SpriteManager Class Reference
[Game Objects and Event Loop]

Class to manage movement, collision, and drawing of sprites. More...

#include <spritemanager.h>

Collaboration diagram for SpriteManager:

[legend]List of all members.

Public Member Functions
void	SendEvent (int code, void *data1=NULL, void *data2=NULL)
	Calls the Event() member of every sprite with this data.
bool	AddUpdateRect (SDL_Rect &r)
	Attempts to add the specified rect to the screen update list.
Constructors
SpriteManager has two constructors, one for dealing with preset video modes and backgrounds, and one for setting the video mode and such. The video-initializing constructor initializes SDL if it's needed.
	SpriteManager (Uint16 w, Uint16 h, Uint8 depth, Uint32 vflags)
	Constructor that sets screen mode.
	SpriteManager (Uint16 flags=0, SDL_Surface *screenin=NULL, const char *bgnd=NULL)
	Constructor - all parameters optional.
Contents-control functions
These do what they say they do. RemoveSprite does not delete the sprite, just removes it from the list.
bool	AddSprite (Sprite *spr)
	Attempts to add a sprite to the list.
bool	RemoveSprite (Sprite *spr)
	Attempts to remove a sprite from the list.
Overloadable virtual functions
These functions are stubs that you can overload to do what you want in response to SDL_USEREVENTs, unhandled SDL events, destruction, and in the game loop's free time. Event(), Idle(), and Handler() are all called by Run() while the game loop is running.
virtual int	Event (int code, void *data1, void *data2)
	Handler function for SDL_USEREVENTs.
virtual void	Idle ()
	Function called when event loop has time to kill.
virtual void	Handler (SDL_Event *event)
	Function called for unhandled SDL events.
virtual	~SpriteManager ()
	Destructor, frees all data.
Event Loop functions
The four game-loop functions are called together by the Run() functions, or by whatever custom routine you devise for the same function. They need to be called in the order Preserve() Move() Draw() Update(). Move() can be called several times in succession.
SMRun_Return	Run (Sint32 frametick)
	Runs the game event loop until SDL_QUIT.
SMRun_Return	Run (Sint32 frametick, Sint32 gametick)
	Runs the game event loop with a guaranteed game tick.
void	Preserve ()
	Preserves previous position of sprites.
void	Move (Sint32 dtick)
	Calls the Update() member of every sprite.
void	Draw ()
	Draws the sprites on the screen.
void	Update ()
	Updates relevant portions of the screen.
Status Flag Functions
Routines to set, query, and clear various status flags in SpriteManager.
void	Redraw ()
	Sets SM_TOTALREDRAW flag.
int	Paused ()
	Returns nonzero if paused, zero if not.
void	Pause ()
	Sets the SM_PAUSED flag.
void	Unpause ()
	Clears the SM_PAUSED flag.
Background-access functions
These functions allow you to modify the background image from outside SpriteManager. Locks the mutex, to prevent another thread from using the surface while modification is in progress.
SDL_Surface *	CheckOutBG ()
	Returns the background surface and locks the SpriteManager.
bool	CheckInBG (SDL_Surface *bg_in)
	Checks the surface back in and unlocks the SpriteManager.
void	DrawOnBG (SDL_Surface *src, SDL_Rect *srcrect, SDL_Rect *destrect)
	Blits specified portion of surface onto background image.
Protected Member Functions
void	Lock ()
	Locks the mutex, to prevent simultaneous access.
void	Unlock ()
	Unlocks the mutex, leaving the manager free for use.
Sprite Blitters
These are the different sprite blitters available. SimpleBlit() is called whenever a total redraw is needed. FastBlit() is more efficient, but still redraws every sprite instead of only ones that need updating. QuadBlit() is theoretically more efficient but still under test. SpriteLib uses QuadBlit() by default
void	SimpleBlit ()
	Updates the entire screen.
void	FastBlit ()
	Redraws only sprites and the areas under them.
void	QuadBlit ()
	Redraws only things in disturbed quadrants.
Protected Attributes
Uint16	flag
	Status flags.
SDL_mutex *	lock
	Mutex; locks during operations to make it threadsafe.
SDL_Surface *	screen
	The surface that gets drawn to.
SDL_Surface *	bg
	The background image.
SpriteList	sprites
	Linked list of sprites.
RectList	rects
	Big stack of rectangles.

