/* * PostScript filter functions * * Copyright 2003 Huw D M Davies * * This library 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. * * This library 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 this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA */ #include <ctype.h> #include <stdio.h> #include <string.h> #include "psdrv.h" DWORD RLE_encode(BYTE *in_buf, DWORD len, BYTE *out_buf) { BYTE *next_in = in_buf, *next_out = out_buf; DWORD rl; while(next_in < in_buf + len) { if(next_in + 1 < in_buf + len) { if(*next_in == *(next_in + 1)) { next_in += 2; rl = 2; while(next_in < in_buf + len && *next_in == *(next_in - 1) && rl < 128) { next_in++; rl++; } *next_out++ = 257 - rl; *next_out++ = *(next_in - 1); } else { rl = 0; next_out++; while(next_in < in_buf + len && rl < 128) { if(next_in + 2 < in_buf + len && *next_in == *(next_in + 1)) { if(rl == 127 || *next_in == *(next_in + 2)) break; } *next_out++ = *next_in++; rl++; } *(next_out - rl - 1) = rl - 1; } } else { /* special case: begin of run on last byte */ *next_out++ = 0; *next_out++ = *next_in; break; } } *next_out++ = 128; return next_out - out_buf; } DWORD ASCII85_encode(BYTE *in_buf, DWORD len, BYTE *out_buf) { DWORD number; BYTE *next_in = in_buf, *next_out = out_buf; int i; while(next_in + 3 < in_buf + len) { number = (next_in[0] << 24) | (next_in[1] << 16) | (next_in[2] << 8) | (next_in[3] ); next_in += 4; if(number == 0) *next_out++ = 'z'; else { for(i = 4; i >= 0; i--) { next_out[i] = number % 85 + '!'; number /= 85; } next_out += 5; } } if(next_in != in_buf + len) { number = (*next_in++ << 24) & 0xff000000; if(next_in < in_buf + len) number |= ((*next_in++ << 16) & 0x00ff0000); if(next_in < in_buf + len) number |= ((*next_in++ << 8) & 0x0000ff00); for(i = len % 4 + 1; i < 5; i++) number /= 85; for(i = len % 4; i >= 0; i--) { next_out[i] = number % 85 + '!'; number /= 85; } next_out += len % 4 + 1; } return next_out - out_buf; }