Exemplo n.º 1
0
def _set_segments(glyph, segments, reverse_direction):
    """Draw segments as extracted by GetSegmentsPen back to a glyph."""

    glyph.clearContours()
    pen = glyph.getPen()
    if reverse_direction:
        pen = ReverseContourPen(pen)
    for tag, args in segments:
        if tag == 'move':
            pen.moveTo(*args)
        elif tag == 'line':
            pen.lineTo(*args)
        elif tag == 'curve':
            pen.curveTo(*args[1:])
        elif tag == 'qcurve':
            pen.qCurveTo(*args[1:])
        elif tag == 'close':
            pen.closePath()
        elif tag == 'end':
            pen.endPath()
        else:
            raise AssertionError('Unhandled segment type "%s"' % tag)
Exemplo n.º 2
0
class Cu2QuPen(AbstractPen):
    """ A filter pen to convert cubic bezier curves to quadratic b-splines
    using the FontTools SegmentPen protocol.

    Args:

        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.
        ignore_single_points: don't emit contours containing only a single point

    NOTE: The "ignore_single_points" argument is deprecated since v1.3.0,
    which dropped Robofab subpport. It's no longer needed to special-case
    UFO2-style anchors (aka "named points") when using ufoLib >= 2.0,
    as these are no longer drawn onto pens as single-point contours,
    but are handled separately as anchors.
    """
    def __init__(self,
                 other_pen,
                 max_err,
                 reverse_direction=False,
                 stats=None,
                 ignore_single_points=False):
        if reverse_direction:
            self.pen = ReverseContourPen(other_pen)
        else:
            self.pen = other_pen
        self.max_err = max_err
        self.stats = stats
        if ignore_single_points:
            import warnings
            warnings.warn(
                "ignore_single_points is deprecated and "
                "will be removed in future versions",
                UserWarning,
                stacklevel=2)
        self.ignore_single_points = ignore_single_points
        self.start_pt = None
        self.current_pt = None

    def _check_contour_is_open(self):
        if self.current_pt is None:
            raise AssertionError("moveTo is required")

    def _check_contour_is_closed(self):
        if self.current_pt is not None:
            raise AssertionError("closePath or endPath is required")

    def _add_moveTo(self):
        if self.start_pt is not None:
            self.pen.moveTo(self.start_pt)
            self.start_pt = None

    def moveTo(self, pt):
        self._check_contour_is_closed()
        self.start_pt = self.current_pt = pt
        if not self.ignore_single_points:
            self._add_moveTo()

    def lineTo(self, pt):
        self._check_contour_is_open()
        self._add_moveTo()
        self.pen.lineTo(pt)
        self.current_pt = pt

    def qCurveTo(self, *points):
        self._check_contour_is_open()
        n = len(points)
        if n == 1:
            self.lineTo(points[0])
        elif n > 1:
            self._add_moveTo()
            self.pen.qCurveTo(*points)
            self.current_pt = points[-1]
        else:
            raise AssertionError("illegal qcurve segment point count: %d" % n)

    def _curve_to_quadratic(self, pt1, pt2, pt3):
        curve = (self.current_pt, pt1, pt2, pt3)
        quadratic = curve_to_quadratic(curve, self.max_err)
        if self.stats is not None:
            n = str(len(quadratic) - 2)
            self.stats[n] = self.stats.get(n, 0) + 1
        self.qCurveTo(*quadratic[1:])

    def curveTo(self, *points):
        self._check_contour_is_open()
        n = len(points)
        if n == 3:
            # this is the most common case, so we special-case it
            self._curve_to_quadratic(*points)
        elif n > 3:
            for segment in decomposeSuperBezierSegment(points):
                self._curve_to_quadratic(*segment)
        elif n == 2:
            self.qCurveTo(*points)
        elif n == 1:
            self.lineTo(points[0])
        else:
            raise AssertionError("illegal curve segment point count: %d" % n)

    def closePath(self):
        self._check_contour_is_open()
        if self.start_pt is None:
            # if 'start_pt' is _not_ None, we are ignoring single-point paths
            self.pen.closePath()
        self.current_pt = self.start_pt = None

    def endPath(self):
        self._check_contour_is_open()
        if self.start_pt is None:
            self.pen.endPath()
        self.current_pt = self.start_pt = None

    def addComponent(self, glyphName, transformation):
        self._check_contour_is_closed()
        self.pen.addComponent(glyphName, transformation)