, [img]
203 
	mov	[eax + Image.Previous], edx
1079 diamond 204 
	push	sizeof.gif.LogicalScreenDescriptor
205 
	pop	ecx
999 diamond 206 
	test	edx, edx
207 
	jz	@f
208 
	mov	[edx + Image.Next], eax
1079 diamond 209 
	xor	ecx, ecx
210 
  @@:
211 
	push	eax
2733 dunkaist 212 
	mov	[eax + Image.Type], Image.bpp8i
717 mikedld 213 
 
1079 diamond 214 
	add	ecx, sizeof.gif.Image
215 
	invoke	mem.alloc, ecx
216 
	pop	edx
717 mikedld 217 
	or	eax, eax
1079 diamond 218 
	jz	.error2
717 mikedld 219 
	mov	[edx + Image.Extended], eax
1079 diamond 220 
	xor	ecx, ecx
221 
	cmp	[img], ecx
222 
	jnz	@f
223 
	mov	esi, [_data]
224 
	add	esi, gif.Header.lsd
225 
	lea	edi, [eax + sizeof.gif.Image]
226 
	mov	cl, sizeof.gif.LogicalScreenDescriptor
227 
	rep	movsb
228 
	mov	[main_img], edx
229 
  @@:
230 
	mov	[img], edx
717 mikedld 231 
 
232 
	stdcall ._.process_extensions
233 
 
1079 diamond 234 
	cmp	al, gif.Block.Introducer.ImageDescriptor
717 mikedld 235 
	jne	.error
1079 diamond 236 
	sub	[_length], sizeof.gif.ImageDescriptor
237 
	jc	.error
717 mikedld 238 
	movzx	eax, [ebx + gif.ImageDescriptor.Width]
239 
	movzx	ecx, [ebx + gif.ImageDescriptor.Height]
1079 diamond 240 
	push	edx
783 mikedld 241 
	stdcall img._.resize_data, [img], eax, ecx
1079 diamond 242 
	pop	edx
717 mikedld 243 
	or	eax, eax
244 
	jz	.error
245 
 
999 diamond 246 
	mov	esi, ebx
247 
	mov	edi, [edx + Image.Extended]
248 
	mov	ecx, sizeof.gif.ImageDescriptor
249 
	rep	movsb
250 
 
251 
	mov	edi, [edx + Image.Palette]
252 
	mov	esi, [global_color_table]
253 
	mov	ecx, [global_color_table_size]
717 mikedld 254 
	test	[ebx + gif.ImageDescriptor.Packed], gif.ID.Packed.LocalColorTableFlag
255 
	jz	@f
999 diamond 256 
	lea	esi, [ebx + sizeof.gif.ImageDescriptor]
717 mikedld 257 
	mov	cl, [ebx + gif.ImageDescriptor.Packed]
258 
	and	cl, gif.ID.Packed.SizeOfLocalColorTableMask
1079 diamond 259 
; here Shift = 0
260 
;	shr	cl, gif.ID.Packed.SizeOfLocalColorTableShift
261 
	push	2
262 
	pop	eax
717 mikedld 263 
	shl	eax, cl
999 diamond 264 
	mov	ecx, eax
265 
	lea	eax, [eax*3]
266 
	add	ebx, eax
1079 diamond 267 
	sub	[_length], eax
268 
	jbe	.error	; because we load additional byte, check is 'jbe', not 'jc'
999 diamond 269 
@@:
1079 diamond 270 
	mov	[cur_color_table_size], ecx
271 
	dec	[cur_color_table_size]
272 
@@:
999 diamond 273 
	lodsd
274 
	dec	esi
275 
	bswap	eax
276 
	shr	eax, 8
277 
	stosd
278 
	loop	@b
279 
	add	ebx, sizeof.gif.ImageDescriptor
280 
	stdcall ._.process_image
1079 diamond 281 
	push	ebx
282 
	mov	edx, [img]
283 
	push	edx
284 
	stdcall	._.superimpose
285 
	pop	edx
286 
	push	edx
287 
	stdcall	._.dispose
288 
	pop	edx
289 
	mov	edx, [edx + Image.Previous]
290 
	test	edx, edx
291 
	jz	.nofreeprev
292 
	mov	ebx, [edx + Image.Extended]
1121 diamond 293 
	cmp	[edx + Image.Delay], 0
1079 diamond 294 
	jnz	.nofreeprev
295 
	mov	esi, [prev_palette]
296 
	cmp	esi, [edx + Image.Palette]
297 
	jnz	@f
298 
	mov	ecx, [prev_num_colors]
299 
	stdcall	._.alloc_aux_palette
300 
	test	eax, eax
301 
	jz	.nofreeprev
302 
	mov	[prev_palette], eax
303 
    @@:
304 
	mov	esi, [prev_img_data]
305 
	cmp	esi, [edx + Image.Data]
306 
	jnz	.noprevdata
307 
	push	1
308 
	pop	eax
2733 dunkaist 309 
	cmp	[edx + Image.Type], Image.bpp8i
717 mikedld 310 
	jz	@f
1079 diamond 311 
	mov	al, 3
312 
    @@:
313 
	cmp	[aux_img_type], eax
314 
	jb	.resetaux
315 
	mov	edi, [aux_img_data]
316 
	imul	eax, [edx + Image.Width]
317 
	imul	eax, [edx + Image.Height]
318 
	xchg	eax, ecx
319 
	rep	movsb
320 
	jmp	.noprevdata
321 
    .resetaux:
322 
	mov	[aux_img_type], eax
323 
	mov	eax, [aux_img_data]
324 
	test	eax, eax
325 
	jz	@f
326 
	invoke	mem.free, eax
327 
    @@:
328 
	xor	eax, eax
329 
	xchg	eax, [edx + Image.Data]
330 
	mov	[aux_img_data], eax
331 
    .noprevdata:
332 
	cmp	edx, [main_img]
333 
	jnz	@f
334 
	mov	eax, [edx + Image.Next]
335 
	mov	[main_img], eax
336 
	mov	esi, [eax + Image.Extended]
337 
	mov	edi, [edx + Image.Extended]
338 
	mov	[edx + Image.Extended], esi
339 
	mov	[eax + Image.Extended], edi
340 
	push	sizeof.gif.Image
341 
	pop	ecx
342 
	rep	movsb
343 
    @@:
344 
	stdcall	img.destroy.layer, edx
345 
  .nofreeprev:
346 
	pop	ebx
347 
	test	ebx, ebx
348 
	jz	.ret
349 
	jmp	.next_image
717 mikedld 350 
 
