cu2quPen

class fontTools.pens.cu2quPen.Cu2QuMultiPen(other_pens, max_err, reverse_direction=False)[source]

A filter multi-pen to convert cubic bezier curves to quadratic b-splines in a interpolation-compatible manner, using the FontTools SegmentPen protocol.

Parameters:
  • other_pens – list of SegmentPens used to draw the transformed outlines.

  • max_err – maximum approximation error in font units. For optimal results, if you know the UPEM of the font, we recommend setting this to a value equal, or close to UPEM / 1000.

  • reverse_direction – flip the contours’ direction but keep starting point.

This pen does not follow the normal SegmentPen protocol. Instead, its moveTo/lineTo/qCurveTo/curveTo methods take a list of tuples that are arguments that would normally be passed to a SegmentPen, one item for each of the pens in other_pens.

addComponent(glyphName, transformations)[source]
closePath()[source]
curveTo(pointsList)[source]
endPath()[source]
lineTo(pts)[source]
moveTo(pts)[source]
qCurveTo(pointsList)[source]
class fontTools.pens.cu2quPen.Cu2QuPen(other_pen, max_err, reverse_direction=False, stats=None, all_quadratic=True)[source]

A filter pen to convert cubic bezier curves to quadratic b-splines using the FontTools SegmentPen protocol.

Parameters:
  • other_pen – another SegmentPen used to draw the transformed outline.

  • max_err – maximum approximation error in font units. For optimal results, if you know the UPEM of the font, we recommend setting this to a value equal, or close to UPEM / 1000.

  • reverse_direction – flip the contours’ direction but keep starting point.

  • stats – a dictionary counting the point numbers of quadratic segments.

  • all_quadratic – if True (default), only quadratic b-splines are generated. if False, quadratic curves or cubic curves are generated depending on which one is more economical.

addComponent(glyphName, transformation, **kwargs)

Add a sub glyph. The ‘transformation’ argument must be a 6-tuple containing an affine transformation, or a Transform object from the fontTools.misc.transform module. More precisely: it should be a sequence containing 6 numbers.

addVarComponent(glyphName: str, transformation: DecomposedTransform, location: Dict[str, float]) None

Add a VarComponent sub glyph. The ‘transformation’ argument must be a DecomposedTransform from the fontTools.misc.transform module, and the ‘location’ argument must be a dictionary mapping axis tags to their locations.

closePath()

Close the current sub path. You must call either pen.closePath() or pen.endPath() after each sub path.

curveTo(*points)[source]

Draw a cubic bezier with an arbitrary number of control points.

The last point specified is on-curve, all others are off-curve (control) points. If the number of control points is > 2, the segment is split into multiple bezier segments. This works like this:

Let n be the number of control points (which is the number of arguments to this call minus 1). If n==2, a plain vanilla cubic bezier is drawn. If n==1, we fall back to a quadratic segment and if n==0 we draw a straight line. It gets interesting when n>2: n-1 PostScript-style cubic segments will be drawn as if it were one curve. See decomposeSuperBezierSegment().

The conversion algorithm used for n>2 is inspired by NURB splines, and is conceptually equivalent to the TrueType “implied points” principle. See also decomposeQuadraticSegment().

endPath()

End the current sub path, but don’t close it. You must call either pen.closePath() or pen.endPath() after each sub path.

lineTo(pt)

Draw a straight line from the current point to ‘pt’.

moveTo(pt)

Begin a new sub path, set the current point to ‘pt’. You must end each sub path with a call to pen.closePath() or pen.endPath().

qCurveTo(*points)

Draw a whole string of quadratic curve segments.

The last point specified is on-curve, all others are off-curve points.

This method implements TrueType-style curves, breaking up curves using ‘implied points’: between each two consequtive off-curve points, there is one implied point exactly in the middle between them. See also decomposeQuadraticSegment().

The last argument (normally the on-curve point) may be None. This is to support contours that have NO on-curve points (a rarely seen feature of TrueType outlines).

class fontTools.pens.cu2quPen.Cu2QuPointPen(other_point_pen, max_err, reverse_direction=False, stats=None, all_quadratic=True)[source]

A filter pen to convert cubic bezier curves to quadratic b-splines using the FontTools PointPen protocol.

Parameters:
  • other_point_pen – another PointPen used to draw the transformed outline.

  • max_err – maximum approximation error in font units. For optimal results, if you know the UPEM of the font, we recommend setting this to a value equal, or close to UPEM / 1000.

  • reverse_direction – reverse the winding direction of all contours.

  • stats – a dictionary counting the point numbers of quadratic segments.

  • all_quadratic – if True (default), only quadratic b-splines are generated. if False, quadratic curves or cubic curves are generated depending on which one is more economical.

addComponent(baseGlyphName, transformation)[source]

Add a sub glyph.

addPoint(pt, segmentType=None, smooth=False, name=None, identifier=None, **kwargs)

Add a point to the current sub path.

addVarComponent(glyphName: str, transformation: DecomposedTransform, location: Dict[str, float], identifier: str | None = None, **kwargs: Any) None

Add a VarComponent sub glyph. The ‘transformation’ argument must be a DecomposedTransform from the fontTools.misc.transform module, and the ‘location’ argument must be a dictionary mapping axis tags to their locations.

beginPath(identifier=None, **kwargs)

Start a new sub path.

endPath()

End the current sub path.