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-rw-r--r--dom/svg/SVGPathData.cpp1059
1 files changed, 1059 insertions, 0 deletions
diff --git a/dom/svg/SVGPathData.cpp b/dom/svg/SVGPathData.cpp
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+++ b/dom/svg/SVGPathData.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 "SVGPathData.h"
+
+#include "gfx2DGlue.h"
+#include "gfxPlatform.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/Types.h"
+#include "mozilla/gfx/Point.h"
+#include "mozilla/RefPtr.h"
+#include "nsError.h"
+#include "nsString.h"
+#include "SVGPathDataParser.h"
+#include <stdarg.h>
+#include "nsStyleConsts.h"
+#include "SVGContentUtils.h"
+#include "SVGGeometryElement.h"
+#include "SVGPathSegUtils.h"
+#include <algorithm>
+
+using namespace mozilla::dom::SVGPathSeg_Binding;
+using namespace mozilla::gfx;
+
+namespace mozilla {
+
+static inline bool IsMoveto(uint16_t aSegType) {
+ return aSegType == PATHSEG_MOVETO_ABS || aSegType == PATHSEG_MOVETO_REL;
+}
+
+static inline bool IsMoveto(StylePathCommand::Tag aSegType) {
+ return aSegType == StylePathCommand::Tag::MoveTo;
+}
+
+static inline bool IsValidType(uint16_t aSegType) {
+ return SVGPathSegUtils::IsValidType(aSegType);
+}
+
+static inline bool IsValidType(StylePathCommand::Tag aSegType) {
+ return aSegType != StylePathCommand::Tag::Unknown;
+}
+
+static inline bool IsClosePath(uint16_t aSegType) {
+ return aSegType == PATHSEG_CLOSEPATH;
+}
+
+static inline bool IsClosePath(StylePathCommand::Tag aSegType) {
+ return aSegType == StylePathCommand::Tag::ClosePath;
+}
+
+nsresult SVGPathData::CopyFrom(const SVGPathData& rhs) {
+ if (!mData.Assign(rhs.mData, fallible)) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+ return NS_OK;
+}
+
+void SVGPathData::GetValueAsString(nsAString& aValue) const {
+ // we need this function in DidChangePathSegList
+ aValue.Truncate();
+ if (!Length()) {
+ return;
+ }
+ uint32_t i = 0;
+ for (;;) {
+ nsAutoString segAsString;
+ SVGPathSegUtils::GetValueAsString(&mData[i], segAsString);
+ // We ignore OOM, since it's not useful for us to return an error.
+ aValue.Append(segAsString);
+ i += 1 + SVGPathSegUtils::ArgCountForType(mData[i]);
+ if (i >= mData.Length()) {
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt");
+ return;
+ }
+ aValue.Append(' ');
+ }
+}
+
+nsresult SVGPathData::SetValueFromString(const nsAString& aValue) {
+ // We don't use a temp variable since the spec says to parse everything up to
+ // the first error. We still return any error though so that callers know if
+ // there's a problem.
+
+ SVGPathDataParser pathParser(aValue, this);
+ return pathParser.Parse() ? NS_OK : NS_ERROR_DOM_SYNTAX_ERR;
+}
+
+nsresult SVGPathData::AppendSeg(uint32_t aType, ...) {
+ uint32_t oldLength = mData.Length();
+ uint32_t newLength = oldLength + 1 + SVGPathSegUtils::ArgCountForType(aType);
+ if (!mData.SetLength(newLength, fallible)) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ mData[oldLength] = SVGPathSegUtils::EncodeType(aType);
+ va_list args;
+ va_start(args, aType);
+ for (uint32_t i = oldLength + 1; i < newLength; ++i) {
+ // NOTE! 'float' is promoted to 'double' when passed through '...'!
+ mData[i] = float(va_arg(args, double));
+ }
+ va_end(args);
+ return NS_OK;
+}
+
+float SVGPathData::GetPathLength() const {
+ SVGPathTraversalState state;
+
+ uint32_t i = 0;
+ while (i < mData.Length()) {
+ SVGPathSegUtils::TraversePathSegment(&mData[i], state);
+ i += 1 + SVGPathSegUtils::ArgCountForType(mData[i]);
+ }
+
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt");
+
+ return state.length;
+}
+
+#ifdef DEBUG
+uint32_t SVGPathData::CountItems() const {
+ uint32_t i = 0, count = 0;
+
+ while (i < mData.Length()) {
+ i += 1 + SVGPathSegUtils::ArgCountForType(mData[i]);
+ count++;
+ }
+
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt");
+
+ return count;
+}
+#endif
+
+bool SVGPathData::GetDistancesFromOriginToEndsOfVisibleSegments(
+ FallibleTArray<double>* aOutput) const {
+ SVGPathTraversalState state;
+
+ aOutput->Clear();
+
+ uint32_t i = 0;
+ while (i < mData.Length()) {
+ uint32_t segType = SVGPathSegUtils::DecodeType(mData[i]);
+ SVGPathSegUtils::TraversePathSegment(&mData[i], state);
+
+ // With degenerately large point coordinates, TraversePathSegment can fail
+ // and end up producing NaNs.
