/[svn]/linuxsampler/trunk/src/engines/common/LFOSawIntMathOld.h
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Contents of /linuxsampler/trunk/src/engines/common/LFOSawIntMathOld.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
File MIME type: text/x-c++hdr
File size: 8647 byte(s)
* 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_SAWLFOINTOLD_H__
23 #define __LS_SAWLFOINTOLD_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 LFOSawIntMathOld : public LFOBase<RANGE> {
36 public:
37
38 /**
39 * Constructor
40 *
41 * @param Max - maximum value of the output levels
42 */
43 LFOSawIntMathOld(float Max) : LFOBase<RANGE>::LFOBase(Max) {
44 //NOTE: DO NOT add any custom initialization here, since it would break LFOCluster construction !
45 }
46
47 /**
48 * Calculates exactly one sample point of the LFO wave.
49 *
50 * @returns next LFO level
51 */
52 inline float render() {
53 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
54
55 uiLevel += c;
56 if (RANGE == LFO::range_unsigned)
57 return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel);
58 else /* signed range */
59 return normalizer * (float) (SAWUP ? uiLevel : intLimit - uiLevel) + offset;
60 }
61
62 /**
63 * Update LFO depth with a new external controller value.
64 *
65 * @param ExtControlValue - new external controller value
66 */
67 inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
68 this->ExtControlValue = ExtControlValue;
69
70 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
71 const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
72 if (RANGE == LFO::range_unsigned) {
73 normalizer = max / (float) intLimit;
74 } else { // signed range
75 normalizer = max / (float) intLimit * 2.0f;
76 offset = -max;
77 }
78 }
79
80 /**
81 * Will be called by the voice when the key / voice was triggered.
82 *
83 * @param Frequency - frequency of the oscillator in Hz
84 * @param StartLevel - not implemented
85 * @param InternalDepth - firm, internal oscillator amplitude
86 * @param ExtControlDepth - defines how strong the external MIDI
87 * controller has influence on the
88 * oscillator amplitude
89 * @param FlipPhase - not implemented
90 * @param SampleRate - current sample rate of the engines
91 * audio output signal
92 */
93 virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
94 this->Frequency = Frequency;
95 this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
96 this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
97 this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
98 this->pFinalDepth = NULL;
99 this->pFinalFrequency = NULL;
100
101 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
102 const float freq = Frequency * this->ScriptFrequencyFactor;
103 const float r = freq / (float) SampleRate; // frequency alteration quotient
104 c = (int) (intLimit * r);
105
106 uiLevel = 0;
107 }
108
109 /**
110 * Should be invoked after the LFO is triggered.
111 * @param phase From 0 to 360 degrees.
112 */
113 void setPhase(float phase) {
114 if (phase < 0) phase = 0;
115 if (phase > 360) phase = 360;
116 phase /= 360.0f;
117 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
118 uiLevel = intLimit * phase;
119 }
120
121 void setFrequency(float Frequency, unsigned int SampleRate) {
122 this->Frequency = Frequency;
123 const float freq = Frequency * this->ScriptFrequencyFactor;
124 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
125 float r = freq / (float) SampleRate; // frequency alteration quotient
126 c = (int) (intLimit * r);
127 }
128
129 void setScriptDepthFactor(float factor, bool isFinal) {
130 this->ScriptDepthFactor = factor;
131 // set or reset this script depth parameter to be the sole
132 // source for the LFO depth
133 if (isFinal && !this->pFinalDepth)
134 this->pFinalDepth = &this->ScriptDepthFactor;
135 else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
136 this->pFinalDepth = NULL;
137 // recalculate upon new depth
138 updateByMIDICtrlValue(this->ExtControlValue);
139 }
140
141 void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
142 this->ScriptFrequencyFactor = factor;
143 // in case script frequency was set as "final" value before,
144 // reset it so that all sources are processed from now on
145 if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
146 this->pFinalFrequency = NULL;
147 // recalculate upon new frequency
148 setFrequency(this->Frequency, SampleRate);
149 }
150
151 void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
152 this->ScriptFrequencyFactor = hz;
153 // assign script's given frequency as sole source for the LFO
154 // frequency, thus ignore all other sources
155 if (!this->pFinalFrequency)
156 this->pFinalFrequency = &this->ScriptFrequencyFactor;
157 // recalculate upon new frequency
158 setFrequency(this->Frequency, SampleRate);
159 }
160
161 protected:
162 unsigned int uiLevel;
163 int c;
164 float offset; ///< only needed for signed range
165 float normalizer;
166 };
167
168
169 template<LFO::range_type_t RANGE>
170 class SawUpLFO : public LFOSawIntMathOld<RANGE, true> {
171 public:
172 SawUpLFO(float Max) : LFOSawIntMathOld<RANGE, true>::LFOSawIntMathOld(Max) { }
173 };
174
175 template<LFO::range_type_t RANGE>
176 class SawDownLFO : public LFOSawIntMathOld<RANGE, false> {
177 public:
178 SawDownLFO(float Max) : LFOSawIntMathOld<RANGE, false>::LFOSawIntMathOld(Max) { }
179 };
180
181 } // namespace LinuxSampler
182
183 #endif // __LS_SAWLFOINTOLD_H__

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