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-rw-r--r--dom/svg/SVGPathDataParser.cpp464
1 files changed, 464 insertions, 0 deletions
diff --git a/dom/svg/SVGPathDataParser.cpp b/dom/svg/SVGPathDataParser.cpp
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+++ b/dom/svg/SVGPathDataParser.cpp
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+/* -*- 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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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() || IsAsciiAlpha(*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