A layer for drawable entities. More...

#include <RenderLayer.h>

Inheritance diagram for ime::RenderLayer:

Public Types
using	Ptr = std::shared_ptr< RenderLayer >
	Shared render layer pointer. More...

Public Member Functions
	RenderLayer (const RenderLayer &)=delete
	Copy constructor. More...

RenderLayer &	operator= (const RenderLayer &)=delete
	Copy assignment operator. More...

	RenderLayer (RenderLayer &&) noexcept=default
	Move constructor. More...

RenderLayer &	operator= (RenderLayer &&) noexcept=default
	Move assignment operator. More...

std::string	getClassName () const override
	Get the name of this class. More...

void	setDrawable (bool render)
	Set whether or not the layer should be drawn by the scene. More...

bool	isDrawable () const
	Check whether or not the layer is drawn by the scene. More...

void	toggleDrawable ()
	Toggle the draw state of the layer. More...

unsigned int	getIndex () const
	Get the index of the layer in the RenderLayerContainer. More...

const std::string &	getName () const
	Get the name of the layer. More...

void	add (Drawable &drawable, int renderOrder=0)
	Add a drawable to the layer. More...

bool	has (const Drawable &drawable) const
	Check if the render layer has a given drawable or not. More...

bool	remove (Drawable &drawable)
	Remove a drawable from the render layer. More...

void	removeAll ()
	Remove all drawables from the render layer. More...

std::size_t	getCount () const
	Get the number of drawables rendered by the layer. More...

void	render (priv::RenderTarget &window) const

	~RenderLayer () override
	Destructor. More...

void	setTag (const std::string &tag)
	Assign the object an alias. More...

const std::string &	getTag () const
	Get the tag assigned to the object. More...

unsigned int	getObjectId () const
	Get the unique id of the object. More...

virtual std::string	getClassType () const
	Get the name of the direct parent of an object instance. More...

int	onPropertyChange (const std::string &property, const Callback< Property > &callback, bool oneTime=false)
	Add an event listener to a specific property change event. More...

int	onPropertyChange (const Callback< Property > &callback, bool oneTime=false)
	Add an event listener to any property change event. More...

void	suspendedEventListener (int id, bool suspend)
	Pause or resume execution of an event listener. More...

bool	isEventListenerSuspended (int id) const
	Check if an event listener is suspended or not. More...

bool	removeEventListener (const std::string &event, int id)
	Remove an event listener from an event. More...

bool	removeEventListener (int id)
	Remove an event listener. More...

int	onDestruction (const Callback<> &callback)
	Add a destruction listener. More...

bool	isSameObjectAs (const Object &other) const
	Check if another object is the same instance as this object. More...

Protected Member Functions
void	emitChange (const Property &property)
	Dispatch a property change event. More...

void	emitDestruction ()
	Emit a destruction event. More...

Protected Attributes
EventEmitter	eventEmitter_
	Event dispatcher. More...

Friends
class	RenderLayerContainer
	Needs access to constructor. More...

Detailed Description

A layer for drawable entities.

Typically you add objects that should be drawn together to the same layer. The order in which render layers are rendered is specified in the RenderLayerContainer. Objects in the same layer can also be sorted. For example, you may have a background layer which has mountains, trees and valleys. However you don't want the objects to be drawn non-deterministically. You can specify which objects are drawn over which and which objects are drawn under which by specifying the render order of the object when adding it to the layer. Objects with the lowest render order are drawn first whilst objects with the highest render order are drawn last. When objects have the same render order, the object that was added first to the layer will be rendered first.

By default, all objects have the same render order, as a result, they are drawn in the order in which they were added to the layer

A layer is not instantiated directly but rather using a ime::RenderLayerContainer::create

Definition at line 64 of file RenderLayer.h.

Member Typedef Documentation

◆ Ptr

using ime::RenderLayer::Ptr = std::shared_ptr<RenderLayer>

Shared render layer pointer.

Definition at line 66 of file RenderLayer.h.

Constructor & Destructor Documentation

◆ RenderLayer() [1/2]

ime::RenderLayer::RenderLayer ( const RenderLayer & )

delete

Copy constructor.

◆ RenderLayer() [2/2]

ime::RenderLayer::RenderLayer ( RenderLayer && )

defaultnoexcept

Move constructor.

◆ ~RenderLayer()

ime::RenderLayer::~RenderLayer ( )

override

Destructor.

Member Function Documentation

◆ add()

void ime::RenderLayer::add	(	Drawable &	drawable,
		int	renderOrder = `0`
	)

Add a drawable to the layer.

Parameters

drawable	The drawable to be added
renderOrder	The layer level render order of the drawable

The render order determines which game objects get rendered first and which game objects get rendered last in the layer. Therefore the order in which drawables are added to the layer does not necessarily matter. Drawables with the smallest render order are be rendered first. Note that multiple drawables can have the same render order, in such a case the drawables will be drawn in the order in which they were added to the layer

By default, all drawables have the same render order of 0

Warning: Th render layer keeps a reference to the drawable, therefore, it must remain alive for as long as it is used by the render layer

◆ emitChange()

void ime::Object::emitChange ( const Property & property )

protectedinherited

Dispatch a property change event.

