Example of using the Flyweight Pattern in C#. More...

Collaboration diagram for Flyweight_Exercise:

Public Member Functions
void	Run ()
	Executes the example for the Flyweight Pattern in C#.

Private Member Functions
int	_Flyweight_GenerateBigResource (int numImages, int width, int height)
	Generate a big resource, in this case, a text master "image" of the specified height, containing the specified number of smaller images laid out horizontally, using the given width for each image.

List< char[]>	_Flyweight_GenerateDisplay (int width, int height)
	Generate a display area in which to render the big resource.

void	_Flyweight_ShowDisplay (List< char[]> display)
	Render the display to the screen.

void	_Flyweight_ClearDisplay (List< char[]> display)
	Clear the "display" to a background image, erasing whatever was there before.

void	_Flyweight_MoveFlyweights (List< Flyweight_Class > flyweightInstances, int display_width, int display_height)
	Move the given flyweight instances within the display, bouncing them off the edges of the display.

void	_Flyweight_RenderFlyweights (List< Flyweight_Class > flyweightInstances, List< char[]> displayArea)
	Render the image into the display, once for each flyweight instance.

double	GenerateVelocity (Random randomizer)
	Generate a random velocity, which includes a speed and a direction. The velocity is 0.2 to 1.0 (in increments of 0.2) and the direction is either + or -.

List< Flyweight_Class >	_Flyweight_GenerateFlyweightClasses (int bigResourceId, int numFlyweights, int image_width, int image_height, int display_width, int display_height)
	Helper method to generate the specified number of flyweight class instances and associate those instances with individual contexts and a single big resource.

Detailed Description

Example of using the Flyweight Pattern in C#.

The Flyweight pattern is used when a large object needs to be represented by a much lighter weight class, possibly multiple instances of said light-weight class.

In this example, a large object is represented by a so-called "big resource" (a two-dimensional array of text characters) containing multiple images, one associated with each flyweight class. Flyweight classes that represent offset into the big resource, along with position and velocity, are attached to the big resource image so they all share the same image but have different positions and velocities. The image is rendered to a display area through the Flyweight class. The Flyweight class instances then have their positions updated, bouncing off the edges of the display area 60 times a second. This continues for 1000 iterations or until a key is pressed.

Definition at line 31 of file Flyweight_Exercise.cs.

Member Function Documentation

◆ _Flyweight_ClearDisplay()

void _Flyweight_ClearDisplay ( List< char[]> display )

inlineprivate

Clear the "display" to a background image, erasing whatever was there before.

Parameters

display A list of character arrays representing the display.

Definition at line 139 of file Flyweight_Exercise.cs.

Referenced by Flyweight_Exercise._Flyweight_GenerateDisplay(), and Flyweight_Exercise.Run().

◆ _Flyweight_GenerateBigResource()

int _Flyweight_GenerateBigResource	(	int	numImages,
		int	width,
		int	height
	)

inlineprivate

Generate a big resource, in this case, a text master "image" of the specified height, containing the specified number of smaller images laid out horizontally, using the given width for each image.

If there are 5 images requested, then create a single image that is 5 * width wide and 1 * height tall.

Parameters

numImages	Number of images to images to store in the single big resource (horizontally), between 1 and 9.
width	Width of each "text" image, in characters. Minimum width is 3.
height	Height of each "text" image, in characters. Minimum height is 3.

Returns: An index to the generated index in the BigResourceManager.

Definition at line 48 of file Flyweight_Exercise.cs.

References BigResourceManager.AddResource().

Referenced by Flyweight_Exercise.Run().

◆ _Flyweight_GenerateDisplay()

List< char[]> _Flyweight_GenerateDisplay	(	int	width,
		int	height
	)

inlineprivate

Generate a display area in which to render the big resource.

Parameters

width	Width of the display area.
height	Height of the display area.

Returns: A List of character arrays representing the display area.

Definition at line 101 of file Flyweight_Exercise.cs.

References Flyweight_Exercise._Flyweight_ClearDisplay().

Referenced by Flyweight_Exercise.Run().

