From a22ea1882391cc5c84136060636d5c952c1f34b3 Mon Sep 17 00:00:00 2001 From: egdaniel Date: Wed, 11 Jun 2014 06:51:51 -0700 Subject: [PATCH] Move Dashing filterPath to a dashing utils file From inside GrContext, we have a need to create an SkPath an original path and some dashing info. We do not have access to the original path effect so we need a way to make the FilterPath function accessible outside of the effect. So I moved the core filterPath code (and all need helper functions) out of SkDashPathEffect and created a SkDashPath in utils to store these helper functions. BUG=skia: Committed: https://skia.googlesource.com/skia/+/576dcdc793a762ec63fbecdbfd5768066b548fe5 Author: egdaniel@google.com Review URL: https://codereview.chromium.org/314623004 --- gyp/utils.gypi | 2 + include/effects/SkDashPathEffect.h | 2 - src/effects/SkDashPathEffect.cpp | 311 +-------------------------- src/utils/SkDashPath.cpp | 328 +++++++++++++++++++++++++++++ src/utils/SkDashPathPriv.h | 32 +++ 5 files changed, 373 insertions(+), 302 deletions(-) create mode 100644 src/utils/SkDashPath.cpp create mode 100644 src/utils/SkDashPathPriv.h diff --git a/gyp/utils.gypi b/gyp/utils.gypi index 309744672b..761fbf7f4c 100644 --- a/gyp/utils.gypi +++ b/gyp/utils.gypi @@ -56,6 +56,8 @@ '<(skia_src_path)/utils/SkCanvasStateUtils.cpp', '<(skia_src_path)/utils/SkCubicInterval.cpp', '<(skia_src_path)/utils/SkCullPoints.cpp', + '<(skia_src_path)/utils/SkDashPath.cpp', + '<(skia_src_path)/utils/SkDashPathPriv.h', '<(skia_src_path)/utils/SkDeferredCanvas.cpp', '<(skia_src_path)/utils/SkDumpCanvas.cpp', '<(skia_src_path)/utils/SkEventTracer.cpp', diff --git a/include/effects/SkDashPathEffect.h b/include/effects/SkDashPathEffect.h index 10d8d2db4e..6fab962261 100644 --- a/include/effects/SkDashPathEffect.h +++ b/include/effects/SkDashPathEffect.h @@ -61,8 +61,6 @@ protected: virtual void flatten(SkWriteBuffer&) const SK_OVERRIDE; private: - void setInternalMembers(SkScalar phase); - SkScalar* fIntervals; int32_t fCount; SkScalar fPhase; diff --git a/src/effects/SkDashPathEffect.cpp b/src/effects/SkDashPathEffect.cpp index 4fd4185e06..2838b1ff3e 100644 --- a/src/effects/SkDashPathEffect.cpp +++ b/src/effects/SkDashPathEffect.cpp @@ -6,74 +6,10 @@ */ #include "SkDashPathEffect.h" + +#include "SkDashPathPriv.h" #include "SkReadBuffer.h" #include "SkWriteBuffer.h" -#include "SkPathMeasure.h" - -static inline int is_even(int x) { - return (~x) << 31; -} - -static SkScalar FindFirstInterval(const SkScalar intervals[], SkScalar phase, - int32_t* index, int count) { - for (int i = 0; i < count; ++i) { - if (phase > intervals[i]) { - phase -= intervals[i]; - } else { - *index = i; - return intervals[i] - phase; - } - } - // If we get here, phase "appears" to be larger than our length. This - // shouldn't happen with perfect precision, but we can accumulate errors - // during the initial length computation (rounding can make our sum be too - // big or too small. In that event, we just have to eat the error here. - *index = 0; - return intervals[0]; -} - -void SkDashPathEffect::setInternalMembers(SkScalar phase) { - SkScalar len = 0; - for (int i = 0; i < fCount; i++) { - len += fIntervals[i]; - } - fIntervalLength = len; - - // watch out for values that might make us go out of bounds - if ((len > 0) && SkScalarIsFinite(phase) && SkScalarIsFinite(len)) { - - // Adjust phase to be between 0 and len, "flipping" phase if negative. - // e.g., if len is 100, then phase of -20 (or -120) is equivalent to 80 - if (phase < 0) { - phase = -phase; - if (phase > len) { - phase = SkScalarMod(phase, len); - } - phase = len - phase; - - // Due to finite precision, it's possible that phase == len, - // even after the subtract (if len >>> phase), so fix that here. - // This fixes http://crbug.com/124652 . - SkASSERT(phase <= len); - if (phase == len) { - phase = 0; - } - } else if (phase >= len) { - phase = SkScalarMod(phase, len); - } - SkASSERT(phase >= 0 && phase < len); - - fPhase = phase; - - fInitialDashLength = FindFirstInterval(fIntervals, fPhase, - &fInitialDashIndex, fCount); - - SkASSERT(fInitialDashLength >= 0); - SkASSERT(fInitialDashIndex >= 0 && fInitialDashIndex < fCount); - } else { - fInitialDashLength = -1; // signal bad dash intervals - } -} SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count, SkScalar phase) { @@ -87,247 +23,19 @@ SkDashPathEffect::SkDashPathEffect(const SkScalar intervals[], int count, fIntervals[i] = intervals[i]; } - this->setInternalMembers(phase); + // set the internal data members + SkDashPath::CalcDashParameters(phase, fIntervals, fCount, &fInitialDashLength, + &fInitialDashIndex, &fIntervalLength, &fPhase); } SkDashPathEffect::~SkDashPathEffect() { sk_free(fIntervals); } -static void outset_for_stroke(SkRect* rect, const SkStrokeRec& rec) { - SkScalar radius = SkScalarHalf(rec.getWidth()); - if (0 == radius) { - radius = SK_Scalar1; // hairlines - } - if (SkPaint::kMiter_Join == rec.getJoin()) { - radius = SkScalarMul(radius, rec.getMiter()); - } - rect->outset(radius, radius); -} - -// Only handles lines for now. If returns true, dstPath is the new (smaller) -// path. If returns false, then dstPath parameter is ignored. -static bool cull_path(const SkPath& srcPath, const SkStrokeRec& rec, - const SkRect* cullRect, SkScalar intervalLength, - SkPath* dstPath) { - if (NULL == cullRect) { - return false; - } - - SkPoint pts[2]; - if (!srcPath.isLine(pts)) { - return false; - } - - SkRect bounds = *cullRect; - outset_for_stroke(&bounds, rec); - - SkScalar dx = pts[1].x() - pts[0].x(); - SkScalar dy = pts[1].y() - pts[0].y(); - - // just do horizontal lines for now (lazy) - if (dy) { - return false; - } - - SkScalar minX = pts[0].fX; - SkScalar maxX = pts[1].fX; - - if (maxX < bounds.fLeft || minX > bounds.fRight) { - return false; - } - - if (dx < 0) { - SkTSwap(minX, maxX); - } - - // Now we actually perform the chop, removing the excess to the left and - // right of the bounds (keeping our new line "in phase" with the dash, - // hence the (mod intervalLength). - - if (minX < bounds.fLeft) { - minX = bounds.fLeft - SkScalarMod(bounds.fLeft - minX, - intervalLength); - } - if (maxX > bounds.fRight) { - maxX = bounds.fRight + SkScalarMod(maxX - bounds.fRight, - intervalLength); - } - - SkASSERT(maxX >= minX); - if (dx < 0) { - SkTSwap(minX, maxX); - } - pts[0].fX = minX; - pts[1].fX = maxX; - - dstPath->moveTo(pts[0]); - dstPath->lineTo(pts[1]); - return true; -} - -class SpecialLineRec { -public: - bool init(const SkPath& src, SkPath* dst, SkStrokeRec* rec, - int intervalCount, SkScalar intervalLength) { - if (rec->isHairlineStyle() || !src.isLine(fPts)) { - return false; - } - - // can relax this in the future, if we handle square and round caps - if (SkPaint::kButt_Cap != rec->getCap()) { - return false; - } - - SkScalar pathLength = SkPoint::Distance(fPts[0], fPts[1]); - - fTangent = fPts[1] - fPts[0]; - if (fTangent.isZero()) { - return false; - } - - fPathLength = pathLength; - fTangent.scale(SkScalarInvert(pathLength)); - fTangent.rotateCCW(&fNormal); - fNormal.scale(SkScalarHalf(rec->getWidth())); - - // now estimate how many quads will be added to the path - // resulting segments = pathLen * intervalCount / intervalLen - // resulting points = 4 * segments - - SkScalar ptCount = SkScalarMulDiv(pathLength, - SkIntToScalar(intervalCount), - intervalLength); - int n = SkScalarCeilToInt(ptCount) << 2; - dst->incReserve(n); - - // we will take care of the stroking - rec->setFillStyle(); - return true; - } - - void addSegment(SkScalar d0, SkScalar d1, SkPath* path) const { - SkASSERT(d0 < fPathLength); - // clamp the segment to our length - if (d1 > fPathLength) { - d1 = fPathLength; - } - - SkScalar x0 = fPts[0].fX + SkScalarMul(fTangent.fX, d0); - SkScalar x1 = fPts[0].fX + SkScalarMul(fTangent.fX, d1); - SkScalar y0 = fPts[0].fY + SkScalarMul(fTangent.fY, d0); - SkScalar y1 = fPts[0].fY + SkScalarMul(fTangent.fY, d1); - - SkPoint pts[4]; - pts[0].set(x0 + fNormal.fX, y0 + fNormal.fY); // moveTo - pts[1].set(x1 + fNormal.fX, y1 + fNormal.fY); // lineTo - pts[2].set(x1 - fNormal.fX, y1 - fNormal.fY); // lineTo - pts[3].set(x0 - fNormal.fX, y0 - fNormal.fY); // lineTo - - path->addPoly(pts, SK_ARRAY_COUNT(pts), false); - } - -private: - SkPoint fPts[2]; - SkVector fTangent; - SkVector fNormal; - SkScalar fPathLength; -}; - bool SkDashPathEffect::filterPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec, const SkRect* cullRect) const { - // we do nothing if the src wants to be filled, or if our dashlength is 0 - if (rec->isFillStyle() || fInitialDashLength < 0) { - return false; - } - - const SkScalar* intervals = fIntervals; - SkScalar dashCount = 0; - int segCount = 0; - - SkPath cullPathStorage; - const SkPath* srcPtr = &src; - if (cull_path(src, *rec, cullRect, fIntervalLength, &cullPathStorage)) { - srcPtr = &cullPathStorage; - } - - SpecialLineRec lineRec; - bool specialLine = lineRec.init(*srcPtr, dst, rec, fCount >> 1, fIntervalLength); - - SkPathMeasure meas(*srcPtr, false); - - do { - bool skipFirstSegment = meas.isClosed(); - bool addedSegment = false; - SkScalar length = meas.getLength(); - int index = fInitialDashIndex; - - // Since the path length / dash length ratio may be arbitrarily large, we can exert - // significant memory pressure while attempting to build the filtered path. To avoid this, - // we simply give up dashing beyond a certain threshold. - // - // The original bug report (http://crbug.com/165432) is based on a path yielding more than - // 90 million dash segments and crashing the memory allocator. A limit of 1 million - // segments seems reasonable: at 2 verbs per segment * 9 bytes per verb, this caps the - // maximum dash memory overhead at roughly 17MB per path. - static const SkScalar kMaxDashCount = 1000000; - dashCount += length * (fCount >> 1) / fIntervalLength; - if (dashCount > kMaxDashCount) { - dst->reset(); - return false; - } - - // Using double precision to avoid looping indefinitely due to single precision rounding - // (for extreme path_length/dash_length ratios). See test_infinite_dash() unittest. - double distance = 0; - double dlen = fInitialDashLength; - - while (distance < length) { - SkASSERT(dlen >= 0); - addedSegment = false; - if (is_even(index) && dlen > 0 && !skipFirstSegment) { - addedSegment = true; - ++segCount; - - if (specialLine) { - lineRec.addSegment(SkDoubleToScalar(distance), - SkDoubleToScalar(distance + dlen), - dst); - } else { - meas.getSegment(SkDoubleToScalar(distance), - SkDoubleToScalar(distance + dlen), - dst, true); - } - } - distance += dlen; - - // clear this so we only respect it the first time around - skipFirstSegment = false; - - // wrap around our intervals array if necessary - index += 1; - SkASSERT(index <= fCount); - if (index == fCount) { - index = 0; - } - - // fetch our next dlen - dlen = intervals[index]; - } - - // extend if we ended on a segment and we need to join up with the (skipped) initial segment - if (meas.isClosed() && is_even(fInitialDashIndex) && - fInitialDashLength > 0) { - meas.getSegment(0, fInitialDashLength, dst, !addedSegment); - ++segCount; - } - } while (meas.nextContour()); - - if (segCount > 1) { - dst->setConvexity(SkPath::kConcave_Convexity); - } - - return true; + return SkDashPath::FilterDashPath(dst, src, rec, cullRect, fIntervals, fCount, + fInitialDashLength, fInitialDashIndex, fIntervalLength); } // Currently