An interface that provides methods for low level 2D drawing operations. More...

#include <Renderer2D.hpp>

Inheritance diagram for CDPL::Vis::Renderer2D:

Public Member Functions
virtual	~Renderer2D ()
	Virtual destructor. More...

virtual void	saveState ()=0
	Saves the current renderer state. More...

virtual void	restoreState ()=0
	Restores the last renderer state saved by a call to saveState(). More...

virtual void	setTransform (const Math::Matrix3D &xform)=0
	Sets the applied affine transformation matrix to xform. More...

virtual void	transform (const Math::Matrix3D &xform)=0
	Multiplies the current affine transformation matrix by xform. More...

virtual void	setPen (const Pen &pen)=0
	Sets the pen to be used in subsequent drawing operations. More...

virtual void	setBrush (const Brush &brush)=0
	Sets the brush to be used in subsequent drawing operations. More...

virtual void	setFont (const Font &font)=0
	Sets the font to be used in subsequent text drawing operations. More...

virtual void	drawRectangle (double x, double y, double width, double height)=0
	Draws an axis aligned rectangle of the specified width and height whose upper-left corner is located at (x, y). More...

virtual void	drawPolygon (const Math::Vector2DArray &points)=0
	Draws the polygon defined by points. More...

virtual void	drawLine (double x1, double y1, double x2, double y2)=0
	Draws a line segment from (x1, y1) to (x2, y2). More...

virtual void	drawPolyline (const Math::Vector2DArray &points)=0
	Draws the polyline defined by points. More...

virtual void	drawLineSegments (const Math::Vector2DArray &points)=0
	Draws the sequence of disjoint line segments defined by points. More...

virtual void	drawPoint (double x, double y)=0
	Draws a point at the position (x, y). More...

virtual void	drawEllipse (double x, double y, double width, double height)=0
	Draws an ellipse with the given width and height around the center position (x, y). More...

virtual void	drawPath (const Path2D &path)=0
	Draws the given path. More...

virtual void	drawText (double x, double y, const std::string &txt)=0
	Draws the specified text at the position (x, y). More...

virtual void	setClipPath (const Path2D &path)=0

virtual void	clearClipPath ()=0
	Disables clipping. More...

Detailed Description

An interface that provides methods for low level 2D drawing operations.

For the drawing of graphical primitives the following methods are provided:

drawPoint() for drawing points
drawLine() for drawing single line segments
drawPolyline() for drawing connected line segments
drawLineSegments() for drawing a set of disjoint line segments
drawPolygon() for drawing polygons
drawRectangle() for drawing axis aligned rectangles
drawPath() for drawing arbitrary shapes
and drawText() for drawing text

Drawing operations can be clipped to arbitrary shapes defined by a Vis::Path2D object. A new clip region is set by calling the method setClipPath() and disabled by calling clearClipPath().

Coordinates of points that define the geometry of graphical primitives are normally directly mapped to the coordinate system of the drawing device (e.g. an off-screen image buffer). This 1:1 mapping can be changed by applying affine transformations to the input coordinates.

Affine coordinate transformations can be specified by calling the methods:

setTransform()
and transform()

The former method replaces the current transformation matrix by a matrix that was provided as argument. When the latter method is called, the current matrix gets multiplied with the argument matrix to produce a combined affine transformation. To restore the 1:1 coordinate mapping, call setTransform() with a default constructed Math::AffineTransform3D instance.

The style and color of lines and shape outlines is defined by the current pen which is specified by setPen(). The current pen also defines the color of rendered text and the color and diameter of points. The fill pattern and fill color of shapes (rectangles and polygons) is defined by the current brush which is specified by setBrush().

The current state of the renderer (brush, pen, font and transformation matrix) may be saved by saveState() and restored by restoreState().

Constructor & Destructor Documentation

◆ ~Renderer2D()

virtual CDPL::Vis::Renderer2D::~Renderer2D ( )

inlinevirtual

Virtual destructor.

Member Function Documentation

◆ saveState()

virtual void CDPL::Vis::Renderer2D::saveState ( )

pure virtual

Saves the current renderer state.

The method saves the current pen, brush, font and transformation matrix on an internal stack. The last saved state can be restored later on by a call to restoreState().

See also: restoreState()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ restoreState()

virtual void CDPL::Vis::Renderer2D::restoreState ( )

pure virtual

Restores the last renderer state saved by a call to saveState().

See also: saveState()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ setTransform()

virtual void CDPL::Vis::Renderer2D::setTransform ( const Math::Matrix3D & xform )

pure virtual

Sets the applied affine transformation matrix to xform.

Parameters

xform The new affine transformation matrix.

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ transform()

virtual void CDPL::Vis::Renderer2D::transform ( const Math::Matrix3D & xform )

pure virtual

Multiplies the current affine transformation matrix by xform.

Parameters

xform The matrix by which the current affine transformation matrix is multiplied.

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ setPen()

virtual void CDPL::Vis::Renderer2D::setPen ( const Pen & pen )

pure virtual

Sets the pen to be used in subsequent drawing operations.

Parameters

pen	The new pen for subsequent drawing operations.

See also: Vis::Pen

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ setBrush()

virtual void CDPL::Vis::Renderer2D::setBrush ( const Brush & brush )

pure virtual

Sets the brush to be used in subsequent drawing operations.

Parameters

brush The new brush for subsequent drawing operations.

