Path.h revision 39126e9b09dbffc2ff1f80df0c67d1f28a3f14f6
/*
* Path.h
* nlivarot
*
* Created by fred on Tue Jun 17 2003.
*
*/
#ifndef my_path
#define my_path
#include <vector>
#include "LivarotDefs.h"
#include <2geom/point.h>
struct PathDescr;
struct PathDescrLineTo;
struct PathDescrArcTo;
struct PathDescrCubicTo;
struct PathDescrBezierTo;
struct PathDescrIntermBezierTo;
class SPStyle;
/*
* the Path class: a structure to hold path description and their polyline approximation (not kept in sync)
* the path description is built with regular commands like MoveTo() LineTo(), etc
* the polyline approximation is built by a call to Convert() or its variants
* another possibility would be to call directly the AddPoint() functions, but that is not encouraged
* the conversion to polyline can salvage data as to where on the path each polyline's point lies; use
* ConvertWithBackData() for this. after this call, it's easy to rewind the polyline: sequences of points
* of the same path command can be reassembled in a command
*/
// polyline description commands
enum
{
polyline_lineto = 0, // a lineto
polyline_moveto = 1, // a moveto
polyline_forced = 2 // a forced point, ie a point that was an angle or an intersection in a previous life
// or more realistically a control point in the path description that created the polyline
// forced points are used as "breakable" points for the polyline -> cubic bezier patch operations
// each time the bezier fitter encounters such a point in the polyline, it decreases its treshhold,
// so that it is more likely to cut the polyline at that position and produce a bezier patch
};
class Shape;
// path creation: 2 phases: first the path is given as a succession of commands (MoveTo, LineTo, CurveTo...); then it
// is converted in a polyline
// a polylone can be stroked or filled to make a polygon
class Path
{
friend class Shape;
public:
// flags for the path construction
enum
{
descr_ready = 0,
descr_adding_bezier = 1, // we're making a bezier spline, so you can expect pending_bezier_* to have a value
descr_doing_subpath = 2, // we're doing a path, so there is a moveto somewhere
descr_delayed_bezier = 4,// the bezier spline we're doing was initiated by a TempBezierTo(), so we'll need an endpoint
descr_dirty = 16 // the path description was modified
};
// some data for the construction: what's pending, and some flags
int descr_flags;
int pending_bezier_cmd;
int pending_bezier_data;
int pending_moveto_cmd;
int pending_moveto_data;
// the path description
std::vector<PathDescr*> descr_cmd;
// polyline storage: a series of coordinates (and maybe weights)
// also back data: info on where this polyline's segment comes from, ie wich command in the path description: "piece"
// and what abcissis on the chunk of path for this command: "t"
// t=0 means it's at the start of the command's chunk, t=1 it's at the end
struct path_lineto
{
path_lineto(bool m, Geom::Point pp) : isMoveTo(m), p(pp), piece(-1), t(0), closed(false) {}
path_lineto(bool m, Geom::Point pp, int pie, double tt) : isMoveTo(m), p(pp), piece(pie), t(tt), closed(false) {}
int isMoveTo;
Geom::Point p;
int piece;
double t;
bool closed; // true if subpath is closed (this point is the last point of a closed subpath)
};
std::vector<path_lineto> pts;
bool back;
Path();
virtual ~Path();
// creation of the path description
void Reset(); // reset to the empty description
void Copy (Path * who);
// the commands...
int ForcePoint();
int Close();
int MoveTo ( Geom::Point const &ip);
int LineTo ( Geom::Point const &ip);
int CubicTo ( Geom::Point const &ip, Geom::Point const &iStD, Geom::Point const &iEnD);
int ArcTo ( Geom::Point const &ip, double iRx, double iRy, double angle, bool iLargeArc, bool iClockwise);
int IntermBezierTo ( Geom::Point const &ip); // add a quadratic bezier spline control point
int BezierTo ( Geom::Point const &ip); // quadratic bezier spline to this point (control points can be added after this)
int TempBezierTo(); // start a quadratic bezier spline (control points can be added after this)
int EndBezierTo();
int EndBezierTo ( Geom::Point const &ip); // ends a quadratic bezier spline (for curves started with TempBezierTo)
// transforms a description in a polyline (for stroking and filling)
// treshhold is the max length^2 (sort of)
void Convert (double treshhold);
void ConvertEvenLines (double treshhold); // decomposes line segments too, for later recomposition
// same function for use when you want to later recompose the curves from the polyline
void ConvertWithBackData (double treshhold);
// creation of the polyline (you can tinker with these function if you want)
void SetBackData (bool nVal); // has back data?