Parameters

property The property that changed

This function will invoke all the event listeners of the specified property

See also: emit

◆ emitDestruction()

void ime::Object::emitDestruction ( )

protectedinherited

Emit a destruction event.

Note: This function must be the first statement in the definition of a destructor to avoid undefined behavior. In addition, note that destruction listeners are invoked once. Therefore, multiple classes in a hierarchy may call this function but the class that makes the call first will be the one that invokes the destruction listeners

◆ getClassName()

std::string ime::RenderLayer::getClassName ( ) const

overridevirtual

Get the name of this class.

Returns: The name of this class

Implements ime::Object.

◆ getClassType()

virtual std::string ime::Object::getClassType ( ) const

virtualinherited

Get the name of the direct parent of an object instance.

Returns: The name of the direct parent of an object instance

In contrast to getClassName() which returns the name of the concrete class, this function returns the name of the concrete class's base class. This function is implemented by all derived classes of ime::Object which also serve as base classes. For classes whose direct parent is this class, this function will return the name of this class

auto rectangle = ime::RectangleShape(); // RectangleShape is derived from Shape
std::cout << rectangle->getClassName(); // Prints "RectangleShape"
std::cout << rectangle->getClassType(); // Prints "Shape"

See also: getClassName

Reimplemented in ime::audio::Audio, ime::GameObject, ime::GridMover, ime::Collider, ime::Joint, ime::Drawable, ime::Shape, and ime::SpriteImage.

◆ getCount()

std::size_t ime::RenderLayer::getCount ( ) const

Get the number of drawables rendered by the layer.

Returns: The number of drawables rendered by the layer

◆ getIndex()

unsigned int ime::RenderLayer::getIndex ( ) const

Get the index of the layer in the RenderLayerContainer.

Returns: The index of the layer in the RenderLayerContainer

The index indicates the render order of the layer. The bigger the index the further away the layer is from the foreground. The layer with the an index of 0 is always the foreground layer and all other layers are rendered behind it

◆ getName()

const std::string & ime::RenderLayer::getName ( ) const

Get the name of the layer.

Returns: The name of the layer

◆ getObjectId()

unsigned int ime::Object::getObjectId ( ) const

inherited

Get the unique id of the object.

Returns: The unique id of the object

Note that each instance of ime::Object has a unique id

See also: setTag

◆ getTag()

const std::string & ime::Object::getTag ( ) const

inherited

Get the tag assigned to the object.

Returns: The tag of the object

See also: setTag

◆ has()

bool ime::RenderLayer::has ( const Drawable & drawable ) const

Check if the render layer has a given drawable or not.

Parameters

drawable The drawable to be checked

Returns: True if the render layer has the drawable, otherwise false

When a render layer "has" a drawable, it means that the drawable is rendered by that layer to the render window

◆ isDrawable()

bool ime::RenderLayer::isDrawable ( ) const

Check whether or not the layer is drawn by the scene.

Returns: True if drawn by the scene, otherwise false

See also: setDrawable

◆ isEventListenerSuspended()

bool ime::Object::isEventListenerSuspended ( int id ) const

inherited

Check if an event listener is suspended or not.

Parameters

id	The identification number of the listener to be checked

Returns: True if suspended, otherwise false

This function also returns false if the specified event listener does not exist

See also: suspendedEventListener

◆ isSameObjectAs()

bool ime::Object::isSameObjectAs ( const Object & other ) const

inherited

Check if another object is the same instance as this object.

Parameters

other The object to compare against this object

Returns: True if other is the same instance as this object, otherwise false

◆ onDestruction()

int ime::Object::onDestruction ( const Callback<> & callback )

inherited

Add a destruction listener.

Parameters

callback Function to be executed when the object is destroyed

Returns: The unique id of the destruction listener

The destruction listener is called when the object reaches the end of its lifetime. Note that an object may have multiple destruction listeners registered to it

Warning: It's not advised to call virtual functions in the destruction callback as some parts of the object may have already been destroyed by the time the callback is invoked. In such an event, the behavior is undefined

See also: removeEventListener

◆ onPropertyChange() [1/2]

int ime::Object::onPropertyChange	(	const Callback< Property > &	callback,
		bool	oneTime = `false`
	)

inherited

Add an event listener to any property change event.

Parameters

callback	The function to be executed when any property changes
oneTime	True to execute the callback one-time or false to execute it every time the event is triggered

Returns: The unique id of the event listener

When unsubscribing the any property change event handler, you must pass "propertyChange" as the name of the event

See also: onPropertyChange(const std::string&, const ime::Callback<ime::Property>&)

◆ onPropertyChange() [2/2]

int ime::Object::onPropertyChange	(	const std::string &	property,
		const Callback< Property > &	callback,
		bool	oneTime = `false`
	)

inherited

Add an event listener to a specific property change event.