1079 diamond 351 
  .error2:
352 
	mov	[img], edx
353 
 
717 mikedld 354 
  .error:
999 diamond 355 
	mov	eax, [img]
356 
	test	eax, eax
1079 diamond 357 
	jz	.ret
358 
	cmp	[main_img], eax
359 
	jnz	@f
360 
	and	[main_img], 0
361 
  @@:
362 
	stdcall	img.destroy.layer, eax
363 
  .ret:
364 
	mov	eax, [aux_img_data]
365 
	test	eax, eax
999 diamond 366 
	jz	@f
1079 diamond 367 
	invoke	mem.free, eax
368 
  @@:
369 
	mov	eax, [aux_palette]
370 
	test	eax, eax
371 
	jz	@f
372 
	invoke	mem.free, eax
373 
  @@:
374 
	mov	eax, [main_img]
375 
	cmp	[eax + Image.Next], 0
376 
	jz	@f
377 
	or	[eax + Image.Flags], Image.IsAnimated
378 
  @@:
379 
	pop	edi esi ebx
717 mikedld 380 
	ret
381 
endp
382 
 
383 
;;================================================================================================;;
384 
proc img.encode.gif _img, _p_length ;/////////////////////////////////////////////////////////////;;
385 
;;------------------------------------------------------------------------------------------------;;
386 
;? Encode image into raw data in GIF format                                                       ;;
387 
;;------------------------------------------------------------------------------------------------;;
388 
;> _img = pointer to image                                                                        ;;
389 
;;------------------------------------------------------------------------------------------------;;
390 
;< eax = 0 (error) or pointer to encoded data                                                     ;;
391 
;< _p_length = encoded data length                                                                ;;
392 
;;================================================================================================;;
393 
	xor	eax, eax
394 
	ret
395 
endp
396 
 
397 
 
398 
;;================================================================================================;;
399 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
400 
;;================================================================================================;;
401 
;! Below are private procs you should never call directly from your code                          ;;
402 
;;================================================================================================;;
403 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
404 
;;================================================================================================;;
405 
 
406 
 
407 
;;================================================================================================;;
408 
proc img.decode.gif._.process_extensions ;////////////////////////////////////////////////////////;;
409 
;;------------------------------------------------------------------------------------------------;;
410 
;? --- TBD ---                                                                                    ;;
411 
;;------------------------------------------------------------------------------------------------;;
412 
;> ebx = raw image data                                                                           ;;
413 
;> edx = image data                                                                               ;;
414 
;;------------------------------------------------------------------------------------------------;;
415 
;< --- TBD ---                                                                                    ;;
416 
;;================================================================================================;;
417 
	mov	esi, ebx
1079 diamond 418 
	xor	eax, eax
419 
	mov	[edx + Image.Delay], eax
717 mikedld 420 
 
421 
  .next_block:
1079 diamond 422 
	dec	[img.decode.gif._length]
423 
	js	.exit_err
424 
	lodsb	; load gif.Block.Introducer
717 mikedld 425 
	cmp	al, gif.Block.Introducer.Extension
1079 diamond 426 
	jne	.exit
717 mikedld 427 
 
428 
  .ext_block:
1079 diamond 429 
	dec	[img.decode.gif._length]
430 
	js	.exit_err
431 
	lodsb	; load gif.Extension.Label
717 mikedld 432 
	cmp	al, gif.Extension.Label.GraphicsControl
433 
	je	.graphics_control_ext
1079 diamond 434 
;	cmp	al, gif.Extension.Label.PlainText
435 
;	je	.plain_text_ext
436 
;	cmp	al, gif.Extension.Label.Comment
437 
;	je	.comment_ext
438 
;	cmp	al, gif.Extension.Label.Application
439 
;	je	.application_ext
440 
; skip all other extensions
441 
  .skip_ext:
442 
	dec	[img.decode.gif._length]
443 
	js	.exit_err
444 
	lodsb	; load BlockSize
445 
  .1:
446 
	test	al, al
447 
	jz	.next_block
448 
	sub	[img.decode.gif._length], eax
449 
	jc	.exit_err
450 
	add	esi, eax
451 
	jmp	.skip_ext
717 mikedld 452 
 
453 
  .graphics_control_ext:
1079 diamond 454 
	dec	[img.decode.gif._length]
455 
	js	.exit_err
456 
	lodsb	; load BlockSize; must be sizeof.gif.GraphicsControlExtension
457 
	cmp	al, sizeof.gif.GraphicsControlExtension
458 
	jnz	.1
459 
	sub	[img.decode.gif._length], eax
460 
	jc	.exit_err
717 mikedld 461 
	push	edi
1079 diamond 462 
	movzx	edi, [esi + gif.GraphicsControlExtension.DelayTime]
463 
	mov	[edx + Image.Delay], edi
717 mikedld 464 
	mov	edi, [edx + Image.Extended]
465 
	add	edi, gif.Image.gce
1079 diamond 466 
	mov	ecx, eax
717 mikedld 467 
	rep	movsb
468 
	pop	edi
1079 diamond 469 
	jmp	.skip_ext
717 mikedld 470 
 
1079 diamond 471 
  .exit_err:
472 
	xor	eax, eax
717 mikedld 473 
 
474 
  .exit:
475 
	mov	ebx, esi
476 
	ret
477 
endp
478 
 
479 
;;================================================================================================;;
999 diamond 480 
proc img.decode.gif._.process_image ;/////////////////////////////////////////////////////////////;;
717 mikedld 481 
;;------------------------------------------------------------------------------------------------;;
482 
;? --- TBD ---                                                                                    ;;
483 
;;------------------------------------------------------------------------------------------------;;
484 
;> ebx = raw image data                                                                           ;;
485 
;> edx = image data                                                                               ;;
486 
;;------------------------------------------------------------------------------------------------;;
487 
;< --- TBD ---                                                                                    ;;
488 
;;================================================================================================;;
489 
locals
490 
  width      dd ?
491 
  img_start  dd ?
492 
  img_end    dd ?
493 
  row_end    dd ?
494 
  pass	     dd ?
495 
  codesize   dd ?
496 
  compsize   dd ?
497 
  workarea   dd ?
498 
  block_ofs  dd ?
499 
  bit_count  dd ?
500 
  CC	     dd ?
501 
  EOI	     dd ?
502 
endl
503 
 
504 
	invoke	mem.alloc, 16 * 1024
505 
	mov	[workarea], eax
506 
	or	eax, eax
507 
	jz	.error
508 
 
509 
	mov	ecx, [edx + Image.Width]
510 
	mov	[width], ecx
511 
	mov	eax, [edx + Image.Height]
512 
	imul	eax, ecx
513 
	mov	[img_end], eax
514 
	inc	eax
515 
	mov	[row_end], eax
516 
	and	[pass], 0
1079 diamond 517 
	and	dword [img.decode.gif.max_color_child], 0
717 mikedld 518 
	mov	eax, [edx + Image.Extended]
519 
	test	[eax + gif.Image.info.Packed], gif.ID.Packed.InterleaceFlag
520 
	jz	@f
521 
	mov	[row_end], ecx
522 
 
