SFML - Simple and Fast Multimedia Library

SFML

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sf
RenderTexture

Target for off-screen 2D rendering into a texture. More...

#include <RenderTexture.hpp>

Inheritance diagram for sf::RenderTexture:

Public Member Functions
	RenderTexture ()
	Default constructor. More...

virtual	~RenderTexture ()
	Destructor. More...

bool	create (unsigned int width, unsigned int height, bool depthBuffer=false)
	Create the render-texture. More...

void	setSmooth (bool smooth)
	Enable or disable texture smoothing. More...

bool	isSmooth () const
	Tell whether the smooth filtering is enabled or not. More...

void	setRepeated (bool repeated)
	Enable or disable texture repeating. More...

bool	isRepeated () const
	Tell whether the texture is repeated or not. More...

bool	generateMipmap ()
	Generate a mipmap using the current texture data. More...

bool	setActive (bool active=true)
	Activate or deactivate the render-texture for rendering. More...

void	display ()
	Update the contents of the target texture. More...

virtual Vector2u	getSize () const
	Return the size of the rendering region of the texture. More...

const Texture &	getTexture () const
	Get a read-only reference to the target texture. More...

void	clear (const Color &color=Color(0, 0, 0, 255))
	Clear the entire target with a single color. More...

void	setView (const View &view)
	Change the current active view. More...

const View &	getView () const
	Get the view currently in use in the render target. More...

const View &	getDefaultView () const
	Get the default view of the render target. More...

IntRect	getViewport (const View &view) const
	Get the viewport of a view, applied to this render target. More...

Vector2f	mapPixelToCoords (const Vector2i &point) const
	Convert a point from target coordinates to world coordinates, using the current view. More...

Vector2f	mapPixelToCoords (const Vector2i &point, const View &view) const
	Convert a point from target coordinates to world coordinates. More...

Vector2i	mapCoordsToPixel (const Vector2f &point) const
	Convert a point from world coordinates to target coordinates, using the current view. More...

Vector2i	mapCoordsToPixel (const Vector2f &point, const View &view) const
	Convert a point from world coordinates to target coordinates. More...

void	draw (const Drawable &drawable, const RenderStates &states=RenderStates::Default)
	Draw a drawable object to the render target. More...

void	draw (const Vertex *vertices, std::size_t vertexCount, PrimitiveType type, const RenderStates &states=RenderStates::Default)
	Draw primitives defined by an array of vertices. More...

void	pushGLStates ()
	Save the current OpenGL render states and matrices. More...

void	popGLStates ()
	Restore the previously saved OpenGL render states and matrices. More...

void	resetGLStates ()
	Reset the internal OpenGL states so that the target is ready for drawing. More...

Protected Member Functions
void	initialize ()
	Performs the common initialization step after creation. More...

Detailed Description

Target for off-screen 2D rendering into a texture.

sf::RenderTexture is the little brother of sf::RenderWindow.

It implements the same 2D drawing and OpenGL-related functions (see their base class sf::RenderTarget for more details), the difference is that the result is stored in an off-screen texture rather than being show in a window.

Rendering to a texture can be useful in a variety of situations:

precomputing a complex static texture (like a level's background from multiple tiles)
applying post-effects to the whole scene with shaders
creating a sprite from a 3D object rendered with OpenGL
etc.

Usage example:

// Create a new render-window
sf::RenderWindow window(sf::VideoMode(800, 600), "SFML window");
// Create a new render-texture
sf::RenderTexture texture;
if (!texture.create(500, 500))
 return -1;
// The main loop
while (window.isOpen())
{
 // Event processing
 // ...
 // Clear the whole texture with red color
   texture.clear(sf::Color::Red);
 // Draw stuff to the texture
   texture.draw(sprite);  // sprite is a sf::Sprite
   texture.draw(shape);   // shape is a sf::Shape
   texture.draw(text);    // text is a sf::Text
 // We're done drawing to the texture
   texture.display();
 // Now we start rendering to the window, clear it first
   window.clear();
 // Draw the texture
 sf::Sprite sprite(texture.getTexture());
   window.draw(sprite);
 // End the current frame and display its contents on screen
   window.display();
}

Like sf::RenderWindow, sf::RenderTexture is still able to render direct OpenGL stuff. It is even possible to mix together OpenGL calls and regular SFML drawing commands. If you need a depth buffer for 3D rendering, don't forget to request it when calling RenderTexture::create.

See also: sf::RenderTarget, sf::RenderWindow, sf::View, sf::Texture

Definition at line 47 of file RenderTexture.hpp.

Constructor & Destructor Documentation

sf::RenderTexture::RenderTexture ( )

Default constructor.

Constructs an empty, invalid render-texture. You must call create to have a valid render-texture.

See also: create

virtual sf::RenderTexture::~RenderTexture ( )

virtual

Destructor.