Parameters

property	The name of the property to add an event listener to
oneTime	True to execute the callback one-time or false to execute it every time the event is triggered
callback	The function to be executed when the property changes

Returns: The unique id of the event listener

A property change event is triggered by any function that begins with set, where the the text after set is the name of the property. For example, the setTag() function, modifies the tag property of the object, thus will generate a "tag" change event each time it is called

Note that multiple event listeners may be registered to the same property change event. In addition, when adding a property change event listener, the name of the property must be in lowercase.

// Prints the tag of the player object to the console everytime it changes
player.onPropertyChange("tag", [](const Property& property) {
     cout << "New tag: " <<  property.getValue<std::string>() << endl;
});
 
...
//Sets tag = "player1" and invokes event listener(s)
player.setTag("player1");

See also: unsubscribe and onPropertyChange(const ime::Callback<ime::Property>&)

◆ operator=() [1/2]

RenderLayer & ime::RenderLayer::operator= ( const RenderLayer & )

delete

Copy assignment operator.

◆ operator=() [2/2]

RenderLayer & ime::RenderLayer::operator= ( RenderLayer && )

defaultnoexcept

Move assignment operator.

◆ remove()

bool ime::RenderLayer::remove ( Drawable & drawable )

Remove a drawable from the render layer.

Parameters

drawable The drawable to be removed

Returns: True if the drawable was removed, otherwise false

When a drawable is removed from the render layer, it will no longer be rendered by the scene, hence it won't appear on the game window

◆ removeAll()

void ime::RenderLayer::removeAll ( )

Remove all drawables from the render layer.

◆ removeEventListener() [1/2]

bool ime::Object::removeEventListener	(	const std::string &	event,
		int	id
	)

inherited

Remove an event listener from an event.

Parameters

event	The name of the event to remove an event listener from
id	The unique id of the event listener to be removed

Returns: True if the event listener was removed or false if the event or the event listener is does not exist

// Display the tag of the object to console every time it changes
auto tagChangeId = object.onPropertyChange("tag", [](ime::Property tag) {
     std::cout << name.getValue<std::string>() << std::endl;
});
 
// Stop displaying the tag of the object when it changes
object.removeEventListener("tag", tagChangeId);

◆ removeEventListener() [2/2]

bool ime::Object::removeEventListener ( int id )

inherited

Remove an event listener.

Parameters

id	The id of the event listener to be removed

Returns: True if the event listener was removed or false if no such handler exists

◆ setDrawable()

void ime::RenderLayer::setDrawable ( bool render )

Set whether or not the layer should be drawn by the scene.

Parameters

render True to have the layer drawn by the scene otherwise false

By default the layer is drawable

◆ setTag()

void ime::Object::setTag ( const std::string & tag )

inherited

Assign the object an alias.

Parameters

tag	The alias of the object

This function is useful if you want to refer to the object by a tag instead of its object id. Unlike an object id, multiple objects may have the same tag

By default, the tag is an empty string

See also: getObjectId

◆ suspendedEventListener()

void ime::Object::suspendedEventListener	(	int	id,
		bool	suspend
	)

inherited

Pause or resume execution of an event listener.

Parameters

id	The event listeners unique identification number
suspend	True to suspend/pause or false to unsuspend/resume

See also: isEventListenerSuspended

◆ toggleDrawable()

void ime::RenderLayer::toggleDrawable ( )

Toggle the draw state of the layer.

This function will set the layer to drawable if its currently not drawable and vice versa

See also: setDrawable

Friends And Related Function Documentation

◆ RenderLayerContainer

friend class RenderLayerContainer

friend

Needs access to constructor.

Definition at line 228 of file RenderLayer.h.

Member Data Documentation

◆ eventEmitter_

EventEmitter ime::Object::eventEmitter_

protectedinherited

Event dispatcher.

Definition at line 289 of file Object.h.

The documentation for this class was generated from the following file:

RenderLayer.h

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ Ptr

Constructor & Destructor Documentation

◆ RenderLayer() [1/2]

◆ RenderLayer() [2/2]

◆ ~RenderLayer()

Member Function Documentation

◆ add()

◆ emitChange()

◆ emitDestruction()

◆ getClassName()

◆ getClassType()

◆ getCount()

◆ getIndex()

◆ getName()

◆ getObjectId()

◆ getTag()

◆ has()

◆ isDrawable()

◆ isEventListenerSuspended()

◆ isSameObjectAs()

◆ onDestruction()

◆ onPropertyChange() [1/2]

◆ onPropertyChange() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ remove()

◆ removeAll()

◆ removeEventListener() [1/2]

◆ removeEventListener() [2/2]

◆ setDrawable()

◆ setTag()

◆ suspendedEventListener()

◆ toggleDrawable()

Friends And Related Function Documentation

◆ RenderLayerContainer

Member Data Documentation

◆ eventEmitter_