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

Inheritance diagram for CDPL.Vis.Renderer2D:

Public Member Functions
None	__init__ ()
	Initializes the Renderer2D instance.

int	getObjectID ()
	Returns the numeric identifier (ID) of the wrapped C++ class instance. More...

None	saveState ()
	Saves the current renderer state. More...

None	restoreState ()
	Restores the last renderer state saved by a call to saveState(). More...

None	setTransform (Math.Matrix3D xform)
	Sets the applied affine transformation matrix to xform. More...

None	transform (Math.Matrix3D xform)
	Multiplies the current affine transformation matrix by xform. More...

None	setPen (Pen pen)
	Sets the pen to be used in subsequent drawing operations. More...

None	setBrush (Brush brush)
	Sets the brush to be used in subsequent drawing operations. More...

None	setFont (Font font)
	Sets the font to be used in subsequent text drawing operations. More...

None	drawRectangle (float x, float y, float width, float height)
	Draws an axis aligned rectangle of the specified width and height whose upper-left corner is located at (x, y). More...

None	drawEllipse (float x, float y, float width, float height)
	Draws an ellipse with the given width and height around the center position (x, y). More...

None	drawPolygon (Math.Vector2DArray points)
	Draws the polygon defined by points. More...

None	drawLine (float x1, float y1, float x2, float y2)
	Draws a line segment from (x1, y1) to (x2, y2). More...

None	drawPolyline (Math.Vector2DArray points)
	Draws the polyline defined by points. More...

None	drawLineSegments (Math.Vector2DArray points)
	Draws the sequence of disjoint line segments defined by points. More...

None	drawPoint (float x, float y)
	Draws a point at the position (x, y). More...

None	drawText (float x, float y, str txt)
	Draws the specified text at the position (x, y). More...

None	drawPath (Path2D path)
	Draws the given path. More...

None	setClipPath (Path2D path)

None	clearClipPath ()
	Disables clipping.

Properties
	objectID = property(getObjectID)

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().

Member Function Documentation

◆ getObjectID()

int CDPL.Vis.Renderer2D.getObjectID ( )

Returns the numeric identifier (ID) of the wrapped C++ class instance.

Different Python Renderer2D instances may reference the same underlying C++ class instance. The commonly used Python expression a is not b thus cannot tell reliably whether the two Renderer2D instances a and b reference different C++ objects. The numeric identifier returned by this method allows to correctly implement such an identity test via the simple expression a.getObjectID() != b.getObjectID().

Returns: The numeric ID of the internally referenced C++ class instance.

◆ saveState()

None CDPL.Vis.Renderer2D.saveState ( )

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ restoreState()

None CDPL.Vis.Renderer2D.restoreState ( )

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

See also: saveState()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ setTransform()

None CDPL.Vis.Renderer2D.setTransform ( Math.Matrix3D xform )

Sets the applied affine transformation matrix to xform.

Parameters

xform The new affine transformation matrix.

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ transform()

None CDPL.Vis.Renderer2D.transform ( Math.Matrix3D xform )

Multiplies the current affine transformation matrix by xform.

Parameters

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

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ setPen()

None CDPL.Vis.Renderer2D.setPen ( Pen pen )

Sets the pen to be used in subsequent drawing operations.

Parameters

pen	The new pen for subsequent drawing operations.

See also: Vis.Pen

◆ setBrush()

None CDPL.Vis.Renderer2D.setBrush ( Brush brush )

Sets the brush to be used in subsequent drawing operations.

Parameters

brush The new brush for subsequent drawing operations.

See also: Vis.Brush

◆ setFont()

None CDPL.Vis.Renderer2D.setFont ( Font font )

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

◆ drawRectangle()

None CDPL.Vis.Renderer2D.drawRectangle	(	float	x,
		float	y,
		float	width,
		float	height
	)

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawEllipse()

None CDPL.Vis.Renderer2D.drawEllipse	(	float	x,
		float	y,
		float	width,
		float	height
	)

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawPolygon()

None CDPL.Vis.Renderer2D.drawPolygon ( Math.Vector2DArray points )

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawLine()

None CDPL.Vis.Renderer2D.drawLine	(	float	x1,
		float	y1,
		float	x2,
		float	y2
	)

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawPolyline()

None CDPL.Vis.Renderer2D.drawPolyline ( Math.Vector2DArray points )

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawLineSegments()

None CDPL.Vis.Renderer2D.drawLineSegments ( Math.Vector2DArray points )

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawPoint()

None CDPL.Vis.Renderer2D.drawPoint	(	float	x,
		float	y
	)

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawText()

None CDPL.Vis.Renderer2D.drawText	(	float	x,
		float	y,
		str	txt
	)

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()

Reimplemented in CDPL.Vis.QtBackend.QtRenderer2D, and CDPL.Vis.CairoBackend.CairoRenderer2D.

◆ drawPath()

None CDPL.Vis.Renderer2D.drawPath ( Path2D path )

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()

◆ setClipPath()

None CDPL.Vis.Renderer2D.setClipPath ( Path2D path )

Parameters

path

Public Member Functions

Properties

Detailed Description

Member Function Documentation

◆ getObjectID()

◆ saveState()

◆ restoreState()

◆ setTransform()

◆ transform()

◆ setPen()

◆ setBrush()

◆ setFont()

◆ drawRectangle()

◆ drawEllipse()

◆ drawPolygon()

◆ drawLine()

◆ drawPolyline()

◆ drawLineSegments()

◆ drawPoint()

◆ drawText()

◆ drawPath()

◆ setClipPath()