core/animation/curve.h

/*
 * Copyright (c) 2021-2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef FOUNDATION_ACE_FRAMEWORKS_CORE_ANIMATION_CURVE_H
#define FOUNDATION_ACE_FRAMEWORKS_CORE_ANIMATION_CURVE_H

#include "base/memory/ace_type.h"
#include "base/utils/macros.h"
#include "base/utils/utils.h"
#ifdef LINUX_PLATFORM
#include <functional>
#endif

namespace OHOS::Ace {
class NativeCurveHelper;

constexpr double SQUARE = 2.0;

// The running time of the curve needs to be normalized to the interval of 0.0 to 1.0;
// Relatively, the corresponding value of the curve also needs to be normalized to the interval of 0.0 to 1.0;
class ACE_EXPORT_WITH_PREVIEW Curve : public AceType {
    DECLARE_ACE_TYPE(Curve, AceType);

public:
    Curve() = default;
    ~Curve() override = default;

    // Returns the value at specific time.
    // Notice: The value of time must be between 0.0 and 1.0 since the curve uses normalized timestamp.
    float Move(float time)
    {
        // time always between 0.0 and 1.0
        return MoveInternal(time);
    }

    // Each subclass needs to override this method to implement motion in the 0.0 to 1.0 time range.
    virtual float MoveInternal(float time) = 0;
    virtual const std::string ToString()
    {
        return "";
    }
};

// The reverse curve is used to convert the direction of motion.
// It uses the 1.0->0.0 motion of the child curve to achieve the reverse purpose.
class ReverseCurve final : public Curve {
    DECLARE_ACE_TYPE(ReverseCurve, Curve);

public:
    explicit ReverseCurve(const RefPtr<Curve>& curve) : curve_(curve) {}
    ~ReverseCurve() override = default;

    float MoveInternal(float time) final
    {
        if (!curve_) {
            return 0.0f;
        }

        if (time > 1.0f || time < 0.0f) {
            return curve_->MoveInternal(0.0f);
        }
        return curve_->MoveInternal(1.0f - time);
    }

private:
    const RefPtr<Curve> curve_;
};

class ComplementaryCurve final : public Curve {
    DECLARE_ACE_TYPE(ComplementaryCurve, Curve);

public:
    explicit ComplementaryCurve(const RefPtr<Curve>& curve) : curve_(curve) {}
    ~ComplementaryCurve() override = default;

    float MoveInternal(float time) final
    {
        if (!curve_) {
            return 0.0f;
        }

        if (time > 1.0f || time < 0.0f) {
            return curve_->MoveInternal(0.0f);
        }
        return 1.0f - curve_->MoveInternal(time);
    }

private:
    const RefPtr<Curve> curve_;
};

class DecelerationCurve final : public Curve {
    DECLARE_ACE_TYPE(DecelerationCurve, Curve);

public:
    float MoveInternal(float time) override
    {
        return 1.0f - std::pow(1.0f - time, SQUARE);
    }
};

class LinearCurve final : public Curve {
    DECLARE_ACE_TYPE(LinearCurve, Curve);

public:
    float MoveInternal(float time) override
    {
        if (time < fractionMin || time > fractionMax) {
            LOGE("LinearCurve MoveInternal: time is less than 0 or larger than 1, return 1");
            return fractionMax;
        }
        return time;
    }
private:
    float fractionMin = 0.0f;
    float fractionMax = 1.0f;
};

class SineCurve final : public Curve {
    DECLARE_ACE_TYPE(SineCurve, Curve);

public:
    float MoveInternal(float time) override
    {
        static constexpr float PI = 3.14f;
        return std::sin(PI * time / 2.0f); // half period
    }
};

class ElasticsCurve final : public Curve {
    DECLARE_ACE_TYPE(ElasticsCurve, Curve);

public:
    explicit ElasticsCurve(float tension) : tension_(tension) {}
    ~ElasticsCurve() override = default;
    float MoveInternal(float time) override
    {
        float para = time - 1.0f;
        return para * para * ((tension_ + 1.0f) * para + tension_) + 1.0f;
    }

