/[svn]/libgig/trunk/src/helper.h
ViewVC logotype

Diff of /libgig/trunk/src/helper.h

Parent Directory Parent Directory | Revision Log Revision Log | View Patch Patch

revision 803 by schoenebeck, Sat Nov 12 12:36:49 2005 UTC revision 933 by schoenebeck, Fri Nov 24 12:50:05 2006 UTC
# Line 1  Line 1 
1  /***************************************************************************  /***************************************************************************
2   *                                                                         *   *                                                                         *
3   *   libgig - C++ cross-platform Gigasampler format file loader library    *   *   libgig - C++ cross-platform Gigasampler format file access library    *
4   *                                                                         *   *                                                                         *
5   *   Copyright (C) 2003-2005 by Christian Schoenebeck                      *   *   Copyright (C) 2003-2006 by Christian Schoenebeck                      *
6   *                              <cuse@users.sourceforge.net>               *   *                              <cuse@users.sourceforge.net>               *
7   *                                                                         *   *                                                                         *
8   *   This library is free software; you can redistribute it and/or modify  *   *   This library is free software; you can redistribute it and/or modify  *
# Line 24  Line 24 
24  #ifndef __LIBGIG_HELPER_H__  #ifndef __LIBGIG_HELPER_H__
25  #define __LIBGIG_HELPER_H__  #define __LIBGIG_HELPER_H__
26    
27    #include <string.h>
28  #include <string>  #include <string>
29  #include <sstream>  #include <sstream>
30    
31    #include "RIFF.h"
32    
33  // *************** Helper Functions **************  // *************** Helper Functions **************
34  // *  // *
35    
# Line 36  template<class T> inline std::string ToS Line 39  template<class T> inline std::string ToS
39      return ss.str();      return ss.str();
40  }  }
41    
42    inline long Min(long A, long B) {
43        return (A > B) ? B : A;
44    }
45    
46    inline long Abs(long val) {
47        return (val > 0) ? val : -val;
48    }
49    
50    /**
51     * Swaps the order of the data words in the given memory area
52     * with a granularity given by \a WordSize.
53     *
54     * @param pData    - pointer to the memory area to be swapped
55     * @param AreaSize - size of the memory area to be swapped (in bytes)
56     * @param WordSize - size of the data words (in bytes)
57     */
58    inline void SwapMemoryArea(void* pData, unsigned long AreaSize, uint WordSize) {
59        switch (WordSize) { // TODO: unefficient
60            case 1: {
61                uint8_t* pDst = (uint8_t*) pData;
62                uint8_t  cache;
63                unsigned long lo = 0, hi = AreaSize - 1;
64                for (; lo < hi; hi--, lo++) {
65                    cache    = pDst[lo];
66                    pDst[lo] = pDst[hi];
67                    pDst[hi] = cache;
68                }
69                break;
70            }
71            case 2: {
72                uint16_t* pDst = (uint16_t*) pData;
73                uint16_t  cache;
74                unsigned long lo = 0, hi = (AreaSize >> 1) - 1;
75                for (; lo < hi; hi--, lo++) {
76                    cache    = pDst[lo];
77                    pDst[lo] = pDst[hi];
78                    pDst[hi] = cache;
79                }
80                break;
81            }
82            case 4: {
83                uint32_t* pDst = (uint32_t*) pData;
84                uint32_t  cache;
85                unsigned long lo = 0, hi = (AreaSize >> 2) - 1;
86                for (; lo < hi; hi--, lo++) {
87                    cache    = pDst[lo];
88                    pDst[lo] = pDst[hi];
89                    pDst[hi] = cache;
90                }
91                break;
92            }
93            default: {
94                uint8_t* pCache = new uint8_t[WordSize]; // TODO: unefficient
95                unsigned long lo = 0, hi = AreaSize - WordSize;
96                for (; lo < hi; hi -= WordSize, lo += WordSize) {
97                    memcpy(pCache, (uint8_t*) pData + lo, WordSize);
98                    memcpy((uint8_t*) pData + lo, (uint8_t*) pData + hi, WordSize);
99                    memcpy((uint8_t*) pData + hi, pCache, WordSize);
100                }
101                delete[] pCache;
102                break;
103            }
104        }
105    }
106    
107    /** @brief Load given info field (string).
108     *
109     * Load info field string from given info chunk (\a ck) and save value to \a s.
110     */
111    inline void LoadString(RIFF::Chunk* ck, std::string& s) {
112        if (ck) {
113            const char* str = (char*)ck->LoadChunkData();
114            int size = ck->GetSize();
115            int len;
116            for (len = 0 ; len < size ; len++)
117                if (str[len] == '\0') break;
118            s.assign(str, len);
119            ck->ReleaseChunkData();
120        }
121    }
122    
123    /** @brief Apply given INFO field to the respective chunk.
124     *
125     * Apply given info value string to given info chunk, which is a
126     * subchunk of INFO list chunk \a lstINFO. If the given chunk already
127     * exists, value \a s will be applied. Otherwise if it doesn't exist yet
128     * and either \a s or \a sDefault is not an empty string, such a chunk
129     * will be created and either \a s or \a sDefault will be applied
130     * (depending on which one is not an empty string, if both are not an
131     * empty string \a s will be preferred).
132     *
133     * @param ChunkID  - 32 bit RIFF chunk ID of INFO subchunk (only used in case \a ck is NULL)
134     * @param ck       - INFO (sub)chunk where string should be stored to
135     * @param lstINFO  - parent (INFO) RIFF list chunk
136     * @param s        - current value of info field
137     * @param sDefault - default value
138     * @param bUseFixedLengthStrings - should a specific string size be forced in the chunk?
139     * @param size     - wanted size of the INFO chunk. This is ignored if bUseFixedLengthStrings is false.
140     */
141    inline void SaveString(uint32_t ChunkID, RIFF::Chunk* ck, RIFF::List* lstINFO, const std::string& s, const std::string& sDefault, bool bUseFixedLengthStrings, int size) {
142        if (ck) { // if chunk exists already, use 's' as value
143            if (!bUseFixedLengthStrings) size = s.size() + 1;
144            ck->Resize(size);
145            char* pData = (char*) ck->LoadChunkData();
146            strncpy(pData, s.c_str(), size);
147        } else if (s != "" || sDefault != "") { // create chunk
148            const std::string& sToSave = (s != "") ? s : sDefault;
149            if (!bUseFixedLengthStrings) size = sToSave.size() + 1;
150            ck = lstINFO->AddSubChunk(ChunkID, size);
151            char* pData = (char*) ck->LoadChunkData();
152            strncpy(pData, sToSave.c_str(), size);
153        }
154    }
155    
156  #endif // __LIBGIG_HELPER_H__  #endif // __LIBGIG_HELPER_H__
Legend:
Removed from v.803  
changed lines
  Added in v.933
  ViewVC Help
Powered by ViewVC