70 lines
2.0 KiB
C
70 lines
2.0 KiB
C
/* vim:expandtab:ts=2 sw=2:
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*/
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/* Grafx2 - The Ultimate 256-color bitmap paint program
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Copyright 2018-2019 Thomas Bernard
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Copyright 2008 Yves Rizoud
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Copyright 2007 Adrien Destugues
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Copyright 1996-2001 Sunset Design (Guillaume Dorme & Karl Maritaud)
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Grafx2 is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; version 2
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of the License.
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Grafx2 is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with Grafx2; if not, see <http://www.gnu.org/licenses/>
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*/
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///@file packbits.c
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/// Packbits compression as used in IFF etc.
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/// see http://fileformats.archiveteam.org/wiki/PackBits
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#include <stdio.h>
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#include <string.h>
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#include "struct.h"
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#include "gfx2log.h"
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#include "packbits.h"
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int PackBits_unpack_from_file(FILE * f, byte * dest, unsigned int count)
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{
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unsigned int i = 0;
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while (i < count)
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{
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byte cmd;
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if (fread(&cmd, 1, 1, f) != 1)
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return PACKBITS_UNPACK_READ_ERROR;
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if (cmd > 128)
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{
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// cmd > 128 => repeat (257 - cmd) the next byte
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byte v;
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if (fread(&v, 1, 1, f) != 1)
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return PACKBITS_UNPACK_READ_ERROR;
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if (count < (i + 257 - cmd))
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return PACKBITS_UNPACK_OVERFLOW_ERROR;
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memset(dest + i, v, (257 - cmd));
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i += (257 - cmd);
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}
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else if (cmd < 128)
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{
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// cmd < 128 => copy (cmd + 1) bytes
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if (count < (i + cmd + 1))
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return PACKBITS_UNPACK_OVERFLOW_ERROR;
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if (fread(dest + i, 1, (cmd + 1), f) != (unsigned)(cmd + 1))
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return PACKBITS_UNPACK_READ_ERROR;
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i += (cmd + 1);
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}
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else
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{
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// 128 = NOP
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GFX2_Log(GFX2_WARNING, "NOP in packbits stream\n");
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}
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}
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return PACKBITS_UNPACK_OK;
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}
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