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/* |
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* Copyright (c) 2019 Christian Schoenebeck |
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* |
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* http://www.linuxsampler.org |
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* |
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* This file is part of LinuxSampler and released under the same terms. |
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* See README file for details. |
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*/ |
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|
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#ifndef LS_LFO_H |
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#define LS_LFO_H |
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|
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#include "../common/global.h" |
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#include "../common/optional.h" |
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|
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namespace LinuxSampler { |
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|
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// *************** types *************** |
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// * |
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|
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/** @brief Low Frequency Oscillator (public API class) |
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* |
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* Generalized, convenient cluster class encapsulating all the sampler's |
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* Low Frequency Oscillator implementations. |
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* |
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* @b NOTE: This class is @b NOT used by the sampler at all! This class is |
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* solely exported to the sampler's public API to allow third-party apps |
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* (e.g. Gigedit) to use our LFO implementations (e.g. for visualizing an |
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* LFO's wave form in an instrument editor GUI application) in a convenient |
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* way and by an unified API, and exactly with same LFO wave form values |
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* that would be generated by the sampler at playback time. |
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* |
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* @b NOTE: For sampler internal purposes use the template variant class |
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* LFOCluster for efficiency reasons instead! See the discussion on |
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* LFOCluster for details why. |
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*/ |
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class LFO { |
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public: |
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/** |
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* Oscillator's fundamental function type / wave form type. |
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*/ |
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enum wave_t { |
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wave_sine, |
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wave_triangle, |
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wave_saw, |
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wave_square, |
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}; |
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|
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/** |
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* Whether the LFO should have positive AND negative value range |
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* (signed) or only a positive value range (unsigned). |
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*/ |
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enum range_type_t { |
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range_signed, ///< LFO's level will wave between -max ... +max |
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range_unsigned ///< LFO's level will wave between 0 ... +max |
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}; |
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|
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/** |
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* Defines the start level of the LFO wave within the given value range. |
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*/ |
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enum start_level_t { |
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start_level_max, ///< wave starts from given maximum level |
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start_level_mid, ///< wave starts from the middle of the given value range |
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start_level_min ///< wave starts from given minimum level |
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}; |
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|
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struct SetupOpt { |
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optional<wave_t> waveType; ///< LFO's fundamental function type, that its wave form type, e.g. sine, triangle, saw, etc. (default: sine) |
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optional<range_type_t> rangeType; |
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optional<float> frequency; ///< frequency of the oscillator in Hz (default: 1 Hz) |
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optional<float> phase; ///< optional phase displacement of the LFO function in degrees, between 0��..360�� (default: 0��) |
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optional<start_level_t> startLevel; ///< on which initial value level the LFO wave should start (default: start_level_mid) |
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optional<uint16_t> internalDepth; ///< firm, internal oscillator's amplitude (0..1200, default: 0) |
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optional<uint16_t> midiControllerDepth; ///< defines how strong the external MIDI controller has influence on the oscillator's amplitude (0..1200, default: 0) |
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optional<bool> flipPolarity; ///< if true: inverts the oscillator wave vertically (default: false) |
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optional<float> samplerate; ///< sample rate to be assumed by the LFO (default: 44100) |
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optional<float> maxValue; |
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}; |
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|
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/** @brief Constructs LFO with default values. |
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* |
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* Initializes the LFO with default values for all LFO parameters |
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* (that is for e.g. frequency, sample rate, wave form type, etc.). |
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* |
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* You should call setup() afterwards to actually initialize the LFO |
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* with the desired parameters. |
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*/ |
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LFO(); |
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|
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/** @brief Frees LFO's resources. |
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* |
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* De-allocates all resources previously been allocated by this LFO |
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* object. |
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*/ |
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virtual ~LFO(); |
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|
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/** |
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* Setup the LFO with the relevant parameters (e.g. frequency, wave |
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* form type, etc.). |
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*/ |
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void setup(const SetupOpt& opt); |
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|
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/** |
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* Calculates exactly one sample point of the LFO wave. |
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* |
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* @returns next LFO level |
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*/ |
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float render(); |
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|
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/** |
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* Update LFO depth with a new external MIDI controller value. |
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* |
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* @param midiCCValue - new MIDI controller value (0..127) |
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*/ |
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void setMIDICtrlValue(uint8_t midiCCValue); |
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|
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private: |
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struct LFOPriv* SELF; |
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}; |
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|
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} // namespace LinuxSampler |
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|
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#endif // LS_LFO_H |