void ResetPoints(); // resets to the empty polyline
int AddPoint ( Geom::Point const &iPt, bool mvto = false); // add point
int AddPoint ( Geom::Point const &iPt, int ip, double it, bool mvto = false);
int AddForcedPoint ( Geom::Point const &iPt); // add point
int AddForcedPoint ( Geom::Point const &iPt, int ip, double it);
int ReplacePoint(Geom::Point const &iPt); // replace point
// transform in a polygon (in a graph, in fact; a subsequent call to ConvertToShape is needed)
// - fills the polyline; justAdd=true doesn't reset the Shape dest, but simply adds the polyline into it
// closeIfNeeded=false prevent the function from closing the path (resulting in a non-eulerian graph
// pathID is a identification number for the path, and is used for recomposing curves from polylines
// give each different Path a different ID, and feed the appropriate orig[] to the ConvertToForme() function
void Fill(Shape &dest, int pathID = -1, bool justAdd = false,
bool closeIfNeeded = true, bool invert = false);
// - stroke the path; usual parameters: type of cap=butt, type of join=join and miter (see LivarotDefs.h)
// doClose treat the path as closed (ie a loop)
void Stroke(Shape &dest, bool doClose, double width, JoinType join,
ButtType butt, double miter, bool justAdd = false);
// build a Path that is the outline of the Path instance's description (the result is stored in dest)
// it doesn't compute the exact offset (it's way too complicated, but an approximation made of cubic bezier patches
// and segments. the algorithm was found in a plugin for Impress (by Chris Cox), but i can't find it back...
void Outline(Path &dest, double width, JoinType join, ButtType butt,
double miter);
// half outline with edges having the same direction as the original
void OutsideOutline(Path &dest, double width, JoinType join, ButtType butt,
double miter);
// half outline with edges having the opposite direction as the original
void InsideOutline (Path & dest, double width, JoinType join, ButtType butt,
double miter);
// polyline to cubic bezier patches
void Simplify (double treshhold);
// description simplification
void Coalesce (double tresh);
// utilities
// piece is a command no in the command list
// "at" is an abcissis on the path portion associated with this command
// 0=beginning of portion, 1=end of portion.
void PointAt (int piece, double at, Geom::Point & pos);
void PointAndTangentAt (int piece, double at, Geom::Point & pos, Geom::Point & tgt);
// last control point before the command i (i included)
// used when dealing with quadratic bezier spline, cause these can contain arbitrarily many commands
const Geom::Point PrevPoint (const int i) const;
// dash the polyline
// the result is stored in the polyline, so you lose the original. make a copy before if needed
void DashPolyline(float head,float tail,float body,int nbD,float *dashs,bool stPlain,float stOffset);
void DashPolylineFromStyle(SPStyle *style, float scale, float min_len);
//utilitaire pour inkscape
void LoadPath(Geom::Path const &path, Geom::Affine const &tr, bool doTransformation, bool append = false);
void LoadPathVector(Geom::PathVector const &pv, Geom::Affine const &tr, bool doTransformation);
void LoadPathVector(Geom::PathVector const &pv);
Geom::PathVector MakePathVector();
void Transform(const Geom::Affine &trans);
// decompose le chemin en ses sous-chemin
// killNoSurf=true -> oublie les chemins de surface nulle
Path** SubPaths(int &outNb,bool killNoSurf);
// pour recuperer les trous
// nbNest= nombre de contours
// conts= debut de chaque contour
// nesting= parent de chaque contour
Path** SubPathsWithNesting(int &outNb,bool killNoSurf,int nbNest,int* nesting,int* conts);
// surface du chemin (considere comme ferme)
double Surface();
void PolylineBoundingBox(double &l,double &t,double &r,double &b);
void FastBBox(double &l,double &t,double &r,double &b);
// longueur (totale des sous-chemins)
double Length();
void ConvertForcedToMoveTo();
void ConvertForcedToVoid();
struct cut_position {
int piece;
double t;
};
cut_position* CurvilignToPosition(int nbCv,double* cvAbs,int &nbCut);
cut_position PointToCurvilignPosition(Geom::Point const &pos, unsigned seg = 0) const;
//Should this take a cut_position as a param?
