metaforce/Runtime/Character/CTimeScaleFunctions.hpp

#pragma once

#include "RetroTypes.hpp"
#include "CCharAnimTime.hpp"

namespace urde
{

enum class EVaryingAnimationTimeScaleType
{
    Constant,
    Linear
};

class IVaryingAnimationTimeScale
{
public:
    virtual ~IVaryingAnimationTimeScale() = default;
    virtual EVaryingAnimationTimeScaleType GetType() const=0;
    virtual float VTimeScaleIntegral(float lowerLimit, float upperLimit) const=0;
    virtual float VFindUpperLimit(float lowerLimit, float root) const=0;
    virtual std::unique_ptr<IVaryingAnimationTimeScale> VClone() const=0;
    virtual std::unique_ptr<IVaryingAnimationTimeScale> VGetFunctionMirrored(float value) const=0;
    std::unique_ptr<IVaryingAnimationTimeScale> Clone() const;
};

class CConstantAnimationTimeScale  : public IVaryingAnimationTimeScale
{
private:
    float x4_scale;
public:
    CConstantAnimationTimeScale(float scale) : x4_scale(scale) {}

    EVaryingAnimationTimeScaleType GetType() const { return EVaryingAnimationTimeScaleType::Constant; }
    float VTimeScaleIntegral(float lowerLimit, float upperLimit) const;
    float VFindUpperLimit(float lowerLimit, float root) const;
    std::unique_ptr<IVaryingAnimationTimeScale> VClone() const;
    std::unique_ptr<IVaryingAnimationTimeScale> VGetFunctionMirrored(float value) const;
};

class CLinearAnimationTimeScale : public IVaryingAnimationTimeScale
{
    struct CFunctionDescription
    {
        float x4_slope;
        float x8_yIntercept;
        float xc_t1;
        float x10_t2;
        std::unique_ptr<IVaryingAnimationTimeScale> FunctionMirroredAround(float value) const;
    } x4_desc;
    static float FindUpperLimitFromRoot(const CFunctionDescription& desc,
                                        float lowerLimit, float root);
    static float TimeScaleIntegralWithSortedLimits(const CFunctionDescription& desc,
                                                   float lowerLimit, float upperLimit);
public:
    CLinearAnimationTimeScale(const CCharAnimTime& t1, float y1,
                              const CCharAnimTime& t2, float y2);

    EVaryingAnimationTimeScaleType GetType() const {return EVaryingAnimationTimeScaleType::Linear;}
    float VTimeScaleIntegral(float lowerLimit, float upperLimit) const;
    float VFindUpperLimit(float lowerLimit, float root) const;
    std::unique_ptr<IVaryingAnimationTimeScale> VClone() const;
    std::unique_ptr<IVaryingAnimationTimeScale> VGetFunctionMirrored(float value) const;
};

}