/[svn]/linuxsampler/trunk/src/engines/common/LFOBase.h
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Contents of /linuxsampler/trunk/src/engines/common/LFOBase.h

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Revision 722 - (show annotations) (download) (as text)
Sun Jul 24 19:45:15 2005 UTC (15 years, 9 months ago) by schoenebeck
File MIME type: text/x-c++hdr
File size: 5434 byte(s)
just a little API doc change

1 /***************************************************************************
2 * *
3 * Copyright (C) 2005 Christian Schoenebeck *
4 * *
5 * This library is free software; you can redistribute it and/or modify *
6 * it under the terms of the GNU General Public License as published by *
7 * the Free Software Foundation; either version 2 of the License, or *
8 * (at your option) any later version. *
9 * *
10 * This library is distributed in the hope that it will be useful, *
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of *
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
13 * GNU General Public License for more details. *
14 * *
15 * You should have received a copy of the GNU General Public License *
16 * along with this library; if not, write to the Free Software *
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
18 * MA 02111-1307 USA *
19 ***************************************************************************/
20
21 #ifndef __LS_LFOBASE_H__
22 #define __LS_LFOBASE_H__
23
24 #ifdef HAVE_CONFIG_H
25 # include "../../common/global.h"
26 # include "../../common/RTMath.h"
27
28 // IDs of the two possible implementations
29 // we get the implementation to pick from config.h
30 // the implementation IDs should be the same like in benchmarks/triang.cpp !
31 # define INT_MATH_SOLUTION 2
32 # define DI_HARMONIC_SOLUTION 3
33 #else
34 # include <math.h>
35 # include <stdint.h>
36 #endif
37
38 namespace LinuxSampler {
39
40 // *************** types ***************
41 // *
42
43 /**
44 * Whether the LFO should have positive AND negative value range
45 * (signed) or only a positive value range (unsigned).
46 */
47 enum range_type_t {
48 range_signed, ///< LFO's level will wave between -max ... +max
49 range_unsigned ///< LFO's level will wave between 0 ... +max
50 };
51
52 /**
53 * Defines the start level of the LFO wave within the given value range.
54 */
55 enum start_level_t {
56 start_level_max, ///< wave starts from given max. level
57 start_level_mid, ///< wave starts from the middle of the given value range
58 start_level_min ///< wave starts from given min. level
59 };
60
61 /** @brief LFO (abstract base class)
62 *
63 * Abstract base class for all Low Frequency Oscillator implementations.
64 */
65 template<range_type_t RANGE>
66 class LFOBase {
67 public:
68
69 // *************** attributes ***************
70 // *
71
72 uint8_t ExtController; ///< MIDI control change controller number if the LFO is controlled by an external controller, 0 otherwise.
73
74
75 // *************** methods ***************
76 // *
77
78 /**
79 * Constructor
80 *
81 * @param Max - maximum value of the output levels
82 */
83 LFOBase(float Max) {
84 this->ExtController = 0;
85 this->Max = Max;
86 }
87
88 virtual ~LFOBase() {
89 }
90
91 /**
92 * Calculates exactly one sample point of the LFO wave. This
93 * inline method has to be implemented by the descendant.
94 *
95 * @returns next LFO level
96 */
97 //abstract inline float render(); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)
98
99 /**
100 * Update LFO depth with a new external controller value. This
101 * inline method has to be implemented by the descendant.
102 *
103 * @param ExtControlValue - new external controller value
104 */
105 //abstract inline void update(const uint16_t& ExtControlValue); //< what a pity that abstract inliners are not supported by C++98 (probably by upcoming C++0x?)
106
107 /**
108 * Will be called by the voice when the key / voice was triggered.
109 *
110 * @param Frequency - frequency of the oscillator in Hz
111 * @param StartLevel - on which level the wave should start
112 * @param InternalDepth - firm, internal oscillator amplitude
113 * @param ExtControlDepth - defines how strong the external MIDI
114 * controller has influence on the
115 * oscillator amplitude
116 * @param FlipPhase - inverts the oscillator wave against
117 * a horizontal axis
118 * @param SampleRate - current sample rate of the engines
119 * audio output signal
120 */
121 virtual void trigger(float Frequency, start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) = 0;
122
123 protected:
124 float Max;
125 float InternalDepth;
126 float ExtControlDepthCoeff;
127 };
128
129 } // namespace LinuxSampler
130
131 #endif // __LS_LFOBASE_H__

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