fonttools/Lib/fontTools/pens/roundingPen.py

from fontTools.misc.roundTools import noRound, otRound
from fontTools.misc.transform import Transform
from fontTools.pens.filterPen import FilterPen, FilterPointPen


__all__ = ["RoundingPen", "RoundingPointPen"]


class RoundingPen(FilterPen):
    """
    Filter pen that rounds point coordinates and component XY offsets to integer. For
    rounding the component transform values, a separate round function can be passed to
    the pen.

    >>> from fontTools.pens.recordingPen import RecordingPen
    >>> recpen = RecordingPen()
    >>> roundpen = RoundingPen(recpen)
    >>> roundpen.moveTo((0.4, 0.6))
    >>> roundpen.lineTo((1.6, 2.5))
    >>> roundpen.qCurveTo((2.4, 4.6), (3.3, 5.7), (4.9, 6.1))
    >>> roundpen.curveTo((6.4, 8.6), (7.3, 9.7), (8.9, 10.1))
    >>> roundpen.addComponent("a", (1.5, 0, 0, 1.5, 10.5, -10.5))
    >>> recpen.value == [
    ...     ('moveTo', ((0, 1),)),
    ...     ('lineTo', ((2, 3),)),
    ...     ('qCurveTo', ((2, 5), (3, 6), (5, 6))),
    ...     ('curveTo', ((6, 9), (7, 10), (9, 10))),
    ...     ('addComponent', ('a', (1.5, 0, 0, 1.5, 11, -10))),
    ... ]
    True
    """

    def __init__(self, outPen, roundFunc=otRound, transformRoundFunc=noRound):
        super().__init__(outPen)
        self.roundFunc = roundFunc
        self.transformRoundFunc = transformRoundFunc

    def moveTo(self, pt):
        self._outPen.moveTo((self.roundFunc(pt[0]), self.roundFunc(pt[1])))

    def lineTo(self, pt):
        self._outPen.lineTo((self.roundFunc(pt[0]), self.roundFunc(pt[1])))

    def curveTo(self, *points):
        self._outPen.curveTo(
            *((self.roundFunc(x), self.roundFunc(y)) for x, y in points)
        )

    def qCurveTo(self, *points):
        self._outPen.qCurveTo(
            *((self.roundFunc(x), self.roundFunc(y)) for x, y in points)
        )

    def addComponent(self, glyphName, transformation):
        xx, xy, yx, yy, dx, dy = transformation
        self._outPen.addComponent(
            glyphName,
            Transform(
                self.transformRoundFunc(xx),
                self.transformRoundFunc(xy),
                self.transformRoundFunc(yx),
                self.transformRoundFunc(yy),
                self.roundFunc(dx),
                self.roundFunc(dy),
            ),
        )


class RoundingPointPen(FilterPointPen):
    """
    Filter point pen that rounds point coordinates and component XY offsets to integer.
    For rounding the component scale values, a separate round function can be passed to
    the pen.

    >>> from fontTools.pens.recordingPen import RecordingPointPen
    >>> recpen = RecordingPointPen()
    >>> roundpen = RoundingPointPen(recpen)
    >>> roundpen.beginPath()
    >>> roundpen.addPoint((0.4, 0.6), 'line')
    >>> roundpen.addPoint((1.6, 2.5), 'line')
    >>> roundpen.addPoint((2.4, 4.6))
    >>> roundpen.addPoint((3.3, 5.7))
    >>> roundpen.addPoint((4.9, 6.1), 'qcurve')
    >>> roundpen.endPath()
    >>> roundpen.addComponent("a", (1.5, 0, 0, 1.5, 10.5, -10.5))
    >>> recpen.value == [
    ...     ('beginPath', (), {}),
    ...     ('addPoint', ((0, 1), 'line', False, None), {}),
    ...     ('addPoint', ((2, 3), 'line', False, None), {}),
    ...     ('addPoint', ((2, 5), None, False, None), {}),
    ...     ('addPoint', ((3, 6), None, False, None), {}),
    ...     ('addPoint', ((5, 6), 'qcurve', False, None), {}),
    ...     ('endPath', (), {}),
    ...     ('addComponent', ('a', (1.5, 0, 0, 1.5, 11, -10)), {}),
    ... ]
    True
    """

    def __init__(self, outPen, roundFunc=otRound, transformRoundFunc=noRound):
        super().__init__(outPen)
        self.roundFunc = roundFunc
        self.transformRoundFunc = transformRoundFunc

    def addPoint(
        self, pt, segmentType=None, smooth=False, name=None, identifier=None, **kwargs
    ):
        self._outPen.addPoint(
            (self.roundFunc(pt[0]), self.roundFunc(pt[1])),
            segmentType=segmentType,
            smooth=smooth,
            name=name,
            identifier=identifier,
            **kwargs,
        )

    def addComponent(self, baseGlyphName, transformation, identifier=None, **kwargs):
        xx, xy, yx, yy, dx, dy = transformation
        self._outPen.addComponent(
            baseGlyphName=baseGlyphName,
            transformation=Transform(
                self.transformRoundFunc(xx),
                self.transformRoundFunc(xy),
                self.transformRoundFunc(yx),
                self.transformRoundFunc(yy),
                self.roundFunc(dx),
                self.roundFunc(dy),
            ),
            identifier=identifier,
            **kwargs,
        )