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;;================================================================================================;;

;;//// wbmp.asm //// (c) dunkaist, 2011-2012 /////////////////////////////////////////////////////;;

;;================================================================================================;;

;;                                                                                                ;;

;; This file is part of Common development libraries (Libs-Dev).                                  ;;

;;                                                                                                ;;

;; Libs-Dev is free software: you can redistribute it and/or modify it under the terms of the GNU ;;

;; Lesser General Public License as published by the Free Software Foundation, either version 2.1 ;;

;; of the License, or (at your option) any later version.                                         ;;

;;                                                                                                ;;

;; Libs-Dev is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without  ;;

;; even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU  ;;

;; Lesser General Public License for more details.                                                ;;

;;                                                                                                ;;

;; You should have received a copy of the GNU Lesser General Public License along with Libs-Dev.  ;;

;; If not, see .                                                    ;;

;;                                                                                                ;;

;;================================================================================================;;

;;                                                                                                ;;

;; References:                                                                                    ;;

;;   1. WAP WAE Specification                                                                     ;;

;;      http://www.wapforum.org/what/technical/SPEC-WAESpec-19990524.pdf                          ;;

;;   2. "Converting a BMP picture to WBMP format"                                                 ;;

;;      by Sajjitha Gunawardana                                                                   ;;

;;      http://www.codeproject.com/KB/graphics/bmp_to_wbmp_converter.aspx                         ;;

;;                                                                                                ;;

;;================================================================================================;;

;include 'wbmp.inc'			; wbmp is too simple, so we do not need any *.inc files

;;================================================================================================;;

proc img.is.wbmp _data, _length ;/////////////////////////////////////////////////////////////////;;

;;------------------------------------------------------------------------------------------------;;

;? Determine if raw data could be decoded (is in wbmp format)                                     ;;

;;------------------------------------------------------------------------------------------------;;

;> _data = raw data as read from file/stream                                                      ;;

;> _length = data length                                                                          ;;

;;------------------------------------------------------------------------------------------------;;

;< eax = false / true                                                                             ;;

;;================================================================================================;;

	push	esi

	mov	esi, [_data]

	lodsw

	test	ax, ax			; two first bytes of any wbmp file are zeros, check this signature

	jnz	.is_not_wbmp

					; but two byte signature is not enough to be sure it is wbmp file

					; let's calculate the whole image size and compare it with [_length]

					; calculate width first. you can read how this number is stored in wbmp format specification (see "References" above)

	xor	eax, eax

    @@:

	shl	eax, 7

	lodsb

	sal	al, 1

	jc	@b

	shr	eax, 1

	add	eax, 7

	shr	eax, 3

	mov	ecx, eax

					; calculate height

	xor	eax, eax

    @@:

	shl	eax, 7

	lodsb

	sal	al, 1

	jc	@b

	shr	eax, 1

	imul	eax, ecx		; image_size = width*height

					; raw file consists of a header and data. our image_size is the size of data only

	sub	esi, [_data]		; get header size

	add	eax, esi

	cmp	eax, [_length]

	je	.is_wbmp

  .is_not_wbmp:				; return 0

	pop	esi

	xor	eax, eax

	ret

  .is_wbmp:				; return 1

	pop	esi

	xor	eax, eax

	inc	eax

	ret

endp

;;================================================================================================;;

proc img.decode.wbmp _data, _length, _options ;///////////////////////////////////////////////////;;

;;------------------------------------------------------------------------------------------------;;

;? Decode data into image if it contains correctly formed raw data in wbmp format                 ;;

;;------------------------------------------------------------------------------------------------;;

;> _data = raw data as read from file/stream                                                      ;;

;> _length = data length                                                                          ;;

;;------------------------------------------------------------------------------------------------;;

;< eax = 0 (error) or pointer to image                                                            ;;

;;================================================================================================;;

	push	ebx edx esi edi

	mov	esi, [_data]

	lodsw

	xor	eax, eax

    @@:

	shl	eax, 7

	lodsb

	sal	al, 1

	jc	@b

	shr	eax, 1

	mov	ebx, eax

	xor	eax, eax

    @@:

	shl	eax, 7

	lodsb

	sal	al, 1

	jc	@b

	shr	eax, 1

	mov	edx, eax

	push	ebx ecx edx

	stdcall	img.create, ebx, edx, Image.bpp1

	pop	edx ecx ebx

	test	eax, eax

	jz	.quit

	mov	edi, [eax + Image.Palette]

	mov	[edi], dword 0xff000000

	mov	[edi + 4], dword 0xffffffff

	add	ebx, 7

	shr	ebx, 3

	imul	ebx, edx

	mov	ecx, ebx

	mov	edi, [eax + Image.Data]

	rep	movsb

  .quit:

	pop	edi esi edx ebx

	ret

endp

;;================================================================================================;;

proc img.encode.wbmp _img, _p_length, _options ;//////////////////////////////////////////////////;;

;;------------------------------------------------------------------------------------------------;;

;? Encode image into raw data in wbmp format                                                      ;;

;;------------------------------------------------------------------------------------------------;;

;> _img = pointer to image                                                                        ;;

;;------------------------------------------------------------------------------------------------;;

;< eax = 0 (error) or pointer to encoded data                                                     ;;

;< _p_length = encoded data length                                                                ;;

;;================================================================================================;;

	xor	eax, eax

	ret

endp

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;;////////////////////////////////////////////////////////////////////////////////////////////////;;

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;! Below are private procs you should never call directly from your code                          ;;

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;! Below is private data you should never use directly from your code                             ;;

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