Member Function Documentation

void sf::RenderTarget::clear ( const Color & color = Color(0, 0, 0, 255) )

inherited

Clear the entire target with a single color.

This function is usually called once every frame, to clear the previous contents of the target.

Parameters

color Fill color to use to clear the render target

bool sf::RenderTexture::create	(	unsigned int	width,
		unsigned int	height,
		bool	depthBuffer = `false`
	)

Create the render-texture.

Before calling this function, the render-texture is in an invalid state, thus it is mandatory to call it before doing anything with the render-texture. The last parameter, depthBuffer, is useful if you want to use the render-texture for 3D OpenGL rendering that requires a depth buffer. Otherwise it is unnecessary, and you should leave this parameter to false (which is its default value).

Parameters

width	Width of the render-texture
height	Height of the render-texture
depthBuffer	Do you want this render-texture to have a depth buffer?

Returns: True if creation has been successful

void sf::RenderTexture::display ( )

Update the contents of the target texture.

This function updates the target texture with what has been drawn so far. Like for windows, calling this function is mandatory at the end of rendering. Not calling it may leave the texture in an undefined state.

void sf::RenderTarget::draw	(	const Drawable &	drawable,
		const RenderStates &	states = `RenderStates::Default`
	)

inherited

Draw a drawable object to the render target.

Parameters

drawable	Object to draw
states	Render states to use for drawing

void sf::RenderTarget::draw	(	const Vertex *	vertices,
		std::size_t	vertexCount,
		PrimitiveType	type,
		const RenderStates &	states = `RenderStates::Default`
	)

inherited

Draw primitives defined by an array of vertices.

Parameters

vertices	Pointer to the vertices
vertexCount	Number of vertices in the array
type	Type of primitives to draw
states	Render states to use for drawing

bool sf::RenderTexture::generateMipmap ( )

Generate a mipmap using the current texture data.

This function is similar to Texture::generateMipmap and operates on the texture used as the target for drawing. Be aware that any draw operation may modify the base level image data. For this reason, calling this function only makes sense after all drawing is completed and display has been called. Not calling display after subsequent drawing will lead to undefined behavior if a mipmap had been previously generated.

Returns: True if mipmap generation was successful, false if unsuccessful

const View& sf::RenderTarget::getDefaultView ( ) const

inherited

Get the default view of the render target.

The default view has the initial size of the render target, and never changes after the target has been created.

Returns: The default view of the render target

See also: setView, getView

virtual Vector2u sf::RenderTexture::getSize ( ) const

virtual

Return the size of the rendering region of the texture.

The returned value is the size that you passed to the create function.

Returns: Size in pixels

Implements sf::RenderTarget.

const Texture& sf::RenderTexture::getTexture ( ) const

Get a read-only reference to the target texture.

After drawing to the render-texture and calling Display, you can retrieve the updated texture using this function, and draw it using a sprite (for example). The internal sf::Texture of a render-texture is always the same instance, so that it is possible to call this function once and keep a reference to the texture even after it is modified.

Returns: Const reference to the texture

const View& sf::RenderTarget::getView ( ) const

inherited

Get the view currently in use in the render target.

Returns: The view object that is currently used

See also: setView, getDefaultView

IntRect sf::RenderTarget::getViewport ( const View & view ) const

inherited

Get the viewport of a view, applied to this render target.

The viewport is defined in the view as a ratio, this function simply applies this ratio to the current dimensions of the render target to calculate the pixels rectangle that the viewport actually covers in the target.

Parameters

view	The view for which we want to compute the viewport

Returns: Viewport rectangle, expressed in pixels

void sf::RenderTarget::initialize ( )

protectedinherited

Performs the common initialization step after creation.

The derived classes must call this function after the target is created and ready for drawing.

bool sf::RenderTexture::isRepeated ( ) const

Tell whether the texture is repeated or not.

Returns: True if texture is repeated

See also: setRepeated

bool sf::RenderTexture::isSmooth ( ) const

Tell whether the smooth filtering is enabled or not.

Returns: True if texture smoothing is enabled

See also: setSmooth

Vector2i sf::RenderTarget::mapCoordsToPixel ( const Vector2f & point ) const

inherited

Convert a point from world coordinates to target coordinates, using the current view.

This function is an overload of the mapCoordsToPixel function that implicitly uses the current view. It is equivalent to:

target.mapCoordsToPixel(point, target.getView());

Parameters

point Point to convert

Returns: The converted point, in target coordinates (pixels)

See also: mapPixelToCoords

Vector2i sf::RenderTarget::mapCoordsToPixel	(	const Vector2f &	point,
		const View &	view
	)		const

inherited

Convert a point from world coordinates to target coordinates.

This function finds the pixel of the render target that matches the given 2D point. In other words, it goes through the same process as the graphics card, to compute the final position of a rendered point.