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Detailed Description

Class implementing a general purpose game loop. Handles motion of game objects; insertion, removal, and deletion of game objects; inter-object communication via SDL_USEREVENTs, framerate timing, and event handling.

Definition at line 76 of file spritemanager.h.

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Constructor & Destructor Documentation

SpriteManager::SpriteManager (  Uint16  w, Uint16  h, Uint8  depth, Uint32  vflags )

Constructor capable of initializing SDL and setting it's own video mode. Fancy huh? Definition at line 56 of file spritemanager.cpp. References bg, flag, lock, screen, SM_DOUBLEBUF, SM_OWNBG, and SM_TOTALREDRAW.

SpriteManager::SpriteManager (  Uint16  flags = 0, SDL_Surface *  screenin = NULL, const char *  bgnd = NULL )

General purpose constructor, taking pre-created video and background surfaces. Definition at line 289 of file spritemanager.cpp. References bg, flag, LoadConvertBMP(), lock, MAX_RECTS, screen, SM_OWNBG, and SM_TOTALREDRAW.

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SpriteManager::~SpriteManager (   )  [virtual]

Frees the background and mutex. Definition at line 494 of file spritemanager.cpp. References bg, flag, lock, Lock(), and SM_OWNBG.

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Member Function Documentation

bool SpriteManager::AddSprite (  Sprite *  spr  )

Attempts to add a sprite. Definition at line 333 of file spritemanager.cpp. References SpriteList::Insert(), Lock(), sprites, and Unlock(). Referenced by main().

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bool SpriteManager::CheckInBG (  SDL_Surface *  bg_in  )

Returns the background surface you checked out. Definition at line 476 of file spritemanager.cpp. References bg, and Unlock().

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SDL_Surface * SpriteManager::CheckOutBG (   )

Allows something outside SpriteManager to 'borrow' the background surface and doodle on it. SpriteManager will want it back, though, and game loops won't run until the surface is returned. Definition at line 468 of file spritemanager.cpp. References bg, and Lock().

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void SpriteManager::Draw (   )

Draws the new frame, but doesn't update it. Definition at line 361 of file spritemanager.cpp. References flag, QuadBlit(), SimpleBlit(), SM_DOUBLEBUF, and SM_TOTALREDRAW. Referenced by Run().

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void SpriteManager::DrawOnBG (  SDL_Surface *  src, SDL_Rect *  srcrect, SDL_Rect *  destrect )

Lets you blit stuff directly onto the background. Definition at line 93 of file spritemanager.cpp. References bg, flag, Lock(), SM_TOTALREDRAW, and Unlock(). Referenced by main().

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int SpriteManager::Event (  int  code, void *  data1, void *  data2 )  [virtual]

Unless this function returns 1, the SDL_USEREVENT is passed along to every sprite in the list. Definition at line 34 of file spritemanager.cpp. Referenced by Run().

void SpriteManager::FastBlit (   )  [protected]

A simple but effective blitter for small numbers of sprites. Redraws every sprite, every frame, but doesn't need to redraw the entire background unlike SimpleBlit. Definition at line 142 of file blitter.cpp. References bg, Sprite::CurRect(), Sprite::Deleteable(), Sprite::Draw(), Sprite::Expired(), SpriteList::Extract(), SpriteList::Head(), Rect::Merge(), Sprite::next, Sprite::PrevRect(), RectList::Push(), rects, screen, and sprites.

