;;================================================================================================;;
;;//// tga.asm //// (c) Nable, 2007-2008, (c) dunkaist, 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 <http://www.gnu.org/licenses/>. ;;
;; ;;
;;================================================================================================;;
;; ;;
;; References: ;;
;; 1. Hiview 1.2 by Mohammad A. REZAEI ;;
;; 2. Truevision TGA FILE FORMAT SPECIFICATION Version 2.0 ;;
;; Technical Manual Version 2.2 January, 1991 ;;
;; ;;
;;================================================================================================;;
include 'tga.inc'
;;================================================================================================;;
proc img.is.tga _data, _length ;//////////////////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? Determine if raw data could be decoded (is in Targa format) ;;
;;------------------------------------------------------------------------------------------------;;
;> _data = raw data as read from file/stream ;;
;> _length = data length ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = false / true ;;
;;================================================================================================;;
push ebx
cmp [_length], 18
jbe .nope
mov ebx, [_data]
mov eax, dword[ebx + tga_header.colormap_type]
cmp al, 1
ja .nope
cmp ah, 11
ja .nope
cmp ah, 9
jae .cont1
cmp ah, 3
ja .nope
.cont1:
mov eax, dword[ebx + tga_header.image_spec.depth]
test eax, 111b ; bpp must be 8, 15, 16, 24 or 32
jnz .maybe15
shr al, 3
cmp al, 4
ja .nope
jmp .cont2
.maybe15:
cmp al, 15
jne .nope
.cont2: ; continue testing
movzx eax, byte[ebx + tga_header.colormap_spec.entry_size] ; palette bpp
cmp eax, 0
je .yep
cmp eax, 16
je .yep
cmp eax, 24
je .yep
cmp eax, 32
je .yep
.nope:
xor eax, eax
pop ebx
ret
.yep:
xor eax, eax
inc eax
pop ebx
ret
endp
;;================================================================================================;;
proc img.decode.tga _data, _length, _options ;////////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? Decode data into image if it contains correctly formed raw data in Targa format ;;
;;------------------------------------------------------------------------------------------------;;
;> _data = raw data as read from file/stream ;;
;> _length = data length ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = 0 (error) or pointer to image ;;
;;================================================================================================;;
locals
width dd ?
height dd ?
bytes_per_pixel dd ?
retvalue dd ?
endl
push ebx esi edi
mov ebx, [_data]
movzx esi, byte[ebx]
lea esi, [esi + ebx + sizeof.tga_header] ; skip comment and header
mov edx, dword[ebx + tga_header.image_spec.width]
movzx ecx, dx ; ecx = width
shr edx, 16 ; edx = height
mov [width], ecx
mov [height], edx
movzx eax, byte[ebx + tga_header.image_spec.depth]
add eax, 7
shr eax, 3
mov [bytes_per_pixel], eax
movzx eax, byte[ebx + tga_header.image_spec.depth]
cmp eax, 8
jne @f
mov eax, Image.bpp8i
jmp .type_defined
@@:
cmp eax, 15
jne @f
mov eax, Image.bpp15
jmp .type_defined
@@:
cmp eax, 16
jne @f
mov eax, Image.bpp15 ; 16bpp tga images are really 15bpp ARGB
jmp .type_defined
@@:
cmp eax, 24
jne @f
mov eax, Image.bpp24
jmp .type_defined
@@:
cmp eax, 32
jne @f
mov eax, Image.bpp32
jmp .type_defined
@@:
.type_defined:
stdcall img.create, ecx, edx, eax
mov [retvalue], eax
test eax, eax ; failed to allocate?
jz .done ; then exit
mov ebx, eax
cmp dword[ebx + Image.Type], Image.bpp8i
jne .palette_parsed
mov edi, [ebx + Image.Palette]
mov ecx, [_data]
cmp byte[ecx + tga_header.image_type], 3 ; we also have grayscale subtype
jz .write_grayscale_palette ; that don't hold palette in file
cmp byte[ecx + tga_header.image_type], 11
jz .write_grayscale_palette
movzx eax, byte[ecx + tga_header.colormap_spec.entry_size] ; size of colormap entries in bits
movzx ecx, word[ecx + tga_header.colormap_spec.colormap_length] ; number of colormap entries
cmp eax, 24
je .24bpp_palette
cmp eax, 16
je .16bpp_palette
rep movsd ; else they are 32 bpp
jmp .palette_parsed
.write_grayscale_palette:
mov ecx, 0x100
xor eax, eax
@@:
stosd
add eax, 0x010101
loop @b
jmp .palette_parsed
.16bpp_palette: ; FIXME: code copypasted from img.do_rgb, should use img.convert
push ebx edx ebp
@@:
movzx eax, word[esi]
mov ebx, eax
add esi, 2
and eax, (0x1F) or (0x1F shl 10)
and ebx, 0x1F shl 5
lea edx, [eax + eax]
shr al, 2
mov ebp, ebx
shr ebx, 2
shr ah, 4
shl dl, 2
shr ebp, 7
add eax, edx
add ebx, ebp
mov [edi], al
mov [edi + 1], bl
mov [edi + 2], ah
add edi, 4
loop @b
pop ebp edx ebx
jmp .palette_parsed
.24bpp_palette:
@@:
lodsd
dec esi
and eax, 0xffffff
stosd
loop @b
.palette_parsed:
mov edi, [ebx + Image.Data]
mov ebx, [width]
imul ebx, [height]
mov edx, [bytes_per_pixel]
mov eax, [_data]
test byte[eax + tga_header.image_type], 0x08
jz .uncompressed
.next_rle_packet:
xor eax, eax
lodsb
btr ax, 7 ; Run-length packet?
jnc .raw_packet
add eax, 1
sub ebx, eax
@@:
mov ecx, edx
rep movsb
sub esi, edx
sub eax, 1
jnz @b
add esi, edx
test ebx, ebx
jnz .next_rle_packet
jmp .done
.raw_packet:
mov ecx, eax
add ecx, 1
sub ebx, ecx
imul ecx, edx
rep movsb
test ebx, ebx
jnz .next_rle_packet
.uncompressed:
imul edx, ebx
mov ecx, edx
rep movsb
.done:
xor ebx, ebx
mov esi, [_data]
test byte[esi + tga_header.image_spec.descriptor], TGA_START_TOP
jnz @f
or ebx, FLIP_VERTICAL
@@:
test byte[esi + tga_header.image_spec.descriptor], TGA_START_RIGHT
jz @f
or ebx, FLIP_HORIZONTAL
@@:
test ebx, ebx
jz @f
stdcall img.flip, [retvalue], ebx
@@:
pop edi esi ebx
mov eax, [retvalue]
ret
endp
;;================================================================================================;;
proc img.encode.tga _img, _p_length, _options ;///////////////////////////////////////////////////;;
;;------------------------------------------------------------------------------------------------;;
;? Encode image into raw data in Targa format ;;
;;------------------------------------------------------------------------------------------------;;
;> _img = pointer to image ;;
;;------------------------------------------------------------------------------------------------;;
;< eax = 0 (error) or pointer to encoded data ;;
;< _p_length = encoded data length ;;
;;================================================================================================;;
xor eax, eax
ret
endp
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;! Below are private procs you should never call directly from your code ;;
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;
;! Below is private data you should never use directly from your code ;;
;;================================================================================================;;
;;////////////////////////////////////////////////////////////////////////////////////////////////;;
;;================================================================================================;;