+ if (!std::isfinite(state.length)) {
+ return false;
+ }
+
+ // We skip all moveto commands except an initial moveto. See the text 'A
+ // "move to" command does not count as an additional point when dividing up
+ // the duration...':
+ //
+ // http://www.w3.org/TR/SVG11/animate.html#AnimateMotionElement
+ //
+ // This is important in the non-default case of calcMode="linear". In
+ // this case an equal amount of time is spent on each path segment,
+ // except on moveto segments which are jumped over immediately.
+
+ if (i == 0 || !IsMoveto(segType)) {
+ if (!aOutput->AppendElement(state.length, fallible)) {
+ return false;
+ }
+ }
+ i += 1 + SVGPathSegUtils::ArgCountForType(segType);
+ }
+
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt?");
+
+ return true;
+}
+
+uint32_t SVGPathData::GetPathSegAtLength(float aDistance) const {
+ // TODO [SVGWG issue] get specified what happen if 'aDistance' < 0, or
+ // 'aDistance' > the length of the path, or the seg list is empty.
+ // Return -1? Throwing would better help authors avoid tricky bugs (DOM
+ // could do that if we return -1).
+
+ uint32_t i = 0, segIndex = 0;
+ SVGPathTraversalState state;
+
+ while (i < mData.Length()) {
+ SVGPathSegUtils::TraversePathSegment(&mData[i], state);
+ if (state.length >= aDistance) {
+ return segIndex;
+ }
+ i += 1 + SVGPathSegUtils::ArgCountForType(mData[i]);
+ segIndex++;
+ }
+
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt");
+
+ return std::max(1U, segIndex) -
+ 1; // -1 because while loop takes us 1 too far
+}
+
+/**
+ * The SVG spec says we have to paint stroke caps for zero length subpaths:
+ *
+ * http://www.w3.org/TR/SVG11/implnote.html#PathElementImplementationNotes
+ *
+ * Cairo only does this for |stroke-linecap: round| and not for
+ * |stroke-linecap: square| (since that's what Adobe Acrobat has always done).
+ * Most likely the other backends that DrawTarget uses have the same behavior.
+ *
+ * To help us conform to the SVG spec we have this helper function to draw an
+ * approximation of square caps for zero length subpaths. It does this by
+ * inserting a subpath containing a single user space axis aligned straight
+ * line that is as small as it can be while minimizing the risk of it being
+ * thrown away by the DrawTarget's backend for being too small to affect
+ * rendering. The idea is that we'll then get stroke caps drawn for this axis
+ * aligned line, creating an axis aligned rectangle that approximates the
+ * square that would ideally be drawn.
+ *
+ * Since we don't have any information about transforms from user space to
+ * device space, we choose the length of the small line that we insert by
+ * making it a small percentage of the stroke width of the path. This should
+ * hopefully allow us to make the line as long as possible (to avoid rounding
+ * issues in the backend resulting in the backend seeing it as having zero
+ * length) while still avoiding the small rectangle being noticeably different
+ * from a square.
+ *
+ * Note that this function inserts a subpath into the current gfx path that
+ * will be present during both fill and stroke operations.
+ */
+static void ApproximateZeroLengthSubpathSquareCaps(PathBuilder* aPB,
+ const Point& aPoint,
+ Float aStrokeWidth) {
+ // Note that caps are proportional to stroke width, so if stroke width is
+ // zero it's actually fine for |tinyLength| below to end up being zero.
+ // However, it would be a waste to inserting a LineTo in that case, so better
+ // not to.
+ MOZ_ASSERT(aStrokeWidth > 0.0f,
+ "Make the caller check for this, or check it here");
+
+ // The fraction of the stroke width that we choose for the length of the
+ // line is rather arbitrary, other than being chosen to meet the requirements
+ // described in the comment above.
+
+ Float tinyLength = aStrokeWidth / SVG_ZERO_LENGTH_PATH_FIX_FACTOR;
+
+ aPB->LineTo(aPoint + Point(tinyLength, 0));
+ aPB->MoveTo(aPoint);
+}
+
+#define MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT \
+ do { \
+ if (!subpathHasLength && hasLineCaps && aStrokeWidth > 0 && \
+ subpathContainsNonMoveTo && IsValidType(prevSegType) && \
+ (!IsMoveto(prevSegType) || IsClosePath(segType))) { \
+ ApproximateZeroLengthSubpathSquareCaps(aBuilder, segStart, \
+ aStrokeWidth); \
+ } \
+ } while (0)
+
+already_AddRefed<Path> SVGPathData::BuildPath(PathBuilder* aBuilder,
+ StyleStrokeLinecap aStrokeLineCap,
+ Float aStrokeWidth) const {
+ if (mData.IsEmpty() || !IsMoveto(SVGPathSegUtils::DecodeType(mData[0]))) {
+ return nullptr; // paths without an initial moveto are invalid
+ }
+
+ bool hasLineCaps = aStrokeLineCap != StyleStrokeLinecap::Butt;
+ bool subpathHasLength = false; // visual length
+ bool subpathContainsNonMoveTo = false;
+
+ uint32_t segType = PATHSEG_UNKNOWN;
+ uint32_t prevSegType = PATHSEG_UNKNOWN;
+ Point pathStart(0.0, 0.0); // start point of [sub]path
+ Point segStart(0.0, 0.0);
+ Point segEnd;
+ Point cp1, cp2; // previous bezier's control points
+ Point tcp1, tcp2; // temporaries
+
+ // Regarding cp1 and cp2: If the previous segment was a cubic bezier curve,
+ // then cp2 is its second control point. If the previous segment was a
+ // quadratic curve, then cp1 is its (only) control point.
