Tween.hpp

A Tween manages the gradual shift in properties of one or more widgets over time.

To create a Tween, a duration must be specified, along with an optional default target. Once a Tween is setup, paths can be added to it, which represent the changes that should occur over the specified duration.

A path can be a function to call (with the 0.0 to 1.0 fraction of the time that’s gone by) or a variable to set to the current fraction. Dependants can also be set to refresh with each Tween update.

Available methods include: Tween & AddPath(std::function<void(double)> set_fun, double start_val, double end_val, std::function<double(double)> timing=LINEAR); Tween & AddPath(double & set_var, double start_val, double end_val, std::function<double(double)> timing=LINEAR); Tween & AddDependant(Widget w); void Start(); void Stop();

Todo:

Need to setup an AddPath that actually uses widgets and properties (stub in place).

Need a Reverse(), which swaps start and end positions.

Need a Reset()

class Tween

#include <Tween.hpp>

Public Functions

inline Tween(double d = 1.0, const Widget &t = nullptr): Build a new tween, specifying the duration it should run for and the widget it should modify.

inline ~Tween()

inline double GetDuration() const: Retrieve the full duration of this Tween.

inline Widget GetDefaultTarget() const: Which widget does this Tween modify?

inline Tween &SetDuration(double d): Change the duration of this Tween.

inline Tween &SetDefaultTarget(const Widget &w): Change the target of this tween.

inline Tween &AddPath(std::function<void(double)> set_fun, double start_val, double end_val, std::function<double(double)> timing = LINEAR): Alter the path of the change that this tween should take and the function it should call.

inline Tween &AddPath(double &set_var, double start_val, double end_val, std::function<double(double)> timing = LINEAR): Alter the path of the change that this tween should take and the variable it should modify.

inline Tween &AddPath(Widget w, std::string setting, double start_val, double end_val): Alter the path of the change that this tween should take and the widget setting it should alter. (TODO!)

inline Tween &AddUpdate(std::function<void(void)> ud_fun): Add an additional function to update as the Tween runs.

inline Tween &AddDependant(Widget w): Add a dependant Widget to update as the Tween runs.

inline void Start(): Start running this Tween, as configured.

inline void Stop(): Pause this Tween.

Private Functions

inline void AdvanceFrame()

Private Members

double duration

Widget default_target

vector<Path*> paths

vector<Event*> events

vector<std::function<void()>> update_funs

vector<Widget> dependants

bool running

size_t callback_id

double start_time

double cur_time

double run_time

Private Static Functions

static inline double LINEAR(double in)

struct Event

Public Members

double time

std::function<void()> trigger

struct Path

Public Functions

inline void Set(const double frac)

Public Members

std::function<void(double)> set_fun

double start_val

double end_val

std::function<double(double)> timing