splash/SplashPath.h

//========================================================================
//
// SplashPath.h
//
//========================================================================

//========================================================================
//
// Modified under the Poppler project - http://poppler.freedesktop.org
//
// All changes made under the Poppler project to this file are licensed
// under GPL version 2 or later
//
// Copyright (C) 2018, 2019, 2021 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2018 Stefan Brüns <stefan.bruens@rwth-aachen.de>
//
// To see a description of the changes please see the Changelog file that
// came with your tarball or type make ChangeLog if you are building from git
//
//========================================================================

#ifndef SPLASHPATH_H
#define SPLASHPATH_H

#include "SplashTypes.h"
#include "poppler_private_export.h"

//------------------------------------------------------------------------
// SplashPathPoint
//------------------------------------------------------------------------

struct SplashPathPoint
{
    SplashCoord x, y;
};

//------------------------------------------------------------------------
// SplashPath.flags
//------------------------------------------------------------------------

// first point on each subpath sets this flag
#define splashPathFirst 0x01

// last point on each subpath sets this flag
#define splashPathLast 0x02

// if the subpath is closed, its first and last points must be
// identical, and must set this flag
#define splashPathClosed 0x04

// curve control points set this flag
#define splashPathCurve 0x08

//------------------------------------------------------------------------
// SplashPathHint
//------------------------------------------------------------------------

struct SplashPathHint
{
    int ctrl0, ctrl1;
    int firstPt, lastPt;
};

//------------------------------------------------------------------------
// SplashPath
//------------------------------------------------------------------------

class POPPLER_PRIVATE_EXPORT SplashPath
{
public:
    // Create an empty path.
    SplashPath();
    ~SplashPath();

    SplashPath(const SplashPath &) = delete;
    SplashPath &operator=(const SplashPath &) = delete;
    SplashPath(SplashPath &&path) noexcept;

    // Append <path> to <this>.
    void append(SplashPath *path);

    // Start a new subpath.
    SplashError moveTo(SplashCoord x, SplashCoord y);

    // Add a line segment to the last subpath.
    SplashError lineTo(SplashCoord x, SplashCoord y);

    // Add a third-order (cubic) Bezier curve segment to the last
    // subpath.
    SplashError curveTo(SplashCoord x1, SplashCoord y1, SplashCoord x2, SplashCoord y2, SplashCoord x3, SplashCoord y3);

    // Close the last subpath, adding a line segment if necessary.  If
    // <force> is true, this adds a line segment even if the current
    // point is equal to the first point in the subpath.
    SplashError close(bool force = false);

    // Add a stroke adjustment hint.  The controlling segments are
    // <ctrl0> and <ctrl1> (where segments are identified by their first
    // point), and the points to be adjusted are <firstPt> .. <lastPt>.
    void addStrokeAdjustHint(int ctrl0, int ctrl1, int firstPt, int lastPt);

    // Add (<dx>, <dy>) to every point on this path.
    void offset(SplashCoord dx, SplashCoord dy);

    // Get the points on the path.
    int getLength() { return length; }
    void getPoint(int i, double *x, double *y, unsigned char *f)
    {
        *x = pts[i].x;
        *y = pts[i].y;
        *f = flags[i];
    }

    // Get the current point.
    bool getCurPt(SplashCoord *x, SplashCoord *y);

    // Reserve space for at least n points
    void reserve(int n);

protected:
    void grow(int nPts);
    bool noCurrentPoint() { return curSubpath == length; }
    bool onePointSubpath() { return curSubpath == length - 1; }
    bool openSubpath() { return curSubpath < length - 1; }

    SplashPathPoint *pts; // array of points
    unsigned char *flags; // array of flags
    int length, size; // length/size of the pts and flags arrays
    int curSubpath; // index of first point in last subpath

    SplashPathHint *hints; // list of hints
    int hintsLength, hintsSize;

    friend class SplashXPath;
    friend class Splash;
};

#endif