engines/common/LFOSawIntMathNew.h

/*
 * Copyright (c) 2019 Christian Schoenebeck
 *
 * http://www.linuxsampler.org
 *
 * This file is part of LinuxSampler and released under the same terms.
 * See README file for details.
 */

#ifndef LS_LFOSAWINTMATH_H
#define LS_LFOSAWINTMATH_H

#include <stdlib.h>
#include "LFOBase.h"

namespace LinuxSampler {

    /** @brief Saw LFO (int math implementation)
     *
     * This is a Saw Low Frequency Oscillator which uses pure integer
     * math (without branches) to synthesize the saw wave.
     */
    template<LFO::range_type_t RANGE>
    class LFOSawIntMath : public LFOBase<RANGE> {
        public:
            /**
             * Constructor
             *
             * @param Max - maximum value of the output levels
             */
            LFOSawIntMath(float Max) : LFOBase<RANGE>::LFOBase(Max) {
            }

            /**
             * Calculates exactly one sample point of the LFO wave.
             *
             * @returns next LFO level
             */
            inline float render() {
                this->slope += this->c;
                if (RANGE == LFO::range_unsigned)
                    return this->denormalizer * float(this->slope);
                else // signed range
                    return this->denormalizer * float(int(this->slope) + this->offset);
            }

            /**
             * Update LFO depth with a new external controller value.
             *
             * @param ExtControlValue - new external controller value
             */
            inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
                this->ExtControlValue = ExtControlValue;

                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
                if (RANGE == LFO::range_unsigned) {
                    denormalizer = max / (float) intLimit / 2.0;
                } else { // signed range
                    denormalizer = max / (float) intLimit * 2.0;
                    offset       = -max;
                }
            }

            /**
             * Will be called by the voice when the key / voice was triggered.
             *
             * @param Frequency       - frequency of the oscillator in Hz
             * @param StartLevel      - on which level the wave should start
             * @param InternalDepth   - firm, internal oscillator amplitude
             * @param ExtControlDepth - defines how strong the external MIDI
             *                          controller has influence on the
             *                          oscillator amplitude
             * @param FlipPhase       - inverts the oscillator wave against
             *                          a horizontal axis
             * @param SampleRate      - current sample rate of the engines
             *                          audio output signal
             */
            void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
                this->Frequency            = Frequency;
                this->InternalDepth        = (InternalDepth / 1200.0f) * this->Max;
                this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
                this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
                if (RANGE == LFO::range_unsigned) {
                    this->InternalDepth        *= 2.0f;
                    this->ExtControlDepthCoeff *= 2.0f;
                }
                this->pFinalDepth = NULL;
                this->pFinalFrequency = NULL;

                this->flipPhaseFactor = FlipPhase ? -1 : 1;
                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                const float freq = Frequency * this->ScriptFrequencyFactor;
                const float r = freq / (float) SampleRate; // frequency alteration quotient
                c = int(intLimit * r * this->flipPhaseFactor);

                const int slopeAtMid = (RANGE == LFO::range_unsigned) ? intLimit / 2 : intLimit;
                const int slopeAtMin = (RANGE == LFO::range_unsigned) ? intLimit : intLimit / 2;

                switch (StartLevel) {
                    case LFO::start_level_mid:
                        //slope = (FlipPhase) ? slopeAtMin : slopeAtMid;
                        slope = slopeAtMid;
                        break;

                    // with saw function, min and max are actually always the same thing
                    // (and no matter if FlipPhase or not)
                    case LFO::start_level_max:
                    case LFO::start_level_min:
                        slope = slopeAtMin;
                        break;
                }
            }