+
+ uint32_t i = 0;
+ while (i < mData.Length()) {
+ segType = SVGPathSegUtils::DecodeType(mData[i++]);
+ uint32_t argCount = SVGPathSegUtils::ArgCountForType(segType);
+
+ switch (segType) {
+ case PATHSEG_CLOSEPATH:
+ // set this early to allow drawing of square caps for "M{x},{y} Z":
+ subpathContainsNonMoveTo = true;
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+ segEnd = pathStart;
+ aBuilder->Close();
+ break;
+
+ case PATHSEG_MOVETO_ABS:
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+ pathStart = segEnd = Point(mData[i], mData[i + 1]);
+ aBuilder->MoveTo(segEnd);
+ subpathHasLength = false;
+ break;
+
+ case PATHSEG_MOVETO_REL:
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+ pathStart = segEnd = segStart + Point(mData[i], mData[i + 1]);
+ aBuilder->MoveTo(segEnd);
+ subpathHasLength = false;
+ break;
+
+ case PATHSEG_LINETO_ABS:
+ segEnd = Point(mData[i], mData[i + 1]);
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(segEnd);
+ }
+ break;
+
+ case PATHSEG_LINETO_REL:
+ segEnd = segStart + Point(mData[i], mData[i + 1]);
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_CUBIC_ABS:
+ cp1 = Point(mData[i], mData[i + 1]);
+ cp2 = Point(mData[i + 2], mData[i + 3]);
+ segEnd = Point(mData[i + 4], mData[i + 5]);
+ if (segEnd != segStart || segEnd != cp1 || segEnd != cp2) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(cp1, cp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_CUBIC_REL:
+ cp1 = segStart + Point(mData[i], mData[i + 1]);
+ cp2 = segStart + Point(mData[i + 2], mData[i + 3]);
+ segEnd = segStart + Point(mData[i + 4], mData[i + 5]);
+ if (segEnd != segStart || segEnd != cp1 || segEnd != cp2) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(cp1, cp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_QUADRATIC_ABS:
+ cp1 = Point(mData[i], mData[i + 1]);
+ // Convert quadratic curve to cubic curve:
+ tcp1 = segStart + (cp1 - segStart) * 2 / 3;
+ segEnd = Point(mData[i + 2], mData[i + 3]); // set before setting tcp2!
+ tcp2 = cp1 + (segEnd - cp1) / 3;
+ if (segEnd != segStart || segEnd != cp1) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(tcp1, tcp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_QUADRATIC_REL:
+ cp1 = segStart + Point(mData[i], mData[i + 1]);
+ // Convert quadratic curve to cubic curve:
+ tcp1 = segStart + (cp1 - segStart) * 2 / 3;
+ segEnd = segStart +
+ Point(mData[i + 2], mData[i + 3]); // set before setting tcp2!
+ tcp2 = cp1 + (segEnd - cp1) / 3;
+ if (segEnd != segStart || segEnd != cp1) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(tcp1, tcp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_ARC_ABS:
+ case PATHSEG_ARC_REL: {
+ Point radii(mData[i], mData[i + 1]);
+ segEnd = Point(mData[i + 5], mData[i + 6]);
+ if (segType == PATHSEG_ARC_REL) {
+ segEnd += segStart;
+ }
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ if (radii.x == 0.0f || radii.y == 0.0f) {
+ aBuilder->LineTo(segEnd);
+ } else {
+ SVGArcConverter converter(segStart, segEnd, radii, mData[i + 2],
+ mData[i + 3] != 0, mData[i + 4] != 0);
+ while (converter.GetNextSegment(&cp1, &cp2, &segEnd)) {
+ aBuilder->BezierTo(cp1, cp2, segEnd);
+ }
+ }
+ }
+ break;
+ }
+
+ case PATHSEG_LINETO_HORIZONTAL_ABS:
+ segEnd = Point(mData[i], segStart.y);
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(segEnd);
+ }
+ break;
+
+ case PATHSEG_LINETO_HORIZONTAL_REL:
+ segEnd = segStart + Point(mData[i], 0.0f);
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(segEnd);
+ }
+ break;
+
+ case PATHSEG_LINETO_VERTICAL_ABS:
+ segEnd = Point(segStart.x, mData[i]);
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(segEnd);
+ }
+ break;
+
+ case PATHSEG_LINETO_VERTICAL_REL:
+ segEnd = segStart + Point(0.0f, mData[i]);
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_CUBIC_SMOOTH_ABS:
+ cp1 = SVGPathSegUtils::IsCubicType(prevSegType) ? segStart * 2 - cp2
+ : segStart;
+ cp2 = Point(mData[i], mData[i + 1]);
+ segEnd = Point(mData[i + 2], mData[i + 3]);
+ if (segEnd != segStart || segEnd != cp1 || segEnd != cp2) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(cp1, cp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_CUBIC_SMOOTH_REL:
+ cp1 = SVGPathSegUtils::IsCubicType(prevSegType) ? segStart * 2 - cp2
+ : segStart;
+ cp2 = segStart + Point(mData[i], mData[i + 1]);
+ segEnd = segStart + Point(mData[i + 2], mData[i + 3]);
+ if (segEnd != segStart || segEnd != cp1 || segEnd != cp2) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(cp1, cp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS:
+ cp1 = SVGPathSegUtils::IsQuadraticType(prevSegType) ? segStart * 2 - cp1
+ : segStart;
+ // Convert quadratic curve to cubic curve:
+ tcp1 = segStart + (cp1 - segStart) * 2 / 3;
+ segEnd = Point(mData[i], mData[i + 1]); // set before setting tcp2!
