diff options
Diffstat (limited to 'dom/svg/SVGPathDataParser.cpp')
| -rw-r--r-- | dom/svg/SVGPathDataParser.cpp | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/dom/svg/SVGPathDataParser.cpp b/dom/svg/SVGPathDataParser.cpp new file mode 100644 index 0000000000..b08b98c98f --- /dev/null +++ b/dom/svg/SVGPathDataParser.cpp @@ -0,0 +1,464 @@ +/* -*- 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 "SVGPathDataParser.h" + +#include "mozilla/gfx/Point.h" +#include "SVGDataParser.h" +#include "SVGContentUtils.h" +#include "SVGPathData.h" +#include "SVGPathSegUtils.h" + +using namespace mozilla::dom::SVGPathSeg_Binding; +using namespace mozilla::gfx; + +namespace mozilla { + +static inline char16_t ToUpper(char16_t aCh) { + return aCh >= 'a' && aCh <= 'z' ? aCh - 'a' + 'A' : aCh; +} + +bool SVGPathDataParser::Parse() { + mPathSegList->Clear(); + return ParsePath(); +} + +//---------------------------------------------------------------------- + +bool SVGPathDataParser::ParseCoordPair(float& aX, float& aY) { + return SVGContentUtils::ParseNumber(mIter, mEnd, aX) && SkipCommaWsp() && + SVGContentUtils::ParseNumber(mIter, mEnd, aY); +} + +bool SVGPathDataParser::ParseFlag(bool& aFlag) { + if (mIter == mEnd || (*mIter != '0' && *mIter != '1')) { + return false; + } + aFlag = (*mIter == '1'); + + ++mIter; + return true; +} + +//---------------------------------------------------------------------- + +bool SVGPathDataParser::ParsePath() { + while (SkipWsp()) { + if (!ParseSubPath()) { + return false; + } + } + + return true; +} + +//---------------------------------------------------------------------- + +bool SVGPathDataParser::ParseSubPath() { + return ParseMoveto() && ParseSubPathElements(); +} + +bool SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::IsStartOfSubPath() const { + return *mIter == 'm' || *mIter == 'M'; +} + +//---------------------------------------------------------------------- + +bool SVGPathDataParser::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 SVGPathDataParser::ParseClosePath() { + return NS_SUCCEEDED(mPathSegList->AppendSeg(PATHSEG_CLOSEPATH)); +} + +//---------------------------------------------------------------------- + +bool SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::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 SVGPathDataParser::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); +} + +SVGArcConverter::SVGArcConverter(const Point& from, const Point& to, + const Point& radii, double angle, + bool largeArcFlag, bool sweepFlag) { + MOZ_ASSERT(radii.x != 0.0f && radii.y != 0.0f, "Bad radii"); + + 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 SVGArcConverter::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; +} + +} // namespace mozilla |