            /**
             * Should be invoked after the LFO is triggered.
             * @param phase From 0 to 360 degrees.
             */
            void setPhase(float phase) {
                if (phase < 0) phase = 0;
                if (phase > 360) phase = 360;
                phase /= 360.0f;
                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                slope += intLimit * phase * flipPhaseFactor;
            }

            void setFrequency(float Frequency, unsigned int SampleRate) {
                this->Frequency = Frequency;
                const float freq = Frequency * this->ScriptFrequencyFactor;
                const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
                float r = freq / (float) SampleRate; // frequency alteration quotient
                c = int(intLimit * r * this->flipPhaseFactor);
            }

            void setScriptDepthFactor(float factor, bool isFinal) {
                this->ScriptDepthFactor = factor;
                // set or reset this script depth parameter to be the sole
                // source for the LFO depth
                if (isFinal && !this->pFinalDepth)
                    this->pFinalDepth = &this->ScriptDepthFactor;
                else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
                    this->pFinalDepth = NULL;
                // recalculate upon new depth
                updateByMIDICtrlValue(this->ExtControlValue);
            }

            void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
                this->ScriptFrequencyFactor = factor;
                // in case script frequency was set as "final" value before,
                // reset it so that all sources are processed from now on
                if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
                    this->pFinalFrequency = NULL;
                // recalculate upon new frequency
                setFrequency(this->Frequency, SampleRate);
            }

            void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
                this->ScriptFrequencyFactor = hz;
                // assign script's given frequency as sole source for the LFO
                // frequency, thus ignore all other sources
                if (!this->pFinalFrequency)
                    this->pFinalFrequency = &this->ScriptFrequencyFactor;
                // recalculate upon new frequency
                setFrequency(this->Frequency, SampleRate);
            }

        protected:
            unsigned int slope;
            unsigned int c;
            float offset; ///< only needed for signed range
            float denormalizer;
            float flipPhaseFactor; ///< Factor instead of boolean to avoid branches.
    };