asPoints is more restrictive then it needs to be. In the future @@ -570,6 +278,9 @@ SkDashPathEffect::SkDashPathEffect(SkReadBuffer& buffer) : INHERITED(buffer) { fPhase += fIntervals[fInitialDashIndex] - fInitialDashLength; } } else { - this->setInternalMembers(fPhase); + // set the internal data members, fPhase should have been between 0 and intervalLength + // when written to buffer so no need to adjust it + SkDashPath::CalcDashParameters(fPhase, fIntervals, fCount, &fInitialDashLength, + &fInitialDashIndex, &fIntervalLength); } } diff --git a/src/utils/SkDashPath.cpp b/src/utils/SkDashPath.cpp new file mode 100644 index 0000000000..3c4aef343d --- /dev/null +++ b/src/utils/SkDashPath.cpp @@ -0,0 +1,328 @@ +/* + * Copyright 2014 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#include "SkDashPathPriv.h" +#include "SkPathMeasure.h" + +static inline int is_even(int x) { + return (~x) << 31; +} + +static SkScalar find_first_interval(const SkScalar intervals[], SkScalar phase, + int32_t* index, int count) { + for (int i = 0; i < count; ++i) { + if (phase > intervals[i]) { + phase -= intervals[i]; + } else { + *index = i; + return intervals[i] - phase; + } + } + // If we get here, phase "appears" to be larger than our length. This + // shouldn't happen with perfect precision, but we can accumulate errors + // during the initial length computation (rounding can make our sum be too + // big or too small. In that event, we just have to eat the error here. + *index = 0; + return intervals[0]; +} + +void SkDashPath::CalcDashParameters(SkScalar phase, const SkScalar intervals[], int32_t count, + SkScalar* initialDashLength, int32_t* initialDashIndex, + SkScalar* intervalLength, SkScalar* adjustedPhase) { + SkScalar len = 0; + for (int i = 0; i < count; i++) { + len += intervals[i]; + } + *intervalLength = len; + + // watch out for values that might make us go out of bounds + if ((len > 0) && SkScalarIsFinite(phase) && SkScalarIsFinite(len)) { + + // Adjust phase to be between 0 and len, "flipping" phase if negative. + // e.g., if len is 100, then phase of -20 (or -120) is equivalent to 80 + if (adjustedPhase) { + if (phase < 0) { + phase = -phase; + if (phase > len) { + phase = SkScalarMod(phase, len); + } + phase = len - phase; + + // Due to finite precision, it's possible that phase == len, + // even after the subtract (if len >>> phase), so fix that here. + // This fixes http://crbug.com/124652 . + SkASSERT(phase <= len); + if (phase == len) { + phase = 0; + } + } else if (phase >= len) { + phase = SkScalarMod(phase, len); + } + *adjustedPhase = phase; + } + SkASSERT(phase >= 0 && phase < len); + + *initialDashLength = find_first_interval(intervals, phase, + initialDashIndex, count); + + SkASSERT(*initialDashLength >= 0); + SkASSERT(*initialDashIndex >= 0 && *initialDashIndex < count); + } else { + *initialDashLength = -1; // signal bad dash intervals + } +} + +static void outset_for_stroke(SkRect* rect, const SkStrokeRec& rec) { + SkScalar radius = SkScalarHalf(rec.getWidth()); + if (0 == radius) { + radius = SK_Scalar1; // hairlines + } + if (SkPaint::kMiter_Join == rec.getJoin()) { + radius = SkScalarMul(radius, rec.getMiter()); + } + rect->outset(radius, radius); +} + +// Only handles lines for now. If returns true, dstPath is the new (smaller) +// path. If returns false, then dstPath parameter is ignored. +static bool cull_path(const SkPath& srcPath, const SkStrokeRec& rec, + const SkRect* cullRect, SkScalar intervalLength, + SkPath* dstPath) { + if (NULL == cullRect) { + return false; + } + + SkPoint pts[2]; + if (!srcPath.isLine(pts)) { + return false; + } + + SkRect bounds = *cullRect; + outset_for_stroke(&bounds, rec); + + SkScalar dx = pts[1].x() - pts[0].x(); + SkScalar dy = pts[1].y() - pts[0].y(); + + // just