diff options
Diffstat (limited to 'basegfx/inc/basegfx/curve/b2dcubicbezier.hxx')
| -rw-r--r-- | basegfx/inc/basegfx/curve/b2dcubicbezier.hxx | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/basegfx/inc/basegfx/curve/b2dcubicbezier.hxx b/basegfx/inc/basegfx/curve/b2dcubicbezier.hxx new file mode 100644 index 000000000000..ea58a0a50b80 --- /dev/null +++ b/basegfx/inc/basegfx/curve/b2dcubicbezier.hxx @@ -0,0 +1,222 @@ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * This file is part of OpenOffice.org. + * + * OpenOffice.org is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 3 + * only, as published by the Free Software Foundation. + * + * OpenOffice.org is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License version 3 for more details + * (a copy is included in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU Lesser General Public License + * version 3 along with OpenOffice.org. If not, see + * <http://www.openoffice.org/license.html> + * for a copy of the LGPLv3 License. + * + ************************************************************************/ + +#ifndef _BGFX_CURVE_B2DCUBICBEZIER_HXX +#define _BGFX_CURVE_B2DCUBICBEZIER_HXX + +#include <basegfx/point/b2dpoint.hxx> +#include <basegfx/range/b2drange.hxx> + +////////////////////////////////////////////////////////////////////////////// +// predeclarations + +namespace basegfx +{ + class B2DPolygon; +} // end of namespace basegfx + +////////////////////////////////////////////////////////////////////////////// + +namespace basegfx +{ + class B2DCubicBezier + { + B2DPoint maStartPoint; + B2DPoint maEndPoint; + B2DPoint maControlPointA; + B2DPoint maControlPointB; + + public: + B2DCubicBezier(); + B2DCubicBezier(const B2DCubicBezier& rBezier); + B2DCubicBezier(const B2DPoint& rStart, const B2DPoint& rEnd); + B2DCubicBezier(const B2DPoint& rStart, const B2DPoint& rControlPointA, const B2DPoint& rControlPointB, const B2DPoint& rEnd); + ~B2DCubicBezier(); + + // assignment operator + B2DCubicBezier& operator=(const B2DCubicBezier& rBezier); + + // compare operators + bool operator==(const B2DCubicBezier& rBezier) const; + bool operator!=(const B2DCubicBezier& rBezier) const; + bool equal(const B2DCubicBezier& rBezier) const; + + // test if vectors are used + bool isBezier() const; + + // test if contained bezier is trivial and reset vectors accordingly + void testAndSolveTrivialBezier(); + + /** get length of edge + + This method handles beziers and simple edges. For + beziers, the deviation describes the maximum allowed + deviation from the real edge length. The default + allows a deviation of 1% from the correct length. + + For beziers, there is no direct way to get the length, + thus this method may subdivide the bezier edge and may + not be cheap. + + @param fDeviation + The maximal allowed deviation between correct length + and bezier edge length + + @return + The length of the edge + */ + double getLength(double fDeviation = 0.01) const; + + // get distance between start and end point + double getEdgeLength() const; + + // get length of control polygon + double getControlPolygonLength() const; + + // data interface + B2DPoint getStartPoint() const { return maStartPoint; } + void setStartPoint(const B2DPoint& rValue) { maStartPoint = rValue; } + + B2DPoint getEndPoint() const { return maEndPoint; } + void setEndPoint(const B2DPoint& rValue) { maEndPoint = rValue; } + + B2DPoint getControlPointA() const { return maControlPointA; } + void setControlPointA(const B2DPoint& rValue) { maControlPointA = rValue; } + + B2DPoint getControlPointB() const { return maControlPointB; } + void setControlPointB(const B2DPoint& rValue) { maControlPointB = rValue; } + + /** get the tangent in point t + + This method handles all the exceptions, e.g. when control point + A is equal to start point and/or control point B is equal to end + point + + @param t + The bezier index in the range [0.0 .. 1.0]. It will be truncated. + + @return + The tangent vector in point t + */ + B2DVector getTangent(double t) const; + + /** adaptive subdivide by angle criteria + no start point is added, but all necessary created edges + and the end point + #i37443# allow the criteria to get unsharp in recursions + */ + void adaptiveSubdivideByAngle(B2DPolygon& rTarget, double fAngleBound, bool bAllowUnsharpen) const; + + /** #i37443# adaptive subdivide by nCount subdivisions + no start point is added, but all necessary created edges + and the end point + */ + void adaptiveSubdivideByCount(B2DPolygon& rTarget, sal_uInt32 nCount) const; + + /** Subdivide cubic bezier segment. + + This function adaptively subdivides the bezier + segment into as much straight line segments as necessary, + such that the maximal orthogonal distance from any of the + segments to the true curve is less than the given error + value. + No start point is added, but all necessary created edges + and the end point + + @param rPoly + Output polygon. The subdivided bezier segment is added to + this polygon via B2DPolygon::append(). + + @param rCurve + The cubic bezier curve to subdivide + + @param fDistanceBound + Bound on the maximal distance of the approximation to the + true curve. + */ + void adaptiveSubdivideByDistance(B2DPolygon& rTarget, double fDistanceBound) const; + + // get point at given relative position + B2DPoint interpolatePoint(double t) const; + + // calculate the smallest distance from given point to this cubic bezier segment + // and return the value. The relative position on the segment is returned in rCut. + double getSmallestDistancePointToBezierSegment(const B2DPoint& rTestPoint, double& rCut) const; + + // do a split at position t and fill both resulting segments + void split(double t, B2DCubicBezier* pBezierA, B2DCubicBezier* pBezierB) const; + + // extract snippet from fStart to fEnd from this bezier + B2DCubicBezier snippet(double fStart, double fEnd) const; + + // get range including conrol points + B2DRange getRange() const; + + /** Get the minimum extremum position t + + @param rfResult + Will be changed and set to a eventually found split value which should be in the + range [0.0 .. 1.0]. It will be the smallest current extremum; there may be more + + @return + Returns true if there was at least one extremum found + */ + bool getMinimumExtremumPosition(double& rfResult) const; + + /** Get all extremum pos of this segment + + This method will calculate all extremum positions of the segment + and add them to rResults if they are in the range ]0.0 .. 1.0[ + + @param rResults + The vector of doubles where the results will be added. Evtl. + existing contents will be removed since an empty vector is a + necessary result to express that there are no extreme positions + anymore. Since there is an upper maximum of 4 values, it makes + sense to use reserve(4) at the vector as preparation. + */ + void getAllExtremumPositions(::std::vector< double >& rResults) const; + + /** Get optimum-split position on this segment + + This method calculates the positions of all points of the segment + that have the maximimum distance to the corresponding line from + startpoint-endpoint. This helps to approximate the bezier curve + with a minimum number of line segments + + @param fResults + Result positions are in the range ]0.0 .. 1.0[ + Cubic beziers have at most two of these positions + + @return + Returns the number of split positions found + */ + int getMaxDistancePositions( double fResults[2]) const; + }; +} // end of namespace basegfx + +#endif /* _BGFX_CURVE_B2DCUBICBEZIER_HXX */ |