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

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Revision 3612 - (show annotations) (download) (as text)
Mon Sep 30 18:03:43 2019 UTC (4 years, 6 months ago) by schoenebeck
File MIME type: text/x-c++hdr
File size: 8435 byte(s) 
Added new LFO implementations:

* Added int math square LFO implementation.

* Added int math saw LFO implementation.

* Added numeric complex nr sine LFO implementation.

* Added public API C++ class "LFO", which is a cluster class
  encapsulating all the sampler's LFO implementations to be used by
  3rd party applications (e.g. by Gigedit).

* Marked class LFOTriangleDiHarmonic as deprecated
  (will be removed in future).

* Added LFOAll.h which includes all LFO implementation's header files.

* Fixed benchmarks/triang.cpp falsely having favoured "int math abs"
  algorithm (since result of 2nd run was not accumulated).

* Added benchmark for saw wave (benchmarks/saw.cpp).

* Added benchmark for sine wave (benchmarks/sine.cpp).

* Added benchmark for square wave (benchmarks/square.cpp).

* Increased amount of benchmarks runs by factor 6 to achieve benchmark
  times which are large enough on modern systems.

* Cleanup of LFO APIs.

* Bumped version (2.1.1.svn18).
1 /***************************************************************************
2 * *
3 * Copyright (C) 2005 Christian Schoenebeck *
4 * Copyright (C) 2011 Christian Schoenebeck and Grigor Iliev *
5 * *
6 * This library is free software; you can redistribute it and/or modify *
7 * it under the terms of the GNU General Public License as published by *
8 * the Free Software Foundation; either version 2 of the License, or *
9 * (at your option) any later version. *
10 * *
11 * This library 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 *
14 * GNU General Public License for more details. *
15 * *
16 * You should have received a copy of the GNU General Public License *
17 * along with this library; if not, write to the Free Software *
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
19 * MA 02111-1307 USA *
20 ***************************************************************************/
21
22 #ifndef __LS_SAWLFO_H__
23 #define __LS_SAWLFO_H__
24
25 #include "LFOBase.h"
26
27 namespace LinuxSampler {
28
29 /** @brief Saw LFO (int math implementation)
30 *
31 * This is a saw Low Frequency Oscillator which uses pure integer
32 * math (without branches) to synthesize the saw wave.
33 */
34 template<LFO::range_type_t RANGE, bool SAWUP>
35 class SawLFO : public LFOBase<RANGE> {
36 public:
37
38 /**
39 * Constructor
40 *
41 * @param Max - maximum value of the output levels
42 */
43 SawLFO(float Max) : LFOBase<RANGE>::LFOBase(Max) {
44 }
45
46 /**
47 * Calculates exactly one sample point of the LFO wave.
48 *
49 * @returns next LFO level
50 */
51 inline float render() {
52 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
53
54 uiLevel += c;
55 if (RANGE == LFO::range_unsigned)
56 return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel);
57 else /* signed range */
58 return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel) + offset;
59 }
60
61 /**
62 * Update LFO depth with a new external controller value.
63 *
64 * @param ExtControlValue - new external controller value
65 */
66 inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
67 this->ExtControlValue = ExtControlValue;
68
69 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
70 const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
71 if (RANGE == LFO::range_unsigned) {
72 normalizer = max / (float) intLimit;
73 } else { // signed range
74 normalizer = max / (float) intLimit * 2.0f;
75 offset = -max;
76 }
77 }
78
79 /**
80 * Will be called by the voice when the key / voice was triggered.
81 *
82 * @param Frequency - frequency of the oscillator in Hz
83 * @param StartLevel - not implemented
84 * @param InternalDepth - firm, internal oscillator amplitude
85 * @param ExtControlDepth - defines how strong the external MIDI
86 * controller has influence on the
87 * oscillator amplitude
88 * @param FlipPhase - not implemented
89 * @param SampleRate - current sample rate of the engines
90 * audio output signal
91 */
92 virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
93 this->Frequency = Frequency;
94 this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
95 this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
96 this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
97 this->pFinalDepth = NULL;
98 this->pFinalFrequency = NULL;
99
100 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
101 const float freq = Frequency * this->ScriptFrequencyFactor;
102 const float r = freq / (float) SampleRate; // frequency alteration quotient
103 c = (int) (intLimit * r);
104
105 uiLevel = 0;
106 }
107
108 /**
109 * Should be invoked after the LFO is triggered.
110 * @param phase From 0 to 360 degrees.
111 */
112 void setPhase(float phase) {
113 if (phase < 0) phase = 0;
114 if (phase > 360) phase = 360;
115 phase /= 360.0f;
116 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
117 uiLevel = intLimit * phase;
118 }
119
120 void setFrequency(float Frequency, unsigned int SampleRate) {
121 this->Frequency = Frequency;
122 const float freq = Frequency * this->ScriptFrequencyFactor;
123 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
124 float r = freq / (float) SampleRate; // frequency alteration quotient
125 c = (int) (intLimit * r);
126 }
127
128 void setScriptDepthFactor(float factor, bool isFinal) {
129 this->ScriptDepthFactor = factor;
130 // set or reset this script depth parameter to be the sole
131 // source for the LFO depth
132 if (isFinal && !this->pFinalDepth)
133 this->pFinalDepth = &this->ScriptDepthFactor;
134 else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
135 this->pFinalDepth = NULL;
136 // recalculate upon new depth
137 updateByMIDICtrlValue(this->ExtControlValue);
138 }
139
140 void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
141 this->ScriptFrequencyFactor = factor;
142 // in case script frequency was set as "final" value before,
143 // reset it so that all sources are processed from now on
144 if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
145 this->pFinalFrequency = NULL;
146 // recalculate upon new frequency
147 setFrequency(this->Frequency, SampleRate);
148 }
149
150 void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
151 this->ScriptFrequencyFactor = hz;
152 // assign script's given frequency as sole source for the LFO
153 // frequency, thus ignore all other sources
154 if (!this->pFinalFrequency)
155 this->pFinalFrequency = &this->ScriptFrequencyFactor;
156 // recalculate upon new frequency
157 setFrequency(this->Frequency, SampleRate);
158 }
159
160 protected:
161 unsigned int uiLevel;
162 int c;
163 float offset; ///< only needed for signed range
164 float normalizer;
165 };
166
167
168 template<LFO::range_type_t RANGE>
169 class SawUpLFO : public SawLFO<RANGE, true> {
170 public:
171 SawUpLFO(float Max) : SawLFO<RANGE, true>::SawLFO(Max) { }
172 };
173
174 template<LFO::range_type_t RANGE>
175 class SawDownLFO : public SawLFO<RANGE, false> {
176 public:
177 SawDownLFO(float Max) : SawLFO<RANGE, false>::SawLFO(Max) { }
178 };
179
180 } // namespace LinuxSampler
181
182 #endif // __LS_SAWLFO_H__
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