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/* |
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* Copyright (c) 2017 - 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_FADE_H |
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#define LS_FADE_H |
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|
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#include "EaseInEaseOut.h" |
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|
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namespace LinuxSampler { |
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|
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#define DEFAULT_FADE_CURVE FADE_CURVE_EASE_IN_EASE_OUT |
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|
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enum fade_curve_t { |
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FADE_CURVE_LINEAR, |
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FADE_CURVE_EASE_IN_EASE_OUT, |
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}; |
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|
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/** @brief Fades a value with a selected curve. |
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* |
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* Implements a smoothed transition from one value to another value in a |
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* requested amount of time, either with an ease-in and ease-out algorithm |
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* (default), or linear. |
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*/ |
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class Fade : public EaseInEaseOut { |
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public: |
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Fade() : EaseInEaseOut() { |
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curveType = DEFAULT_FADE_CURVE; |
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Final = false; |
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} |
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|
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/** |
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* Select another curve type for this Fade and immediately prepare this |
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* Fade for operation with the new curve type. |
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*/ |
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void setCurve(fade_curve_t curve, float sampleRate) { |
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curveType = curve; |
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fadeTo(endValue, duration, sampleRate); |
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} |
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|
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/** |
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* Only set the new curve type. It is your responsibility to prepare this |
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* Fade for subsequent operation, i.e. by calling fadeTo() afterwards, |
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* otherwise the result of render() calls will be undefined. |
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*/ |
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void setCurveOnly(fade_curve_t curve) { |
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curveType = curve; |
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} |
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|
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/** |
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* Fade the current value in @duration seconds to the new value reflected |
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* by @a endValue, assuming the given @a sampleRate. |
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*/ |
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void fadeTo(float endValue, float duration, float sampleRate) { |
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if (curveType == FADE_CURVE_EASE_IN_EASE_OUT) |
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return EaseInEaseOut::fadeTo(endValue, duration, sampleRate); |
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else { |
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if (duration <= 0.f) { |
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setCurrentValue(endValue); |
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return; |
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} |
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this->endValue = endValue; |
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steps = duration * sampleRate; |
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c = (endValue - value) / float(steps); |
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} |
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} |
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|
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/** |
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* Fade the current value in the currently set default duration to the new |
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* value reflected by @a endValue, assuming the given @a sampleRate. |
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*/ |
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void fadeTo(float endValue, float sampleRate) { |
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fadeTo(endValue, duration, sampleRate); |
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} |
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|
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/** |
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* Proceed transition by exactly one sample point and return the current |
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* smoothed value at this stage. |
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*/ |
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inline float render() { |
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if (curveType == FADE_CURVE_EASE_IN_EASE_OUT) |
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return EaseInEaseOut::render(); |
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if (!steps) return endValue; |
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--steps; |
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value += c; |
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return value; |
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} |
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|
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inline void setFinal(bool b) { |
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Final = b; |
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} |
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|
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template<typename T> |
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inline void renderApplyTo(T& dst) { |
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if (Final) |
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dst = render(); |
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else |
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dst *= render(); |
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} |
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|
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template<typename T> |
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inline void applyCurrentValueTo(T& dst) { |
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if (Final) |
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dst = currentValue(); |
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else |
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dst *= currentValue(); |
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} |
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|
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private: |
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fade_curve_t curveType; |
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bool Final; |
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}; |
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|
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} // namespace LinuxSampler |
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|
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#endif // LS_FADE_H |