+ tcp2 = cp1 + (segEnd - cp1) / 3;
+ if (segEnd != segStart || segEnd != cp1) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(tcp1, tcp2, segEnd);
+ }
+ break;
+
+ case PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL:
+ cp1 = SVGPathSegUtils::IsQuadraticType(prevSegType) ? segStart * 2 - cp1
+ : segStart;
+ // Convert quadratic curve to cubic curve:
+ tcp1 = segStart + (cp1 - segStart) * 2 / 3;
+ segEnd = segStart +
+ Point(mData[i], mData[i + 1]); // changed before setting tcp2!
+ tcp2 = cp1 + (segEnd - cp1) / 3;
+ if (segEnd != segStart || segEnd != cp1) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(tcp1, tcp2, segEnd);
+ }
+ break;
+
+ default:
+ MOZ_ASSERT_UNREACHABLE("Bad path segment type");
+ return nullptr; // according to spec we'd use everything up to the bad
+ // seg anyway
+ }
+
+ subpathContainsNonMoveTo = !IsMoveto(segType);
+ i += argCount;
+ prevSegType = segType;
+ segStart = segEnd;
+ }
+
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt");
+ MOZ_ASSERT(prevSegType == segType,
+ "prevSegType should be left at the final segType");
+
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+
+ return aBuilder->Finish();
+}
+
+already_AddRefed<Path> SVGPathData::BuildPathForMeasuring() const {
+ // Since the path that we return will not be used for painting it doesn't
+ // matter what we pass to CreatePathBuilder as aFillRule. Hawever, we do want
+ // to pass something other than NS_STYLE_STROKE_LINECAP_SQUARE as
+ // aStrokeLineCap to avoid the insertion of extra little lines (by
+ // ApproximateZeroLengthSubpathSquareCaps), in which case the value that we
+ // pass as aStrokeWidth doesn't matter (since it's only used to determine the
+ // length of those extra little lines).
+
+ RefPtr<DrawTarget> drawTarget =
+ gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
+ RefPtr<PathBuilder> builder =
+ drawTarget->CreatePathBuilder(FillRule::FILL_WINDING);
+ return BuildPath(builder, StyleStrokeLinecap::Butt, 0);
+}
+
+// We could simplify this function because this is only used by CSS motion path
+// and clip-path, which don't render the SVG Path. i.e. The returned path is
+// used as a reference.
+/* static */
+already_AddRefed<Path> SVGPathData::BuildPath(
+ Span<const StylePathCommand> aPath, PathBuilder* aBuilder,
+ StyleStrokeLinecap aStrokeLineCap, Float aStrokeWidth, float aZoomFactor) {
+ if (aPath.IsEmpty() || !aPath[0].IsMoveTo()) {
+ return nullptr; // paths without an initial moveto are invalid
+ }
+
+ auto toGfxPoint = [](const StyleCoordPair& aPair) {
+ return Point(aPair._0, aPair._1);
+ };
+
+ auto isCubicType = [](StylePathCommand::Tag aType) {
+ return aType == StylePathCommand::Tag::CurveTo ||
+ aType == StylePathCommand::Tag::SmoothCurveTo;
+ };
+
+ auto isQuadraticType = [](StylePathCommand::Tag aType) {
+ return aType == StylePathCommand::Tag::QuadBezierCurveTo ||
+ aType == StylePathCommand::Tag::SmoothQuadBezierCurveTo;
+ };
+
+ bool hasLineCaps = aStrokeLineCap != StyleStrokeLinecap::Butt;
+ bool subpathHasLength = false; // visual length
+ bool subpathContainsNonMoveTo = false;
+
+ StylePathCommand::Tag segType = StylePathCommand::Tag::Unknown;
+ StylePathCommand::Tag prevSegType = StylePathCommand::Tag::Unknown;
+ Point pathStart(0.0, 0.0); // start point of [sub]path
+ Point segStart(0.0, 0.0);
+ Point segEnd;
+ Point cp1, cp2; // previous bezier's control points
+ Point tcp1, tcp2; // temporaries
+
+ auto scale = [aZoomFactor](const Point& p) {
+ return Point(p.x * aZoomFactor, p.y * aZoomFactor);
+ };
+
+ // Regarding cp1 and cp2: If the previous segment was a cubic bezier curve,
+ // then cp2 is its second control point. If the previous segment was a
+ // quadratic curve, then cp1 is its (only) control point.
