The Tor Browser: gfx/skia/trunk/src/core/SkPathMeasure.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/core/SkPathMeasure.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/core/SkPathMeasure.cpp

Sat, 03 Jan 2015 20:18:00 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Sat, 03 Jan 2015 20:18:00 +0100
branch: TOR_BUG_3246
changeset 7: 129ffea94266
permissions: -rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkPathMeasure.h"
 #include "SkGeometry.h"
 #include "SkPath.h"
 #include "SkTSearch.h"
 // these must be 0,1,2 since they are in our 2-bit field
 enum {
     kLine_SegType,
     kQuad_SegType,
     kCubic_SegType
 };
 #define kMaxTValue  32767
 static inline SkScalar tValue2Scalar(int t) {
     SkASSERT((unsigned)t <= kMaxTValue);
     return t * 3.05185e-5f; // t / 32767
 }
 SkScalar SkPathMeasure::Segment::getScalarT() const {
     return tValue2Scalar(fTValue);
 }
 const SkPathMeasure::Segment* SkPathMeasure::NextSegment(const Segment* seg) {
     unsigned ptIndex = seg->fPtIndex;
     do {
         ++seg;
     } while (seg->fPtIndex == ptIndex);
     return seg;
 }
 ///////////////////////////////////////////////////////////////////////////////
 static inline int tspan_big_enough(int tspan) {
     SkASSERT((unsigned)tspan <= kMaxTValue);
     return tspan >> 10;
 }
 // can't use tangents, since we need [0..1..................2] to be seen
 // as definitely not a line (it is when drawn, but not parametrically)
 // so we compare midpoints
 #define CHEAP_DIST_LIMIT    (SK_Scalar1/2)  // just made this value up
 static bool quad_too_curvy(const SkPoint pts[3]) {
     // diff = (a/4 + b/2 + c/4) - (a/2 + c/2)
     // diff = -a/4 + b/2 - c/4
     SkScalar dx = SkScalarHalf(pts[1].fX) -
                         SkScalarHalf(SkScalarHalf(pts[0].fX + pts[2].fX));
     SkScalar dy = SkScalarHalf(pts[1].fY) -
                         SkScalarHalf(SkScalarHalf(pts[0].fY + pts[2].fY));
     SkScalar dist = SkMaxScalar(SkScalarAbs(dx), SkScalarAbs(dy));
     return dist > CHEAP_DIST_LIMIT;
 }
 static bool cheap_dist_exceeds_limit(const SkPoint& pt,
                                      SkScalar x, SkScalar y) {
     SkScalar dist = SkMaxScalar(SkScalarAbs(x - pt.fX), SkScalarAbs(y - pt.fY));
     // just made up the 1/2
     return dist > CHEAP_DIST_LIMIT;
 }
 static bool cubic_too_curvy(const SkPoint pts[4]) {
     return  cheap_dist_exceeds_limit(pts[1],
                          SkScalarInterp(pts[0].fX, pts[3].fX, SK_Scalar1/3),
                          SkScalarInterp(pts[0].fY, pts[3].fY, SK_Scalar1/3))
                          ||
             cheap_dist_exceeds_limit(pts[2],
                          SkScalarInterp(pts[0].fX, pts[3].fX, SK_Scalar1*2/3),
                          SkScalarInterp(pts[0].fY, pts[3].fY, SK_Scalar1*2/3));
 }
 SkScalar SkPathMeasure::compute_quad_segs(const SkPoint pts[3],
                           SkScalar distance, int mint, int maxt, int ptIndex) {
     if (tspan_big_enough(maxt - mint) && quad_too_curvy(pts)) {
         SkPoint tmp[5];
         int     halft = (mint + maxt) >> 1;
         SkChopQuadAtHalf(pts, tmp);
         distance = this->compute_quad_segs(tmp, distance, mint, halft, ptIndex);
         distance = this->compute_quad_segs(&tmp[2], distance, halft, maxt, ptIndex);
     } else {
         SkScalar d = SkPoint::Distance(pts[0], pts[2]);
         SkScalar prevD = distance;
         distance += d;
         if (distance > prevD) {
             Segment* seg = fSegments.append();
             seg->fDistance = distance;
             seg->fPtIndex = ptIndex;
             seg->fType = kQuad_SegType;
             seg->fTValue = maxt;
         }
     }
     return distance;
 }
 SkScalar SkPathMeasure::compute_cubic_segs(const SkPoint pts[4],
                            SkScalar distance, int mint, int maxt, int ptIndex) {
     if (tspan_big_enough(maxt - mint) && cubic_too_curvy(pts)) {
         SkPoint tmp[7];
         int     halft = (mint + maxt) >> 1;
         SkChopCubicAtHalf(pts, tmp);
         distance = this->compute_cubic_segs(tmp, distance, mint, halft, ptIndex);
         distance = this->compute_cubic_segs(&tmp[3], distance, halft, maxt, ptIndex);
     } else {
         SkScalar d = SkPoint::Distance(pts[0], pts[3]);
         SkScalar prevD = distance;
         distance += d;
         if (distance > prevD) {
             Segment* seg = fSegments.append();
             seg->fDistance = distance;
             seg->fPtIndex = ptIndex;
             seg->fType = kCubic_SegType;
             seg->fTValue = maxt;
         }
     }
     return distance;
 }
 void SkPathMeasure::buildSegments() {
     SkPoint         pts[4];
     int             ptIndex = fFirstPtIndex;
     SkScalar        distance = 0;
     bool            isClosed = fForceClosed;
     bool            firstMoveTo = ptIndex < 0;
     Segment*        seg;
     /*  Note:
      *  as we accumulate distance, we have to check that the result of +=
      *  actually made it larger, since a very small delta might be > 0, but
      *  still have no effect on distance (if distance >>> delta).
