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Diffstat (limited to 'dom/svg/nsSVGPathDataParser.cpp')
| -rw-r--r-- | dom/svg/nsSVGPathDataParser.cpp | 516 |
1 files changed, 516 insertions, 0 deletions
diff --git a/dom/svg/nsSVGPathDataParser.cpp b/dom/svg/nsSVGPathDataParser.cpp new file mode 100644 index 000000000..8ab526820 --- /dev/null +++ b/dom/svg/nsSVGPathDataParser.cpp @@ -0,0 +1,516 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsSVGPathDataParser.h" + +#include "mozilla/gfx/Point.h" +#include "nsSVGDataParser.h" +#include "SVGContentUtils.h" +#include "SVGPathData.h" +#include "SVGPathSegUtils.h" + +using namespace mozilla; +using namespace mozilla::gfx; + +static inline char16_t ToUpper(char16_t aCh) +{ + return aCh >= 'a' && aCh <= 'z' ? aCh - 'a' + 'A' : aCh; +} + +bool +nsSVGPathDataParser::Parse() +{ + mPathSegList->Clear(); + return ParsePath(); +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseCoordPair(float& aX, float& aY) +{ + return SVGContentUtils::ParseNumber(mIter, mEnd, aX) && + SkipCommaWsp() && + SVGContentUtils::ParseNumber(mIter, mEnd, aY); +} + +bool +nsSVGPathDataParser::ParseFlag(bool& aFlag) +{ + if (mIter == mEnd || (*mIter != '0' && *mIter != '1')) { + return false; + } + aFlag = (*mIter == '1'); + + ++mIter; + return true; +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParsePath() +{ + while (SkipWsp()) { + if (!ParseSubPath()) { + return false; + } + } + + return true; +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseSubPath() +{ + return ParseMoveto() && ParseSubPathElements(); +} + +bool +nsSVGPathDataParser::ParseSubPathElements() +{ + while (SkipWsp() && !IsStartOfSubPath()) { + char16_t commandType = ToUpper(*mIter); + + // Upper case commands have absolute co-ordinates, + // lower case commands have relative co-ordinates. + bool absCoords = commandType == *mIter; + + ++mIter; + SkipWsp(); + + if (!ParseSubPathElement(commandType, absCoords)) { + return false; + } + } + return true; +} + +bool +nsSVGPathDataParser::ParseSubPathElement(char16_t aCommandType, + bool aAbsCoords) +{ + switch (aCommandType) { + case 'Z': + return ParseClosePath(); + case 'L': + return ParseLineto(aAbsCoords); + case 'H': + return ParseHorizontalLineto(aAbsCoords); + case 'V': + return ParseVerticalLineto(aAbsCoords); + case 'C': + return ParseCurveto(aAbsCoords); + case 'S': + return ParseSmoothCurveto(aAbsCoords); + case 'Q': + return ParseQuadBezierCurveto(aAbsCoords); + case 'T': + return ParseSmoothQuadBezierCurveto(aAbsCoords); + case 'A': + return ParseEllipticalArc(aAbsCoords); + } + return false; +} + +bool +nsSVGPathDataParser::IsStartOfSubPath() const +{ + return *mIter == 'm' || *mIter == 'M'; +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseMoveto() +{ + if (!IsStartOfSubPath()) { + return false; + } + + bool absCoords = (*mIter == 'M'); + + ++mIter; + SkipWsp(); + + float x, y; + if (!ParseCoordPair(x, y)) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + absCoords ? PATHSEG_MOVETO_ABS : PATHSEG_MOVETO_REL, + x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + + SkipCommaWsp(); + + // Per SVG 1.1 Section 8.3.2 + // If a moveto is followed by multiple pairs of coordinates, + // the subsequent pairs are treated as implicit lineto commands + return ParseLineto(absCoords); +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseClosePath() +{ + return NS_SUCCEEDED(mPathSegList->AppendSeg(PATHSEG_CLOSEPATH)); +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseLineto(bool aAbsCoords) +{ + while (true) { + float x, y; + if (!ParseCoordPair(x, y)) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_LINETO_ABS : PATHSEG_LINETO_REL, + x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseHorizontalLineto(bool aAbsCoords) +{ + while (true) { + float x; + if (!SVGContentUtils::ParseNumber(mIter, mEnd, x)) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_LINETO_HORIZONTAL_ABS : PATHSEG_LINETO_HORIZONTAL_REL, + x))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseVerticalLineto(bool aAbsCoords) +{ + while (true) { + float y; + if (!SVGContentUtils::ParseNumber(mIter, mEnd, y)) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_LINETO_VERTICAL_ABS : PATHSEG_LINETO_VERTICAL_REL, + y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseCurveto(bool aAbsCoords) +{ + while (true) { + float x1, y1, x2, y2, x, y; + + if (!(ParseCoordPair(x1, y1) && + SkipCommaWsp() && + ParseCoordPair(x2, y2) && + SkipCommaWsp() && + ParseCoordPair(x, y))) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_CURVETO_CUBIC_ABS : PATHSEG_CURVETO_CUBIC_REL, + x1, y1, x2, y2, x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseSmoothCurveto(bool aAbsCoords) +{ + while (true) { + float x2, y2, x, y; + if (!(ParseCoordPair(x2, y2) && + SkipCommaWsp() && + ParseCoordPair(x, y))) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_CURVETO_CUBIC_SMOOTH_ABS : PATHSEG_CURVETO_CUBIC_SMOOTH_REL, + x2, y2, x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseQuadBezierCurveto(bool aAbsCoords) +{ + while (true) { + float x1, y1, x, y; + if (!(ParseCoordPair(x1, y1) && + SkipCommaWsp() && + ParseCoordPair(x, y))) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_CURVETO_QUADRATIC_ABS : PATHSEG_CURVETO_QUADRATIC_REL, + x1, y1, x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // Start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseSmoothQuadBezierCurveto(bool aAbsCoords) +{ + while (true) { + float x, y; + if (!ParseCoordPair(x, y)) { + return false; + } + + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS : PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL, + x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//---------------------------------------------------------------------- + +bool +nsSVGPathDataParser::ParseEllipticalArc(bool aAbsCoords) +{ + while (true) { + float r1, r2, angle, x, y; + bool largeArcFlag, sweepFlag; + + if (!(SVGContentUtils::ParseNumber(mIter, mEnd, r1) && + SkipCommaWsp() && + SVGContentUtils::ParseNumber(mIter, mEnd, r2) && + SkipCommaWsp() && + SVGContentUtils::ParseNumber(mIter, mEnd, angle)&& + SkipCommaWsp() && + ParseFlag(largeArcFlag) && + SkipCommaWsp() && + ParseFlag(sweepFlag) && + SkipCommaWsp() && + ParseCoordPair(x, y))) { + return false; + } + + // We can only pass floats after 'type', and per the SVG spec for arc, + // non-zero args are treated at 'true'. + if (NS_FAILED(mPathSegList->AppendSeg( + aAbsCoords ? PATHSEG_ARC_ABS : PATHSEG_ARC_REL, + r1, r2, angle, + largeArcFlag ? 1.0f : 0.0f, + sweepFlag ? 