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::shared_ptr< Object >
	Shared 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...

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

const std::string &	getTag () const
	Get the alias of the object. More...

unsigned int	getObjectId () const
	Get the 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)
	Add an event listener to a specific property change event. More...

void	onPropertyChange (const Callback< Property > &callback)
	Add an event listener to a property change event. More...

int	onEvent (const std::string &event, const Callback<> &callback)
	Add an event listener to an event. More...

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

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

bool	removeDestructionListener (int id)
	Remove a destruction listener form the object. More...

bool	operator== (const Object &rhs) const
	Check if two objects are the same object or not. More...

bool	operator!= (const Object &rhs) const
	Check if two objects are not the same object. More...

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

void	emit (const std::string &event)
	Dispatch an action event. More...

The name of the layer to be created
Create a layer 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
class	Scene
	Needs access to the constructor More...

class	TileMap

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

void	add (const 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)
	Execute a callback for each layer in the container. More...

void	render (Window &window) const

	~RenderLayerContainer () override
	Destructor. More...

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 and vice versa.

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

Definition at line 59 of file RenderLayerContainer.h.

Member Typedef Documentation

◆ Callback

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

Callback.

Definition at line 61 of file RenderLayerContainer.h.

◆ Ptr

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

inherited

Shared object pointer.

Definition at line 45 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	(	const 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

Note: You should only use this function if you don't want to the scene to keep an instance of the drawable on your behalf, otherwise you should use the container classes found in the Scene class, the drawable will be automatically added to the specified render layer

◆ 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

◆ emit()

void ime::Object::emit ( const std::string & event )

protectedinherited

Dispatch an action event.

Parameters

event The name of the event to be dispatched

This function will invoke all event listeners of the specified event. The function should be used for events that represent an action, rather than those that represent a property change (Use emitChange for that)

See also: emitChange

◆ 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

◆ 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 )

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 Object which also serve as base classes for other Objects. 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::SpriteImage, ime::Shape, ime::Drawable, ime::GridMover, ime::Joint, ime::Collider, and ime::GameObject.

◆ 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 id of the object.

Returns: The id of the object

Each object has a unique id

◆ getTag()

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

inherited

Get the alias of the object.

Returns: The alias of the object

See also: setTag and getObjectId

◆ 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

◆ 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

◆ 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 id of the destruction listener

Note that an object may have more than one destruction listeners, however, you have to keep the returned id if you may want to remove the callback at a later time

Warning: The callback is called when the object is destroyed. Do not try to access the object in the callback. Doing so is undefined behavior

See also: removeDestructionListener

◆ onEvent()

int ime::Object::onEvent	(	const std::string &	event,
		const Callback<> &	callback
	)

inherited

Add an event listener to an event.

Parameters

event	The name of the event to add an an event listener to
callback	The function to be executed when the event takes place

Returns: The unique identification number of the event listener

Unlike onPropertyChange, this function registers event listeners to events that occur when something happens to the object, or when the object does something (action events). Usually the name of the event/action is the name of the function:

// Add event listeners to the object
object.onEvent("attachRigidBody", [] {
    std::cout << "Rigid body attached to object << std::endl;
});
 
object.onEvent("removeRigidBody", [] {
    std::cout << "Rigid body removed from object << std::endl;
});
 
// Invokes event listener(s)
object.attachRigidBody(body);
object.removeRigidBody();

See also: onPropertyChange and unsubscribe

◆ onPropertyChange() [1/2]

void ime::Object::onPropertyChange ( const Callback< Property > & callback )

inherited

Add an event listener to a property change event.

Parameters

callback The function to be executed when the property changes

Returns: The unique id of the event listener

Note that only one callback function may be registered with this function. This means that adding a new event listener overwrites the previous event listener. To remove the callback, pass a nullptr as an argument. The function may be useful if you want to write the logic for property changes in one function.

See also: onPropertyChange(std::string, Callback)

◆ onPropertyChange() [2/2]

int ime::Object::onPropertyChange	(	const std::string &	property,
		const Callback< Property > &	callback
	)

inherited

Add an event listener to a specific property change event.

Parameters

property	The name of the property to listen for
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, for the setTag function, the property that the function modifies is Tag.

Note that 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");

Unlike onPropertyChange(const Callback&) you can add multiple event listeners to the same property using this function. However you must store the unique id of the event listener if you wish to remove it at a later time

See also: unsubscribe and onPropertyChange(Callback)

◆ operator!=()

bool ime::Object::operator!= ( const Object & rhs ) const

inherited

Check if two objects are not the same object.

Parameters

rhs	Object to compare against this object

Returns: True if rhs is NOT the same object as this object, otherwise false

Two objects are different from each other if they have different object id's

See also: getObjectId and operator==

◆ 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.

◆ operator==()

bool ime::Object::operator== ( const Object & rhs ) const

inherited

Check if two objects are the same object or not.

Parameters

rhs	Object to compare against this object

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

Two objects are the same object if they have the same object id. Recall that each object instance has a unique id

See also: getObjectId and 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

◆ removeDestructionListener()

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

inherited

Remove a destruction listener form the object.

Parameters

The	id of the destruction listener to be removed

Returns: True if the destruction listener was removed or false if the listener with the given id does not exist

◆ 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

name	The alias of the object

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

By default, the tag is an empty string

◆ 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&)

◆ unsubscribe()

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

inherited

Remove an event listener from an event.

Parameters

event	The name of the event to remove 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 name of the object to console every time it changes
auto nameChangeId = object.onPropertyChange("name", [](Property name) {
     std::cout << name.getValue<std::string>() << std::endl;
});
 
// Stop displaying the name of the object when it changes
object.unsubscribe("name", id);

Friends And Related Function Documentation

◆ Scene

friend class Scene

friend

Needs access to the constructor

Definition at line 359 of file RenderLayerContainer.h.

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

RenderLayerContainer.h

Public Types

Public Member Functions

Protected Member Functions

The name of the layer to be created

Detailed Description

Member Typedef Documentation

◆ Callback

◆ Ptr

Constructor & Destructor Documentation

◆ RenderLayerContainer() [1/2]

◆ RenderLayerContainer() [2/2]

◆ ~RenderLayerContainer()

Member Function Documentation

◆ add()

◆ back()

◆ emit()

◆ emitChange()

◆ findByIndex()

◆ findByName()

◆ forEachLayer()

◆ front()

◆ getClassName()

◆ getClassType()

◆ getCount()

◆ getObjectId()

◆ getTag()

◆ hasLayer()

◆ isIndexValid()

◆ moveDown() [1/2]

◆ moveDown() [2/2]

◆ moveToFront() [1/2]

◆ moveToFront() [2/2]

◆ moveUp() [1/2]

◆ moveUp() [2/2]

◆ onDestruction()

◆ onEvent()

◆ onPropertyChange() [1/2]

◆ onPropertyChange() [2/2]

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ removeAll()

◆ removeByIndex()

◆ removeByName()

◆ removeDestructionListener()

◆ sendToBack() [1/2]

◆ sendToBack() [2/2]

◆ setTag()

◆ swap() [1/2]

◆ swap() [2/2]

◆ unsubscribe()

Friends And Related Function Documentation

◆ Scene