splash/SplashPath.cc

//========================================================================
//
// SplashPath.cc
//
//========================================================================

//========================================================================
//
// 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 Stefan Brüns <stefan.bruens@rwth-aachen.de>
// Copyright (C) 2018-2021 Albert Astals Cid <aacid@kde.org>
// Copyright (C) 2018 Adam Reichold <adam.reichold@t-online.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
//
//========================================================================

#include <config.h>

#include <cstring>
#include "goo/gmem.h"
#include "goo/GooLikely.h"
#include "SplashErrorCodes.h"
#include "SplashPath.h"

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

// A path can be in three possible states:
//
// 1. no current point -- zero or more finished subpaths
//    [curSubpath == length]
//
// 2. one point in subpath
//    [curSubpath == length - 1]
//
// 3. open subpath with two or more points
//    [curSubpath < length - 1]

SplashPath::SplashPath()
{
    pts = nullptr;
    flags = nullptr;
    length = size = 0;
    curSubpath = 0;
    hints = nullptr;
    hintsLength = hintsSize = 0;
}

SplashPath::SplashPath(SplashPath &&path) noexcept
{
    length = path.length;
    size = path.size;
    pts = path.pts;
    flags = path.flags;
    curSubpath = path.curSubpath;

    hints = path.hints;
    hintsLength = hintsSize = path.hintsLength;

    path.pts = nullptr;
    path.flags = nullptr;
    path.length = path.size = 0;
    path.hints = nullptr;
    path.hintsLength = path.hintsSize = 0;
}

SplashPath::~SplashPath()
{
    gfree(pts);
    gfree(flags);
    gfree(hints);
}

void SplashPath::reserve(int nPts)
{
    grow(nPts - size);
}

// Add space for <nPts> more points.
void SplashPath::grow(int nPts)
{
    if (length + nPts > size) {
        if (size == 0) {
            size = 32;
        }
        while (size < length + nPts) {
            size *= 2;
        }
        pts = (SplashPathPoint *)greallocn_checkoverflow(pts, size, sizeof(SplashPathPoint));
        flags = (unsigned char *)greallocn_checkoverflow(flags, size, sizeof(unsigned char));
        if (unlikely(!pts || !flags)) {
            length = size = curSubpath = 0;
        }
    }
}

void SplashPath::append(SplashPath *path)
{
    int i;

    grow(path->length);
    if (unlikely(size == 0)) {
        return;
    }

    curSubpath = length + path->curSubpath;
    for (i = 0; i < path->length; ++i) {
        pts[length] = path->pts[i];
        flags[length] = path->flags[i];
        ++length;
    }
}

SplashError SplashPath::moveTo(SplashCoord x, SplashCoord y)
{
    if (onePointSubpath()) {
        return splashErrBogusPath;
    }
    grow(1);
    if (unlikely(size == 0)) {
        return splashErrBogusPath;
    }
    pts[length].x = x;
    pts[length].y = y;
    flags[length] = splashPathFirst | splashPathLast;
    curSubpath = length++;
    return splashOk;
}

SplashError SplashPath::lineTo(SplashCoord x, SplashCoord y)
{
    if (noCurrentPoint()) {
        return splashErrNoCurPt;
    }
    flags[length - 1] &= ~splashPathLast;
    grow(1);
    if (unlikely(size == 0)) {
        return splashErrBogusPath;
    }
    pts[length].x = x;
    pts[length].y = y;
    flags[length] = splashPathLast;
    ++length;
    return splashOk;
}

SplashError SplashPath::curveTo(SplashCoord x1, SplashCoord y1, SplashCoord x2, SplashCoord y2, SplashCoord x3, SplashCoord y3)
{
    if (noCurrentPoint()) {
        return splashErrNoCurPt;
    }
    flags[length - 1] &= ~splashPathLast;
    grow(3);
    if (unlikely(size == 0)) {
        return splashErrBogusPath;
    }
    pts[length].x = x1;
    pts[length].y = y1;
    flags[length] = splashPathCurve;
    ++length;
    pts[length].x = x2;
    pts[length].y = y2;
    flags[length] = splashPathCurve;
    ++length;
    pts[length].x = x3;
    pts[length].y = y3;
    flags[length] = splashPathLast;
    ++length;
    return splashOk;
}

SplashError SplashPath::close(bool force)
{
    if (noCurrentPoint()) {
        return splashErrNoCurPt;
    }
    if (force || curSubpath == length - 1 || pts[length - 1].x != pts[curSubpath].x || pts[length - 1].y != pts[curSubpath].y) {
        const auto lineToStatus = lineTo(pts[curSubpath].x, pts[curSubpath].y);
        if (lineToStatus != splashOk) {
            return lineToStatus;
        }
    }
    flags[curSubpath] |= splashPathClosed;
    flags[length - 1] |= splashPathClosed;
    curSubpath = length;
    return splashOk;
}

void SplashPath::addStrokeAdjustHint(int ctrl0, int ctrl1, int firstPt, int lastPt)
{
    if (hintsLength == hintsSize) {
        hintsSize = hintsLength ? 2 * hintsLength : 8;
        hints = (SplashPathHint *)greallocn_checkoverflow(hints, hintsSize, sizeof(SplashPathHint));
    }
    if (unlikely(!hints)) {
        return;
    }
    hints[hintsLength].ctrl0 = ctrl0;
    hints[hintsLength].ctrl1 = ctrl1;
    hints[hintsLength].firstPt = firstPt;
    hints[hintsLength].lastPt = lastPt;
    ++hintsLength;
}

void SplashPath::offset(SplashCoord dx, SplashCoord dy)
{
    int i;

    for (i = 0; i < length; ++i) {
        pts[i].x += dx;
        pts[i].y += dy;
    }
}

bool SplashPath::getCurPt(SplashCoord *x, SplashCoord *y)
{
    if (noCurrentPoint()) {
        return false;
    }
    *x = pts[length - 1].x;
    *y = pts[length - 1].y;
    return true;
}