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Class CL_Surface

Image class in ClanLib.
Contained in: global
Derived from: none
Derived by: none
Group: Display (Display 2D)

#include <ClanLib/display.h>


public function member index:

Static_init:

static CL_Surface* load(const std::string& resource_id, CL_ResourceManager* manager);
static CL_Surface* create(CL_SurfaceProvider* provider, bool delete_provider=false);
static CL_Surface* create_dynamic(CL_SurfaceProvider* provider, bool delete_provider=false);

Construction:

CL_Surface();
CL_Surface(CL_SurfaceProvider* provider, bool delete_provider = false, bool dynamic = false);
CL_Surface(const std::string& resource_id, CL_ResourceManager* manager);
CL_Surface(const std::string& filename, bool dynamic = false);
CL_Surface(const CL_Surface& surface);
virtual ~CL_Surface();

Operations:

operator bool() const;
const CL_Surface& operator =(const CL_Surface& surf);
void reload();
CL_SurfaceProvider* get_provider() const;
void put_screen(int x, int y, int spr_no=0, CL_DisplayCard* card=NULL);
void put_screen(int x, int y, float scale_x, float scale_y, int spr_no=0, CL_DisplayCard* card=NULL);
void put_screen(int x, int y, int size_x, int size_y, int spr_no=0, CL_DisplayCard* card=NULL);
void put_target(int x, int y, int spr_no, CL_Target* target);
unsigned int get_width() const;
unsigned int get_height() const;
unsigned int get_num_frames() const;
bool is_video(CL_DisplayCard* card = NULL) const;
bool is_loaded(CL_DisplayCard* card = NULL) const;
bool convert_video(CL_DisplayCard* card = NULL);
bool convert_system(CL_DisplayCard* card = NULL);
void flush(CL_DisplayCard* card = NULL);

Implementation:

CL_Surface(class CL_Surface_Generic* impl);
 

Description:

This class is used to draw 2D images onto the backbuffer or to a CL_Target renderer target.

In ClanLib, a surface is understood to be an image represented in a form, where it is most suitable for as fast rendering as possible. Unlike many other libraries, it is not possible to get direct access to the surface data.

A surface uses a CL_SurfaceProvider surface provider to load its data. It is passed at creation time, and you can either roll your own provider, or use one already available in ClanLib.

It is also possible to create a surface from a resource source. This will allow you to load an image using a resource ID instead of directly specifying the image in your source code.

Dynamic surfaces

If you have an image which changes very frequently (eg. each frame), you want to use a dynamic surface instead. The difference is that the surface won't cache the image, and it won't convert it to another image format more suitable for the display target. Note that this is only faster if you change your image very frequently - otherwise a normal surface is the best solution.

When constructing your own images, you will most likely find the CL_Canvas canvas surface provider interesting. This class will make it easier to create a custom drawing area where you can draw your image.

All surfaceproviders is a CL_Target renderer target. However, most of the normal surface providers are "read only", meaning that their image data will only remain intact during a lock session. This is because the providers consume less memory when the image is only available, when someone needs it. Only the CL_Canvas canvas provider will not destroy the image.

A surface can blit (draw itself) itself to the backbuffer, or to a renderer target. This means that you can use the surface to draw one surface provider to another.


Function Member Descriptions:

CL_Surface::CL_Surface - Loads a surface from an image file.
CL_Surface(const std::string& filename, bool dynamic = false);


CL_Surface::CL_Surface - Make a copy of an other surface, but share the image data.
CL_Surface(const CL_Surface& surface);


CL_Surface::CL_Surface - Surface Constructor
CL_Surface(class CL_Surface_Generic* impl);


CL_Surface::CL_Surface - Empty constructor, you need to assign a surface to the
CL_Surface object first before it becomes useable
CL_Surface();


CL_Surface::CL_Surface - This function creates a CL_Surface.
If dynamic is true, the surface will be a dynamic blitter. If false, it will be a caching blitter.
CL_Surface(CL_SurfaceProvider* provider, bool delete_provider = false, bool dynamic = false);
provider - Image source.
delete_provider - If true, the surface will delete the provider when deleted itself.
dynamic - If true, a dynamic blitter will be chosen. If false, a caching blitter will be used.
Returns - The surface created.