523 
    @@: mov	esi, ebx
524 
	mov	edi, [edx + Image.Data]
525 
 
1079 diamond 526 
	sub	dword [img.decode.gif._length_child], 2
527 
	jc	.error
717 mikedld 528 
	movzx	ecx, byte[esi]
529 
	inc	esi
1079 diamond 530 
	cmp	cl, 12
531 
	jae	.error
717 mikedld 532 
	mov	[codesize], ecx
533 
	inc	[codesize]
534 
	xor	eax, eax
535 
	lodsb				; eax - block_count
1079 diamond 536 
	sub	[img.decode.gif._length_child], eax
537 
	jc	.error
717 mikedld 538 
	add	eax, esi
1079 diamond 539 
	push	edi
540 
	mov	edi, [workarea]
717 mikedld 541 
	mov	[block_ofs], eax
542 
	mov	[bit_count], 8
543 
	mov	eax, 1
544 
	shl	eax, cl
545 
	mov	[CC], eax
546 
	mov	ecx, eax
547 
	inc	eax
548 
	mov	[EOI], eax
549 
	mov	eax, gif.Null shl 16
550 
  .filltable:
551 
	stosd
552 
	inc	eax
553 
	loop	.filltable
554 
	pop	edi
555 
	mov	[img_start], edi
556 
	add	[img_end], edi
557 
	add	[row_end], edi
558 
  .reinit:
559 
	mov	edx, [EOI]
560 
	inc	edx
561 
	push	[codesize]
562 
	pop	[compsize]
563 
	call	.get_symbol
564 
	cmp	eax, [CC]
565 
	je	.reinit
566 
	call	.output
567 
  .cycle:
568 
	movzx	ebx, ax
569 
	call	.get_symbol
1079 diamond 570 
	cmp	eax, [EOI]
571 
	je	.end
717 mikedld 572 
	cmp	eax, edx
1079 diamond 573 
	ja	.error
574 
	je	.notintable
717 mikedld 575 
	cmp	eax, [CC]
576 
	je	.reinit
577 
	call	.output
578 
  .add:
1079 diamond 579 
	cmp	edx, 0x00001000
580 
	jae	.cycle
717 mikedld 581 
	mov	ecx, [workarea]
582 
	mov	[ecx + edx * 4], ebx
583 
	inc	edx
1079 diamond 584 
	cmp	edx, 0x1000
585 
	je	.noinc
717 mikedld 586 
	bsr	ebx, edx
587 
	cmp	ebx, [compsize]
588 
	jne	.noinc
589 
	inc	[compsize]
590 
  .noinc:
591 
	jmp	.cycle
592 
  .notintable:
593 
	push	eax
594 
	mov	eax, ebx
595 
	call	.output
596 
	push	ebx
597 
	movzx	eax, bx
598 
	call	.output
599 
	pop	ebx eax
600 
	jmp	.add
601 
  .end:
602 
	mov	edi, [img_end]
603 
	xor	eax, eax
604 
 
605 
  .exit:
606 
	cmp	[workarea], 0
607 
	je	@f
608 
	invoke	mem.free, [workarea]
1079 diamond 609 
    @@:
610 
	mov	ebx, [block_ofs]
611 
    @@:
612 
	dec	[img.decode.gif._length_child]
613 
	js	@f
614 
	movzx	eax, byte [ebx]
615 
	inc	ebx
616 
	test	eax, eax
617 
	jz	.ret
618 
	sub	[img.decode.gif._length_child], eax
619 
	jc	@f
620 
	add	ebx, eax
621 
	jmp	@b
717 mikedld 622 
 
623 
  .error:
624 
	cmp	[workarea], 0
625 
	je	@f
626 
	invoke	mem.free, [workarea]
1079 diamond 627 
    @@: xor	ebx, ebx
628 
  .ret:
717 mikedld 629 
	ret
630 
 
631 
;;------------------------------------------------------------------------------------------------;;
632 
 
633 
img.decode.gif._.process_image.get_symbol:
634 
	mov	ecx, [compsize]
635 
	push	ecx
636 
	xor	eax, eax
637 
 
638 
  .shift:
639 
	dec	[bit_count]
1079 diamond 640 
	jns	.loop1
717 mikedld 641 
	inc	esi
642 
	cmp	esi, [block_ofs]
643 
	jb	.noblock
644 
	push	eax
645 
	xor	eax, eax
1079 diamond 646 
	sub	[img.decode.gif._length_child], 1
647 
	jc	.error_eof
717 mikedld 648 
	lodsb
649 
	test	eax, eax
650 
	jnz	.nextbl
1079 diamond 651 
  .error_eof:
652 
	add	esp, 12
653 
	jmp	img.decode.gif._.process_image.error
717 mikedld 654 
 
655 
  .nextbl:
1079 diamond 656 
	sub	[img.decode.gif._length_child], eax
657 
	jc	.error_eof
717 mikedld 658 
	add	eax, esi
659 
	mov	[block_ofs], eax
660 
	pop	eax
661 
 
662 
  .noblock:
1079 diamond 663 
	mov	[bit_count], 7
717 mikedld 664 
 
665 
  .loop1:
1079 diamond 666 
	ror	byte[esi], 1
667 
	rcr	eax,1
717 mikedld 668 
	loop	.shift
669 
	pop	ecx
670 
	rol	eax, cl
671 
 
672 
  .exit:
673 
	xor	ecx, ecx
674 
	retn
675 
 
676 
;;------------------------------------------------------------------------------------------------;;
677 
 
678 
img.decode.gif._.process_image.output:
679 
	push	esi eax edx
680 
	mov	edx, [workarea]
681 
 
682 
  .next:
683 
	pushw	[edx + eax * 4]
684 
	mov	ax, [edx + eax * 4 + 2]
685 
	inc	ecx
686 
	cmp	ax, gif.Null
687 
	jnz	.next
688 
	shl	ebx, 16
689 
	mov	bx, [esp]
690 
 
691 
  .loop2:
692 
	pop	ax
1079 diamond 693 
	cmp	al, byte [img.decode.gif.cur_color_table_size_child]
694 
	jbe	@f	; guard against incorrect GIFs
695 
	mov	al, 0
696 
    @@: cmp	al, byte [img.decode.gif.max_color_child]
697 
	jbe	@f
698 
	mov	[img.decode.gif.max_color_child], al
699 
    @@:	stosb
717 mikedld 700 
 
701 
	cmp	edi, [row_end]
702 
	jb	.norowend
703 
	mov	eax, [width]
704 
	push	eax
705 
	sub	edi, eax
706 
	add	eax, eax
707 
	cmp	[pass], 3
708 
	je	@f
709 
	add	eax, eax
710 
	cmp	[pass], 2
711 
	je	@f
712 
	add	eax, eax
713 
    @@: add	edi, eax
714 
	pop	eax
715 
	cmp	edi, [img_end]
716 
	jb	.nextrow
717 
	mov	edi, [img_start]
718 
	inc	[pass]
1121 diamond 719 
	cmp	[pass], 4
720 
	je	.done
717 mikedld 721 
	add	edi, eax
722 
	cmp	[pass], 3
723 
	je	@f
724 
	add	edi, eax
725 
	cmp	[pass], 2
726 
	je	@f
727 
	add	edi, eax
728 
	add	edi, eax
729 
    @@:
730 
 