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void SpriteManager::Handler (  SDL_Event *  event  )  [virtual]

SDL events that the event loop doesn't know how to handle get passed along to here. Definition at line 41 of file spritemanager.cpp. Referenced by Run().

void SpriteManager::Idle (   )  [virtual]

Game event loop calls this when it's not busy, can overload this to put in periodic checks and such Definition at line 48 of file spritemanager.cpp. Referenced by Run().

void SpriteManager::Move (  Sint32  dtick  )

Handles sprite movement, removal, deletion, and collision. Definition at line 378 of file spritemanager.cpp. References Sprite::CanCollide(), Sprite::ClearFlags(), Sprite::Expired(), Sprite::GetColIndex(), SpriteList::Head(), Lock(), Sprite::Moved(), Sprite::New(), Sprite::next, Sprite::OnCollide(), Sprite::SetFlags(), SPRITE_MOVED, SPRITE_WAIT, sprites, Unlock(), and Sprite::Update(). Referenced by Run().

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void SpriteManager::Preserve (   )

Iterates through the list and preserves the previous coordinates of every sprite. Definition at line 274 of file spritemanager.cpp. References SpriteList::Head(), Sprite::next, Sprite::Preserve(), and sprites. Referenced by Run().

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void SpriteManager::QuadBlit (   )  [protected]

A theoretically more efficient blitter. It divides the screen into squares and only redraws the squares that have changed. Definition at line 35 of file blitter.cpp. References bg, Sprite::CurRect(), Sprite::Deleteable(), Sprite::Draw(), Sprite::Expired(), SpriteList::Extract(), SpriteList::Head(), Rect::Merge(), Sprite::Moved(), Rect::MoveTo(), Sprite::next, Sprite::PrevRect(), RectList::Push(), rects, screen, and sprites. Referenced by Draw().

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bool SpriteManager::RemoveSprite (  Sprite *  spr  )

This doesn't destroy the sprite, just removes it from the list. Definition at line 347 of file spritemanager.cpp. References SpriteList::Extract(), Lock(), sprites, and Unlock().

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SMRun_Return SpriteManager::Run (  Sint32  frametick, Sint32  gametick )

Game Loop. The framerate can differ from the game tick, and the game tick is guaranteed to ALWAYS be 'gametick'. Can fail if you give it a gametick of zero, or the computer has insufficient power to calculate sprite movements as many times per second as you want. Definition at line 125 of file spritemanager.cpp. References Draw(), Event(), flag, Handler(), Idle(), Move(), Paused(), Preserve(), TickTimer::Reset(), SendEvent(), SM_RUNNING, SMRUN_OK, SMRun_Return, SMRUN_TIMESTEP, and Update().

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SMRun_Return SpriteManager::Run (  Sint32  frametick  )

Runs the game event loop until an SDL_QUIT message is recieved. Calls nearly every other member while it's running, including the virtual Idle(), Event(), and Handler() functions that you can overload to do whatever you please. Definition at line 209 of file spritemanager.cpp. References Draw(), Event(), flag, Handler(), Idle(), Move(), Paused(), Preserve(), TickTimer::Reset(), SendEvent(), SM_RUNNING, SMRUN_OK, SMRun_Return, SMRUN_TIMESTEP, and Update(). Referenced by main().

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void SpriteManager::SendEvent (  int  code, void *  data1 = NULL, void *  data2 = NULL )

Sends SDL_USEREVENTs to EVERY sprite in the list. Definition at line 107 of file spritemanager.cpp. References Sprite::Event(), SpriteList::Head(), Sprite::next, and sprites. Referenced by Run().

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void SpriteManager::SimpleBlit (   )  [protected]

Redraws the entire screen, a brute force blitter. Needs to be called every once in awhile, if the background changes and such. Definition at line 107 of file blitter.cpp. References bg, RectList::Clear(), Sprite::Deleteable(), Sprite::Draw(), Sprite::Expired(), SpriteList::Extract(), SpriteList::Head(), Sprite::next, RectList::Push(), rects, screen, and sprites. Referenced by Draw().

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

• spritemanager.h
• blitter.cpp
• spritemanager.cpp

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