// $Id: fitcurve.h 751 2006-03-31 15:43:49Z alex $ /* @@tag:xara-cn@@ DO NOT MODIFY THIS LINE ================================XARAHEADERSTART=========================== Xara LX, a vector drawing and manipulation program. Copyright (C) 1993-2006 Xara Group Ltd. Copyright on certain contributions may be held in joint with their respective authors. See AUTHORS file for details. LICENSE TO USE AND MODIFY SOFTWARE ---------------------------------- This file is part of Xara LX. Xara LX is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License version 2 as published by the Free Software Foundation. Xara LX and its component source files are 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 General Public License for more details. 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Xara Group Ltd, Gaddesden Place, Hemel Hempstead, HP2 6EX, UK. http://www.xara.com/ =================================XARAHEADEREND============================ */ // Header file for the functions #ifndef INC_FITCURVE #define INC_FITCURVE #include /******************************************************************************************** > class FitPoint Author: Rik_Heywood (Xara Group Ltd) Created: 02/03/94 Purpose: This class is really a vector class that is used by the curve fitting functions. It is also used as a coordinate class in the curve fitting functions, but these are really regarded as vectors from the origin. It has the following public member variables :- MonoOn double x; - The X coord of the vector MonoOff MonoOn double y; - The Y Coord of the vecotr MonoOff ********************************************************************************************/ class FitPoint : public CC_CLASS_MEMDUMP { // Give my name in memory dumps CC_DECLARE_MEMDUMP(FitPoint); public: // Construction FitPoint() {} FitPoint(double cx, double cy) { x=cx; y=cy;} FitPoint(DocCoord coord) { x=coord.x; y=coord.y; } FitPoint(const FitPoint& Other) {x=Other.x; y=Other.y;} // destruction ~FitPoint() {} // operator = void operator = (const FitPoint& Other) { x=Other.x; y=Other.y; } void operator = (const DocCoord& Other) { x=Other.x; y=Other.y; } // Length Functions FitPoint SetLength( double NewLen ); // Addition/Subtraction operators friend FitPoint operator + (const FitPoint& Point1, const FitPoint& Point2); friend FitPoint operator - (const FitPoint& Point1, const FitPoint& Point2); // Unary minus FitPoint operator - (); // Scale FitPoint operator * ( double Factor ); // General geometry functions double SquaredLength() { return (x*x + y*y); } double Length() { return sqrt(x*x + y*y); } double Dot(const FitPoint& Other) { return (Other.x*x + Other.y*y); } // Debug functions void Dump(); public: double x; double y; }; /******************************************************************************************** > class CurveFitObject : public CC_CLASS_MEMDUMP Author: Rik_Heywood (Xara Group Ltd) Created: 22/9/94 Purpose: Fits bezier curves to a serious of coordinates. Call the constructor, Initialise and finally FitCurve to fit a bezier curve to the coords. SeeAlso: FitPoint ********************************************************************************************/ class CurveFitObject : public CC_CLASS_MEMDUMP { // Give my name in memory dumps CC_DECLARE_MEMDUMP(CurveFitObject); public: // Constructor that makes a note of things we will need to fit the curve CurveFitObject(Path* LongPath, double Error); ~CurveFitObject(); // Strip useful points out of the path and puts them in the array BOOL Initialise(Path* CopyPath, INT32 NumPoints); // Fit the curve void FitCurve(); // Private member functions to help out the above functions private: // The heart of the curve fitting code void FitCubic( INT32 FirstPoint, INT32 LastPoint, FitPoint Tangent1, FitPoint Tangent2, BOOL IsStartCusp = TRUE, BOOL IsEndCusp = TRUE); // The function that does the actual maths void GenerateBezier( INT32 FirstPoint, INT32 LastPoint, FitPoint Tangent1, FitPoint Tangent2, FitPoint* Bezier ); // Functions to determine how close a fit we have FitPoint BezierPoint( FitPoint* Bez, double u ); double CalcMaxError( INT32 FirstPoint, INT32 LastPoint, FitPoint* Bezier, INT32* SplitPoint ); // Functions to find the tangents to the curve at various points FitPoint LeftTangent(INT32 Start); FitPoint RightTangent(INT32 End); FitPoint CentreTangent(INT32 Centre); // Functions to evaluate various components of the bezier function double Bezier0(double u) { double t=1.0-u; return (t*t*t); } double Bezier1(double u) { double t=1.0-u; return (3*u*t*t); } double Bezier2(double u) { double t=1.0-u; return (3*u*u*t); } double Bezier3(double u) { return (u*u*u); } // Functions to put curve elements into the path void InsertBezier( FitPoint* Bezier, BOOL, BOOL); void InsertLine( const DocCoord& Start, const DocCoord& End, FitPoint Tangent1, FitPoint Tangent2, BOOL, BOOL); void InsertStraightLine(const DocCoord& End); // Member vars private: // Pointers to the actual path object to get and store the points in and an array to // hold the coords that we will use in the smoothing process Path* LongPath; DocCoord* PathArray; INT32* LineArray; // An array that holds the distance of each point from the start of the path INT32* Distances; // The accuracy of the required fit. The larger this number, the smoother the fit. // Values of about 27,000,000 give smooth curves in millipoints at 100% zoom factor double Error; // count of the total number of coordinates INT32 TotalCoords; INT32 TotalStraightLines; }; /******************************************************************************************** > class FitCurveNoChangeGeometry : public CC_CLASS_MEMDUMP Author: David_McClarnon (Xara Group Ltd) Created: 12/1/2000 Purpose: This class uses the fit curve functionality to reduce the number of points in a path, whereas keeping the geometry as close to the original as possible ********************************************************************************************/ class FitCurveNoChangeGeometry : public CC_CLASS_MEMDUMP { // Give my name in memory dumps CC_DECLARE_MEMDUMP(CurveFitObject); public: static void SmoothPath(Path * pPath, double Error); private: static void SmoothPathNoChangeGeometry(Path * pPath, double Error); static void EliminateColinearPointsFromPath(Path * pPath); } ; #endif