+
+ for (const StylePathCommand& cmd : aPath) {
+ segType = cmd.tag;
+ switch (segType) {
+ case StylePathCommand::Tag::ClosePath:
+ // set this early to allow drawing of square caps for "M{x},{y} Z":
+ subpathContainsNonMoveTo = true;
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+ segEnd = pathStart;
+ aBuilder->Close();
+ break;
+ case StylePathCommand::Tag::MoveTo: {
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+ const Point& p = toGfxPoint(cmd.move_to.point);
+ pathStart = segEnd =
+ cmd.move_to.absolute == StyleIsAbsolute::Yes ? p : segStart + p;
+ aBuilder->MoveTo(scale(segEnd));
+ subpathHasLength = false;
+ break;
+ }
+ case StylePathCommand::Tag::LineTo: {
+ const Point& p = toGfxPoint(cmd.line_to.point);
+ segEnd =
+ cmd.line_to.absolute == StyleIsAbsolute::Yes ? p : segStart + p;
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(scale(segEnd));
+ }
+ break;
+ }
+ case StylePathCommand::Tag::CurveTo:
+ cp1 = toGfxPoint(cmd.curve_to.control1);
+ cp2 = toGfxPoint(cmd.curve_to.control2);
+ segEnd = toGfxPoint(cmd.curve_to.point);
+
+ if (cmd.curve_to.absolute == StyleIsAbsolute::No) {
+ cp1 += segStart;
+ cp2 += segStart;
+ segEnd += segStart;
+ }
+
+ if (segEnd != segStart || segEnd != cp1 || segEnd != cp2) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(scale(cp1), scale(cp2), scale(segEnd));
+ }
+ break;
+
+ case StylePathCommand::Tag::QuadBezierCurveTo:
+ cp1 = toGfxPoint(cmd.quad_bezier_curve_to.control1);
+ segEnd = toGfxPoint(cmd.quad_bezier_curve_to.point);
+
+ if (cmd.quad_bezier_curve_to.absolute == StyleIsAbsolute::No) {
+ cp1 += segStart;
+ segEnd += segStart; // set before setting tcp2!
+ }
+
+ // Convert quadratic curve to cubic curve:
+ tcp1 = segStart + (cp1 - segStart) * 2 / 3;
+ tcp2 = cp1 + (segEnd - cp1) / 3;
+
+ if (segEnd != segStart || segEnd != cp1) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(scale(tcp1), scale(tcp2), scale(segEnd));
+ }
+ break;
+
+ case StylePathCommand::Tag::EllipticalArc: {
+ const auto& arc = cmd.elliptical_arc;
+ Point radii(arc.rx, arc.ry);
+ segEnd = toGfxPoint(arc.point);
+ if (arc.absolute == StyleIsAbsolute::No) {
+ segEnd += segStart;
+ }
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ if (radii.x == 0.0f || radii.y == 0.0f) {
+ aBuilder->LineTo(scale(segEnd));
+ } else {
+ SVGArcConverter converter(segStart, segEnd, radii, arc.angle,
+ arc.large_arc_flag._0, arc.sweep_flag._0);
+ while (converter.GetNextSegment(&cp1, &cp2, &segEnd)) {
+ aBuilder->BezierTo(scale(cp1), scale(cp2), scale(segEnd));
+ }
+ }
+ }
+ break;
+ }
+ case StylePathCommand::Tag::HorizontalLineTo:
+ if (cmd.horizontal_line_to.absolute == StyleIsAbsolute::Yes) {
+ segEnd = Point(cmd.horizontal_line_to.x, segStart.y);
+ } else {
+ segEnd = segStart + Point(cmd.horizontal_line_to.x, 0.0f);
+ }
+
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(scale(segEnd));
+ }
+ break;
+
+ case StylePathCommand::Tag::VerticalLineTo:
+ if (cmd.vertical_line_to.absolute == StyleIsAbsolute::Yes) {
+ segEnd = Point(segStart.x, cmd.vertical_line_to.y);
+ } else {
+ segEnd = segStart + Point(0.0f, cmd.vertical_line_to.y);
+ }
+
+ if (segEnd != segStart) {
+ subpathHasLength = true;
+ aBuilder->LineTo(scale(segEnd));
+ }
+ break;
+
+ case StylePathCommand::Tag::SmoothCurveTo:
+ cp1 = isCubicType(prevSegType) ? segStart * 2 - cp2 : segStart;
+ cp2 = toGfxPoint(cmd.smooth_curve_to.control2);
+ segEnd = toGfxPoint(cmd.smooth_curve_to.point);
+
+ if (cmd.smooth_curve_to.absolute == StyleIsAbsolute::No) {
+ cp2 += segStart;
+ segEnd += segStart;
+ }
+
+ if (segEnd != segStart || segEnd != cp1 || segEnd != cp2) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(scale(cp1), scale(cp2), scale(segEnd));
+ }
+ break;
+
+ case StylePathCommand::Tag::SmoothQuadBezierCurveTo: {
+ cp1 = isQuadraticType(prevSegType) ? segStart * 2 - cp1 : segStart;
+ // Convert quadratic curve to cubic curve:
+ tcp1 = segStart + (cp1 - segStart) * 2 / 3;
+
+ const Point& p = toGfxPoint(cmd.smooth_quad_bezier_curve_to.point);
+ // set before setting tcp2!
