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Viewing changes to Lib/fontTools/pens/boundsPen.py

  • Committer: Bazaar Package Importer
  • Author(s): Anthony Fok
  • Date: 2003-11-18 00:53:59 UTC
  • Revision ID: james.westby@ubuntu.com-20031118005359-pqirsxbgdz0f0xmx
Tags: upstream-1.99+2.0b1+cvs20031014
Import upstream version 1.99+2.0b1+cvs20031014

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