do horizontal lines for now (lazy) + if (dy) { + return false; + } + + SkScalar minX = pts[0].fX; + SkScalar maxX = pts[1].fX; + + if (maxX < bounds.fLeft || minX > bounds.fRight) { + return false; + } + + if (dx < 0) { + SkTSwap(minX, maxX); + } + + // Now we actually perform the chop, removing the excess to the left and + // right of the bounds (keeping our new line "in phase" with the dash, + // hence the (mod intervalLength). + + if (minX < bounds.fLeft) { + minX = bounds.fLeft - SkScalarMod(bounds.fLeft - minX, + intervalLength); + } + if (maxX > bounds.fRight) { + maxX = bounds.fRight + SkScalarMod(maxX - bounds.fRight, + intervalLength); + } + + SkASSERT(maxX >= minX); + if (dx < 0) { + SkTSwap(minX, maxX); + } + pts[0].fX = minX; + pts[1].fX = maxX; + + dstPath->moveTo(pts[0]); + dstPath->lineTo(pts[1]); + return true; +} + +class SpecialLineRec { +public: + bool init(const SkPath& src, SkPath* dst, SkStrokeRec* rec, + int intervalCount, SkScalar intervalLength) { + if (rec->isHairlineStyle() || !src.isLine(fPts)) { + return false; + } + + // can relax this in the future, if we handle square and round caps + if (SkPaint::kButt_Cap != rec->getCap()) { + return false; + } + + SkScalar pathLength = SkPoint::Distance(fPts[0], fPts[1]); + + fTangent = fPts[1] - fPts[0]; + if (fTangent.isZero()) { + return false; + } + + fPathLength = pathLength; + fTangent.scale(SkScalarInvert(pathLength)); + fTangent.rotateCCW(&fNormal); + fNormal.scale(SkScalarHalf(rec->getWidth())); + + // now estimate how many quads will be added to the path + // resulting segments = pathLen * intervalCount / intervalLen + // resulting points = 4 * segments + + SkScalar ptCount = SkScalarMulDiv(pathLength, + SkIntToScalar(intervalCount), + intervalLength); + int n = SkScalarCeilToInt(ptCount) << 2; + dst->incReserve(n); + + // we will take care of the stroking + rec->setFillStyle(); + return true; + } + + void addSegment(SkScalar d0, SkScalar d1, SkPath* path) const { + SkASSERT(d0 < fPathLength); + // clamp the segment to our length + if (d1 > fPathLength) { + d1 = fPathLength; + } + + SkScalar x0 = fPts[0].fX + SkScalarMul(fTangent.fX, d0); + SkScalar x1 = fPts[0].fX + SkScalarMul(fTangent.fX, d1); + SkScalar y0 = fPts[0].fY + SkScalarMul(fTangent.fY, d0); + SkScalar y1 = fPts[0].fY + SkScalarMul(fTangent.fY, d1); + + SkPoint pts[4]; + pts[0].set(x0 + fNormal.fX, y0 + fNormal.fY); // moveTo + pts[1].set(x1 + fNormal.fX, y1 + fNormal.fY); // lineTo + pts[2].set(x1 - fNormal.fX, y1 - fNormal.fY); // lineTo + pts[3].set(x0 - fNormal.fX, y0 - fNormal.fY); // lineTo + + path->addPoly(pts, SK_ARRAY_COUNT(pts), false); + } + +private: + SkPoint fPts[2]; + SkVector fTangent; + SkVector fNormal; + SkScalar fPathLength; +}; + + +bool SkDashPath::FilterDashPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec, + const SkRect* cullRect, const SkScalar aIntervals[], + int32_t count, SkScalar initialDashLength, int32_t initialDashIndex, + SkScalar intervalLength) { + + // we do nothing if the src wants to be filled, or if our dashlength is 0 + if (rec->isFillStyle() || initialDashLength < 0) { + return false; + } + + const SkScalar* intervals = aIntervals; + SkScalar dashCount = 0; + int segCount = 0; + + SkPath cullPathStorage; + const SkPath* srcPtr = &src; + if (cull_path(src, *rec, cullRect, intervalLength, &cullPathStorage)) { + srcPtr = &cullPathStorage; + } + + SpecialLineRec lineRec; + bool specialLine = lineRec.init(*srcPtr, dst, rec, count >> 1, intervalLength); + + SkPathMeasure meas(*srcPtr, false); + + do { + bool skipFirstSegment = meas.isClosed(); + bool addedSegment = false; + SkScalar length = meas.getLength(); + int index = initialDashIndex; + + // Since the path length / dash length ratio may be arbitrarily large, we can exert + // significant