731 
  .nextrow:
732 
	add	eax, edi
733 
	mov	[row_end], eax
734 
	xor	eax, eax
735 
 
736 
  .norowend:
1121 diamond 737 
	cmp	edi, [img_end]
738 
	jz	.done
717 mikedld 739 
	loop	.loop2
740 
	pop	edx eax esi
741 
	retn
742 
 
1079 diamond 743 
  .done:
744 
	lea	esp, [esp+(ecx-1)*2]
745 
	pop	edx eax esi eax
746 
	jmp	img.decode.gif._.process_image.exit
747 
 
717 mikedld 748 
endp
749 
 
1079 diamond 750 
;;================================================================================================;;
751 
proc img.decode.gif._.is_logical_screen ;/////////////////////////////////////////////////////////;;
752 
;;------------------------------------------------------------------------------------------------;;
753 
;? Determines whether GIF image occupies the whole logical screen                                 ;;
754 
;;------------------------------------------------------------------------------------------------;;
755 
;> eax = extended image data                                                                      ;;
756 
;> ebx = main image                                                                               ;;
757 
;;------------------------------------------------------------------------------------------------;;
758 
;< ZF set <=> image area equals logical screen                                                    ;;
759 
;;================================================================================================;;
760 
	mov	ebx, [ebx + Image.Extended]
761 
	cmp	[eax + gif.Image.info.Left], 0
762 
	jnz	@f
763 
	cmp	[eax + gif.Image.info.Top], 0
764 
	jnz	@f
765 
	mov	cx, [eax + gif.Image.info.Width]
766 
	cmp	cx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenWidth]
767 
	jnz	@f
768 
	mov	cx, [eax + gif.Image.info.Height]
769 
	cmp	cx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenHeight]
770 
@@:	retn
771 
endp
717 mikedld 772 
 
1079 diamond 773 
main_img equ img.decode.gif.main_img
774 
transparent_color equ img.decode.gif.transparent_color
775 
background_color equ img.decode.gif.background_color
776 
prev_num_colors equ img.decode.gif.prev_num_colors
777 
prev_palette equ img.decode.gif.prev_palette
778 
max_color equ img.decode.gif.max_color
779 
prev_img_data equ img.decode.gif.prev_img_data
780 
_data equ img.decode.gif._data
781 
aux_img_data equ img.decode.gif.aux_img_data
782 
aux_img_type equ img.decode.gif.aux_img_type
783 
aux_palette equ img.decode.gif.aux_palette
784 
 
717 mikedld 785 
;;================================================================================================;;
1079 diamond 786 
proc img.decode.gif._.superimpose ;///////////////////////////////////////////////////////////////;;
787 
;;------------------------------------------------------------------------------------------------;;
788 
;? --- TBD ---                                                                                    ;;
789 
;;------------------------------------------------------------------------------------------------;;
790 
;> edx = image data                                                                               ;;
791 
;;------------------------------------------------------------------------------------------------;;
792 
;< --- TBD ---                                                                                    ;;
793 
;;================================================================================================;;
794 
	mov	ebx, [main_img]
795 
	mov	eax, [edx + Image.Extended]
796 
	or	[transparent_color], -1		; no transparent color
797 
	test	byte [eax + gif.Image.gce.Packed], 1
798 
	jz	@f
799 
	movzx	ecx, byte [eax + gif.Image.gce.ColorIndex]
800 
	mov	[transparent_color], ecx
801 
	cmp	edx, ebx
802 
	jnz	.has_transparency
803 
	shl	ecx, 2
804 
	add	ecx, [edx + Image.Palette]
1102 diamond 805 
	push	eax
806 
	mov	eax, [img.decode.gif.options_bgr]
807 
	mov	dword [background_color], eax
808 
	mov	dword [ecx], eax
809 
	pop	eax
1079 diamond 810 
@@:
811 
	call	img.decode.gif._.is_logical_screen
812 
	jnz	.has_transparency
813 
; image is not transparent, so keep it as is
814 
	retn
815 
 
