Animate.hpp

Manage animations on a web site.

To build an animation, you must provide a function to be run repeatedly. When Start() is triggered, the function will be called 60 time per second (or as close as possible), until Stop() is caled.

class Animate

#include <Animate.hpp>

An object that, when active, repeatedly calls a function as fast as possible, to a maximum of 60 frames per second.

Parameters to the animation function can be:

double (representing time since the last frame)
a const reference to the animation object itself
nothing

Control methods: void Start() void Stop() void Step() void ToggleActive()

Access methods: bool GetActive() const bool GetDoStep() const double GetStartTime() const double GetPrevTime() const double GetCurTime() const double GetStepTime() const double GetRunTime() const int GetFrameCount() const

Config methods: void SetCallback(const std::function<void(const Animate &)> & fun) void SetCallback(const std::function<void(double)> & fun) void SetCallback(const std::function<void()> & fun)

Public Functions

inline Animate(): Setup an Animate object to call an anim_fun as fast as possible, at most 60 times a second. Call virtual function DoFrame() if no other functon is provided (which can be overridden if you derive a new class from Animate)

template<typename ...W_TYPES> inline Animate(const anim_fun_t &fun, W_TYPES&... targets): Construct an Animate object with the function to run each animation step and zero or more UI elements that should be updated after each frame.

template<typename ...W_TYPES> inline Animate(const std::function<void(double)> &fun, W_TYPES&... targets)

template<typename ...W_TYPES> inline Animate(const std::function<void()> &fun, W_TYPES&... targets)

inline virtual ~Animate()

Animate(const Animate&) = delete: Do not copy animations directly.

Animate &operator=(const Animate&) = delete

inline void Start(): Start this animation running.

inline void Stop(): Halt this animation for now.

inline void Step(): Take a single step in this animation.

inline void ToggleActive(): Toggle whether this animation is running or paused.

inline bool GetActive() const: Determine if this animation is currently running.

inline bool GetDoStep() const: Determine if this animation is currently in the process of running a single step.

inline double GetStartTime() const: Return the time point that this animation started MOST RECENTLY.

inline double GetPrevTime() const: Determine the time point when this animation last updated a frame.

inline double GetCurTime() const: Get the current time of the animation.

inline double GetStepTime() const: Determine how long the last step between frames took.

inline double GetRunTime() const: Determine the total amount of time that this animation has run.

inline int GetFrameCount() const: Determine how many total frames have existed thus far in this animation.

inline void SetCallback(const anim_fun_t &fun): Set a new function for this animation to call when running that takes a const reference to the Animation object as an argument.

inline void SetCallback(const std::function<void(double)> &fun): Set a new function for this animation to call when running that takes the amount of time since the last frame (a double) as an argument.

inline void SetCallback(const std::function<void()> &fun): Set a new function for this animation to call when running that takes no arguments.

inline Button GetToggleButton(const std::string &but_name, const std::string &start_label = "Start", const std::string &stop_label = "Stop")

Get a toggle button that will start/stop this animation.

Parameters:

but_name – The HTML identifier used for this button.
start_label – The name on the button when it will start the animation (default=”Start”)
stop_label – The name on the button when it will halt the animation (default=”Stop”)

inline Button GetStepButton(const std::string &but_name, const std::string &label = "Step")

Get a step button that will advance this animation one frame.

Parameters:

but_name – The HTML identifier used for this button.
label – The name shown on the button.

Protected Types

using anim_fun_t = std::function<void(const Animate&)>: The full version of the animate function takes a const reference to the animate object.

Protected Functions

inline virtual void DoFrame(): DoFrame() is called by default if no animation function is provided. As such, an animation can be built by deriving a class from Animate and overriding this function.

Protected Attributes

anim_fun_t anim_fun: Function to repeatedly run for animation.

vector<Widget> targets: What widgets should be refreshed after each frame?

bool active: Is this animation currently running?

bool do_step: Should this animation take just a single step?

size_t callback_id: Intenral ID for javascript to call back AdvanceFrame()

double start_time: At what time did this animation most recently start?

double prev_time: What was the time point of the previous frame?

double cur_time: What time did the current frame start?

double run_time: How much run time has accumulated?

int frame_count: How many animation frames have gone by?

Button toggle_but: A button to start/stop this animation.

Button step_but: A button to advance this animation one step.