double PositionToLength(int piece, double t);
// caution: not tested on quadratic b-splines, most certainly buggy
void ConvertPositionsToMoveTo(int nbPos,cut_position* poss);
void ConvertPositionsToForced(int nbPos,cut_position* poss);
void Affiche();
char *svg_dump_path() const;
bool IsLineSegment(int piece);
private:
// utilitary functions for the path contruction
void CancelBezier ();
void CloseSubpath();
void InsertMoveTo (Geom::Point const &iPt,int at);
void InsertForcePoint (int at);
void InsertLineTo (Geom::Point const &iPt,int at);
void InsertArcTo (Geom::Point const &ip, double iRx, double iRy, double angle, bool iLargeArc, bool iClockwise,int at);
void InsertCubicTo (Geom::Point const &ip, Geom::Point const &iStD, Geom::Point const &iEnD,int at);
void InsertBezierTo (Geom::Point const &iPt,int iNb,int at);
void InsertIntermBezierTo (Geom::Point const &iPt,int at);
// creation of dashes: take the polyline given by spP (length spL) and dash it according to head, body, etc. put the result in
// the polyline of this instance
void DashSubPath(int spL, int spP, std::vector<path_lineto> const &orig_pts, float head,float tail,float body,int nbD,float *dashs,bool stPlain,float stOffset);
// Functions used by the conversion.
// they append points to the polyline
void DoArc ( Geom::Point const &iS, Geom::Point const &iE, double rx, double ry,
double angle, bool large, bool wise, double tresh);
void RecCubicTo ( Geom::Point const &iS, Geom::Point const &iSd, Geom::Point const &iE, Geom::Point const &iEd, double tresh, int lev,
double maxL = -1.0);
void RecBezierTo ( Geom::Point const &iPt, Geom::Point const &iS, Geom::Point const &iE, double treshhold, int lev, double maxL = -1.0);
void DoArc ( Geom::Point const &iS, Geom::Point const &iE, double rx, double ry,
double angle, bool large, bool wise, double tresh, int piece);
void RecCubicTo ( Geom::Point const &iS, Geom::Point const &iSd, Geom::Point const &iE, Geom::Point const &iEd, double tresh, int lev,
double st, double et, int piece);
void RecBezierTo ( Geom::Point const &iPt, Geom::Point const &iS, const Geom::Point &iE, double treshhold, int lev, double st, double et,
int piece);
// don't pay attention
struct offset_orig
{
Path *orig;
int piece;
double tSt, tEn;
double off_dec;
};
void DoArc ( Geom::Point const &iS, Geom::Point const &iE, double rx, double ry,
double angle, bool large, bool wise, double tresh, int piece,
offset_orig & orig);
void RecCubicTo ( Geom::Point const &iS, Geom::Point const &iSd, Geom::Point const &iE, Geom::Point const &iEd, double tresh, int lev,
double st, double et, int piece, offset_orig & orig);
void RecBezierTo ( Geom::Point const &iPt, Geom::Point const &iS, Geom::Point const &iE, double treshhold, int lev, double st, double et,
int piece, offset_orig & orig);
static void ArcAngles ( Geom::Point const &iS, Geom::Point const &iE, double rx,
double ry, double angle, bool large, bool wise,
double &sang, double &eang);
static void QuadraticPoint (double t, Geom::Point &oPt, Geom::Point const &iS, Geom::Point const &iM, Geom::Point const &iE);
static void CubicTangent (double t, Geom::Point &oPt, Geom::Point const &iS,
Geom::Point const &iSd, Geom::Point const &iE,
Geom::Point const &iEd);
struct outline_callback_data
{
Path *orig;
int piece;
double tSt, tEn;
Path *dest;
double x1, y1, x2, y2;
union
{
struct
{
double dx1, dy1, dx2, dy2;
}
c;
struct
{
double mx, my;
}
b;
struct
{
double rx, ry, angle;
bool clock, large;
double stA, enA;
}
a;
}
d;
};
typedef void (outlineCallback) (outline_callback_data * data, double tol, double width);
struct outline_callbacks
{
outlineCallback *cubicto;
outlineCallback *bezierto;