} // namespace LinuxSampler

#endif // LS_LFOSAWINTMATH_H
1	schoenebeck	3612	/*
2			* Copyright (c) 2019 Christian Schoenebeck
3			*
4			* http://www.linuxsampler.org
5			*
6			* This file is part of LinuxSampler and released under the same terms.
7			* See README file for details.
8			*/
9
10			#ifndef LS_LFOSAWINTMATH_H
11			#define LS_LFOSAWINTMATH_H
12
13			#include <stdlib.h>
14			#include "LFOBase.h"
15
16			namespace LinuxSampler {
17
18			/** @brief Saw LFO (int math implementation)
19			*
20			* This is a Saw Low Frequency Oscillator which uses pure integer
21			* math (without branches) to synthesize the saw wave.
22			*/
23			template<LFO::range_type_t RANGE>
24			class LFOSawIntMath : public LFOBase<RANGE> {
25			public:
26			/**
27			* Constructor
28			*
29			* @param Max - maximum value of the output levels
30			*/
31			LFOSawIntMath(float Max) : LFOBase<RANGE>::LFOBase(Max) {
32			}
33
34			/**
35			* Calculates exactly one sample point of the LFO wave.
36			*
37			* @returns next LFO level
38			*/
39			inline float render() {
40			this->slope += this->c;
41			if (RANGE == LFO::range_unsigned)
42			return this->denormalizer * float(this->slope);
43			else // signed range
44			return this->denormalizer * float(int(this->slope) + this->offset);
45			}
46
47			/**
48			* Update LFO depth with a new external controller value.
49			*
50			* @param ExtControlValue - new external controller value
51			*/
52			inline void updateByMIDICtrlValue(const uint16_t& ExtControlValue) {
53			this->ExtControlValue = ExtControlValue;
54
55			const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
56			const float max = (this->InternalDepth + ExtControlValue * this->ExtControlDepthCoeff) * this->ScriptDepthFactor;
57			if (RANGE == LFO::range_unsigned) {
58			denormalizer = max / (float) intLimit / 2.0;
59			} else { // signed range
60			denormalizer = max / (float) intLimit * 2.0;
61			offset = -max;
62			}
63			}
64
65			/**
66			* Will be called by the voice when the key / voice was triggered.
67			*
68			* @param Frequency - frequency of the oscillator in Hz
69			* @param StartLevel - on which level the wave should start
70			* @param InternalDepth - firm, internal oscillator amplitude
71			* @param ExtControlDepth - defines how strong the external MIDI
72			* controller has influence on the
73			* oscillator amplitude
74			* @param FlipPhase - inverts the oscillator wave against
75			* a horizontal axis
76			* @param SampleRate - current sample rate of the engines
77			* audio output signal
78			*/
79			void trigger(float Frequency, LFO::start_level_t StartLevel, uint16_t InternalDepth, uint16_t ExtControlDepth, bool FlipPhase, unsigned int SampleRate) {
80			this->Frequency = Frequency;
81			this->InternalDepth = (InternalDepth / 1200.0f) * this->Max;
82			this->ExtControlDepthCoeff = (((float) ExtControlDepth / 1200.0f) / 127.0f) * this->Max;
83			this->ScriptFrequencyFactor = this->ScriptDepthFactor = 1.f; // reset for new voice
84			if (RANGE == LFO::range_unsigned) {
85			this->InternalDepth *= 2.0f;
86			this->ExtControlDepthCoeff *= 2.0f;
87			}
88			this->pFinalDepth = NULL;
89			this->pFinalFrequency = NULL;
90
91			this->flipPhaseFactor = FlipPhase ? -1 : 1;
92			const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
93			const float freq = Frequency * this->ScriptFrequencyFactor;
94			const float r = freq / (float) SampleRate; // frequency alteration quotient
95			c = int(intLimit * r * this->flipPhaseFactor);
96
97			const int slopeAtMid = (RANGE == LFO::range_unsigned) ? intLimit / 2 : intLimit;
98			const int slopeAtMin = (RANGE == LFO::range_unsigned) ? intLimit : intLimit / 2;
99
100			switch (StartLevel) {
101			case LFO::start_level_mid:
102			//slope = (FlipPhase) ? slopeAtMin : slopeAtMid;
103			slope = slopeAtMid;
104			break;
105
106			// with saw function, min and max are actually always the same thing
107			// (and no matter if FlipPhase or not)
108			case LFO::start_level_max:
109			case LFO::start_level_min:
110			slope = slopeAtMin;
111			break;
112			}
113			}
114
115			/**
116			* Should be invoked after the LFO is triggered.
117			* @param phase From 0 to 360 degrees.
118			*/
119			void setPhase(float phase) {
120			if (phase < 0) phase = 0;
121			if (phase > 360) phase = 360;
122			phase /= 360.0f;
123			const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
124			slope += intLimit * phase * flipPhaseFactor;
125			}
126
127			void setFrequency(float Frequency, unsigned int SampleRate) {
128			this->Frequency = Frequency;
129			const float freq = Frequency * this->ScriptFrequencyFactor;
130			const unsigned int intLimit = (unsigned int) -1; // all 0xFFFF...
131			float r = freq / (float) SampleRate; // frequency alteration quotient
132			c = int(intLimit * r * this->flipPhaseFactor);
133			}
134
135			void setScriptDepthFactor(float factor, bool isFinal) {
136			this->ScriptDepthFactor = factor;
137			// set or reset this script depth parameter to be the sole
138			// source for the LFO depth
139			if (isFinal && !this->pFinalDepth)
140			this->pFinalDepth = &this->ScriptDepthFactor;
141			else if (!isFinal && this->pFinalDepth == &this->ScriptDepthFactor)
142			this->pFinalDepth = NULL;
143			// recalculate upon new depth
144			updateByMIDICtrlValue(this->ExtControlValue);
145			}
146
147			void setScriptFrequencyFactor(float factor, unsigned int SampleRate) {
148			this->ScriptFrequencyFactor = factor;
149			// in case script frequency was set as "final" value before,
150			// reset it so that all sources are processed from now on
151			if (this->pFinalFrequency == &this->ScriptFrequencyFactor)
152			this->pFinalFrequency = NULL;
153			// recalculate upon new frequency
154			setFrequency(this->Frequency, SampleRate);
155			}
156
157			void setScriptFrequencyFinal(float hz, unsigned int SampleRate) {
158			this->ScriptFrequencyFactor = hz;
159			// assign script's given frequency as sole source for the LFO
160			// frequency, thus ignore all other sources
161			if (!this->pFinalFrequency)
162			this->pFinalFrequency = &this->ScriptFrequencyFactor;
163			// recalculate upon new frequency
164			setFrequency(this->Frequency, SampleRate);
165			}
166
167			protected:
168			unsigned int slope;
169			unsigned int c;
170			float offset; ///< only needed for signed range
171			float denormalizer;
172			float flipPhaseFactor; ///< Factor instead of boolean to avoid branches.
173			};
174
175			} // namespace LinuxSampler
176
177			#endif // LS_LFOSAWINTMATH_H