816 
.has_transparency:
817 
; image has transparent areas, we must superimpose it on the previous
818 
	mov	ecx, [prev_num_colors]
819 
	cmp	ecx, 0x100
820 
	ja	.superimpose_on_rgb
821 
; create common palette
822 
	sub	esp, 3FCh
823 
	push	eax
824 
	mov	edi, esp
825 
	push	ecx
826 
	mov	esi, [prev_palette]
827 
	rep	movsd
828 
	pop	ecx
829 
	mov	esi, [edx + Image.Palette]
830 
	xor	ebx, ebx
831 
	mov	edi, esp
832 
	sub	esp, 100h
833 
.create_palette_loop:
834 
	push	ecx
835 
	lodsd
836 
	cmp	ebx, [transparent_color]
837 
	jz	.nochange
838 
	cmp	ebx, ecx
839 
	jae	@f
840 
	cmp	eax, [edi+ebx*4]
841 
	jz	.nochange
842 
@@:
843 
	push	edi
844 
	repnz	scasd
845 
	pop	edi
846 
	jnz	.increase_palette
847 
	sub	ecx, [esp]
848 
	not	ecx	; cl = index of new color in current palette
849 
	jmp	.palette_common
850 
.increase_palette:
851 
	mov	ecx, [esp]
852 
	test	ch, ch
853 
	jnz	.output_to_rgb
854 
	inc	dword [esp]
855 
	mov	[edi+ecx*4], eax
856 
	jmp	.palette_common
857 
.nochange:
858 
	mov	ecx, ebx
859 
.palette_common:
860 
	mov	[ebx+esp+4], cl
861 
	pop	ecx
862 
	inc	ebx
863 
	cmp	ebx, [max_color]
864 
	jbe	.create_palette_loop
865 
	mov	[max_color], ecx
866 
; if image occupies only part of logical screen, allocate memory for full logical screen
867 
	mov	ebx, [main_img]
868 
	mov	eax, [edx + Image.Extended]
869 
	mov	esi, [edx + Image.Data]
870 
	call	img.decode.gif._.is_logical_screen
871 
	jz	@f
872 
	and	[edx + Image.Data], 0
873 
	push	edx
874 
	movzx	eax, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenHeight]
875 
	push	eax
876 
	movzx	eax, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenWidth]
877 
	stdcall	img._.resize_data, edx, eax
878 
	pop	edx
879 
	test	eax, eax
880 
	jz	.palette_nomem
881 
@@:
882 
; copy final palette to Image.Palette
883 
	push	esi esi
884 
	mov	esi, edi
885 
	mov	edi, [edx + Image.Palette]
886 
	mov	ecx, [max_color]
887 
	dec	[max_color]
888 
	rep	movsd
889 
	mov	esi, [prev_img_data]
890 
	mov	edi, [edx + Image.Data]
891 
; do superimpose, [esp] -> source data, esi -> prev image data
892 
;   (NULL if previous image is filled with background color), esp+8 -> correspondence between
893 
;   used palette and final palette, edi -> destination data
894 
	mov	ebx, [edx + Image.Extended]
895 
; first Top rows are copied from [prev_img_data] or filled with bgr
896 
	movzx	ecx, [ebx + gif.Image.info.Top]
897 
	cmp	ecx, [edx + Image.Height]
898 
	jb	@f
899 
	mov	ecx, [edx + Image.Height]
900 
@@:
901 
	push	ecx
902 
	imul	ecx, [edx + Image.Width]
903 
	call	.rep_movsb_or_stosb
904 
	pop	ecx
905 
; convert rows
906 
	sub	ecx, [edx + Image.Height]
907 
	neg	ecx
908 
	push	ecx
909 
	cmp	cx, [ebx + gif.Image.info.Height]
910 
	jbe	@f
911 
	mov	cx, [ebx + gif.Image.info.Height]
912 
@@:
913 
	jecxz	.norows
914 
.convert_rows:
915 
	push	ecx
916 
	movzx	ecx, [ebx + gif.Image.info.Left]
917 
	cmp	ecx, [edx + Image.Width]
918 
	jb	@f
919 
	mov	ecx, [edx + Image.Width]
920 
@@:
921 
	push	ecx
922 
	call	.rep_movsb_or_stosb
923 
	pop	ecx
924 
	sub	ecx, [edx + Image.Width]
925 
	neg	ecx
926 
	push	ecx edx
927 
	mov	edx, [esp+16]	; source data
928 
	cmp	cx, [ebx + gif.Image.info.Width]
929 
	jbe	@f
930 
	mov	cx, [ebx + gif.Image.info.Width]
931 
@@:
932 
	jecxz	.norowsi
933 
.rowsloop:
934 
	movzx	eax, byte [edx]
935 
	inc	edx
936 
	cmp	eax, [transparent_color]
937 
	jz	.rows_transparent
938 
	mov	al, [eax+esp+24]
939 
	stosb
940 
	call	.lodsb
941 
	jmp	@f
942 
.rows_transparent:
943 
	call	.lodsb
944 
	stosb
945 
@@:
946 
	loop	.rowsloop
947 
.norowsi:
948 
	pop	edx ecx
949 
	sub	cx, [ebx + gif.Image.info.Width]
950 
	jbe	@f
951 
	call	.rep_movsb_or_stosb
952 
@@:
953 
	movzx	eax, [ebx + gif.Image.info.Width]
954 
	add	[esp+8], eax
955 
	pop	ecx
956 
	loop	.convert_rows
957 
.norows:
958 
	pop	ecx
959 
	sub	cx, [ebx + gif.Image.info.Height]
960 
	jbe	@f
961 
	imul	ecx, [edx + Image.Width]
962 
	call	.rep_movsb_or_stosb
963 
@@:
964 
; free old image data if we have allocated new copy
965 
	pop	esi esi
966 
	cmp	esi, [edx + Image.Data]
967 
	jz	@f
968 
	invoke	mem.free, esi
969 
@@:
970 
; cleanup stack and return
971 
	add	esp, 500h
972 
	retn
973 
.palette_nomem:
974 
	mov	[edx + Image.Data], esi
975 
	jmp	@b
976 
 
977 
.output_to_rgb:
978 
	pop	ecx
979 
	add	esp, 500h
980 
; compose two palette-based images to one RGB image
981 
	xor	esi, esi
982 
	xchg	esi, [edx + Image.Data]
983 
	push	esi
984 
	mov	ebx, [_data]
985 
	push	[edx + Image.Palette]
986 
	mov	byte [edx + Image.Type], Image.bpp24
987 
	push	edx
988 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
989 
	push	eax
990 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
991 
	stdcall	img._.resize_data, edx, eax
992 
	pop	edx
993 
	test	eax, eax
994 
	jz	.convrgb_nomem
995 
	push	esi
996 
	mov	edi, [edx + Image.Data]
997 
	mov	esi, [prev_img_data]
998 
	mov	ebx, [edx + Image.Extended]
999 
; first Top rows are copied from [prev_img_data] or filled with bgr
1000 
	movzx	ecx, [ebx + gif.Image.info.Top]
1001 
	cmp	ecx, [edx + Image.Height]
1002 
	jb	@f
1003 
	mov	ecx, [edx + Image.Height]
1004 
@@:
1005 
	push	ecx
1006 
	imul	ecx, [edx + Image.Width]
1007 
	call	.convrgb_prev
1008 
	pop	ecx
1009 
; convert rows
1010 
	sub	ecx, [edx + Image.Height]
1011 
	neg	ecx
1012 
	push	ecx
1013 
	cmp	cx, [ebx + gif.Image.info.Height]
1014 
	jbe	@f
1015 
	mov	cx, [ebx + gif.Image.info.Height]
1016 
@@:
1017 
	jecxz	.convrgb_norows
1018 
.convrgb_convert_rows:
1019 
	push	ecx
1020 
	movzx	ecx, [ebx + gif.Image.info.Left]
1021 
	cmp	ecx, [edx + Image.Width]
1022 
	jb	@f
1023 
	mov	ecx, [edx + Image.Width]
1024 
@@:
1025 
	push	ecx
1026 
	call	.convrgb_prev
1027 
	pop	ecx
1028 
	sub	ecx, [edx + Image.Width]
1029 
	neg	ecx
1030 
	push	ecx edx
1031 
	mov	edx, [esp+16]	; source data
1032 
	cmp	cx, [ebx + gif.Image.info.Width]
1033 
	jbe	@f
1034 
	mov	cx, [ebx + gif.Image.info.Width]
1035 
@@:
1036 
	jecxz	.convrgb_norowsi
1037 
.convrgb_rowsloop:
1038 
	movzx	eax, byte [edx]
1039 
	inc	edx
1040 
	cmp	eax, [transparent_color]
1041 
	jz	.convrgb_rows_transparent
1042 
	shl	eax, 2
1043 
	add	eax, [esp+20]	; source palette
1044 
	mov	eax, [eax]
1045 
	stosw
1046 
	shr	eax, 16
1047 
	stosb
1048 
	call	.convrgb_lodsb
1049 
	jmp	@f
1050 
.convrgb_rows_transparent:
1051 
	call	.convrgb_lodsb
1052 
	stosw
1053 
	shr	eax, 16
1054 
	stosb
1055 
@@:
1056 
	loop	.convrgb_rowsloop
1057 
.convrgb_norowsi:
1058 
	pop	edx ecx
1059 
	sub	cx, [ebx + gif.Image.info.Width]
1060 
	jbe	@f
1061 
	call	.convrgb_prev
1062 
@@:
1063 
	movzx	eax, [ebx + gif.Image.info.Width]
1064 
	add	[esp+8], eax
1065 
	pop	ecx
1066 
	loop	.convrgb_convert_rows
1067 
.convrgb_norows:
1068 
	pop	ecx
1069 
	sub	cx, [ebx + gif.Image.info.Height]
1070 
	jbe	@f
1071 
	imul	ecx, [edx + Image.Width]
1072 
	call	.convrgb_prev
1073 
@@:
1074 
; free old image data
1075 
	pop	esi esi ;esi
1076 
	invoke	mem.free;, esi
1077 
	retn
1078 
.convrgb_nomem:
1079 
	pop	esi esi
1080 
	retn
1081 
 