◆ _Flyweight_GenerateFlyweightClasses()

List< Flyweight_Class > _Flyweight_GenerateFlyweightClasses	(	int	bigResourceId,
		int	numFlyweights,
		int	image_width,
		int	image_height,
		int	display_width,
		int	display_height
	)

inlineprivate

Helper method to generate the specified number of flyweight class instances and associate those instances with individual contexts and a single big resource.

The image and display sizes are provided so as to randomize the position of each flyweight within the display.

Parameters

bigResourceId	ID of the big resource to use.
numFlyweights	Number of flyweight instances to create.
image_width	Width of the big resource image.
image_height	Height of the big resource image.
display_width	Width of the display in which the flyweight is to be rendered.
display_height	Height of the display in which the flyweight is to be rendered.

Returns

Definition at line 253 of file Flyweight_Exercise.cs.

References BigResourceManager.CreateFlyweight(), and GenerateVelocity().

Referenced by Flyweight_Exercise.Run().

◆ _Flyweight_MoveFlyweights()

void _Flyweight_MoveFlyweights	(	List< Flyweight_Class >	flyweightInstances,
		int	display_width,
		int	display_height
	)

inlineprivate

Move the given flyweight instances within the display, bouncing them off the edges of the display.

The display size and image size are provided here

Parameters

flyweightInstances	List of Flyweight_Class instances to move.
display_width	Width of display.
display_height	Height of display.

Definition at line 160 of file Flyweight_Exercise.cs.

References Flyweight_Class.Context, Flyweight_Class.ImageHeight, Flyweight_Class.ImageWidth, Flyweight_Context.Velocity_X, and Flyweight_Context.Velocity_Y.

Referenced by Flyweight_Exercise.Run().

◆ _Flyweight_RenderFlyweights()

void _Flyweight_RenderFlyweights	(	List< Flyweight_Class >	flyweightInstances,
		List< char[]>	displayArea
	)

inlineprivate

Render the image into the display, once for each flyweight instance.

Parameters

flyweightInstances	List of Flyweight_Class instances to render.
displayArea	The "display" in which to render.

Definition at line 210 of file Flyweight_Exercise.cs.

References Flyweight_Class.Context, Flyweight_Class.ImageHeight, Flyweight_Class.ImageWidth, Flyweight_Context.OffsetXToImage, Flyweight_Context.Position_X, Flyweight_Context.Position_Y, and Flyweight_Class.Render().

Referenced by Flyweight_Exercise.Run().

◆ _Flyweight_ShowDisplay()

void _Flyweight_ShowDisplay ( List< char[]> display )

inlineprivate

Render the display to the screen.

Parameters

display A list of character arrays representing the display.

Definition at line 119 of file Flyweight_Exercise.cs.

Referenced by Flyweight_Exercise.Run().

◆ GenerateVelocity()

double GenerateVelocity ( Random randomizer )

inlineprivate

Generate a random velocity, which includes a speed and a direction. The velocity is 0.2 to 1.0 (in increments of 0.2) and the direction is either + or -.

Returns: Returns the velocity.

Definition at line 231 of file Flyweight_Exercise.cs.

◆ Run()

void Run ( )

inline

Executes the example for the Flyweight Pattern in C#.

Definition at line 293 of file Flyweight_Exercise.cs.

References Flyweight_Exercise._Flyweight_ClearDisplay(), Flyweight_Exercise._Flyweight_GenerateBigResource(), Flyweight_Exercise._Flyweight_GenerateDisplay(), Flyweight_Exercise._Flyweight_GenerateFlyweightClasses(), Flyweight_Exercise._Flyweight_MoveFlyweights(), Flyweight_Exercise._Flyweight_RenderFlyweights(), and Flyweight_Exercise._Flyweight_ShowDisplay().

Referenced by Program.Run().

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

Flyweight_Exercise.cs

Public Member Functions

Private Member Functions

Detailed Description

Member Function Documentation

◆ _Flyweight_ClearDisplay()

◆ _Flyweight_GenerateBigResource()

◆ _Flyweight_GenerateDisplay()

◆ _Flyweight_GenerateFlyweightClasses()

◆ _Flyweight_MoveFlyweights()

◆ _Flyweight_RenderFlyweights()

◆ _Flyweight_ShowDisplay()

◆ GenerateVelocity()

◆ Run()