Stores and manages a scene's render layers. More...

#include <RenderLayerContainer.h>

Inheritance diagram for ime::RenderLayerContainer:

Public Types
using	Callback = std::function< void(const RenderLayer::Ptr &)>
	Callback. More...

using	Ptr = std::unique_ptr< Object >
	Unique object pointer. More...

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

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

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

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

RenderLayer::Ptr	create (const std::string &name)
	Create a layer. More...

void	add (Drawable &drawable, int renderOrder=0u, const std::string &renderLayer="default")
	Add a drawable object to a render layer in the container. More...

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

RenderLayer::Ptr	front () const
	Get the render layer at the front. More...

RenderLayer::Ptr	back () const
	Get the render layer at the back. More...

RenderLayer::Ptr	findByIndex (unsigned int index) const
	Get the layer at a given index. More...

RenderLayer::Ptr	findByName (const std::string &name) const
	Get a layer with the given name. More...

bool	isIndexValid (unsigned int index) const
	Check if a given index is within bounds or not. More...

bool	hasLayer (const std::string &name) const
	Check if the container has a layer with the given name. More...

bool	removeByIndex (unsigned int index)
	Remove the layer at the given index. More...

bool	removeByName (const std::string &name)
	Remove the layer with the given name from the container. More...

void	removeAll ()
	Remove all layers from the container. More...

void	moveUp (unsigned int index)
	Move a layer one level up. More...

void	moveUp (const std::string &name)
	Move the layer up one level. More...

void	moveDown (unsigned int index)
	Move a layer one level down. More...

void	moveDown (const std::string &name)
	Move a layer one level down. More...

void	moveToFront (unsigned int index)
	Move a layer to the highest level (foreground) More...

void	moveToFront (const std::string &name)
	Move a layer to the highest level (foreground) More...

void	sendToBack (unsigned int index)
	Move a layer to the lowest level (background) More...

void	sendToBack (const std::string &name)
	Move a layer to the lowest level (background) More...

bool	swap (unsigned int layerOneIndex, unsigned int layerTwoIndex)
	Swap the render positions of two layers. More...

void	swap (const std::string &layerOne, const std::string &layerTwo)
	Swap the positions of two layers. More...

std::size_t	getCount () const
	Get the number of layer in the container. More...

void	forEachLayer (const Callback &callback) const
	Execute a callback for each layer in the container. More...

void	render (priv::RenderTarget &window) const

	~RenderLayerContainer () 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	Scene
	‍Needs access to the constructor More...

class	Grid2D

Detailed Description

Stores and manages a scene's render layers.

A render layer container determines the order in which objects are drawn to the render window. After creating an object (e.g sprite), you specify the RenderLayer in which the object belongs to and the object will be rendered on top or below other objects depending on the index of its render layer in the render layer container.

Render layers are added to the container in ascending order with an index of 0 representing the the furthest background. Therefore, the last added render layer will always be the foreground. The layers are drawn from index 0 going upwards. Note that you cannot change the index of a layer (indexes will always be arranged in ascending order), however you can change the layer at a given index. This means that you can specify which layer gets rendered on top of which layer using appropriate member function. For example if you add a mountain sprite to a render layer at index 5 and a tree sprite to a render layer at index 6, then the mountain will be rendered first followed by the tree

This class is not directly instantiatable, it is created when you instantiate a Scene object. Each scene instance has its own render layers and a single render layer container accessed with ime::Scene::getRenderLayers

Definition at line 60 of file RenderLayerContainer.h.

Member Typedef Documentation

◆ Callback

using ime::RenderLayerContainer::Callback = std::function<void(const RenderLayer::Ptr&)>

Callback.

Definition at line 62 of file RenderLayerContainer.h.

◆ Ptr

using ime::Object::Ptr = std::unique_ptr<Object>

inherited

Unique object pointer.

Definition at line 42 of file Object.h.

Constructor & Destructor Documentation

◆ RenderLayerContainer() [1/2]

ime::RenderLayerContainer::RenderLayerContainer ( const RenderLayerContainer & )

delete

Copy constructor.

◆ RenderLayerContainer() [2/2]

ime::RenderLayerContainer::RenderLayerContainer ( RenderLayerContainer && )

defaultnoexcept

Move constructor.

◆ ~RenderLayerContainer()

ime::RenderLayerContainer::~RenderLayerContainer ( )

override

Destructor.