private:
    float tension_ = 2.0f; // Default Elastics tension.
};

enum class StepsCurvePosition {
    START,
    END,
};

class StepsCurve : public Curve {
    DECLARE_ACE_TYPE(StepsCurve, Curve);

public:
    explicit StepsCurve(int32_t steps, StepsCurvePosition position = StepsCurvePosition::START)
        : steps_(steps <= 0 ? 1 : steps), position_(position) {}
    ~StepsCurve() override = default;

    float MoveInternal(float time) override
    {
        if (time < fractionMin || time > fractionMax) {
            LOGE("StepsCurve MoveInternal: time is less than 0 or larger than 1, return 1");
            return fractionMax;
        }
        auto currentStep = static_cast<int32_t>(time * steps_);
        if (position_ == StepsCurvePosition::START) {
            currentStep++;
        }
        return static_cast<float>(currentStep) / steps_;
    }
    const std::string ToString() override
    {
        std::string curveString("steps");
        std::string comma(",");
        curveString.append(std::string("(") + std::to_string(steps_) + comma);
        if (position_ == StepsCurvePosition::START) {
            curveString.append(std::string("start"));
        } else {
            curveString.append(std::string("end"));
        }
        curveString.append(std::string(")"));
        return curveString;
    }
private:
    int32_t steps_;
    const StepsCurvePosition position_;
    float fractionMin = 0.0f;
    float fractionMax = 1.0f;

    friend class NativeCurveHelper;
};

class CustomCurve final : public Curve {
    DECLARE_ACE_TYPE(CustomCurve, Curve);

public:
    explicit CustomCurve(const std::function<float(float)>& func) : interpolateFunc_(func) {}
    ~CustomCurve() override = default;
    float MoveInternal(float time) override
    {
        float value = interpolateFunc_(time);
        return std::clamp(value, 0.f, 1.f);
    }

private:
    std::function<float(float)> interpolateFunc_;

    friend class NativeCurveHelper;
};

class ResponsiveSpringMotion final : public Curve {
    DECLARE_ACE_TYPE(ResponsiveSpringMotion, Curve);

public:
    ResponsiveSpringMotion(float response, float dampingRatio, float blendDuration = 0.0f)
        : response_(response), dampingRatio_(dampingRatio), blendDuration_(blendDuration) {}
    ~ResponsiveSpringMotion() override = default;
    // this MoveInterval function is not the real implementation of the function.
    // The curve should use the curve in rosen.
    float MoveInternal(float time) override
    {
        return 0.0f;
    }
    const std::string ToString() override
    {
        std::string curveString("responsive-spring-motion");
        std::string comma(",");
        curveString.append(std::string("(") + std::to_string(response_) + comma + std::to_string(dampingRatio_) +
                            comma + std::to_string(blendDuration_) + std::string(")"));
        return curveString;
    }
    float GetResponse() const
    {
        return response_;
    }
    float GetDampingRatio() const
    {
        return dampingRatio_;
    }
    float GetBlendDuration() const
    {
        return blendDuration_;
    }
    static constexpr float DEFAULT_SPRING_MOTION_RESPONSE = 0.55f;
    static constexpr float DEFAULT_SPRING_MOTION_DAMPING_RATIO = 0.825f;
    static constexpr float DEFAULT_SPRING_MOTION_BLEND_DURATION = 0.0f;
    static constexpr float DEFAULT_RESPONSIVE_SPRING_MOTION_RESPONSE = 0.15f;
    static constexpr float DEFAULT_RESPONSIVE_SPRING_MOTION_DAMPING_RATIO = 0.86f;
    static constexpr float DEFAULT_RESPONSIVE_SPRING_MOTION_BLEND_DURATION = 0.25f;
private:
    float response_;
    float dampingRatio_;
    float blendDuration_;
};

} // namespace OHOS::Ace

#endif // FOUNDATION_ACE_FRAMEWORKS_CORE_ANIMATION_CURVE_H