1082 
.superimpose_on_rgb:
1083 
; previous image is RGB, new image has transparent areas
1084 
	xor	esi, esi
1085 
	xchg	esi, [edx + Image.Data]
1086 
	push	esi
1087 
	mov	ebx, [_data]
1088 
	push	[edx + Image.Palette]
1089 
	mov	byte [edx + Image.Type], Image.bpp24
1090 
	push	edx
1091 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
1092 
	push	eax
1093 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1094 
	stdcall	img._.resize_data, edx, eax
1095 
	pop	edx
1096 
	test	eax, eax
1097 
	jz	.rgb_nomem
1098 
	push	esi
1099 
	mov	edi, [edx + Image.Data]
1100 
	mov	esi, [prev_img_data]
1101 
	mov	ebx, [edx + Image.Extended]
1102 
; first Top rows are copied from [prev_img_data] or filled with bgr
1103 
	movzx	ecx, [ebx + gif.Image.info.Top]
1104 
	cmp	ecx, [edx + Image.Height]
1105 
	jb	@f
1106 
	mov	ecx, [edx + Image.Height]
1107 
@@:
1108 
	push	ecx
1109 
	lea	ecx, [ecx*3]
1110 
	imul	ecx, [edx + Image.Width]
1111 
	rep	movsb
1112 
	pop	ecx
1113 
; convert rows
1114 
	sub	ecx, [edx + Image.Height]
1115 
	neg	ecx
1116 
	push	ecx
1117 
	cmp	cx, [ebx + gif.Image.info.Height]
1118 
	jbe	@f
1119 
	mov	cx, [ebx + gif.Image.info.Height]
1120 
@@:
1121 
	jecxz	.rgb_norows
1122 
.rgb_convert_rows:
1123 
	push	ecx
1124 
	movzx	ecx, [ebx + gif.Image.info.Left]
1125 
	cmp	ecx, [edx + Image.Width]
1126 
	jb	@f
1127 
	mov	ecx, [edx + Image.Width]
1128 
@@:
1129 
	push	ecx
1130 
	lea	ecx, [ecx*3]
1131 
	rep	movsb
1132 
	pop	ecx
1133 
	sub	ecx, [edx + Image.Width]
1134 
	neg	ecx
1135 
	push	ecx edx
1136 
	mov	edx, [esp+16]	; source data
1137 
	cmp	cx, [ebx + gif.Image.info.Width]
1138 
	jbe	@f
1139 
	mov	cx, [ebx + gif.Image.info.Width]
1140 
@@:
1141 
	jecxz	.rgb_norowsi
1142 
.rgb_rowsloop:
1143 
	movzx	eax, byte [edx]
1144 
	inc	edx
1145 
	cmp	eax, [transparent_color]
1146 
	jz	.rgb_rows_transparent
1147 
	shl	eax, 2
1148 
	add	eax, [esp+20]	; source palette
1149 
	mov	eax, [eax]
1150 
	stosw
1151 
	shr	eax, 16
1152 
	stosb
1153 
	add	esi, 3
1154 
	jmp	@f
1155 
.rgb_rows_transparent:
1156 
	movsb
1157 
	movsb
1158 
	movsb
1159 
@@:
1160 
	loop	.rgb_rowsloop
1161 
.rgb_norowsi:
1162 
	pop	edx ecx
1163 
	sub	cx, [ebx + gif.Image.info.Width]
1164 
	jbe	@f
1165 
	lea	ecx, [ecx*3]
1166 
	rep	movsb
1167 
@@:
1168 
	movzx	eax, [ebx + gif.Image.info.Width]
1169 
	add	[esp+8], eax
1170 
	pop	ecx
1171 
	loop	.rgb_convert_rows
1172 
.rgb_norows:
1173 
	pop	ecx
1174 
	sub	cx, [ebx + gif.Image.info.Height]
1175 
	jbe	@f
1176 
	imul	ecx, [edx + Image.Width]
1177 
	lea	ecx, [ecx*3]
1178 
	rep	movsb
1179 
@@:
1180 
; free old image data
1181 
	pop	esi esi ;esi
1182 
	invoke	mem.free;, esi
1183 
	retn
1184 
.rgb_nomem:
1185 
	pop	esi esi
1186 
	retn
1187 
 
1188 
.lodsb:
1189 
	xor	eax, eax
1190 
	test	esi, esi
1191 
	jz	@f
1192 
	lodsb
1193 
@@:	retn
1194 
 
1195 
.rep_movsb_or_stosb:
1196 
	test	esi, esi
1197 
	jz	.rmos1
1198 
	rep	movsb
1199 
	jmp	.rmos2
1200 
.rmos1:	xor	eax, eax	; background index in final palette is 0 in bgr mode
1201 
	rep	stosb
1202 
.rmos2:	retn
1203 
 
1204 
.convrgb_prev:
1205 
	jecxz	.convrgb_noprev
1206 
	test	esi, esi
1207 
	jz	.convrgb_prev_bgr
1208 
@@:
1209 
	xor	eax, eax
1210 
	lodsb
1211 
	shl	eax, 2
1212 
	add	eax, [prev_palette]
1213 
	mov	eax, [eax]
1214 
	stosw
1215 
	shr	eax, 16
1216 
	stosb
1217 
	loop	@b
1218 
	retn
1219 
.convrgb_prev_bgr:
1220 
@@:
1221 
	mov	eax, [background_color]
1222 
	stosw
1223 
	shr	eax, 16
1224 
	stosb
1225 
	loop	@b
1226 
.convrgb_noprev:
1227 
	retn
1228 
.convrgb_lodsb:
1229 
	xor	eax, eax
1230 
	test	esi, esi
1231 
	jz	@f
1232 
	lodsb
1233 
	shl	eax, 2
1234 
	add	eax, [prev_palette]
1235 
	mov	eax, [eax]
1236 
	retn
1237 
@@:	mov	eax, [background_color]
1238 
	retn
1239 
 
