/[svn]/linuxsampler/trunk/src/engines/common/LFOPulse.h
ViewVC logotype

Annotation of /linuxsampler/trunk/src/engines/common/LFOPulse.h

Parent Directory Parent Directory | Revision Log Revision Log


Revision 3625 - (hide annotations) (download) (as text)
Thu Oct 3 13:37:25 2019 UTC (4 years, 6 months ago) by schoenebeck
File MIME type: text/x-c++hdr
File size: 8095 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 iliev 2223 /***************************************************************************
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_PULSELFO_H__
23     #define __LS_PULSELFO_H__
24    
25     #include "LFOBase.h"
26    
27     namespace LinuxSampler {
28    
29     /** @brief Pulse LFO (int math implementation)
30     *
31     * This is a pulse Low Frequency Oscillator which uses pure integer
32     * math (without branches) to synthesize the pulse wave.
33     */
34 schoenebeck 3612 template<LFO::range_type_t RANGE, int WIDTH /* in permilles */>
35 schoenebeck 3614 class LFOPulse : public LFOBase<RANGE> {
36 iliev 2223 public:
37    
38     /**
39     * Constructor
40     *
41     * @param Max - maximum value of the output levels
42     */
43 schoenebeck 3614 LFOPulse(float Max) : LFOBase<RANGE>::LFOBase(Max) {
44 schoenebeck 3625 //NOTE: DO NOT add any custom initialization here, since it would break LFOCluster construction !
45 iliev 2223 }
46    
47     /**
48     * Calculates exactly one sample point of the LFO wave.
49     *
50     * @returns next LFO level
51     */
52     inline float render() {
53     uiLevel += c;
54 schoenebeck 3612 if (RANGE == LFO::range_unsigned)
55 iliev 2223 return uiLevel <= width ? normalizer : 0;
56     else /* signed range */
57     return uiLevel <= width ? normalizer : -normalizer;
58     }
59    
60     /**
61     * Update LFO depth with a new external controller value.
62     *
63     * @param ExtControlValue - new external controller value
64     */
65 schoenebeck 3118 inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
66     this->ExtControlValue = ExtControlValue;
67    
68     const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
69 iliev 2223 normalizer = max;
70     }
71    
72     /**
73     * Will be called by the voice when the key / voice was triggered.
74     *
75     * @param Frequency - frequency of the oscillator in Hz
76     * @param InternalDepth - firm, internal oscillator amplitude
77     * @param ExtControlDepth - defines how strong the external MIDI
78     * controller has influence on the
79     * oscillator amplitude
80     * @param FlipPhase - inverts the oscillator wave against
81     * a horizontal axis
82     * @param SampleRate - current sample rate of the engines
83     * audio output signal
84     * @param PulseWidth - the pulse width in percents
85     */
86     void trigger(float Frequency, uint16_t InternalDepth, uint16_t ExtControlDepth, float PulseWidth, unsigned int SampleRate) {
87 schoenebeck 3118 this->Frequency = Frequency;
88 iliev 2223 this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
89     this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
90 schoenebeck 3118 this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
91 schoenebeck 3561 this->pFinalDepth = NULL;
92     this->pFinalFrequency = NULL;
93 iliev 2223
94     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
95 schoenebeck 3118 const float freq = Frequency * this->ScriptFrequencyFactor;
96     const float r = freq / (float) SampleRate; // frequency alteration quotient
97 iliev 2223 c = (int) (intLimit * r);
98     width = (PulseWidth / 100.0) * intLimit;
99    
100     uiLevel = 0;
101     }
102    
103 schoenebeck 3612 virtual void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
104 iliev 2223 trigger(Frequency, InternalDepth, ExtControlDepth, WIDTH / 10.0f, SampleRate);
105     }
106 iliev 2225
107     /**
108     * Should be invoked after the LFO is triggered.
109     * @param phase From 0 to 360 degrees.
110     */
111     void setPhase(float phase) {
112     if (phase < 0) phase = 0;
113     if (phase > 360) phase = 360;
114     phase /= 360.0f;
115     const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
116     uiLevel = intLimit * phase;
117     }
118 iliev 2227
119     void setFrequency(float Frequency, unsigned int SampleRate) {
120 schoenebeck 3118 this->Frequency = Frequency;
121     const float freq = Frequency * this->ScriptFrequencyFactor;
122 iliev 2227 const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
123 schoenebeck 3118 float r = freq / (float) SampleRate; // frequency alteration quotient
124 iliev 2227 c = (int) (intLimit * r);
125     }
126 iliev 2223
127 schoenebeck 3561 void setScriptDepthFactor(float factor, bool isFinal) {
128 schoenebeck 3118 this->ScriptDepthFactor = factor;
129 schoenebeck 3561 // set or reset this script depth parameter to be the sole
130     // source for the LFO depth
131     if (isFinal && !this->pFinalDepth)
132     this->pFinalDepth = &this->ScriptDepthFactor;
133     else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
134     this->pFinalDepth = NULL;
135     // recalculate upon new depth
136 schoenebeck 3118 updateByMIDICtrlValue(this->ExtControlValue);
137     }
138    
139     void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
140     this->ScriptFrequencyFactor = factor;
141 schoenebeck 3561 // in case script frequency was set as "final" value before,
142     // reset it so that all sources are processed from now on
143     if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
144     this->pFinalFrequency = NULL;
145     // recalculate upon new frequency
146 schoenebeck 3118 setFrequency(this->Frequency, SampleRate);
147     }
148    
149 schoenebeck 3561 void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
150     this->ScriptFrequencyFactor = hz;
151     // assign script's given frequency as sole source for the LFO
152     // frequency, thus ignore all other sources
153     if (!this->pFinalFrequency)
154     this->pFinalFrequency = &this->ScriptFrequencyFactor;
155     // recalculate upon new frequency
156     setFrequency(this->Frequency, SampleRate);
157     }
158    
159 iliev 2223 protected:
160     unsigned int uiLevel;
161     unsigned int width;
162     int c;
163     float normalizer;
164     };
165    
166     } // namespace LinuxSampler
167    
168     #endif // __LS_PULSELFO_H__

  ViewVC Help
Powered by ViewVC