memory pressure while attempting to build the filtered path. To avoid this, + // we simply give up dashing beyond a certain threshold. + // + // The original bug report (http://crbug.com/165432) is based on a path yielding more than + // 90 million dash segments and crashing the memory allocator. A limit of 1 million + // segments seems reasonable: at 2 verbs per segment * 9 bytes per verb, this caps the + // maximum dash memory overhead at roughly 17MB per path. + static const SkScalar kMaxDashCount = 1000000; + dashCount += length * (count >> 1) / intervalLength; + if (dashCount > kMaxDashCount) { + dst->reset(); + return false; + } + + // Using double precision to avoid looping indefinitely due to single precision rounding + // (for extreme path_length/dash_length ratios). See test_infinite_dash() unittest. + double distance = 0; + double dlen = initialDashLength; + + while (distance < length) { + SkASSERT(dlen >= 0); + addedSegment = false; + if (is_even(index) && dlen > 0 && !skipFirstSegment) { + addedSegment = true; + ++segCount; + + if (specialLine) { + lineRec.addSegment(SkDoubleToScalar(distance), + SkDoubleToScalar(distance + dlen), + dst); + } else { + meas.getSegment(SkDoubleToScalar(distance), + SkDoubleToScalar(distance + dlen), + dst, true); + } + } + distance += dlen; + + // clear this so we only respect it the first time around + skipFirstSegment = false; + + // wrap around our intervals array if necessary + index += 1; + SkASSERT(index <= count); + if (index == count) { + index = 0; + } + + // fetch our next dlen + dlen = intervals[index]; + } + + // extend if we ended on a segment and we need to join up with the (skipped) initial segment + if (meas.isClosed() && is_even(initialDashIndex) && + initialDashLength > 0) { + meas.getSegment(0, initialDashLength, dst, !addedSegment); + ++segCount; + } + } while (meas.nextContour()); + + if (segCount > 1) { + dst->setConvexity(SkPath::kConcave_Convexity); + } + + return true; +} + +bool SkDashPath::FilterDashPath(SkPath* dst, const SkPath& src, SkStrokeRec* rec, + const SkRect* cullRect, const SkPathEffect::DashInfo& info) { + SkScalar initialDashLength = 0; + int32_t initialDashIndex = 0; + SkScalar intervalLength = 0; + CalcDashParameters(info.fPhase, info.fIntervals, info.fCount, + &initialDashLength, &initialDashIndex, &intervalLength); + return FilterDashPath(dst, src, rec, cullRect, info.fIntervals, info.fCount, initialDashLength, + initialDashIndex, intervalLength); +} diff --git a/src/utils/SkDashPathPriv.h b/src/utils/SkDashPathPriv.h new file mode 100644 index 0000000000..94222a271a --- /dev/null +++ b/src/utils/SkDashPathPriv.h @@ -0,0 +1,32 @@ +/* + * Copyright 2014 Google Inc. + * + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ + +#ifndef SkDashPathPriv_DEFINED +#define SkDashPathPriv_DEFINED + +#include "SkPathEffect.h" + +namespace SkDashPath { + /* + * Calculates the initialDashLength, initialDashIndex, and intervalLength based on the + * inputed phase and intervals. If adjustedPhase is passed in, then the phase will be + * adjusted to be between 0 and intervalLength. The result will be stored in adjustedPhase. + * If adjustedPhase is NULL then it is assumed phase is already between 0 and intervalLength + */ + void CalcDashParameters(SkScalar phase, const SkScalar intervals[], int32_t count, + SkScalar* initialDashLength, int32_t* initialDashIndex, + SkScalar* intervalLength, SkScalar* adjustedPhase = NULL); + + bool FilterDashPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect*, + const SkScalar aIntervals[], int32_t count, SkScalar initialDashLength, + int32_t initialDashIndex, SkScalar intervalLength); + + bool FilterDashPath(SkPath* dst, const SkPath& src, SkStrokeRec*, const SkRect*, + const SkPathEffect::DashInfo& info); +} + +#endif