1240 
endp
1241 
 
1242 
;;================================================================================================;;
1243 
proc img.decode.gif._.dispose ;///////////////////////////////////////////////////////////////////;;
1244 
;;------------------------------------------------------------------------------------------------;;
1245 
;? --- TBD ---                                                                                    ;;
1246 
;;------------------------------------------------------------------------------------------------;;
1247 
;> edx = image data                                                                               ;;
1248 
;;------------------------------------------------------------------------------------------------;;
1249 
;< --- TBD ---                                                                                    ;;
1250 
;;================================================================================================;;
1251 
	mov	ebx, [edx + Image.Extended]
1252 
	mov	al, [ebx + gif.Image.gce.Packed]
1253 
	shr	al, 2
1254 
	and	al, 7
1255 
	cmp	al, 2
1256 
	jz	.background
1257 
	cmp	al, 3
1258 
	jz	.previous
1259 
; don't dispose - set prev_img and related vars to current image
1260 
	mov	eax, [edx + Image.Data]
1261 
	mov	[prev_img_data], eax
2733 dunkaist 1262 
	cmp	[edx + Image.Type], Image.bpp8i
1079 diamond 1263 
	jnz	@f
1264 
	mov	eax, [max_color]
1265 
	inc	eax
1266 
	mov	[prev_num_colors], eax
1267 
	mov	eax, [edx + Image.Palette]
1268 
	mov	[prev_palette], eax
1269 
	retn
1270 
@@:
1271 
	or	[prev_num_colors], -1
1272 
	and	[prev_palette], 0
1273 
.previous:
1274 
	retn
1275 
.background:
1276 
	cmp	[prev_img_data], 0
1277 
	jz	.bgr_full
1278 
	mov	ebx, [main_img]
1279 
	mov	eax, [edx + Image.Extended]
1280 
	call	img.decode.gif._.is_logical_screen
1281 
	jnz	@f
1282 
.bgr_full:
1283 
	xor	eax, eax
1284 
	mov	[prev_img_data], eax
1285 
	inc	eax
1286 
	mov	[prev_num_colors], eax
1287 
	lea	eax, [background_color]
1288 
	mov	[prev_palette], eax
1289 
	retn
1290 
@@:
1291 
	cmp	[prev_num_colors], 0x100
1292 
	ja	.rgb
1293 
	mov	eax, [background_color]
1294 
	mov	edi, [prev_palette]
1295 
	mov	ecx, [prev_num_colors]
1296 
	repnz	scasd
1297 
	jz	.palette_ok
1298 
	cmp	[prev_num_colors], 0x100
1299 
	jz	.convert_rgb
1300 
	push	1
1301 
	pop	eax
1302 
	stdcall	img.decode.gif._.alloc_aux_img
1303 
	test	eax, eax
1304 
	jz	.previous
1305 
	mov	ecx, [prev_num_colors]
1306 
	mov	esi, [prev_palette]
1307 
	call	img.decode.gif._.alloc_aux_palette
1308 
	test	eax, eax
1309 
	jz	.previous
1310 
	mov	[prev_palette], eax
1311 
	mov	eax, [background_color]
1312 
	stosd
1313 
	mov	eax, [prev_num_colors]	; eax = index of background color
1314 
	inc	[prev_num_colors]
1315 
	jmp	.bpp8_common
1316 
.palette_ok:
1317 
	push	1
1318 
	pop	eax
1319 
	stdcall	img.decode.gif._.alloc_aux_img
1320 
	test	eax, eax
1321 
	jz	.previous
1322 
	sub	edi, [prev_palette]
1323 
	shr	edi, 2
1324 
	lea	eax, [edi-1]	; eax = index of background color
1325 
.bpp8_common:
1326 
	push	eax
1327 
	mov	ebx, [_data]
1328 
	mov	esi, [prev_img_data]
1329 
	mov	edi, [aux_img_data]
1330 
	mov	[prev_img_data], edi
1331 
	cmp	esi, edi
1332 
	jz	@f
1333 
	movzx	ecx, [ebx + gif.Header.lsd.ScreenWidth]
1334 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
1335 
	imul	ecx, eax
1336 
	push	edi
1337 
	rep	movsb
1338 
	pop	edi
1339 
@@:
1340 
	movzx	esi, [ebx + gif.Header.lsd.ScreenHeight]
1341 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1342 
	mov	edx, [edx + Image.Extended]
1343 
	movzx	ecx, [edx + gif.Image.info.Top]
1344 
	sub	esi, ecx
1345 
	jbe	.bpp8_ret
1346 
	imul	ecx, eax
1347 
	add	edi, ecx
1348 
	cmp	si, [edx + gif.Image.info.Height]
1349 
	jb	@f
1350 
	mov	si, [edx + gif.Image.info.Height]
1351 
@@:
1352 
	movzx	ecx, [edx + gif.Image.info.Left]
1353 
	sub	eax, ecx
1354 
	jbe	.bpp8_ret
1355 
	add	edi, ecx
1356 
	cmp	ax, [edx + gif.Image.info.Width]
1357 
	jb	@f
1358 
	mov	ax, [edx + gif.Image.info.Width]
1359 
@@:
1360 
	xchg	eax, ecx
1361 
	movzx	edx, [ebx + gif.Header.lsd.ScreenWidth]
1362 
	sub	edx, ecx
1363 
	pop	eax
1364 
@@:
1365 
	push	ecx
1366 
	rep	stosb
1367 
	pop	ecx
1368 
	add	edi, edx
1369 
	dec	esi
1370 
	jnz	@b
1371 
	push	eax
1372 
.bpp8_ret:
1373 
	pop	eax
1374 
	retn
1375 
.convert_rgb:
1376 
	push	3
1377 
	pop	eax
1378 
	stdcall	img.decode.gif._.alloc_aux_img
1379 
	test	eax, eax
1380 
	jz	.previous
1381 
	or	[prev_num_colors], -1
1382 
	mov	ebx, [_data]
1383 
	mov	esi, [prev_img_data]
1384 
	mov	edi, [aux_img_data]
1385 
	mov	[prev_img_data], edi
1386 
	movzx	ecx, [ebx + gif.Header.lsd.ScreenWidth]
1387 
	movzx	eax, [ebx + gif.Header.lsd.ScreenHeight]
1388 
	imul	ecx, eax
1389 
	push	edx
1390 
	xor	edx, edx
1391 
	xchg	edx, [prev_palette]
1392 
	add	edi, ecx
1393 
	add	esi, ecx
1394 
	add	edi, ecx
1395 
	add	edi, ecx
1396 
@@:
1397 
	dec	esi
1398 
	movzx	eax, byte [esi]
1399 
	mov	eax, [eax*4+edx]
1400 
	sub	edi, 3
1401 
	mov	[edi], ax
1402 
	shr	eax, 16
1403 
	mov	[edi+2], al
1404 
	loop	@b
1405 
	pop	edx
1406 
	movzx	esi, [ebx + gif.Header.lsd.ScreenHeight]
1407 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1408 
	mov	edx, [edx + Image.Extended]
1409 
	movzx	ecx, [edx + gif.Image.info.Top]
1410 
	sub	esi, ecx
1411 
	jbe	.convert_rgb_ret
1412 
	imul	ecx, eax
1413 
	lea	ecx, [ecx*3]
1414 
	add	edi, ecx
1415 
	cmp	si, [edx + gif.Image.info.Height]
1416 
	jb	@f
1417 
	mov	si, [edx + gif.Image.info.Height]
1418 
@@:
1419 
	movzx	ecx, [edx + gif.Image.info.Left]
1420 
	sub	eax, ecx
1421 
	jbe	.convert_rgb_ret
1422 
	lea	ecx, [ecx*3]
1423 
	add	edi, ecx
1424 
	cmp	ax, [edx + gif.Image.info.Width]
1425 
	jb	@f
1426 
	mov	ax, [edx + gif.Image.info.Width]
1427 
@@:
1428 
	xchg	eax, ecx
1429 
	movzx	edx, [ebx + gif.Header.lsd.ScreenWidth]
1430 
	sub	edx, ecx
1431 
	mov	eax, [background_color]
1432 
	lea	edx, [edx*3]
1433 
.convert_rgb_loop:
1434 
	push	ecx
1435 
@@:
1436 
	stosw
1437 
	shr	eax, 16
1438 
	stosb
1439 
	loop	@b
1440 
	pop	ecx
1441 
	add	edi, edx
1442 
	dec	esi
1443 
	jnz	.convert_rgb_loop
1444 
.convert_rgb_ret:
1445 
	retn
1446 
.rgb:
1447 
	push	3
1448 
	pop	eax
1449 
	stdcall	img.decode.gif._.alloc_aux_img
1450 
	test	eax, eax
1451 
	jz	.previous
1452 
	or	[prev_num_colors], -1
1453 
	and	[prev_palette], 0
1454 
	mov	ebx, [_data]
1455 
	mov	esi, [prev_img_data]
1456 
	mov	edi, [aux_img_data]
1457 
	mov	[prev_img_data], edi
1458 
	cmp	esi, edi
1459 
	jz	@f
1460 
	movzx	ecx, [ebx + gif.Header.lsd.ScreenHeight]
1461 
	push	ecx
1462 
	movzx	eax, [ebx + gif.Header.lsd.ScreenWidth]
1463 
	imul	ecx, eax
1464 
	lea	ecx, [ecx*3]
1465 
	push	edi
1466 
	rep	movsb
1467 
	pop	edi
1468 
	pop	esi
1469 
	mov	edx, [edx + Image.Extended]
1470 
	movzx	ecx, [edx + gif.Image.info.Top]
1471 
	sub	esi, ecx
1472 
	jbe	.rgb_ret
1473 
	imul	ecx, eax
1474 
	lea	ecx, [ecx*3]
1475 
	add	edi, ecx
1476 
	cmp	si, [edx + gif.Image.info.Height]
1477 
	jb	@f
1478 
	mov	si, [edx + gif.Image.info.Height]
1479 
@@:
1480 
	movzx	ecx, [edx + gif.Image.info.Left]
1481 
	sub	eax, ecx
1482 
	jbe	.rgb_ret
1483 
	lea	ecx, [ecx*3]
1484 
	add	edi, ecx
1485 
	cmp	ax, [edx + gif.Image.info.Width]
1486 
	jb	@f
1487 
	mov	ax, [edx + gif.Image.info.Width]
1488 
@@:
1489 
	xchg	eax, ecx
1490 
	movzx	edx, [ebx + gif.Header.lsd.ScreenWidth]
1491 
	sub	edx, ecx
1492 
	mov	eax, [background_color]
1493 
	lea	edx, [edx*3]
1494 
.rgb_loop:
1495 
	push	ecx
1496 
@@:
1497 
	stosw
1498 
	shr	eax, 16
1499 
	stosb
1500 
	loop	@b
1501 
	pop	ecx
1502 
	add	edi, edx
1503 
	dec	esi
1504 
	jnz	.rgb_loop
1505 
.rgb_ret:
1506 
	retn
1507 
 