Initially, both coordinate systems (world units and target pixels) match perfectly. But if you define a custom view or resize your render target, this assertion is not true anymore, i.e. a point located at (150, 75) in your 2D world may map to the pixel (10, 50) of your render target – if the view is translated by (140, 25).

This version uses a custom view for calculations, see the other overload of the function if you want to use the current view of the render target.

Parameters

point	Point to convert
view	The view to use for converting the point

Returns: The converted point, in target coordinates (pixels)

See also: mapPixelToCoords

Vector2f sf::RenderTarget::mapPixelToCoords ( const Vector2i & point ) const

inherited

Convert a point from target coordinates to world coordinates, using the current view.

This function is an overload of the mapPixelToCoords function that implicitly uses the current view. It is equivalent to:

target.mapPixelToCoords(point, target.getView());

Parameters

point Pixel to convert

Returns: The converted point, in "world" coordinates

See also: mapCoordsToPixel

Vector2f sf::RenderTarget::mapPixelToCoords	(	const Vector2i &	point,
		const View &	view
	)		const

inherited

Convert a point from target coordinates to world coordinates.

This function finds the 2D position that matches the given pixel of the render target. In other words, it does the inverse of what the graphics card does, to find the initial position of a rendered pixel.

Initially, both coordinate systems (world units and target pixels) match perfectly. But if you define a custom view or resize your render target, this assertion is not true anymore, i.e. a point located at (10, 50) in your render target may map to the point (150, 75) in your 2D world – if the view is translated by (140, 25).

For render-windows, this function is typically used to find which point (or object) is located below the mouse cursor.

This version uses a custom view for calculations, see the other overload of the function if you want to use the current view of the render target.

Parameters

point	Pixel to convert
view	The view to use for converting the point

Returns: The converted point, in "world" units

See also: mapCoordsToPixel

void sf::RenderTarget::popGLStates ( )

inherited

Restore the previously saved OpenGL render states and matrices.

See the description of pushGLStates to get a detailed description of these functions.

See also: pushGLStates

void sf::RenderTarget::pushGLStates ( )

inherited

Save the current OpenGL render states and matrices.

This function can be used when you mix SFML drawing and direct OpenGL rendering. Combined with popGLStates, it ensures that:

SFML's internal states are not messed up by your OpenGL code
your OpenGL states are not modified by a call to a SFML function

More specifically, it must be used around code that calls Draw functions. Example:

// OpenGL code here...
window.pushGLStates();
window.draw(...);
window.draw(...);
window.popGLStates();
// OpenGL code here...

Note that this function is quite expensive: it saves all the possible OpenGL states and matrices, even the ones you don't care about. Therefore it should be used wisely. It is provided for convenience, but the best results will be achieved if you handle OpenGL states yourself (because you know which states have really changed, and need to be saved and restored). Take a look at the resetGLStates function if you do so.

See also: popGLStates

void sf::RenderTarget::resetGLStates ( )

inherited

Reset the internal OpenGL states so that the target is ready for drawing.

This function can be used when you mix SFML drawing and direct OpenGL rendering, if you choose not to use pushGLStates/popGLStates. It makes sure that all OpenGL states needed by SFML are set, so that subsequent draw() calls will work as expected.

Example:

// OpenGL code here...
glPushAttrib(...);
window.resetGLStates();
window.draw(...);
window.draw(...);
glPopAttrib(...);
// OpenGL code here...

bool sf::RenderTexture::setActive ( bool active = true )

Activate or deactivate the render-texture for rendering.

This function makes the render-texture's context current for future OpenGL rendering operations (so you shouldn't care about it if you're not doing direct OpenGL stuff). Only one context can be current in a thread, so if you want to draw OpenGL geometry to another render target (like a RenderWindow) don't forget to activate it again.

Parameters

active True to activate, false to deactivate

Returns: True if operation was successful, false otherwise

void sf::RenderTexture::setRepeated ( bool repeated )

Enable or disable texture repeating.

This function is similar to Texture::setRepeated. This parameter is disabled by default.

Parameters

repeated True to enable repeating, false to disable it

See also: isRepeated

void sf::RenderTexture::setSmooth ( bool smooth )

Enable or disable texture smoothing.

This function is similar to Texture::setSmooth. This parameter is disabled by default.

Parameters

smooth True to enable smoothing, false to disable it

See also: isSmooth

void sf::RenderTarget::setView ( const View & view )

inherited

Change the current active view.

The view is like a 2D camera, it controls which part of the 2D scene is visible, and how it is viewed in the render target. The new view will affect everything that is drawn, until another view is set. The render target keeps its own copy of the view object, so it is not necessary to keep the original one alive after calling this function. To restore the original view of the target, you can pass the result of getDefaultView() to this function.

Parameters

view	New view to use

See also: getView, getDefaultView

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

RenderTexture.hpp

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SFML - Simple and Fast Multimedia Library

SFML

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation