src/calf/buffer.h

   1 /* Calf DSP Library
   2  * Buffer abstractions.
   3  *
   4  * Copyright (C) 2007 Krzysztof Foltman
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General
  17  * Public License along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  19  * Boston, MA  02110-1301  USA
  20  */
  21 #ifndef __BUFFER_H
  22 #define __BUFFER_H
  23
  24 namespace dsp {
  25
  26 /// decrease by N if >= N (useful for circular buffers)
  27 template<int N> inline int wrap_around(int a) {
  28     return (a >= N) ? a - N : a;
  29 }
  30
  31 // provide fast specializations for powers of 2
  32 template<> inline int wrap_around<2>(int a) { return a & 1; }
  33 template<> inline int wrap_around<4>(int a) { return a & 3; }
  34 template<> inline int wrap_around<8>(int a) { return a & 7; }
  35 template<> inline int wrap_around<16>(int a) { return a & 15; }
  36 template<> inline int wrap_around<32>(int a) { return a & 31; }
  37 template<> inline int wrap_around<64>(int a) { return a & 63; }
  38 template<> inline int wrap_around<128>(int a) { return a & 127; }
  39 template<> inline int wrap_around<256>(int a) { return a & 255; }
  40 template<> inline int wrap_around<512>(int a) { return a & 511; }
  41 template<> inline int wrap_around<1024>(int a) { return a & 1023; }
  42 template<> inline int wrap_around<2048>(int a) { return a & 2047; }
  43 template<> inline int wrap_around<4096>(int a) { return a & 4095; }
  44 template<> inline int wrap_around<8192>(int a) { return a & 8191; }
  45 template<> inline int wrap_around<16384>(int a) { return a & 16383; }
  46 template<> inline int wrap_around<32768>(int a) { return a & 32767; }
  47 template<> inline int wrap_around<65536>(int a) { return a & 65535; }
  48
  49 template<class Buf, class T>
  50 void fill(Buf &buf, T value) {
  51     T* data = buf.data();
  52     int size = buf.size();
  53     for (int i=0; i<size; i++)
  54         *data++ = value;
  55 }
  56
  57 template<class T>
  58 void fill(T *data, int size, T value) {
  59     for (int i=0; i<size; i++)
  60         *data++ = value;
  61 }
  62
  63 template<class T, class U>
  64 void copy(T *dest, U *src, int size, T scale = 1, T add = 0) {
  65     for (int i=0; i<size; i++)
  66         *dest++ = (*src++) * scale + add;
  67 }
  68
  69 template<class T>
  70 struct sample_traits {
  71     enum {
  72         channels = 1,
  73         bps = sizeof(T)*8
  74     };
  75 };
  76
  77 template<class T>
  78 struct sample_traits<stereo_sample<T> > {
  79     enum {
  80         channels = 2,
  81         bps = sizeof(T)*8
  82     };
  83 };
  84
  85 template<int N, class T = float>
  86 class fixed_size_buffer {
  87 public:
  88     typedef T data_type;
  89     enum { buffer_size = N };
  90     inline int size() { return N; }
  91 };
  92
  93 template<int N, class T = float>
  94 class mem_fixed_size_buffer: public fixed_size_buffer<N, T> {
  95     T *buf;
  96 public:
  97     mem_fixed_size_buffer(T ubuf[N]) { buf = ubuf; }
  98     void set_data(T buf[N]) { this->buf = buf; }
  99     inline T* data() { return buf; }
 100     inline const T* data() const { return buf; }
 101     inline T& operator[](int pos) { return buf[pos]; }
 102     inline const T& operator[](int pos) const { return buf[pos]; }
 103 };
 104
 105 template<int N, class T = float>
 106 class auto_buffer: public fixed_size_buffer<N, T> {
 107     T buf[N];
 108 public:
 109     T* data() const { return buf; }
 110     inline T& operator[](int pos) { return buf[pos]; }
 111     inline const T& operator[](int pos) const { return buf[pos]; }
