;*****************************************************************************
; PNG to RAW convert plugin - for zSea image viewer
; Copyright (c) 2008, 2009, Marat Zakiyanov aka Mario79, aka Mario
; All rights reserved.
;
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are met:
; * Redistributions of source code must retain the above copyright
; notice, this list of conditions and the following disclaimer.
; * Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the distribution.
; * Neither the name of the <organization> nor the
; names of its contributors may be used to endorse or promote products
; derived from this software without specific prior written permission.
;
; THIS SOFTWARE IS PROVIDED BY Marat Zakiyanov ''AS IS'' AND ANY
; EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
; WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
; DISCLAIMED. IN NO EVENT SHALL <copyright holder> BE LIABLE FOR ANY
; DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
; (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
; ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
; (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;---------------------------------------------------------------------
filtering_RGB:
mov ecx,[IHDR_data.Height]
test ecx,ecx
jz .filter_end
.filter:
mov edx,[IHDR_data.Width]
test edx,edx
jz .filter_end
xor eax,eax
mov [previous_pixel_value],eax
mov [first_pixel],byte 1
mov al,[esi]
mov [line_filter_type],eax
inc esi
.filter_x:
mov bh,[previous_pixel_value]
call filtering_sample_8
mov [previous_pixel_value],bl
mov bh,[previous_pixel_value+1]
call filtering_sample_8
mov [previous_pixel_value+1],bl
mov bh,[previous_pixel_value+2]
call filtering_sample_8
mov [previous_pixel_value+2],bl
cmp [IHDR_data.Color_type],byte 6
jne @f
mov bh,[previous_pixel_value+3]
call filtering_sample_8
mov [previous_pixel_value+3],bl
@@:
mov [first_pixel],byte 0
dec edx
jnz .filter_x
mov [first_line],byte 0
dec ecx
jnz .filter
.filter_end:
ret
;-------------------------------
filtering_sample_8:
cld
lodsb
mov bl,al
call filtering
mov al,bl
cld
stosb
ret
;---------------------------------------------------------------------
filtering_RGB_16:
mov ecx,[IHDR_data.Height]
test ecx,ecx
jz .filter_end_16
.filter_16:
mov edx,[IHDR_data.Width]
test edx,edx
jz .filter_end_16
xor eax,eax
mov [previous_pixel_value],eax
mov [previous_pixel_value+4],eax
mov [first_pixel],byte 1
mov al,[esi]
mov [line_filter_type],eax
inc esi
.filter_x_16:
mov bx,[previous_pixel_value]
call filtering_sample_16
mov [previous_pixel_value],bx
mov bx,[previous_pixel_value+2]
call filtering_sample_16
mov [previous_pixel_value+2],bx
mov bx,[previous_pixel_value+4]
call filtering_sample_16
mov [previous_pixel_value+4],bx
cmp [IHDR_data.Color_type],byte 6
jne @f
mov bx,[previous_pixel_value+6]
call filtering_sample_16
mov [previous_pixel_value+6],bx
@@:
mov [first_pixel],byte 0
dec edx
jnz .filter_x_16
mov [first_line],byte 0
dec ecx
jnz .filter_16
.filter_end_16:
ret
;-------------------------------
filtering_sample_16:
shl ebx,16
cld
lodsw
mov bx,ax
call filtering
mov ax,bx
cld
stosw
ret
;---------------------------------------------------------------------
filtering_grayscale:
mov ecx,[IHDR_data.Height]
test ecx,ecx
jz .filter_end_grayscale
mov edx,[IHDR_data.Width]
test edx,edx
jz .filter_end_grayscale
cmp [IHDR_data.Color_type],byte 4
je @f
imul edx,[resolution]
mov eax,edx
shr edx,3
test eax,7
jz @f
inc edx
@@:
.filter_grayscale:
push edx
xor eax,eax
mov [previous_pixel_value],eax
mov [first_pixel],byte 1
mov al,[esi]
mov [line_filter_type],eax
inc esi
.filter_x_grayscale:
mov bh,[previous_pixel_value]
call filtering_sample_8
mov [previous_pixel_value],bl
cmp [IHDR_data.Color_type],byte 4
jne @f
mov bh,[previous_pixel_value+1]
call filtering_sample_8
mov [previous_pixel_value+1],bl
@@:
mov [first_pixel],byte 0
dec edx
jnz .filter_x_grayscale
pop edx
mov [first_line],byte 0
dec ecx
jnz .filter_grayscale
.filter_end_grayscale:
ret
;---------------------------------------------------------------------
filtering_grayscale_16:
mov ecx,[IHDR_data.Height]
test ecx,ecx
jz .filter_end_grayscale_16
.filter_grayscale_Bit_depth_16:
mov edx,[IHDR_data.Width]
test edx,edx
jz .filter_end_grayscale_16
xor eax,eax
mov [previous_pixel_value],eax
mov [first_pixel],byte 1
mov al,[esi]
mov [line_filter_type],eax
inc esi
.filter_x_grayscale_16:
mov bx,[previous_pixel_value]
call filtering_sample_16
mov [previous_pixel_value],bx
cmp [IHDR_data.Color_type],byte 4
jne @f
mov bx,[previous_pixel_value+2]
call filtering_sample_16
mov [previous_pixel_value+2],bx
@@:
mov [first_pixel],byte 0
dec edx
jnz .filter_x_grayscale_16
mov [first_line],byte 0
dec ecx
jnz .filter_grayscale_Bit_depth_16
.filter_end_grayscale_16:
ret
;---------------------------------------------------------------------