outlineCallback *arcto;
};
void SubContractOutline (int off, int num_pd,
Path * dest, outline_callbacks & calls,
double tolerance, double width, JoinType join,
ButtType butt, double miter, bool closeIfNeeded,
bool skipMoveto, Geom::Point & lastP, Geom::Point & lastT);
void DoStroke(int off, int N, Shape *dest, bool doClose, double width, JoinType join,
ButtType butt, double miter, bool justAdd = false);
static void TangentOnSegAt(double at, Geom::Point const &iS, PathDescrLineTo const &fin,
Geom::Point &pos, Geom::Point &tgt, double &len);
static void TangentOnArcAt(double at, Geom::Point const &iS, PathDescrArcTo const &fin,
Geom::Point &pos, Geom::Point &tgt, double &len, double &rad);
static void TangentOnCubAt (double at, Geom::Point const &iS, PathDescrCubicTo const &fin, bool before,
Geom::Point &pos, Geom::Point &tgt, double &len, double &rad);
static void TangentOnBezAt (double at, Geom::Point const &iS,
PathDescrIntermBezierTo & mid,
PathDescrBezierTo & fin, bool before,
Geom::Point & pos, Geom::Point & tgt, double &len, double &rad);
static void OutlineJoin (Path * dest, Geom::Point pos, Geom::Point stNor, Geom::Point enNor,
double width, JoinType join, double miter, int nType);
static bool IsNulCurve (std::vector<PathDescr*> const &cmd, int curD, Geom::Point const &curX);
static void RecStdCubicTo (outline_callback_data * data, double tol,
double width, int lev);
static void StdCubicTo (outline_callback_data * data, double tol,
double width);
static void StdBezierTo (outline_callback_data * data, double tol,
double width);
static void RecStdArcTo (outline_callback_data * data, double tol,
double width, int lev);
static void StdArcTo (outline_callback_data * data, double tol, double width);
// fonctions annexes pour le stroke
static void DoButt (Shape * dest, double width, ButtType butt, Geom::Point pos,
Geom::Point dir, int &leftNo, int &rightNo);
static void DoJoin (Shape * dest, double width, JoinType join, Geom::Point pos,
Geom::Point prev, Geom::Point next, double miter, double prevL,
double nextL, int *stNo, int *enNo);
static void DoLeftJoin (Shape * dest, double width, JoinType join, Geom::Point pos,
Geom::Point prev, Geom::Point next, double miter, double prevL,
double nextL, int &leftStNo, int &leftEnNo,int pathID=-1,int pieceID=0,double tID=0.0);
static void DoRightJoin (Shape * dest, double width, JoinType join, Geom::Point pos,
Geom::Point prev, Geom::Point next, double miter, double prevL,
double nextL, int &rightStNo, int &rightEnNo,int pathID=-1,int pieceID=0,double tID=0.0);
static void RecRound (Shape * dest, int sNo, int eNo,
Geom::Point const &iS, Geom::Point const &iE,
Geom::Point const &nS, Geom::Point const &nE,
Geom::Point &origine,float width);
void DoSimplify(int off, int N, double treshhold);
bool AttemptSimplify(int off, int N, double treshhold, PathDescrCubicTo &res, int &worstP);
static bool FitCubic(Geom::Point const &start,
PathDescrCubicTo &res,
double *Xk, double *Yk, double *Qk, double *tk, int nbPt);
struct fitting_tables {
int nbPt,maxPt,inPt;
double *Xk;
double *Yk;
double *Qk;
double *tk;
double *lk;
char *fk;
double totLen;
};
bool AttemptSimplify (fitting_tables &data,double treshhold, PathDescrCubicTo & res,int &worstP);
bool ExtendFit(int off, int N, fitting_tables &data,double treshhold, PathDescrCubicTo & res,int &worstP);
double RaffineTk (Geom::Point pt, Geom::Point p0, Geom::Point p1, Geom::Point p2, Geom::Point p3, double it);
void FlushPendingAddition(Path* dest,PathDescr *lastAddition,PathDescrCubicTo &lastCubic,int lastAD);
private:
void AddCurve(Geom::Curve const &c);
};
#endif
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :