KTech::Time::Invocation Struct Reference

Calls a function after a given time. More...

#include <invocation.hpp>

Public Member Functions
	Invocation (Engine &engine, const std::function< bool()> &callback)
	Construct an Invocation.
	~Invocation ()
	Safely deregister invocation from Time.
void	Invoke (long time, Measurement measurement)
	Invoke your callback function.
void	Cancel ()
	Cancel the current invocation.

Public Attributes
Engine &	engine
	Parent Engine.
std::function< bool()>	m_callback
	Function to invoke.
bool	m_active = false
	Whether currently invoked (true: invoked, false: stationary).
long	m_timePassed = 0
	How much time (in microseconds) actually passed since invocation started until now (if active), or until invocation ended (if inactive).
long	m_duration = 0
	How much time (in microseconds) should pass before your function gets called (if active), or 0 (if inactive).

Detailed Description

Calls a function after a given time.

This class uses RAII to prevent cases where your member functions are called after their parent structure was deconstructed from memory.

For example:

class MyObject : Object
{
    Invocation myInvocation;
 
    // A member function to invoke.
    bool InvokedMember()
    {
        // Access some memory...
        m_pos = Point(25, 25);
        m_textures.resize(10);
        return true;
    }
 
    MyObject()
        : Object(engine, Point(0, 0)), myInvocation(engine, [this]{ return InvokedMember(); })
    {
        // Invoke the member function:
        myInvocation.Invoke(1, Time::Measurement::seconds);
    }
};
 
int main()
{
    //...
 
    // Construct a `MyObject` instance within a temporary scope:
    {
        MyObject myObject;
    }
    // Scope ends so `myObject` is destructed right away. `myObject.myInvocation` is also destructed, so even though it was just invoked, `myObject.InvokedMember()` will not be called.
 
    //...
}

Constructor & Destructor Documentation

Invocation()

KTech::Time::Invocation::Invocation	(	Engine &	engine,
		const std::function< bool()> &	callback )

Construct an Invocation.

Parameters

engine	Parent Engine.
callback	Your callback function. It should return a bool explained in Output::ShouldRenderThisTick().

See also

Output::ShouldRenderThisTick()

Member Function Documentation

Invoke()

void KTech::Time::Invocation::Invoke	(	long	time,
		Measurement	measurement )

Invoke your callback function.

Can be invoked once at a time. Meaning, invoking while already invoked will restart the current invocation (rather than ). For example:

Engine engine;
 
void Loop()
{
    // Invoke this function after a second:
    static Invocation invocation{engine, Loop, 1, Measurement::seconds};
    invocation.Invoke();
 
    // Print when the game quits how many times this function was called:
    static unsigned int counter = 0;
    engine.output.outputOnQuit.push_back(std::to_string(++counter));
}
 
int main()
{
    // Call `Loop()` twice:
    Loop();
    Loop();
}
 
// Expected `outputOnQuit`:
// 1
// 2
// 3

Parameters

time	Duration to wait for before calling your function.
measurement	The time measurement for your given time.

See also

Time::Measurement

---

The documentation for this struct was generated from the following files:

• ktech/engine/time/invocation.hpp
• ktech/engine/time/invocation.cpp