from fontTools.pens.basePen import BasePen
from fontTools.misc.arrayTools import updateBounds,pointInRect,unionRect
from fontTools.misc.bezierTools import calcCubicBounds,calcQuadraticBounds
__all__ = ["BoundsPen", "ControlBoundsPen"]
class ControlBoundsPen(BasePen):
"""Pen to calculate the "control bounds" of a shape. This is the
bounding box of all control points, so may be larger than the
actual bounding box if there are curves that don't have points
on their extremes.
When the shape has been drawn, the bounds are available as the
'bounds' attribute of the pen object. It's a 4-tuple:
(xMin, yMin, xMax, yMax)
"""
def __init__(self, glyphSet):
BasePen.__init__(self, glyphSet)
self.bounds = None
def _moveTo(self, pt):
bounds = self.bounds
if bounds:
self.bounds = updateBounds(bounds, pt)
else:
x, y = pt
self.bounds = (x, y, x, y)
def _lineTo(self, pt):
self.bounds = updateBounds(self.bounds, pt)
def _curveToOne(self, bcp1, bcp2, pt):
bounds = self.bounds
bounds = updateBounds(bounds, bcp1)
bounds = updateBounds(bounds, bcp2)
bounds = updateBounds(bounds, pt)
self.bounds = bounds
def _qCurveToOne(self, bcp, pt):
bounds = self.bounds
bounds = updateBounds(bounds, bcp)
bounds = updateBounds(bounds, pt)
self.bounds = bounds
class BoundsPen(ControlBoundsPen):
"""Pen to calculate the bounds of a shape. It calculates the
correct bounds even when the shape contains curves that don't
have points on their extremes. This is somewhat slower to compute
than the "control bounds".
When the shape has been drawn, the bounds are available as the
'bounds' attribute of the pen object. It's a 4-tuple:
(xMin, yMin, xMax, yMax)
"""
def _curveToOne(self, bcp1, bcp2, pt):
bounds = self.bounds
bounds = updateBounds(bounds, pt)
if not pointInRect(bcp1, bounds) or not pointInRect(bcp2, bounds):
bounds = unionRect(bounds, calcCubicBounds(
self._getCurrentPoint(), bcp1, bcp2, pt))
self.bounds = bounds
def _qCurveToOne(self, bcp, pt):
bounds = self.bounds
bounds = updateBounds(bounds, pt)
if not pointInRect(bcp, bounds):
bounds = unionRect(bounds, calcQuadraticBounds(
self._getCurrentPoint(), bcp, pt))
self.bounds = bounds
if __name__ == "__main__":
def draw(pen):
pen.moveTo((0, 0))
pen.lineTo((0, 100))
pen.qCurveTo((50, 75), (60, 50), (50, 25), (0, 0))
pen.curveTo((-50, 25), (-60, 50), (-50, 75), (0, 100))
pen.closePath()
pen = ControlBoundsPen(None)
draw(pen)
print pen.bounds
pen = BoundsPen(None)
draw(pen)
print pen.bounds
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