Implementation of the Flyweight_Exercise() function as used in the Flyweight Pattern. More...

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "helpers/checkforkey.h"
#include "helpers/cursor.h"
#include "helpers/readkey.h"
#include "helpers/sleep.h"
#include "Flyweight_BigResourceManager.h"
#include "Flyweight_Display.h"
#include "Flyweight_Image.h"
#include "Flyweight_Exercise.h"

Include dependency graph for Flyweight_Exercise.c:

Go to the source code of this file.

Functions
static 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.

static void	_Flyweight_MoveFlyweights (Flyweight_ImageList *imageList, int display_width, int display_height)
	Move the given flyweight instances within the display, bouncing them off the edges of the display.

static void	_Flyweight_RenderFlyweights (Flyweight_ImageList imageList, Display displayArea)
	Render the image into the display, once for each flyweight instance.

static double	GenerateVelocity (void)
	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 -.

static void	_Flyweight_GenerateFlyweightClasses (int bigResourceId, int numFlyweights, int image_width, int image_height, int display_width, int display_height, Flyweight_ImageList *imageList)
	Helper function to generate the specified number of Flyweight_image objects and associate those objects with individual contexts and a single big resource.

static void	_Flyweight_ClearDisplay (Display *display)
	Clear the "display" to a background image, erasing whatever was there before.

static void	_Flyweight_GenerateDisplay (Display *display, int width, int height)
	Generate a display area in which to render the big resource.

static void	_Flyweight_ShowDisplay (Display *display)
	Render the display to the screen.

void	Flyweight_Exercise (void)
	Example of using the Flyweight design pattern.

Detailed Description

Implementation of the Flyweight_Exercise() function as used in the Flyweight Pattern.

Definition in file Flyweight_Exercise.c.

Function Documentation

◆ _Flyweight_ClearDisplay()

static void _Flyweight_ClearDisplay ( Display * display )

static

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 277 of file Flyweight_Exercise.c.

References Display::area, Display::height, and Display::width.

Referenced by _Flyweight_GenerateDisplay(), DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ _Flyweight_GenerateBigResource()

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

static

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 the "text" image, in characters. Minimum width is 3.
height	Height of the "text" image, in characters. Minimum height is 3.

Returns: An index to the generated index in the BigResourceManager. Returns -1 if something went wrong (out of memory error).

Definition at line 40 of file Flyweight_Exercise.c.

References BigResourceManager_AddResource(), BigResource::data, and BigResource::numImages.

Referenced by DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ _Flyweight_GenerateDisplay()

static void _Flyweight_GenerateDisplay	(	Display *	display,
		int	width,
		int	height
	)

static

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

Parameters

display	A Display object to initialize as the "display" window.
width	Width of the display area.
height	Height of the display area.

Definition at line 299 of file Flyweight_Exercise.c.

References _Flyweight_ClearDisplay(), and Display_Create().

Referenced by DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ _Flyweight_GenerateFlyweightClasses()

static void _Flyweight_GenerateFlyweightClasses	(	int	bigResourceId,
		int	numFlyweights,
		int	image_width,
		int	image_height,
		int	display_width,
		int	display_height,
		Flyweight_ImageList *	imageList
	)

static

Helper function to generate the specified number of Flyweight_image objects and associate those objects 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.
imageList	A Flyweight_ImageList object to be filled in with the generated Flyweight_Image objects.

Definition at line 246 of file Flyweight_Exercise.c.

References Flyweight_Image::BigResourceId, Flyweight_Image::Context, Flyweight_ImageList_Add(), GenerateVelocity(), Flyweight_Context::ImageHeight, Flyweight_Context::ImageWidth, Flyweight_Context::OffsetXToImage, Flyweight_Context::Position_X, Flyweight_Context::Position_Y, Flyweight_Context::Velocity_X, and Flyweight_Context::Velocity_Y.

Referenced by DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ _Flyweight_MoveFlyweights()

static void _Flyweight_MoveFlyweights	(	Flyweight_ImageList *	imageList,
		int	display_width,
		int	display_height
	)

static

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

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

Definition at line 142 of file Flyweight_Exercise.c.

References Flyweight_Image::Context, Flyweight_Context::ImageHeight, Flyweight_ImageList::images, Flyweight_ImageList::images_count, Flyweight_Context::ImageWidth, Flyweight_Context::Position_X, Flyweight_Context::Position_Y, Flyweight_Context::Velocity_X, and Flyweight_Context::Velocity_Y.

Referenced by DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ _Flyweight_RenderFlyweights()

static void _Flyweight_RenderFlyweights	(	Flyweight_ImageList *	imageList,
		Display *	displayArea
	)

static

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

Parameters

imageList	List of Flyweight_Image objects to render.
displayArea	The "display" in which to render.

Definition at line 196 of file Flyweight_Exercise.c.

References BigResource_Render(), Flyweight_Image::BigResourceId, Flyweight_Image::Context, Flyweight_Context::ImageHeight, Flyweight_ImageList::images, Flyweight_ImageList::images_count, Flyweight_Context::ImageWidth, Flyweight_Context::OffsetXToImage, Flyweight_Context::Position_X, and Flyweight_Context::Position_Y.

Referenced by DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ _Flyweight_ShowDisplay()

static void _Flyweight_ShowDisplay ( Display * display )

static

Render the display to the screen.

Parameters

display The Display object to output to the console.

Definition at line 311 of file Flyweight_Exercise.c.

References Display::area, and Display::height.

Referenced by DesignPatternExamples_cpp::Flyweight_Exercise(), and Flyweight_Exercise().

◆ Flyweight_Exercise()

void Flyweight_Exercise ( void )

Example of using the Flyweight design pattern.

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 346 of file Flyweight_Exercise.c.

References _Flyweight_ClearDisplay(), _Flyweight_GenerateBigResource(), _Flyweight_GenerateDisplay(), _Flyweight_GenerateFlyweightClasses(), _Flyweight_MoveFlyweights(), _Flyweight_RenderFlyweights(), _Flyweight_ShowDisplay(), BigResourceManager_Clear(), checkforkey(), disableinputecho(), Display_Destroy(), enableinputecho(), Flyweight_ImageList_Clear(), getcursorposition(), readkey(), setcursorposition(), and sleep().

◆ GenerateVelocity()

static double GenerateVelocity ( void )

static

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 223 of file Flyweight_Exercise.c.

Referenced by Flyweight_Exercise::_Flyweight_GenerateFlyweightClasses(), and _Flyweight_GenerateFlyweightClasses().

Functions

Detailed Description

Function Documentation

◆ _Flyweight_ClearDisplay()

◆ _Flyweight_GenerateBigResource()

◆ _Flyweight_GenerateDisplay()

◆ _Flyweight_GenerateFlyweightClasses()

◆ _Flyweight_MoveFlyweights()

◆ _Flyweight_RenderFlyweights()

◆ _Flyweight_ShowDisplay()

◆ Flyweight_Exercise()

◆ GenerateVelocity()