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

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Revision 3625 - (show annotations) (download) (as text)
Thu Oct 3 13:37:25 2019 UTC (4 years, 5 months ago) by schoenebeck
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* gig format extension: Added support for different LFO wave forms
  (currently either sine [default], triangle, saw or square).

* gig format extension: Added support for LFO phase displacement
  (0°..360°).

* gig format extension: Added support for flipping LFO polarity on LFO 3
  (in the original gig format this was only available for LFO 1 and LFO 2).

* Bumped version (2.1.1.svn22).

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_SINELFO_BUILTIN_H__
23 #define __LS_SINELFO_BUILTIN_H__
24
25 #include "LFOBase.h"
26
27 namespace LinuxSampler {
28
29 /** @brief Sine LFO (using built-in sin() function as implementation)
30 */
31 template<LFO::range_type_t RANGE>
32 class LFOSineBuiltinFn : public LFOBase<RANGE> {
33 public:
34
35 /**
36 * Constructor
37 *
38 * @param Max - maximum value of the output levels
39 */
40 LFOSineBuiltinFn(float Max) : LFOBase<RANGE>::LFOBase(Max) {
41 //NOTE: DO NOT add any custom initialization here, since it would break LFOCluster construction !
42 }
43
44 /**
45 * Calculates exactly one sample point of the LFO wave.
46 *
47 * @returns next LFO level
48 */
49 inline float render() {
50 uiLevel += c;
51 if (RANGE == LFO::range_unsigned)
52 return normalizer * (sin(c2 * (float)uiLevel) + 1.0f);
53 else /* signed range */
54 return normalizer * sin(c2 * (float)uiLevel);
55 }
56
57 /**
58 * Update LFO depth with a new external controller value.
59 *
60 * @param ExtControlValue - new external controller value
61 */
62 inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
63 this->ExtControlValue = ExtControlValue;
64
65 //const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
66 const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
67 if (RANGE == LFO::range_unsigned) {
68 normalizer = max / 2.0f;
69 } else { // signed range
70 normalizer = max;
71 }
72 }
73
74 /**
75 * Will be called by the voice when the key / voice was triggered.
76 *
77 * @param Frequency - frequency of the oscillator in Hz
78 * @param StartLevel - not implemented
79 * @param InternalDepth - firm, internal oscillator amplitude
80 * @param ExtControlDepth - defines how strong the external MIDI
81 * controller has influence on the
82 * oscillator amplitude
83 * @param FlipPhase - not implemented
84 * @param SampleRate - current sample rate of the engines
85 * audio output signal
86 */
87 virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
88 this->Frequency = Frequency;
89 this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
90 this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
91 this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
92 this->pFinalDepth = NULL;
93 this->pFinalFrequency = NULL;
94
95 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
96 const float freq = Frequency * this->ScriptFrequencyFactor;
97 const float r = freq / (float) SampleRate; // frequency alteration quotient
98 c = (int) (intLimit * r);
99 c2 = (2.0f * M_PI) / (float) intLimit;
100
101 uiLevel = 0;
102 }
103
104 /**
105 * @param phase 0 to 360 degrees
106 */
107 void setPhase(float phase) {
108 if (phase < 0) phase = 0;
109 if (phase > 360) phase = 360;
110 phase /= 360.0f;
111 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
112 uiLevel = intLimit * phase;
113 }
114
115 void setFrequency(float Frequency, unsigned int SampleRate) {
116 this->Frequency = Frequency;
117 const float freq = Frequency * this->ScriptFrequencyFactor;
118 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
119 float r = freq / (float) SampleRate; // frequency alteration quotient
120 c = (int) (intLimit * r);
121 }
122
123 void setScriptDepthFactor(float factor, bool isFinal) {
124 this->ScriptDepthFactor = factor;
125 // set or reset this script depth parameter to be the sole
126 // source for the LFO depth
127 if (isFinal && !this->pFinalDepth)
128 this->pFinalDepth = &this->ScriptDepthFactor;
129 else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
130 this->pFinalDepth = NULL;
131 // recalculate upon new depth
132 updateByMIDICtrlValue(this->ExtControlValue);
133 }
134
135 void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
136 this->ScriptFrequencyFactor = factor;
137 // in case script frequency was set as "final" value before,
138 // reset it so that all sources are processed from now on
139 if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
140 this->pFinalFrequency = NULL;
141 // recalculate upon new frequency
142 setFrequency(this->Frequency, SampleRate);
143 }
144
145 void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
146 this->ScriptFrequencyFactor = hz;
147 // assign script's given frequency as sole source for the LFO
148 // frequency, thus ignore all other sources
149 if (!this->pFinalFrequency)
150 this->pFinalFrequency = &this->ScriptFrequencyFactor;
151 // recalculate upon new frequency
152 setFrequency(this->Frequency, SampleRate);
153 }
154
155 protected:
156 unsigned int uiLevel;
157 int c;
158 float c2;
159 float normalizer;
160 };
161
162 } // namespace LinuxSampler
163
164 #endif // __LS_SINELFO_BUILTIN_H__

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