1508 
endp
1509 
 
1510 
;;================================================================================================;;
1511 
proc img.decode.gif._.alloc_aux_img ;/////////////////////////////////////////////////////////////;;
1512 
;;------------------------------------------------------------------------------------------------;;
1513 
;? Allocate auxiliary memory for previous image                                                   ;;
1514 
;;------------------------------------------------------------------------------------------------;;
1515 
;> eax = image type: 1 = bpp8, 3 = bpp24                                                          ;;
1516 
;;------------------------------------------------------------------------------------------------;;
1517 
;< eax = [aux_img_data]                                                                           ;;
1518 
;;================================================================================================;;
1519 
	cmp	[aux_img_type], eax
1520 
	jae	@f
1521 
	push	edx eax
1522 
	movzx	ecx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenWidth]
1523 
	mul	ecx
1524 
	movzx	ecx, [ebx + sizeof.gif.Image + gif.LogicalScreenDescriptor.ScreenHeight]
1525 
	mul	ecx
1526 
	invoke	mem.realloc, [aux_img_data], eax
1527 
	pop	ecx edx
1528 
	test	eax, eax
1529 
	jz	@f
1530 
	mov	[aux_img_type], ecx
1531 
	mov	[aux_img_data], eax
1532 
@@:	retn
1533 
 
1534 
endp
1535 
 
1536 
;;================================================================================================;;
1537 
proc img.decode.gif._.alloc_aux_palette ;/////////////////////////////////////////////////////////;;
1538 
;;------------------------------------------------------------------------------------------------;;
1539 
;? Allocate and fill aux_palette                                                                  ;;
1540 
;;------------------------------------------------------------------------------------------------;;
1541 
;> esi -> palette, ecx = palette size                                                             ;;
1542 
;;------------------------------------------------------------------------------------------------;;
1543 
;< [aux_palette] set                                                                              ;;
1544 
;;================================================================================================;;
1545 
	mov	eax, [aux_palette]
1546 
	test	eax, eax
1547 
	jnz	@f
1548 
	push	edx ecx
1549 
	invoke	mem.alloc, 0x400
1550 
	pop	ecx edx
1551 
	test	eax, eax
1552 
	jz	.ret
1553 
	mov	[aux_palette], eax
1554 
@@:
1555 
	mov	edi, eax
1556 
	rep	movsd
1557 
.ret:
1558 
	retn
1559 
 
1560 
endp
1561 
 
1562 
restore main_img
1563 
restore transparent_color
1564 
restore background_color
1565 
restore prev_num_colors
1566 
restore prev_palette
1567 
restore max_color
1568 
restore prev_img_data
1569 
restore _data
1570 
restore aux_img_data
1571 
restore aux_img_type
1572 
restore aux_palette
1573 
 
1574 
;;================================================================================================;;
717 mikedld 1575 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
1576 
;;================================================================================================;;
1577 
;! Below is private data you should never use directly from your code                             ;;
1578 
;;================================================================================================;;
1579 
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
1580 
;;================================================================================================;;
1581 
 
1582 
 
1583 
;