+ segEnd =
+ cmd.smooth_quad_bezier_curve_to.absolute == StyleIsAbsolute::Yes
+ ? p
+ : segStart + p;
+ tcp2 = cp1 + (segEnd - cp1) / 3;
+
+ if (segEnd != segStart || segEnd != cp1) {
+ subpathHasLength = true;
+ aBuilder->BezierTo(scale(tcp1), scale(tcp2), scale(segEnd));
+ }
+ break;
+ }
+ case StylePathCommand::Tag::Unknown:
+ MOZ_ASSERT_UNREACHABLE("Unacceptable path segment type");
+ return nullptr;
+ }
+
+ subpathContainsNonMoveTo = !IsMoveto(segType);
+ prevSegType = segType;
+ segStart = segEnd;
+ }
+
+ MOZ_ASSERT(prevSegType == segType,
+ "prevSegType should be left at the final segType");
+
+ MAYBE_APPROXIMATE_ZERO_LENGTH_SUBPATH_SQUARE_CAPS_TO_DT;
+
+ return aBuilder->Finish();
+}
+
+static double AngleOfVector(const Point& aVector) {
+ // C99 says about atan2 "A domain error may occur if both arguments are
+ // zero" and "On a domain error, the function returns an implementation-
+ // defined value". In the case of atan2 the implementation-defined value
+ // seems to commonly be zero, but it could just as easily be a NaN value.
+ // We specifically want zero in this case, hence the check:
+
+ return (aVector != Point(0.0, 0.0)) ? atan2(aVector.y, aVector.x) : 0.0;
+}
+
+static float AngleOfVector(const Point& cp1, const Point& cp2) {
+ return static_cast<float>(AngleOfVector(cp1 - cp2));
+}
+
+void SVGPathData::GetMarkerPositioningData(nsTArray<SVGMark>* aMarks) const {
+ // This code should assume that ANY type of segment can appear at ANY index.
+ // It should also assume that segments such as M and Z can appear in weird
+ // places, and repeat multiple times consecutively.
+
+ // info on current [sub]path (reset every M command):
+ Point pathStart(0.0, 0.0);
+ float pathStartAngle = 0.0f;
+ uint32_t pathStartIndex = 0;
+
+ // info on previous segment:
+ uint16_t prevSegType = PATHSEG_UNKNOWN;
+ Point prevSegEnd(0.0, 0.0);
+ float prevSegEndAngle = 0.0f;
+ Point prevCP; // if prev seg was a bezier, this was its last control point
+
+ uint32_t i = 0;
+ while (i < mData.Length()) {
+ // info on current segment:
+ uint16_t segType =
+ SVGPathSegUtils::DecodeType(mData[i++]); // advances i to args
+ Point& segStart = prevSegEnd;
+ Point segEnd;
+ float segStartAngle, segEndAngle;
+
+ switch (segType) // to find segStartAngle, segEnd and segEndAngle
+ {
+ case PATHSEG_CLOSEPATH:
+ segEnd = pathStart;
+ segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
+ break;
+
+ case PATHSEG_MOVETO_ABS:
+ case PATHSEG_MOVETO_REL:
+ if (segType == PATHSEG_MOVETO_ABS) {
+ segEnd = Point(mData[i], mData[i + 1]);
+ } else {
+ segEnd = segStart + Point(mData[i], mData[i + 1]);
+ }
+ pathStart = segEnd;
+ pathStartIndex = aMarks->Length();
+ // If authors are going to specify multiple consecutive moveto commands
+ // with markers, me might as well make the angle do something useful:
+ segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
+ i += 2;
+ break;
+
+ case PATHSEG_LINETO_ABS:
+ case PATHSEG_LINETO_REL:
+ if (segType == PATHSEG_LINETO_ABS) {
+ segEnd = Point(mData[i], mData[i + 1]);
+ } else {
+ segEnd = segStart + Point(mData[i], mData[i + 1]);
+ }
+ segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
+ i += 2;
+ break;
+
+ case PATHSEG_CURVETO_CUBIC_ABS:
+ case PATHSEG_CURVETO_CUBIC_REL: {
+ Point cp1, cp2; // control points
+ if (segType == PATHSEG_CURVETO_CUBIC_ABS) {
+ cp1 = Point(mData[i], mData[i + 1]);
+ cp2 = Point(mData[i + 2], mData[i + 3]);
+ segEnd = Point(mData[i + 4], mData[i + 5]);
+ } else {
+ cp1 = segStart + Point(mData[i], mData[i + 1]);
+ cp2 = segStart + Point(mData[i + 2], mData[i + 3]);
+ segEnd = segStart + Point(mData[i + 4], mData[i + 5]);
+ }
+ prevCP = cp2;
+ segStartAngle = AngleOfVector(
+ cp1 == segStart ? (cp1 == cp2 ? segEnd : cp2) : cp1, segStart);
+ segEndAngle = AngleOfVector(
+ segEnd, cp2 == segEnd ? (cp1 == cp2 ? segStart : cp1) : cp2);
+ i += 6;
+ break;
+ }
+
+ case PATHSEG_CURVETO_QUADRATIC_ABS:
+ case PATHSEG_CURVETO_QUADRATIC_REL: {
+ Point cp1; // control point
+ if (segType == PATHSEG_CURVETO_QUADRATIC_ABS) {
+ cp1 = Point(mData[i], mData[i + 1]);
+ segEnd = Point(mData[i + 2], mData[i + 3]);
+ } else {
+ cp1 = segStart + Point(mData[i], mData[i + 1]);
+ segEnd = segStart + Point(mData[i + 2], mData[i + 3]);
+ }
+ prevCP = cp1;
+ segStartAngle = AngleOfVector(cp1 == segStart ? segEnd : cp1, segStart);
+ segEndAngle = AngleOfVector(segEnd, cp1 == segEnd ? segStart : cp1);
+ i += 4;
+ break;
+ }
+
+ case PATHSEG_ARC_ABS:
+ case PATHSEG_ARC_REL: {
+ double rx = mData[i];
+ double ry = mData[i + 1];
+ double angle = mData[i + 2];
+ bool largeArcFlag = mData[i + 3] != 0.0f;
+ bool sweepFlag = mData[i + 4] != 0.0f;
+ if (segType == PATHSEG_ARC_ABS) {
+ segEnd = Point(mData[i + 5], mData[i + 6]);
+ } else {
+ segEnd = segStart + Point(mData[i + 5], mData[i + 6]);
+ }
+
+ // See section F.6 of SVG 1.1 for details on what we're doing here:
+ // http://www.w3.org/TR/SVG11/implnote.html#ArcImplementationNotes
+
+ if (segStart == segEnd) {
+ // F.6.2 says "If the endpoints (x1, y1) and (x2, y2) are identical,
+ // then this is equivalent to omitting the elliptical arc segment
+ // entirely." We take that very literally here, not adding a mark, and
+ // not even setting any of the 'prev' variables so that it's as if
+ // this arc had never existed; note the difference this will make e.g.
