Documentation of SFML 2.0

sf::RenderTexture Class Reference

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

#include <RenderTexture.hpp>

Inheritance diagram for sf::RenderTexture:
sf::RenderTarget sf::NonCopyable

Public Member Functions

 RenderTexture ()
 Default constructor.
 
virtual ~RenderTexture ()
 Destructor.
 
bool create (unsigned int width, unsigned int height, bool depthBuffer=false)
 Create the render-texture.
 
void setSmooth (bool smooth)
 Enable or disable texture smoothing.
 
bool isSmooth () const
 Tell whether the smooth filtering is enabled or not.
 
void setRepeated (bool repeated)
 Enable or disable texture repeating.
 
bool isRepeated () const
 Tell whether the texture is repeated or not.
 
bool setActive (bool active=true)
 Activate of deactivate the render-texture for rendering.
 
void display ()
 Update the contents of the target texture.
 
virtual Vector2u getSize () const
 Return the size of the rendering region of the texture.
 
const TexturegetTexture () const
 Get a read-only reference to the target texture.
 
void clear (const Color &color=Color(0, 0, 0, 255))
 Clear the entire target with a single color.
 
void setView (const View &view)
 Change the current active view.
 
const ViewgetView () const
 Get the view currently in use in the render target.
 
const ViewgetDefaultView () const
 Get the default view of the render target.
 
IntRect getViewport (const View &view) const
 Get the viewport of a view, applied to this render target.
 
Vector2f mapPixelToCoords (const Vector2i &point) const
 Convert a point from target coordinates to world coordinates, using the current view.
 
Vector2f mapPixelToCoords (const Vector2i &point, const View &view) const
 Convert a point from target coordinates to world coordinates.
 
Vector2i mapCoordsToPixel (const Vector2f &point) const
 Convert a point from world coordinates to target coordinates, using the current view.
 
Vector2i mapCoordsToPixel (const Vector2f &point, const View &view) const
 Convert a point from world coordinates to target coordinates.
 
void draw (const Drawable &drawable, const RenderStates &states=RenderStates::Default)
 Draw a drawable object to the render-target.
 
void draw (const Vertex *vertices, unsigned int vertexCount, PrimitiveType type, const RenderStates &states=RenderStates::Default)
 Draw primitives defined by an array of vertices.
 
void pushGLStates ()
 Save the current OpenGL render states and matrices.
 
void popGLStates ()
 Restore the previously saved OpenGL render states and matrices.
 
void resetGLStates ()
 Reset the internal OpenGL states so that the target is ready for drawing.
 

Protected Member Functions

void initialize ()
 Performs the common initialization step after creation.
 

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
if (!texture.create(500, 500))
return -1;
// The main loop
while (window.isOpen())
{
// Event processing
// ...
// Clear the whole texture with red color
// 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
colorFill 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
widthWidth of the render-texture
heightHeight of the render-texture
depthBufferDo 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
drawableObject to draw
statesRender states to use for drawing
void sf::RenderTarget::draw ( const Vertex vertices,
unsigned int  vertexCount,
PrimitiveType  type,
const RenderStates states = RenderStates::Default 
)
inherited

Draw primitives defined by an array of vertices.

Parameters
verticesPointer to the vertices
vertexCountNumber of vertices in the array
typeType of primitives to draw
statesRender states to use for drawing
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
viewThe 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 implicitely uses the current view. It is equivalent to:

target.mapCoordsToPixel(point, target.getView());
Parameters
pointPoint 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, ie. 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
pointPoint to convert
viewThe 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 implicitely uses the current view. It is equivalent to:

target.mapPixelToCoords(point, target.getView());
Parameters
pointPixel 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, ie. 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
pointPixel to convert
viewThe 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 of 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
activeTrue 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
repeatedTrue 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
smoothTrue 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
viewNew view to use
See Also
getView, getDefaultView

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