0,0 → 1,210 |
|
uglobal |
align 4 |
ReadGIF.globalColor dd ? |
ReadGIF.cur_info dd ? ; image table pointer |
ReadGIF.codesize dd ? |
ReadGIF.compsize dd ? |
ReadGIF.bit_count dd ? |
ReadGIF.CC dd ? |
ReadGIF.EOI dd ? |
ReadGIF.Palette dd ? |
ReadGIF.block_ofs dd ? |
ReadGIF.gif_workarea rb 16*1024 |
endg |
|
; unpacks GIF image |
ReadGIF: |
; in: |
; esi - pointer to GIF file in memory |
; edi - pointer to output image list |
; out: |
; eax=0 -> ok, eax=1 -> invalid signature |
; eax>=8 -> unsupported image attributes |
push esi edi |
mov [.cur_info],edi |
xor eax,eax |
mov [.globalColor],eax |
inc eax |
cmp dword[esi],'GIF8' |
jne .ex ; signature |
mov ecx,[esi+0xa] |
add esi,0xd |
mov edi,esi |
test cl,cl |
jns .nextblock |
mov [.globalColor],esi |
call .Gif_skipmap |
.nextblock: |
cmp byte[edi],0x21 |
jne .noextblock |
inc edi |
inc edi |
.block_skip: |
movzx eax,byte[edi] |
lea edi,[edi+eax+1] |
test eax,eax |
jnz .block_skip |
jmp .nextblock |
.noextblock: |
mov al,8 |
cmp byte[edi],0x2c ; image beginning |
jne .ex |
inc edi |
mov esi,[.cur_info] |
xchg esi,edi |
movzx eax,word[esi+4] |
stosd |
movzx eax,word[esi+6] |
stosd |
add esi,8 |
push edi |
mov ecx,[esi] |
inc esi |
test cl,cl |
js .uselocal |
push [.globalColor] |
mov edi,esi |
jmp .setPal |
.uselocal: |
call .Gif_skipmap |
push esi |
.setPal: |
movzx ecx,byte[edi] |
inc ecx |
mov [.codesize],ecx |
dec ecx |
pop [.Palette] |
lea esi,[edi+1] |
mov edi,.gif_workarea |
xor eax,eax |
lodsb ; eax - block_count |
add eax,esi |
mov [.block_ofs],eax |
mov [.bit_count],8 |
mov eax,1 |
shl eax,cl |
mov [.CC],eax |
mov ecx,eax |
inc eax |
mov [.EOI],eax |
mov eax, 1000h shl 16 |
.filltable: |
stosd |
inc eax |
loop .filltable |
pop edi |
.reinit: |
mov edx,[.EOI] |
inc edx |
push [.codesize] |
pop [.compsize] |
call .Gif_get_sym |
cmp eax,[.CC] |
je .reinit |
call .Gif_output |
.cycle: |
movzx ebx,ax |
call .Gif_get_sym |
cmp eax,edx |
jae .notintable |
cmp eax,[.CC] |
je .reinit |
cmp eax,[.EOI] |
je .end |
call .Gif_output |
.add: |
mov dword [.gif_workarea+edx*4],ebx |
cmp edx,0xFFF |
jae .cycle |
inc edx |
bsr ebx,edx |
cmp ebx,[.compsize] |
jne .noinc |
inc [.compsize] |
.noinc: |
jmp .cycle |
.notintable: |
push eax |
mov eax,ebx |
call .Gif_output |
push ebx |
movzx eax,bx |
call .Gif_output |
pop ebx eax |
jmp .add |
.end: |
xor eax,eax |
.ex: |
pop edi esi |
ret |
|
.Gif_skipmap: |
; in: ecx - image descriptor, esi - pointer to colormap |
; out: edi - pointer to area after colormap |
and ecx,111b |
inc ecx ; color map size |
mov ebx,1 |
shl ebx,cl |
lea ebx,[ebx*2+ebx] |
lea edi,[esi+ebx] |
ret |
|
.Gif_get_sym: |
mov ecx,[.compsize] |
push ecx |
xor eax,eax |
.shift: |
ror byte[esi],1 |
rcr eax,1 |
dec [.bit_count] |
jnz .loop1 |
inc esi |
cmp esi,[.block_ofs] |
jb .noblock |
push eax |
xor eax,eax |
lodsb |
test eax,eax |
jnz .nextbl |
mov eax,[.EOI] |
sub esi,2 |
add esp,8 |
jmp .exx |
.nextbl: |
add eax,esi |
mov [.block_ofs],eax |
pop eax |
.noblock: |
mov [.bit_count],8 |
.loop1: |
loop .shift |
pop ecx |
rol eax,cl |
.exx: |
xor ecx,ecx |
ret |
|
.Gif_output: |
push esi eax edx |
mov edx,.gif_workarea |
.next: |
push word[edx+eax*4] |
mov ax,word[edx+eax*4+2] |
inc ecx |
cmp ax,1000h |
jnz .next |
shl ebx,16 |
mov bx,[esp] |
.loop2: |
pop ax |
lea esi,[eax+eax*2] |
add esi,[.Palette] |
mov esi,[esi] |
bswap esi |
shr esi,8 |
mov [edi],esi |
add edi,3 |
loop .loop2 |
pop edx eax esi |
ret |