/[svn]/libgig/trunk/src/helper.h
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Contents of /libgig/trunk/src/helper.h

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Revision 1875 - (show annotations) (download) (as text)
Thu Mar 26 13:32:59 2009 UTC (11 years, 7 months ago) by schoenebeck
File MIME type: text/x-c++hdr
File size: 7265 byte(s)
* fixed crash which occured when streaming a gig sample with
  bi-directional (a.k.a. 'pingpong') loop type (fixes #102)

1 /***************************************************************************
2 * *
3 * libgig - C++ cross-platform Gigasampler format file access library *
4 * *
5 * Copyright (C) 2003-2009 by Christian Schoenebeck *
6 * <cuse@users.sourceforge.net> *
7 * *
8 * This library is free software; you can redistribute it and/or modify *
9 * it under the terms of the GNU General Public License as published by *
10 * the Free Software Foundation; either version 2 of the License, or *
11 * (at your option) any later version. *
12 * *
13 * This library is distributed in the hope that it will be useful, *
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
16 * GNU General Public License for more details. *
17 * *
18 * You should have received a copy of the GNU General Public License *
19 * along with this library; if not, write to the Free Software *
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
21 * MA 02111-1307 USA *
22 ***************************************************************************/
23
24 #ifndef __LIBGIG_HELPER_H__
25 #define __LIBGIG_HELPER_H__
26
27 #include <string.h>
28 #include <string>
29 #include <sstream>
30
31 #if defined(WIN32) && !HAVE_CONFIG_H
32 # include "../win32/libgig_private.h" // like config.h, automatically generated by Dev-C++
33 # define PACKAGE "libgig"
34 # define VERSION VER_STRING // VER_STRING defined in libgig_private.h
35 #endif // WIN32
36
37 #include "RIFF.h"
38
39 // *************** Helper Functions **************
40 // *
41
42 template<class T> inline std::string ToString(T o) {
43 std::stringstream ss;
44 ss << o;
45 return ss.str();
46 }
47
48 inline long Min(long A, long B) {
49 return (A > B) ? B : A;
50 }
51
52 inline long Abs(long val) {
53 return (val > 0) ? val : -val;
54 }
55
56 /**
57 * Stores a 16 bit integer in memory using little-endian format.
58 *
59 * @param pData - memory pointer
60 * @param data - integer to be stored
61 */
62 inline void store16(uint8_t* pData, uint16_t data) {
63 pData[0] = data;
64 pData[1] = data >> 8;
65 }
66
67 /**
68 * Stores a 32 bit integer in memory using little-endian format.
69 *
70 * @param pData - memory pointer
71 * @param data - integer to be stored
72 */
73 inline void store32(uint8_t* pData, uint32_t data) {
74 pData[0] = data;
75 pData[1] = data >> 8;
76 pData[2] = data >> 16;
77 pData[3] = data >> 24;
78 }
79
80 /**
81 * Swaps the order of the data words in the given memory area
82 * with a granularity given by \a WordSize.
83 *
84 * @param pData - pointer to the memory area to be swapped
85 * @param AreaSize - size of the memory area to be swapped (in bytes)
86 * @param WordSize - size of the data words (in bytes)
87 */
88 inline void SwapMemoryArea(void* pData, unsigned long AreaSize, uint WordSize) {
89 if (!AreaSize) return; // AreaSize==0 would cause a segfault here
90 switch (WordSize) { // TODO: unefficient
91 case 1: {
92 uint8_t* pDst = (uint8_t*) pData;
93 uint8_t cache;
94 unsigned long lo = 0, hi = AreaSize - 1;
95 for (; lo < hi; hi--, lo++) {
96 cache = pDst[lo];
97 pDst[lo] = pDst[hi];
98 pDst[hi] = cache;
99 }
100 break;
101 }
102 case 2: {
103 uint16_t* pDst = (uint16_t*) pData;
104 uint16_t cache;
105 unsigned long lo = 0, hi = (AreaSize >> 1) - 1;
106 for (; lo < hi; hi--, lo++) {
107 cache = pDst[lo];
108 pDst[lo] = pDst[hi];
109 pDst[hi] = cache;
110 }
111 break;
112 }
113 case 4: {
114 uint32_t* pDst = (uint32_t*) pData;
115 uint32_t cache;
116 unsigned long lo = 0, hi = (AreaSize >> 2) - 1;
117 for (; lo < hi; hi--, lo++) {
118 cache = pDst[lo];
119 pDst[lo] = pDst[hi];
120 pDst[hi] = cache;
121 }
122 break;
123 }
124 default: {
125 uint8_t* pCache = new uint8_t[WordSize]; // TODO: unefficient
126 unsigned long lo = 0, hi = AreaSize - WordSize;
127 for (; lo < hi; hi -= WordSize, lo += WordSize) {
128 memcpy(pCache, (uint8_t*) pData + lo, WordSize);
129 memcpy((uint8_t*) pData + lo, (uint8_t*) pData + hi, WordSize);
130 memcpy((uint8_t*) pData + hi, pCache, WordSize);
131 }
132 if (pCache) delete[] pCache;
133 break;
134 }
135 }
136 }
137
138 /** @brief Load given info field (string).
139 *
140 * Load info field string from given info chunk (\a ck) and save value to \a s.
141 */
142 inline void LoadString(RIFF::Chunk* ck, std::string& s) {
143 if (ck) {
144 const char* str = (char*)ck->LoadChunkData();
145 int size = ck->GetSize();
146 int len;
147 for (len = 0 ; len < size ; len++)
148 if (str[len] == '\0') break;
149 s.assign(str, len);
150 ck->ReleaseChunkData();
151 }
152 }
153
154 /** @brief Apply given INFO field to the respective chunk.
155 *
156 * Apply given info value string to given info chunk, which is a
157 * subchunk of INFO list chunk \a lstINFO. If the given chunk already
158 * exists, value \a s will be applied. Otherwise if it doesn't exist yet
159 * and either \a s or \a sDefault is not an empty string, such a chunk
160 * will be created and either \a s or \a sDefault will be applied
161 * (depending on which one is not an empty string, if both are not an
162 * empty string \a s will be preferred).
163 *
164 * @param ChunkID - 32 bit RIFF chunk ID of INFO subchunk (only used in case \a ck is NULL)
165 * @param ck - INFO (sub)chunk where string should be stored to
166 * @param lstINFO - parent (INFO) RIFF list chunk
167 * @param s - current value of info field
168 * @param sDefault - default value
169 * @param bUseFixedLengthStrings - should a specific string size be forced in the chunk?
170 * @param size - wanted size of the INFO chunk. This is ignored if bUseFixedLengthStrings is false.
171 */
172 inline void SaveString(uint32_t ChunkID, RIFF::Chunk* ck, RIFF::List* lstINFO, const std::string& s, const std::string& sDefault, bool bUseFixedLengthStrings, int size) {
173 if (ck) { // if chunk exists already, use 's' as value
174 if (!bUseFixedLengthStrings) size = s.size() + 1;
175 ck->Resize(size);
176 char* pData = (char*) ck->LoadChunkData();
177 strncpy(pData, s.c_str(), size);
178 } else if (s != "" || sDefault != "" || bUseFixedLengthStrings) { // create chunk
179 const std::string& sToSave = (s != "") ? s : sDefault;
180 if (!bUseFixedLengthStrings) size = sToSave.size() + 1;
181 ck = lstINFO->AddSubChunk(ChunkID, size);
182 char* pData = (char*) ck->LoadChunkData();
183 strncpy(pData, sToSave.c_str(), size);
184 }
185 }
186
187 #endif // __LIBGIG_HELPER_H__

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