+ // if the arc is proceeded by a bezier curve and followed by a
+ // "smooth" bezier curve of the same degree!
+ i += 7;
+ continue;
+ }
+
+ // Below we have funny interleaving of F.6.6 (Correction of out-of-range
+ // radii) and F.6.5 (Conversion from endpoint to center
+ // parameterization) which is designed to avoid some unnecessary
+ // calculations.
+
+ if (rx == 0.0 || ry == 0.0) {
+ // F.6.6 step 1 - straight line or coincidental points
+ segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
+ i += 7;
+ break;
+ }
+ rx = fabs(rx); // F.6.6.1
+ ry = fabs(ry);
+
+ // F.6.5.1:
+ angle = angle * M_PI / 180.0;
+ double x1p = cos(angle) * (segStart.x - segEnd.x) / 2.0 +
+ sin(angle) * (segStart.y - segEnd.y) / 2.0;
+ double y1p = -sin(angle) * (segStart.x - segEnd.x) / 2.0 +
+ cos(angle) * (segStart.y - segEnd.y) / 2.0;
+
+ // This is the root in F.6.5.2 and the numerator under that root:
+ double root;
+ double numerator =
+ rx * rx * ry * ry - rx * rx * y1p * y1p - ry * ry * x1p * x1p;
+
+ if (numerator >= 0.0) {
+ root = sqrt(numerator / (rx * rx * y1p * y1p + ry * ry * x1p * x1p));
+ if (largeArcFlag == sweepFlag) root = -root;
+ } else {
+ // F.6.6 step 3 - |numerator < 0.0|. This is equivalent to the result
+ // of F.6.6.2 (lamedh) being greater than one. What we have here is
+ // ellipse radii that are too small for the ellipse to reach between
+ // segStart and segEnd. We scale the radii up uniformly so that the
+ // ellipse is just big enough to fit (i.e. to the point where there is
+ // exactly one solution).
+
+ double lamedh =
+ 1.0 - numerator / (rx * rx * ry * ry); // equiv to eqn F.6.6.2
+ double s = sqrt(lamedh);
+ rx *= s; // F.6.6.3
+ ry *= s;
+ root = 0.0;
+ }
+
+ double cxp = root * rx * y1p / ry; // F.6.5.2
+ double cyp = -root * ry * x1p / rx;
+
+ double theta, delta;
+ theta = AngleOfVector(
+ Point((x1p - cxp) / rx, (y1p - cyp) / ry)); // F.6.5.5
+ delta = AngleOfVector(
+ Point((-x1p - cxp) / rx, (-y1p - cyp) / ry)) - // F.6.5.6
+ theta;
+ if (!sweepFlag && delta > 0)
+ delta -= 2.0 * M_PI;
+ else if (sweepFlag && delta < 0)
+ delta += 2.0 * M_PI;
+
+ double tx1, ty1, tx2, ty2;
+ tx1 = -cos(angle) * rx * sin(theta) - sin(angle) * ry * cos(theta);
+ ty1 = -sin(angle) * rx * sin(theta) + cos(angle) * ry * cos(theta);
+ tx2 = -cos(angle) * rx * sin(theta + delta) -
+ sin(angle) * ry * cos(theta + delta);
+ ty2 = -sin(angle) * rx * sin(theta + delta) +
+ cos(angle) * ry * cos(theta + delta);
+
+ if (delta < 0.0f) {
+ tx1 = -tx1;
+ ty1 = -ty1;
+ tx2 = -tx2;
+ ty2 = -ty2;
+ }
+
+ segStartAngle = static_cast<float>(atan2(ty1, tx1));
+ segEndAngle = static_cast<float>(atan2(ty2, tx2));
+ i += 7;
+ break;
+ }
+
+ case PATHSEG_LINETO_HORIZONTAL_ABS:
+ case PATHSEG_LINETO_HORIZONTAL_REL:
+ if (segType == PATHSEG_LINETO_HORIZONTAL_ABS) {
+ segEnd = Point(mData[i++], segStart.y);
+ } else {
+ segEnd = segStart + Point(mData[i++], 0.0f);
+ }
+ segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
+ break;
+
+ case PATHSEG_LINETO_VERTICAL_ABS:
+ case PATHSEG_LINETO_VERTICAL_REL:
+ if (segType == PATHSEG_LINETO_VERTICAL_ABS) {
+ segEnd = Point(segStart.x, mData[i++]);
+ } else {
+ segEnd = segStart + Point(0.0f, mData[i++]);
+ }
+ segStartAngle = segEndAngle = AngleOfVector(segEnd, segStart);
+ break;
+
