Documentation of SFML 2.4.2

sf::RenderTarget Class Referenceabstract

Base class for all render targets (window, texture, ...) More...

#include <RenderTarget.hpp>

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

Public Member Functions

virtual ~RenderTarget ()
 Destructor. 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 ViewgetView () const
 Get the view currently in use in the render target. More...
 
const ViewgetDefaultView () 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...
 
virtual Vector2u getSize () const =0
 Return the size of the rendering region of the target. 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

 RenderTarget ()
 Default constructor. More...
 
void initialize ()
 Performs the common initialization step after creation. More...
 

Detailed Description

Base class for all render targets (window, texture, ...)

sf::RenderTarget defines the common behavior of all the 2D render targets usable in the graphics module.

It makes it possible to draw 2D entities like sprites, shapes, text without using any OpenGL command directly.

A sf::RenderTarget is also able to use views (sf::View), which are a kind of 2D cameras. With views you can globally scroll, rotate or zoom everything that is drawn, without having to transform every single entity. See the documentation of sf::View for more details and sample pieces of code about this class.

On top of that, render targets are still able to render direct OpenGL stuff. It is even possible to mix together OpenGL calls and regular SFML drawing commands. When doing so, make sure that OpenGL states are not messed up by calling the pushGLStates/popGLStates functions.

See also
sf::RenderWindow, sf::RenderTexture, sf::View

Definition at line 51 of file RenderTarget.hpp.

Constructor & Destructor Documentation

virtual sf::RenderTarget::~RenderTarget ( )
virtual

Destructor.

sf::RenderTarget::RenderTarget ( )
protected

Default constructor.

Member Function Documentation

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

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

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,
std::size_t  vertexCount,
PrimitiveType  type,
const RenderStates states = RenderStates::Default 
)

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

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::RenderTarget::getSize ( ) const
pure virtual

Return the size of the rendering region of the target.

Returns
Size in pixels

Implemented in sf::RenderTexture, and sf::RenderWindow.

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

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

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 ( )
protected

Performs the common initialization step after creation.

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

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

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
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

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
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

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
pointPixel to convert
Returns
The converted point, in "world" coordinates
See also
mapCoordsToPixel
Vector2f sf::RenderTarget::mapPixelToCoords ( const Vector2i point,
const View view 
) const

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
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 ( )

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 ( )

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 ( )

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

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: