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Fixing the behavior of SkPathMeasure to reflect changes in SkPath::Iter.

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This implementation modifies SkPath::Iter extensively to avoid copying
the points when used to measure path length.

BUG=446
TEST=tests/PathMeasureTest.cpp
Review URL: https://codereview.appspot.com/5533074

git-svn-id: http://skia.googlecode.com/svn/trunk@3062 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
schenney@chromium.org 2012-01-18 18:02:10 +00:00
parent 8351aabbfe
commit a6d04d90e2
3 changed files with 40 additions and 63 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/core/SkPath.h
View File

@ -753,7 +753,6 @@ private:
void computeBounds() const;
friend class Iter;
void cons_moveto();
friend class SkPathStroker;
/* Append the first contour of path, ignoring path's initial point. If no
@ -776,7 +775,6 @@ private:
//
inline void injectMoveToIfNeeded();
friend const SkPoint* sk_get_path_points(const SkPath&, int index);
friend class SkAutoPathBoundsUpdate;
};

99
src/core/SkPathMeasure.cpp
View File

@ -15,7 +15,6 @@
// these must be 0,1,2 since they are in our 2-bit field
enum {
kLine_SegType,
kCloseLine_SegType,
kQuad_SegType,
kCubic_SegType
};
@ -154,40 +153,43 @@ void SkPathMeasure::buildSegments() {
Segment* seg;
fSegments.reset();
for (;;) {
bool done = false;
do {
switch (fIter.next(pts)) {
case SkPath::kMove_Verb:
ptIndex += 1;
fPts.append(1, pts);
if (!firstMoveTo) {
goto DONE;
done = true;
break;
}
ptIndex += 1;
firstMoveTo = false;
break;
firstMoveTo = false;
break;
case SkPath::kLine_Verb:
d = SkPoint::Distance(pts[0], pts[1]);
SkASSERT(d >= 0);
if (!SkScalarNearlyZero(d)) {
distance += d;
seg = fSegments.append();
seg->fDistance = distance;
seg->fPtIndex = ptIndex;
seg->fType = fIter.isCloseLine() ?
kCloseLine_SegType : kLine_SegType;
seg->fTValue = kMaxTValue;
}
ptIndex += !fIter.isCloseLine();
distance += d;
seg = fSegments.append();
seg->fDistance = distance;
seg->fPtIndex = ptIndex;
seg->fType = kLine_SegType;
seg->fTValue = kMaxTValue;
fPts.append(1, pts + 1);
ptIndex++;
break;
case SkPath::kQuad_Verb:
distance = this->compute_quad_segs(pts, distance, 0,
kMaxTValue, ptIndex);
fPts.append(2, pts + 1);
ptIndex += 2;
break;
case SkPath::kCubic_Verb:
distance = this->compute_cubic_segs(pts, distance, 0,
kMaxTValue, ptIndex);
fPts.append(3, pts + 1);
ptIndex += 3;
break;
@ -196,13 +198,14 @@ void SkPathMeasure::buildSegments() {
break;
case SkPath::kDone_Verb:
goto DONE;
done = true;
break;
}
}
DONE:
} while (!done);
fLength = distance;
fIsClosed = isClosed;
fFirstPtIndex = ptIndex + 1;
fFirstPtIndex = ptIndex;
#ifdef SK_DEBUG
{
@ -232,31 +235,20 @@ DONE:
#endif
}
// marked as a friend in SkPath.h
const SkPoint* sk_get_path_points(const SkPath& path, int index) {
return &path.fPts[index];
}
static void compute_pos_tan(const SkPath& path, int firstPtIndex, int ptIndex,
static void compute_pos_tan(const SkTDArray<SkPoint>& segmentPts, int ptIndex,
int segType, SkScalar t, SkPoint* pos, SkVector* tangent) {
const SkPoint* pts = sk_get_path_points(path, ptIndex);
const SkPoint* pts = &segmentPts[ptIndex];
switch (segType) {
case kLine_SegType:
case kCloseLine_SegType: {
const SkPoint* endp = (segType == kLine_SegType) ?
&pts[1] :
sk_get_path_points(path, firstPtIndex);
if (pos) {
pos->set(SkScalarInterp(pts[0].fX, endp->fX, t),
SkScalarInterp(pts[0].fY, endp->fY, t));
pos->set(SkScalarInterp(pts[0].fX, pts[1].fX, t),
SkScalarInterp(pts[0].fY, pts[1].fY, t));
}
if (tangent) {
tangent->setNormalize(endp->fX - pts[0].fX, endp->fY - pts[0].fY);
tangent->setNormalize(pts[1].fX - pts[0].fX, pts[1].fY - pts[0].fY);
}
break;
}
case kQuad_SegType:
SkEvalQuadAt(pts, t, pos, tangent);
if (tangent) {
@ -274,7 +266,7 @@ static void compute_pos_tan(const SkPath& path, int firstPtIndex, int ptIndex,
}
}
static void seg_to(const SkPath& src, int firstPtIndex, int ptIndex,
static void seg_to(const SkTDArray<SkPoint>& segmentPts, int ptIndex,
int segType, SkScalar startT, SkScalar stopT, SkPath* dst) {
SkASSERT(startT >= 0 && startT <= SK_Scalar1);
SkASSERT(stopT >= 0 && stopT <= SK_Scalar1);
@ -284,24 +276,18 @@ static void seg_to(const SkPath& src, int firstPtIndex, int ptIndex,
return;
}
const SkPoint* pts = sk_get_path_points(src, ptIndex);
const SkPoint* pts = &segmentPts[ptIndex];
SkPoint tmp0[7], tmp1[7];
switch (segType) {
case kLine_SegType:
case kCloseLine_SegType: {
const SkPoint* endp = (segType == kLine_SegType) ?
&pts[1] :
sk_get_path_points(src, firstPtIndex);
if (stopT == kMaxTValue) {
dst->lineTo(*endp);
dst->lineTo(pts[1]);
} else {
dst->lineTo(SkScalarInterp(pts[0].fX, endp->fX, stopT),
SkScalarInterp(pts[0].fY, endp->fY, stopT));
dst->lineTo(SkScalarInterp(pts[0].fX, pts[1].fX, stopT),
SkScalarInterp(pts[0].fY, pts[1].fY, stopT));
}
break;
}
case kQuad_SegType:
if (startT == 0) {
if (stopT == SK_Scalar1) {
@ -379,6 +365,7 @@ void SkPathMeasure::setPath(const SkPath* path, bool forceClosed) {
fIter.setPath(*path, forceClosed);
}
fSegments.reset();
fPts.reset();
}
SkScalar SkPathMeasure::getLength() {
@ -431,7 +418,6 @@ bool SkPathMeasure::getPosTan(SkScalar distance, SkPoint* pos,
SkVector* tangent) {
SkASSERT(fPath);
if (fPath == NULL) {
EMPTY:
return false;
}
@ -439,7 +425,7 @@ bool SkPathMeasure::getPosTan(SkScalar distance, SkPoint* pos,
int count = fSegments.count();
if (count == 0 || length == 0) {
goto EMPTY;
return false;
}
// pin the distance to a legal range
@ -452,8 +438,7 @@ bool SkPathMeasure::getPosTan(SkScalar distance, SkPoint* pos,
SkScalar t;
const Segment* seg = this->distanceToSegment(distance, &t);
compute_pos_tan(*fPath, fSegments[0].fPtIndex, seg->fPtIndex, seg->fType,
t, pos, tangent);
compute_pos_tan(fPts, seg->fPtIndex, seg->fType, t, pos, tangent);
return true;
}
@ -501,23 +486,19 @@ bool SkPathMeasure::getSegment(SkScalar startD, SkScalar stopD, SkPath* dst,
SkASSERT(seg <= stopSeg);
if (startWithMoveTo) {
compute_pos_tan(*fPath, fSegments[0].fPtIndex, seg->fPtIndex,
seg->fType, startT, &p, NULL);
compute_pos_tan(fPts, seg->fPtIndex, seg->fType, startT, &p, NULL);
dst->moveTo(p);
}
if (seg->fPtIndex == stopSeg->fPtIndex) {
seg_to(*fPath, fSegments[0].fPtIndex, seg->fPtIndex, seg->fType,
startT, stopT, dst);
seg_to(fPts, seg->fPtIndex, seg->fType, startT, stopT, dst);
} else {
do {
seg_to(*fPath, fSegments[0].fPtIndex, seg->fPtIndex, seg->fType,
startT, SK_Scalar1, dst);
seg_to(fPts, seg->fPtIndex, seg->fType, startT, SK_Scalar1, dst);
seg = SkPathMeasure::NextSegment(seg);
startT = 0;
} while (seg->fPtIndex < stopSeg->fPtIndex);
seg_to(*fPath, fSegments[0].fPtIndex, seg->fPtIndex, seg->fType,
0, stopT, dst);
seg_to(fPts, seg->fPtIndex, seg->fType, 0, stopT, dst);
}
return true;
}

2
tests/PathMeasureTest.cpp
View File

@ -44,7 +44,6 @@ static void TestPathMeasure(skiatest::Reporter* reporter) {
#endif
}
#if 0
// Test the behavior following a close not followed by a move.
path.reset();
path.lineTo(SK_Scalar1, 0);
@ -129,7 +128,6 @@ static void TestPathMeasure(skiatest::Reporter* reporter) {
SkScalarNearlyEqual(position.fY, SK_Scalar1 * 2.0f, SK_Scalar1 * 0.0001));
REPORTER_ASSERT(reporter, tangent.fX == -SK_Scalar1);
REPORTER_ASSERT(reporter, tangent.fY == 0);
#endif
}
#include "TestClassDef.h"