| /* |
| * 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; |
| } |