CL_Surface::CL_Surface - Loads a surface from a resource file.
CL_Surface(const std::string& resource_id, CL_ResourceManager* manager);


CL_Surface::bool - You can use this operator to check if the surface is
valid, to do that you write something like this: if (surf) {...}
operator bool() const;


CL_Surface::convert_system - convert surface to system memory - never fails! (or serious heap usage!)
bool convert_system(CL_DisplayCard* card = NULL);


CL_Surface::convert_video - returns true if successfully loaded into videomemory, or already there
bool convert_video(CL_DisplayCard* card = NULL);


CL_Surface::create - This function creates a CL_Surface instance being blitted by a caching blitter.
static CL_Surface* create(CL_SurfaceProvider* provider, bool delete_provider=false);
provider - Image source.
delete_provider - If true, the surface will delete the provider when deleted itself.
Returns - The surface created.



CL_Surface::create_dynamic - This function creates a CL_Surface instance being blitted by the dynamic (non caching) blitter.
You don't need to call reload with dynamic surfaces as they do that by themselves.
static CL_Surface* create_dynamic(CL_SurfaceProvider* provider, bool delete_provider=false);
provider - Image source.
delete_provider - If true, the surface will delete the provider when deleted itself.
Returns - The surface created.



CL_Surface::flush - completely flushes surface (removes from video/system-memory)
void flush(CL_DisplayCard* card = NULL);


CL_Surface::get_height - Returns the height of the surface
unsigned int get_height() const;


CL_Surface::get_num_frames - Returns the number of frames/subsprites in the surface
unsigned int get_num_frames() const;


CL_Surface::get_provider - Returns the surface provider used by this surface.
CL_SurfaceProvider* get_provider() const;
Returns - Surface provider used by this surface.



CL_Surface::get_width - Returns the width of the surface
unsigned int get_width() const;


CL_Surface::is_loaded - returns true if loaded in either video- or system-memory
bool is_loaded(CL_DisplayCard* card = NULL) const;


CL_Surface::is_video - returns true if in videomemory
on the specified card (null = current dispcard).
bool is_video(CL_DisplayCard* card = NULL) const;


CL_Surface::load - This function loads a surface from a resource file (usually a datafile).
static CL_Surface* load(const std::string& resource_id, CL_ResourceManager* manager);


CL_Surface::operator = - Surface operator
const CL_Surface& operator =(const CL_Surface& surf);


CL_Surface::put_screen - Draws the surface onto the backbuffer - scaling it to a specified size.
void put_screen(int x, int y, int size_x, int size_y, int spr_no=0, CL_DisplayCard* card=NULL);
x - x coordinate to draw surface.
y - y coordinate to draw surface.
size_x - width of the image when scaled.
size_y - height of the image when scaled.
spr_no - subsprite number to use.
card - Display card to be drawn onto. If NULL it will use the currently selected video card by CL_Display.



CL_Surface::put_screen - Draws the surface onto the backbuffer.
void put_screen(int x, int y, int spr_no=0, CL_DisplayCard* card=NULL);
x - x coordinate to draw surface.
y - y coordinate to draw surface.
spr_no - subsprite number to use.
card - Display card to be drawn onto. If NULL it will use the currently selected video card by CL_Display.



CL_Surface::put_screen - Draws the surface onto the backbuffer - scaling it to a specified size.
void put_screen(int x, int y, float scale_x, float scale_y, int spr_no=0, CL_DisplayCard* card=NULL);
x - x coordinate to draw surface.
y - y coordinate to draw surface.
scale_x - scale x multiplyer.
scale_y - scale y multiplyer.
spr_no - subsprite number to use.
card - Display card to be drawn onto. If NULL it will use the currently selected video card by CL_Display.



CL_Surface::put_target - Draws the surface to a target.
void put_target(int x, int y, int spr_no, CL_Target* target);
x - x coordinate to draw surface.
y - y coordinate to draw surface.
spr_no - subsprite number to use.
target - target.



CL_Surface::reload - Forces surface to reload surface data from provider.
void reload();


CL_Surface::~CL_Surface - Surface Destructor
virtual ~CL_Surface();



Variable Member Descriptions:

CL_Surface::impl - Surface Implementation
CL_Surface_Generic * impl;

CL_Surface::resource - Surface resource, if any.
CL_Resource resource;