LCW.CPP (7125B)
1 // 2 // Copyright 2020 Electronic Arts Inc. 3 // 4 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is free 5 // software: you can redistribute it and/or modify it under the terms of 6 // the GNU General Public License as published by the Free Software Foundation, 7 // either version 3 of the License, or (at your option) any later version. 8 9 // TiberianDawn.DLL and RedAlert.dll and corresponding source code is distributed 10 // in the hope that it will be useful, but with permitted additional restrictions 11 // under Section 7 of the GPL. See the GNU General Public License in LICENSE.TXT 12 // distributed with this program. You should have received a copy of the 13 // GNU General Public License along with permitted additional restrictions 14 // with this program. If not, see https://github.com/electronicarts/CnC_Remastered_Collection 15 16 /* $Header: /CounterStrike/LCW.CPP 1 3/03/97 10:25a Joe_bostic $ */ 17 /*************************************************************************** 18 ** C O N F I D E N T I A L --- W E S T W O O D S T U D I O S ** 19 *************************************************************************** 20 * * 21 * Project Name : WESTWOOD LIBRARY (PSX) * 22 * * 23 * File Name : LCWUNCMP.CPP * 24 * * 25 * Programmer : Ian M. Leslie * 26 * * 27 * Start Date : May 17, 1995 * 28 * * 29 * Last Update : May 17, 1995 [IML] * 30 * * 31 *-------------------------------------------------------------------------* 32 * Functions: * 33 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ 34 35 36 /*************************************************************************** 37 * LCW_Uncomp -- Decompress an LCW encoded data block. * 38 * * 39 * Uncompress data to the following codes in the format b = byte, w = word * 40 * n = byte code pulled from compressed data. * 41 * * 42 * Command code, n |Description * 43 * ------------------------------------------------------------------------* 44 * n=0xxxyyyy,yyyyyyyy |short copy back y bytes and run x+3 from dest * 45 * n=10xxxxxx,n1,n2,...,nx+1|med length copy the next x+1 bytes from source* 46 * n=11xxxxxx,w1 |med copy from dest x+3 bytes from offset w1 * 47 * n=11111111,w1,w2 |long copy from dest w1 bytes from offset w2 * 48 * n=11111110,w1,b1 |long run of byte b1 for w1 bytes * 49 * n=10000000 |end of data reached * 50 * * 51 * * 52 * INPUT: * 53 * void * source ptr * 54 * void * destination ptr * 55 * unsigned long length of uncompressed data * 56 * * 57 * * 58 * OUTPUT: * 59 * unsigned long # of destination bytes written * 60 * * 61 * WARNINGS: * 62 * 3rd argument is dummy. It exists to provide cross-platform * 63 * compatibility. Note therefore that this implementation does not * 64 * check for corrupt source data by testing the uncompressed length. * 65 * * 66 * HISTORY: * 67 * 03/20/1995 IML : Created. * 68 *=========================================================================*/ 69 int LCW_Uncomp(void const * source, void * dest, unsigned long ) 70 { 71 unsigned char * source_ptr, * dest_ptr, * copy_ptr, op_code, data; 72 unsigned count, * word_dest_ptr, word_data; 73 74 /* Copy the source and destination ptrs. */ 75 source_ptr = (unsigned char*) source; 76 dest_ptr = (unsigned char*) dest; 77 78 while (1 /*TRUE*/) { 79 80 /* Read in the operation code. */ 81 op_code = *source_ptr++; 82 83 if (!(op_code & 0x80)) { 84 85 /* Do a short copy from destination. */ 86 count = (op_code >> 4) + 3; 87 copy_ptr = dest_ptr - ((unsigned) *source_ptr++ + (((unsigned) op_code & 0x0f) << 8)); 88 89 while (count--) *dest_ptr++ = *copy_ptr++; 90 91 } else { 92 93 if (!(op_code & 0x40)) { 94 95 if (op_code == 0x80) { 96 97 /* Return # of destination bytes written. */ 98 return ((unsigned long) (dest_ptr - (unsigned char*) dest)); 99 100 } else { 101 102 /* Do a medium copy from source. */ 103 count = op_code & 0x3f; 104 105 while (count--) *dest_ptr++ = *source_ptr++; 106 } 107 108 } else { 109 110 if (op_code == 0xfe) { 111 112 /* Do a long run. */ 113 count = *source_ptr + ((unsigned) *(source_ptr + 1) << 8); 114 word_data = data = *(source_ptr + 2); 115 word_data = (word_data << 24) + (word_data << 16) + (word_data << 8) + word_data; 116 source_ptr += 3; 117 118 copy_ptr = dest_ptr + 4 - ((unsigned) dest_ptr & 0x3); 119 count -= (copy_ptr - dest_ptr); 120 while (dest_ptr < copy_ptr) *dest_ptr++ = data; 121 122 word_dest_ptr = (unsigned*) dest_ptr; 123 124 dest_ptr += (count & 0xfffffffc); 125 126 while (word_dest_ptr < (unsigned*) dest_ptr) { 127 *word_dest_ptr = word_data; 128 *(word_dest_ptr + 1) = word_data; 129 word_dest_ptr += 2; 130 } 131 132 copy_ptr = dest_ptr + (count & 0x3); 133 while (dest_ptr < copy_ptr) *dest_ptr++ = data; 134 135 } else { 136 137 if (op_code == 0xff) { 138 139 /* Do a long copy from destination. */ 140 count = *source_ptr + ((unsigned) *(source_ptr + 1) << 8); 141 copy_ptr = (unsigned char*) dest + *(source_ptr + 2) + ((unsigned) *(source_ptr + 3) << 8); 142 source_ptr += 4; 143 144 while (count--) *dest_ptr++ = *copy_ptr++; 145 146 } else { 147 148 /* Do a medium copy from destination. */ 149 count = (op_code & 0x3f) + 3; 150 copy_ptr = (unsigned char*) dest + *source_ptr + ((unsigned) *(source_ptr + 1) << 8); 151 source_ptr += 2; 152 153 while (count--) *dest_ptr++ = *copy_ptr++; 154 } 155 } 156 } 157 } 158 } 159 }