 112 };
 113
 114 template<class T = float>
 115 class dynamic_buffer {
 116     T *buf;
 117     int buf_size;
 118     bool owns;
 119 public:
 120     dynamic_buffer() { owns = false; }
 121     dynamic_buffer(T *_buf, int _buf_size, bool _own)
 122     : buf(_buf), buf_size(_buf_size), owns(_own) {
 123     }
 124     dynamic_buffer(int _size) {
 125         buf = new T[_size];
 126         buf_size = _size;
 127         owns = true;
 128     }
 129     inline T* data() { return buf; }
 130     inline const T* data() const { return buf; }
 131     inline int size() { return buf_size; }
 132     void resize(int new_size, bool fill_with_zeros = false) {
 133         T *new_buf = new T[new_size];
 134         memcpy(new_buf, buf, std::min(buf_size, new_size));
 135         if (fill_with_zeros && buf_size < new_size)
 136             dsp::zero(new_buf + buf_size, new_size - buf_size);
 137         if (owns)
 138             delete []buf;
 139         buf = new_buf;
 140         buf_size = new_size;
 141         owns = true;
 142     }
 143     inline T& operator[](int pos) { return buf[pos]; }
 144     inline const T& operator[](int pos) const { return buf[pos]; }
 145     ~dynamic_buffer() {
 146         if (owns)
 147             delete []buf;
 148     }
 149 };
 150
 151 template<class T, class U>
 152 void copy_buf(T &dest_buf, const U &src_buf, T scale = 1, T add = 0) {
 153     typedef typename T::data_type data_type;
 154     data_type *dest = dest_buf.data();
 155     const data_type *src = src_buf.data();
 156     int size = src->size();
 157     for (int i=0; i<size; i++)
 158         *dest++ = (*src++) * scale + add;
 159 }
 160
 161 template<class T>
 162 struct buffer_traits {
 163 };
 164
 165 /// this class template defines some basic position operations for fixed_size_buffers
 166 template<int N, class T>
 167 struct buffer_traits<fixed_size_buffer<N, T> > {
 168     int inc_wrap(int pos) const {
 169         return wrap_around<T::size>(pos+1);
 170     }
 171
 172     int pos_diff(int pos1, int pos2) const {
 173         int pos = pos1 - pos2;
 174         if (pos < 0) pos += T::size;
 175         return pos;
 176     }
 177 };
 178
 179 /// this is useless for now (and untested too)
 180 template<class B>
 181 class circular_buffer: public B {
 182     typedef typename B::data_type data_type;
 183     typedef class buffer_traits<B> traits;
 184     B buffer;
 185     int rpos, wpos;
 186     circular_buffer() {
 187         clear();
 188     }
 189     void clear() {
 190         rpos = 0;
 191         wpos = 0;
 192     }
 193     inline void put(data_type data) {
 194         buffer[wpos] = data;
 195         wpos = traits::inc_wrap(wpos);
 196     }
 197     inline bool empty() {
 198         return rpos == wpos;
 199     }
 200     inline bool full() {
 201         return rpos == traits::inc_wrap(wpos);
 202     }
 203     inline const data_type& get() {
 204         int oldrpos = rpos;
 205         rpos = traits::inc_wrap(rpos);
 206         return buffer[oldrpos];
 207     }
 208     inline int get_rbytes() {
 209         return traits::pos_diff(wpos, rpos);
 210     }
 211     inline int get_wbytes() {
 212         if (full()) return 0;
 213         return traits::pos_diff(rpos, wpos);
 214     }
 215 };
 216
 217 /// this is useless for now
 218 template<int N, class T = float>
 219 class mono_auto_buffer: public auto_buffer<N, T> {
 220 };
 221
 222 /// this is useless for now
 223 template<int N, class T = float>
 224 class stereo_auto_buffer: public auto_buffer<N, stereo_sample<T> > {
 225 };
 226
 227 };
 228
 229 #endif