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/* |
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rdesktop: A Remote Desktop Protocol client. |
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Bitmap decompression routines |
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Copyright (C) Matthew Chapman 1999-2001 |
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|
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program 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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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
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*/ |
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|
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#include "rdesktop.h" |
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|
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#define CVAL(p) (*(p++)) |
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|
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#define UNROLL8(exp) { exp exp exp exp exp exp exp exp } |
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|
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#define REPEAT(statement) \ |
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{ \ |
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while((count & ~0x7) && ((x+8) < width)) \ |
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UNROLL8( statement; count--; x++; ); \ |
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\ |
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while((count > 0) && (x < width)) { statement; count--; x++; } \ |
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} |
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|
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#define MASK_UPDATE() \ |
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{ \ |
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mixmask <<= 1; \ |
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if (mixmask == 0) \ |
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{ \ |
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mask = fom_mask ? fom_mask : CVAL(input); \ |
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mixmask = 1; \ |
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} \ |
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} |
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|
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BOOL |
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bitmap_decompress(unsigned char *output, int width, int height, |
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unsigned char *input, int size) |
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{ |
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unsigned char *end = input + size; |
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unsigned char *prevline = NULL, *line = NULL; |
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int opcode, count, offset, isfillormix, x = width; |
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int lastopcode = -1, insertmix = False, bicolour = False; |
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uint8 code, colour1 = 0, colour2 = 0; |
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uint8 mixmask, mask = 0, mix = 0xff; |
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int fom_mask = 0; |
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|
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while (input < end) |
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{ |
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fom_mask = 0; |
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code = CVAL(input); |
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opcode = code >> 4; |
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|
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/* Handle different opcode forms */ |
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switch (opcode) |
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{ |
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case 0xc: |
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case 0xd: |
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case 0xe: |
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opcode -= 6; |
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count = code & 0xf; |
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offset = 16; |
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break; |
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|
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case 0xf: |
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opcode = code & 0xf; |
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if (opcode < 9) |
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{ |
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count = CVAL(input); |
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count |= CVAL(input) << 8; |
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} |
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else |
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{ |
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count = (opcode < 0xb) ? 8 : 1; |
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} |
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offset = 0; |
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break; |
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|
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default: |
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opcode >>= 1; |
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count = code & 0x1f; |
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offset = 32; |
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break; |
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} |
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|
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/* Handle strange cases for counts */ |
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if (offset != 0) |
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{ |
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isfillormix = ((opcode == 2) || (opcode == 7)); |
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|
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if (count == 0) |
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{ |
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if (isfillormix) |
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count = CVAL(input) + 1; |
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else |
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count = CVAL(input) + offset; |
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} |
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else if (isfillormix) |
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{ |
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count <<= 3; |
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} |
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} |
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|
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/* Read preliminary data */ |
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switch (opcode) |
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{ |
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case 0: /* Fill */ |
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if ((lastopcode == opcode) |
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&& !((x == width) && (prevline == NULL))) |
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insertmix = True; |
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break; |
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case 8: /* Bicolour */ |
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colour1 = CVAL(input); |
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case 3: /* Colour */ |
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colour2 = CVAL(input); |
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break; |
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case 6: /* SetMix/Mix */ |
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case 7: /* SetMix/FillOrMix */ |
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mix = CVAL(input); |
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opcode -= 5; |
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break; |
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case 9: /* FillOrMix_1 */ |
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mask = 0x03; |
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opcode = 0x02; |
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fom_mask = 3; |
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break; |
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case 0x0a: /* FillOrMix_2 */ |
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mask = 0x05; |
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opcode = 0x02; |
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fom_mask = 5; |
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break; |
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|
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} |
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|
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lastopcode = opcode; |
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mixmask = 0; |
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|
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/* Output body */ |
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while (count > 0) |
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{ |
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if (x >= width) |
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{ |
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if (height <= 0) |
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return False; |
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|
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x = 0; |
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height--; |
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|
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prevline = line; |
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line = output + height * width; |
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} |
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|
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switch (opcode) |
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{ |
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case 0: /* Fill */ |
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if (insertmix) |
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{ |
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if (prevline == NULL) |
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line[x] = mix; |
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else |
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line[x] = |
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prevline[x] ^ |
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mix; |
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|
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insertmix = False; |
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count--; |
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x++; |
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} |
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|
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if (prevline == NULL) |
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{ |
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REPEAT(line[x] = 0); |
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} |
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else |
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{ |
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REPEAT(line[x] = prevline[x]); |
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} |
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break; |
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|
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case 1: /* Mix */ |
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if (prevline == NULL) |
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{ |
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REPEAT(line[x] = mix); |
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} |
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else |
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{ |
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REPEAT(line[x] = |
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prevline[x] ^ mix); |
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} |
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break; |
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|
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case 2: /* Fill or Mix */ |
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if (prevline == NULL) |
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{ |
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REPEAT(MASK_UPDATE(); |
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if (mask & mixmask) |
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line[x] = mix; |
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else |
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line[x] = 0;); |
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} |
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else |
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{ |
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REPEAT(MASK_UPDATE(); |
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if (mask & mixmask) |
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line[x] = |
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prevline[x] ^ mix; |
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else |
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line[x] = |
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prevline[x];); |
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} |
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break; |
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|
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case 3: /* Colour */ |
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REPEAT(line[x] = colour2); |
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break; |
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|
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case 4: /* Copy */ |
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REPEAT(line[x] = CVAL(input)); |
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break; |
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|
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case 8: /* Bicolour */ |
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REPEAT(if (bicolour) |
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{ |
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line[x] = colour2; |
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bicolour = False;} |
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else |
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{ |
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line[x] = colour1; |
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bicolour = True; count++;} |
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); |
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break; |
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|
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case 0xd: /* White */ |
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REPEAT(line[x] = 0xff); |
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break; |
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|
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case 0xe: /* Black */ |
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REPEAT(line[x] = 0x00); |
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break; |
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|
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default: |
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unimpl("bitmap opcode 0x%x\n", |
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opcode); |
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return False; |
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} |
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} |
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} |
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|
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return True; |
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} |