See also: Vis::Brush

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ setFont()

virtual void CDPL::Vis::Renderer2D::setFont ( const Font & font )

pure virtual

Sets the font to be used in subsequent text drawing operations.

Parameters

font	The new font used in subsequent text drawing operations.

See also: Vis::Font

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawRectangle()

virtual void CDPL::Vis::Renderer2D::drawRectangle	(	double	x,
		double	y,
		double	width,
		double	height
	)

pure virtual

Draws an axis aligned rectangle of the specified width and height whose upper-left corner is located at (x, y).

The rectangle is filled as specified by the current brush and the outline will be drawn as specified by the current pen.

Parameters

x	The x-coordinate of the upper-left corner.
y	The y-coordinate of the upper-left corner.
width	The width of the rectangle.
height	The height of the rectangle.

See also: setPen(), setBrush()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawPolygon()

virtual void CDPL::Vis::Renderer2D::drawPolygon ( const Math::Vector2DArray & points )

pure virtual

Draws the polygon defined by points.

For a given set of \( N \) corner points \( p_i \) with \( i = 1, 2, \ldots, N \), the polygon's \( N \) edges are given by \( (p_1, p_2), (p_2, p_3), \ldots, (p_N, p_0) \). The polygon is filled as specified by the current brush and the outline will be drawn as specified by the current pen.

Parameters

points An array of points specifying the corners of the polygon.

See also: setPen(), setBrush()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawLine()

virtual void CDPL::Vis::Renderer2D::drawLine	(	double	x1,
		double	y1,
		double	x2,
		double	y2
	)

pure virtual

Draws a line segment from (x1, y1) to (x2, y2).

The line style, color, cap style and line width is specified by the current pen.

Parameters

x1	The x-coordinate of the starting point.
y1	The y-coordinate of the starting point.
x2	The x-coordinate of the end point.
y2	The y-coordinate of the end point.

See also: setPen()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawPolyline()

virtual void CDPL::Vis::Renderer2D::drawPolyline ( const Math::Vector2DArray & points )

pure virtual

Draws the polyline defined by points.

For a given set of \( N \) points \( p_i \) with \( i = 1, 2, \ldots, N \), \( N - 1 \) connected line segments \( (p_1, p_2), (p_2, p_3), \ldots, (p_{N - 1}, p_N) \) will be drawn. The line style, color, cap style, join style and line width is specified by the current pen.

Parameters

points An array of points defining the polyline.

See also: setPen()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawLineSegments()

virtual void CDPL::Vis::Renderer2D::drawLineSegments ( const Math::Vector2DArray & points )

pure virtual

Draws the sequence of disjoint line segments defined by points.

For a given set of \( 2N \) points \( p_i \) with \( i = 1, 2, \ldots, 2N \), \( N \) disjoint line segments \( (p_1, p_2), (p_3, p_4), \ldots, (p_{2N - 1}, p_2N) \) will be drawn. The line style, color, cap style and line width is specified by the current pen.

Parameters

points An array of points defining the line segments.

See also: setPen()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawPoint()

virtual void CDPL::Vis::Renderer2D::drawPoint	(	double	x,
		double	y
	)

pure virtual

Draws a point at the position (x, y).

The diameter and color of the point is specified by the current pen.

Parameters

x	The x-coordinate of the point.
y	The y-coordinate of the point.

See also: setPen()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawEllipse()

virtual void CDPL::Vis::Renderer2D::drawEllipse	(	double	x,
		double	y,
		double	width,
		double	height
	)

pure virtual

Draws an ellipse with the given width and height around the center position (x, y).

The ellipse is filled as specified by the current brush and the outline will be drawn as specified by the current pen.

Parameters

x	The x-coordinate of the center point.
y	The y-coordinate of the center point.
width	The width of the ellipse.
height	The height of the ellipse.

See also: setPen(), setBrush()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawPath()

virtual void CDPL::Vis::Renderer2D::drawPath ( const Path2D & path )

pure virtual

Draws the given path.

The path is filled as specified by the current brush and the outline will be drawn as specified by the current pen.

Parameters

path	The path to draw.

See also: setPen(), setBrush()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ drawText()

virtual void CDPL::Vis::Renderer2D::drawText	(	double	x,
		double	y,
		const std::string &	txt
	)

pure virtual

Draws the specified text at the position (x, y).

The text color is specified by the current pen. The font has to be specified by setFont().

Parameters

x	The x-position of the drawn text.
y	The y-position of the baseline.
txt	The text to draw.

See also: setPen(), setFont()

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ setClipPath()

virtual void CDPL::Vis::Renderer2D::setClipPath ( const Path2D & path )

pure virtual

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

◆ clearClipPath()

virtual void CDPL::Vis::Renderer2D::clearClipPath ( )

pure virtual

Disables clipping.

Implemented in CDPL::Vis::QtRenderer2D, and CDPL::Vis::CairoRenderer2D.

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

Renderer2D.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ ~Renderer2D()

Member Function Documentation

◆ saveState()

◆ restoreState()

◆ setTransform()

◆ transform()

◆ setPen()

◆ setBrush()

◆ setFont()

◆ drawRectangle()

◆ drawPolygon()

◆ drawLine()

◆ drawPolyline()

◆ drawLineSegments()

◆ drawPoint()

◆ drawEllipse()

◆ drawPath()

◆ drawText()

◆ setClipPath()

◆ clearClipPath()