Member Function Documentation

◆ add()

void ime::RenderLayerContainer::add	(	Drawable &	drawable,
		int	renderOrder = `0u`,
		const std::string &	renderLayer = `"default"`
	)

Add a drawable object to a render layer in the container.

Parameters

drawable	The drawable object to be added
renderOrder	The render order of the object in the render layer
renderLayer	The RenderLayer to add the object belongs to

If the render layer is unspecified or the specified layer cannot be found then the drawable will be added to the 'default' layer. The 'default' render layer is created by the Scene when you instantiate it. Note that the 'default' layer may be deleted from the container, however you must make sure that the layer you specify during a call to this function already exists in the container otherwise undefined behavior

See also: ime::Scene::getRenderLayers

◆ back()

RenderLayer::Ptr ime::RenderLayerContainer::back ( ) const

Get the render layer at the back.

Returns: The render layer at the back or a nullptr if the container is empty

See also: front

◆ create()

RenderLayer::Ptr ime::RenderLayerContainer::create ( const std::string & name )

Create a layer.

Parameters

name	The name of the layer to be created

Returns: The created layer

Note that the container keeps a pointer to the layer after it is created, therefore you don't need to keep the returned pointer alive after using it

Warning: The name of the layer must be unique, that is, another layer must not exist in the container with the same name as name otherwise it is undefined behaviour

See also: removeByTag, removeByIndex and removeAll

◆ 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

◆ findByIndex()

RenderLayer::Ptr ime::RenderLayerContainer::findByIndex ( unsigned int index ) const

Get the layer at a given index.

Parameters

index The index of the layer to retrieve

Returns: The index at the specified index or a nullptr if the index is out of bounds

See also: findByTag

◆ findByName()

RenderLayer::Ptr ime::RenderLayerContainer::findByName ( const std::string & name ) const

Get a layer with the given name.

Parameters

name	The name of the layer to retrieve

Returns: The layer with the given name or a nullptr if the layer does not exits

See also: findByIndex

◆ forEachLayer()

void ime::RenderLayerContainer::forEachLayer ( const Callback & callback ) const

Execute a callback for each layer in the container.

Parameters

callback The callback to be executed

◆ front()

RenderLayer::Ptr ime::RenderLayerContainer::front ( ) const

Get the render layer at the front.

Returns: The layer at the front or a nullptr if the container is empty

See also: back

◆ getClassName()

std::string ime::RenderLayerContainer::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::RenderLayerContainer::getCount ( ) const

Get the number of layer in the container.

Returns: The number of layers in the container

◆ 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

◆ hasLayer()

bool ime::RenderLayerContainer::hasLayer ( const std::string & name ) const

Check if the container has a layer with the given name.

Parameters

name	The name of the layer to be checked

Returns: True of the container has the layer otherwise false

See also: findByTag and removeByTag

◆ 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

◆ isIndexValid()

bool ime::RenderLayerContainer::isIndexValid ( unsigned int index ) const

Check if a given index is within bounds or not.

Parameters

index The index to be checked

Returns: True of the container has the layer otherwise false

See also: findByIndex and removeByIndex

◆ 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

◆ moveDown() [1/2]

void ime::RenderLayerContainer::moveDown ( const std::string & name )

Move a layer one level down.

Parameters

name	The name of the layer to be moved

This function has no effect if the layer does not exist or the layer is already at the lowest level

See also: moveUp(const std::string&)

◆ moveDown() [2/2]

void ime::RenderLayerContainer::moveDown ( unsigned int index )

Move a layer one level down.

Parameters

index The index of the layer to be moved

This function has no effect if the layer does not exist or the layer is already at the lowest level

See also: moveUp(unsigned int)

◆ moveToFront() [1/2]

void ime::RenderLayerContainer::moveToFront ( const std::string & name )

Move a layer to the highest level (foreground)

Parameters

name	The name of the level to be moved

This function has no effect if the layer does not exist or the layer is already at the highest level

See also: sendToBack(const std::string&)

◆ moveToFront() [2/2]

void ime::RenderLayerContainer::moveToFront ( unsigned int index )

Move a layer to the highest level (foreground)

Parameters

index The index of the layer to be moved

This function has no effect if the layer does not exist or the layer is already at the highest level

See also: sendToBack(unsigned int)

◆ moveUp() [1/2]

void ime::RenderLayerContainer::moveUp ( const std::string & name )

Move the layer up one level.

Parameters

name	The name of the layer to be moved

This function has no effect if the layer does not exist

See also: moveDown(const std::string&)

◆ moveUp() [2/2]

void ime::RenderLayerContainer::moveUp ( unsigned int index )

Move a layer one level up.

Parameters

index The index of the layer to be moved

This function has no effect if the index is out of bounds or the layer is already at the highest level

See also: moveDown(unsigned int)

◆ 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]

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

delete

Copy assignment operator.

◆ operator=() [2/2]

RenderLayerContainer & ime::RenderLayerContainer::operator= ( RenderLayerContainer && )

defaultnoexcept

Move assignment operator.

◆ removeAll()

void ime::RenderLayerContainer::removeAll ( )

Remove all layers from the container.

See also: removeByIndex and removeByTag

◆ removeByIndex()

bool ime::RenderLayerContainer::removeByIndex ( unsigned int index )

Remove the layer at the given index.

Parameters

index The index of the layer to be removed

Returns: True if the layer was removed or false if the index is out of bounds

See also: removeByTag

◆ removeByName()

bool ime::RenderLayerContainer::removeByName ( const std::string & name )

Remove the layer with the given name from the container.

Parameters

name	The name of the container to be removed

Returns: True if the layer was removed or false if the layer does not exist

See also: removeByIndex

◆ 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

◆ sendToBack() [1/2]

void ime::RenderLayerContainer::sendToBack ( const std::string & name )

Move a layer to the lowest level (background)

Parameters

name	The name of the layer ot be moved

This function has no effect if the layer does not exist or the layer is already at the lowest level

See also: moveToFront(const std::string&)

◆ sendToBack() [2/2]

void ime::RenderLayerContainer::sendToBack ( unsigned int index )

Move a layer to the lowest level (background)

Parameters

index The index of the layer ot be moved

This function has no effect if the layer does not exist or the layer is already at the lowest level

See also: moveToFront(unsigned int)

◆ 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

◆ swap() [1/2]

void ime::RenderLayerContainer::swap	(	const std::string &	layerOne,
		const std::string &	layerTwo
	)

Swap the positions of two layers.

Parameters

layerOne	The name of the first layer
layerTwo	The name iof the second layer

This function has no effect of either of the layers cannot be found

See also: swap(unsigned int, unsigned int)

◆ swap() [2/2]

bool ime::RenderLayerContainer::swap	(	unsigned int	layerOneIndex,
		unsigned int	layerTwoIndex
	)

Swap the render positions of two layers.

Parameters

layerOneIndex	The index of the first layer
layerTwoIndex	The index of the second layer

Returns: True if the two layers were swapped successfully, or false if either one of the given layers does not exist in the container

See also: swap(const std::string&, const std::string&)

Friends And Related Function Documentation

◆ Grid2D

friend class Grid2D

friend

Definition at line 357 of file RenderLayerContainer.h.

◆ Scene

friend class Scene

friend

‍Needs access to the constructor

Definition at line 356 of file RenderLayerContainer.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:

RenderLayerContainer.h

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ Callback

◆ Ptr

Constructor & Destructor Documentation

◆ RenderLayerContainer() [1/2]

◆ RenderLayerContainer() [2/2]

◆ ~RenderLayerContainer()

Member Function Documentation

◆ add()

◆ back()

◆ create()

◆ emitChange()

◆ emitDestruction()

◆ findByIndex()

◆ findByName()

◆ forEachLayer()

◆ front()

◆ getClassName()

◆ getClassType()

◆ getCount()

◆ getObjectId()

◆ getTag()

◆ hasLayer()

◆ isEventListenerSuspended()

◆ isIndexValid()

◆ isSameObjectAs()

◆ moveDown() [1/2]

◆ moveDown() [2/2]

◆ moveToFront() [1/2]

◆ moveToFront() [2/2]

◆ moveUp() [1/2]

◆ moveUp() [2/2]

◆ onDestruction()

◆ onPropertyChange() [1/2]

◆ onPropertyChange() [2/2]

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ removeAll()

◆ removeByIndex()

◆ removeByName()

◆ removeEventListener() [1/2]

◆ removeEventListener() [2/2]

◆ sendToBack() [1/2]

◆ sendToBack() [2/2]

◆ setTag()

◆ suspendedEventListener()

◆ swap() [1/2]

◆ swap() [2/2]

Friends And Related Function Documentation

◆ Grid2D

◆ Scene

Member Data Documentation

◆ eventEmitter_