1.0f : 0.0f, + x, y))) { + return false; + } + + if (!SkipWsp() || IsAlpha(*mIter)) { + // End of data, or start of a new command + return true; + } + SkipCommaWsp(); + } +} + +//----------------------------------------------------------------------- + + + + +static double +CalcVectorAngle(double ux, double uy, double vx, double vy) +{ + double ta = atan2(uy, ux); + double tb = atan2(vy, vx); + if (tb >= ta) + return tb-ta; + return 2 * M_PI - (ta-tb); +} + + +nsSVGArcConverter::nsSVGArcConverter(const Point& from, + const Point& to, + const Point& radii, + double angle, + bool largeArcFlag, + bool sweepFlag) +{ + const double radPerDeg = M_PI/180.0; + mSegIndex = 0; + + if (from == to) { + mNumSegs = 0; + return; + } + + // Convert to center parameterization as shown in + // http://www.w3.org/TR/SVG/implnote.html + mRx = fabs(radii.x); + mRy = fabs(radii.y); + + mSinPhi = sin(angle*radPerDeg); + mCosPhi = cos(angle*radPerDeg); + + double x1dash = mCosPhi * (from.x-to.x)/2.0 + mSinPhi * (from.y-to.y)/2.0; + double y1dash = -mSinPhi * (from.x-to.x)/2.0 + mCosPhi * (from.y-to.y)/2.0; + + double root; + double numerator = mRx*mRx*mRy*mRy - mRx*mRx*y1dash*y1dash - + mRy*mRy*x1dash*x1dash; + + if (numerator < 0.0) { + // If mRx , mRy and are such that there is no solution (basically, + // the ellipse is not big enough to reach from 'from' to 'to' + // then the ellipse is scaled up uniformly until there is + // exactly one solution (until the ellipse is just big enough). + + // -> find factor s, such that numerator' with mRx'=s*mRx and + // mRy'=s*mRy becomes 0 : + double s = sqrt(1.0 - numerator/(mRx*mRx*mRy*mRy)); + + mRx *= s; + mRy *= s; + root = 0.0; + + } + else { + root = (largeArcFlag == sweepFlag ? -1.0 : 1.0) * + sqrt( numerator/(mRx*mRx*y1dash*y1dash + mRy*mRy*x1dash*x1dash) ); + } + + double cxdash = root*mRx*y1dash/mRy; + double cydash = -root*mRy*x1dash/mRx; + + mC.x = mCosPhi * cxdash - mSinPhi * cydash + (from.x+to.x)/2.0; + mC.y = mSinPhi * cxdash + mCosPhi * cydash + (from.y+to.y)/2.0; + mTheta = CalcVectorAngle(1.0, 0.0, (x1dash-cxdash)/mRx, (y1dash-cydash)/mRy); + double dtheta = CalcVectorAngle((x1dash-cxdash)/mRx, (y1dash-cydash)/mRy, + (-x1dash-cxdash)/mRx, (-y1dash-cydash)/mRy); + if (!sweepFlag && dtheta>0) + dtheta -= 2.0*M_PI; + else if (sweepFlag && dtheta<0) + dtheta += 2.0*M_PI; + + // Convert into cubic bezier segments <= 90deg + mNumSegs = static_cast<int>(ceil(fabs(dtheta/(M_PI/2.0)))); + mDelta = dtheta/mNumSegs; + mT = 8.0/3.0 * sin(mDelta/4.0) * sin(mDelta/4.0) / sin(mDelta/2.0); + + mFrom = from; +} + +bool +nsSVGArcConverter::GetNextSegment(Point* cp1, Point* cp2, Point* to) +{ + if (mSegIndex == mNumSegs) { + return false; + } + + double cosTheta1 = cos(mTheta); + double sinTheta1 = sin(mTheta); + double theta2 = mTheta + mDelta; + double cosTheta2 = cos(theta2); + double sinTheta2 = sin(theta2); + + // a) calculate endpoint of the segment: + to->x = mCosPhi * mRx*cosTheta2 - mSinPhi * mRy*sinTheta2 + mC.x; + to->y = mSinPhi * mRx*cosTheta2 + mCosPhi * mRy*sinTheta2 + mC.y; + + // b) calculate gradients at start/end points of segment: + cp1->x = mFrom.x + mT * ( - mCosPhi * mRx*sinTheta1 - mSinPhi * mRy*cosTheta1); + cp1->y = mFrom.y + mT * ( - mSinPhi * mRx*sinTheta1 + mCosPhi * mRy*cosTheta1); + + cp2->x = to->x + mT * ( mCosPhi * mRx*sinTheta2 + mSinPhi * mRy*cosTheta2); + cp2->y = to->y + mT * ( mSinPhi * mRx*sinTheta2 - mCosPhi * mRy*cosTheta2); + + // do next segment + mTheta = theta2; + mFrom = *to; + ++mSegIndex; + + return true; +} |