+ case PATHSEG_CURVETO_CUBIC_SMOOTH_ABS:
+ case PATHSEG_CURVETO_CUBIC_SMOOTH_REL: {
+ Point cp1 = SVGPathSegUtils::IsCubicType(prevSegType)
+ ? segStart * 2 - prevCP
+ : segStart;
+ Point cp2;
+ if (segType == PATHSEG_CURVETO_CUBIC_SMOOTH_ABS) {
+ cp2 = Point(mData[i], mData[i + 1]);
+ segEnd = Point(mData[i + 2], mData[i + 3]);
+ } else {
+ cp2 = segStart + Point(mData[i], mData[i + 1]);
+ segEnd = segStart + Point(mData[i + 2], mData[i + 3]);
+ }
+ prevCP = cp2;
+ segStartAngle = AngleOfVector(
+ cp1 == segStart ? (cp1 == cp2 ? segEnd : cp2) : cp1, segStart);
+ segEndAngle = AngleOfVector(
+ segEnd, cp2 == segEnd ? (cp1 == cp2 ? segStart : cp1) : cp2);
+ i += 4;
+ break;
+ }
+
+ case PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS:
+ case PATHSEG_CURVETO_QUADRATIC_SMOOTH_REL: {
+ Point cp1 = SVGPathSegUtils::IsQuadraticType(prevSegType)
+ ? segStart * 2 - prevCP
+ : segStart;
+ if (segType == PATHSEG_CURVETO_QUADRATIC_SMOOTH_ABS) {
+ segEnd = Point(mData[i], mData[i + 1]);
+ } else {
+ segEnd = segStart + Point(mData[i], mData[i + 1]);
+ }
+ prevCP = cp1;
+ segStartAngle = AngleOfVector(cp1 == segStart ? segEnd : cp1, segStart);
+ segEndAngle = AngleOfVector(segEnd, cp1 == segEnd ? segStart : cp1);
+ i += 2;
+ break;
+ }
+
+ default:
+ // Leave any existing marks in aMarks so we have a visual indication of
+ // when things went wrong.
+ MOZ_ASSERT(false, "Unknown segment type - path corruption?");
+ return;
+ }
+
+ // Set the angle of the mark at the start of this segment:
+ if (aMarks->Length()) {
+ SVGMark& mark = aMarks->LastElement();
+ if (!IsMoveto(segType) && IsMoveto(prevSegType)) {
+ // start of new subpath
+ pathStartAngle = mark.angle = segStartAngle;
+ } else if (IsMoveto(segType) && !IsMoveto(prevSegType)) {
+ // end of a subpath
+ if (prevSegType != PATHSEG_CLOSEPATH) mark.angle = prevSegEndAngle;
+ } else {
+ if (!(segType == PATHSEG_CLOSEPATH && prevSegType == PATHSEG_CLOSEPATH))
+ mark.angle =
+ SVGContentUtils::AngleBisect(prevSegEndAngle, segStartAngle);
+ }
+ }
+
+ // Add the mark at the end of this segment, and set its position:
+ // XXX(Bug 1631371) Check if this should use a fallible operation as it
+ // pretended earlier.
+ aMarks->AppendElement(SVGMark(static_cast<float>(segEnd.x),
+ static_cast<float>(segEnd.y), 0.0f,
+ SVGMark::eMid));
+
+ if (segType == PATHSEG_CLOSEPATH && prevSegType != PATHSEG_CLOSEPATH) {
+ aMarks->LastElement().angle = aMarks->ElementAt(pathStartIndex).angle =
+ SVGContentUtils::AngleBisect(segEndAngle, pathStartAngle);
+ }
+
+ prevSegType = segType;
+ prevSegEnd = segEnd;
+ prevSegEndAngle = segEndAngle;
+ }
+
+ MOZ_ASSERT(i == mData.Length(), "Very, very bad - mData corrupt");
+
+ if (aMarks->Length()) {
+ if (prevSegType != PATHSEG_CLOSEPATH) {
+ aMarks->LastElement().angle = prevSegEndAngle;
+ }
+ aMarks->LastElement().type = SVGMark::eEnd;
+ aMarks->ElementAt(0).type = SVGMark::eStart;
+ }
+}
+
+size_t SVGPathData::SizeOfExcludingThis(MallocSizeOf aMallocSizeOf) const {
+ return mData.ShallowSizeOfExcludingThis(aMallocSizeOf);
+}
+
+size_t SVGPathData::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
+ return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
+}
+
+} // namespace mozilla
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 03:28:45 +0000