      *
      *  We do this check below, and in compute_quad_segs and compute_cubic_segs
      */
     fSegments.reset();
     bool done = false;
     do {
         switch (fIter.next(pts)) {
             case SkPath::kConic_Verb:
                 SkASSERT(0);
                 break;
             case SkPath::kMove_Verb:
                 ptIndex += 1;
                 fPts.append(1, pts);
                 if (!firstMoveTo) {
                     done = true;
                     break;
                 }
                 firstMoveTo = false;
                 break;
             case SkPath::kLine_Verb: {
                 SkScalar d = SkPoint::Distance(pts[0], pts[1]);
                 SkASSERT(d >= 0);
                 SkScalar prevD = distance;
                 distance += d;
                 if (distance > prevD) {
                     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: {
                 SkScalar prevD = distance;
                 distance = this->compute_quad_segs(pts, distance, 0,
                                                    kMaxTValue, ptIndex);
                 if (distance > prevD) {
                     fPts.append(2, pts + 1);
                     ptIndex += 2;
                 }
             } break;
             case SkPath::kCubic_Verb: {
                 SkScalar prevD = distance;
                 distance = this->compute_cubic_segs(pts, distance, 0,
                                                     kMaxTValue, ptIndex);
                 if (distance > prevD) {
                     fPts.append(3, pts + 1);
                     ptIndex += 3;
                 }
             } break;
             case SkPath::kClose_Verb:
                 isClosed = true;
                 break;
             case SkPath::kDone_Verb:
                 done = true;
                 break;
         }
     } while (!done);
     fLength = distance;
     fIsClosed = isClosed;
     fFirstPtIndex = ptIndex;
 #ifdef SK_DEBUG
     {
         const Segment* seg = fSegments.begin();
         const Segment* stop = fSegments.end();
         unsigned        ptIndex = 0;
         SkScalar        distance = 0;
         while (seg < stop) {
             SkASSERT(seg->fDistance > distance);
             SkASSERT(seg->fPtIndex >= ptIndex);
             SkASSERT(seg->fTValue > 0);
             const Segment* s = seg;
             while (s < stop - 1 && s[0].fPtIndex == s[1].fPtIndex) {
                 SkASSERT(s[0].fType == s[1].fType);
                 SkASSERT(s[0].fTValue < s[1].fTValue);
                 s += 1;
             }
             distance = seg->fDistance;
             ptIndex = seg->fPtIndex;
             seg += 1;
         }
     //  SkDebugf("\n");
     }
 #endif
 }
 static void compute_pos_tan(const SkPoint pts[], int segType,
                             SkScalar t, SkPoint* pos, SkVector* tangent) {
     switch (segType) {
         case kLine_SegType:
             if (pos) {
                 pos->set(SkScalarInterp(pts[0].fX, pts[1].fX, t),
                          SkScalarInterp(pts[0].fY, pts[1].fY, t));
             }
             if (tangent) {
                 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) {
                 tangent->normalize();
             }
             break;
         case kCubic_SegType:
             SkEvalCubicAt(pts, t, pos, tangent, NULL);
             if (tangent) {
                 tangent->normalize();
             }
             break;
         default:
             SkDEBUGFAIL("unknown segType");
     }
 }
 static void seg_to(const SkPoint pts[], int segType,
                    SkScalar startT, SkScalar stopT, SkPath* dst) {
     SkASSERT(startT >= 0 && startT <= SK_Scalar1);
     SkASSERT(stopT >= 0 && stopT <= SK_Scalar1);
     SkASSERT(startT <= stopT);
     if (startT == stopT) {
         return; // should we report this, to undo a moveTo?
     }
     SkPoint         tmp0[7], tmp1[7];
     switch (segType) {
         case kLine_SegType:
             if (SK_Scalar1 == stopT) {
                 dst->lineTo(pts[1]);
             } else {
                 dst->lineTo(SkScalarInterp(pts[0].fX, pts[1].fX, stopT),
                             SkScalarInterp(pts[0].fY, pts[1].fY, stopT));
             }
             break;
         case kQuad_SegType:
             if (0 == startT) {
                 if (SK_Scalar1 == stopT) {
                     dst->quadTo(pts[1], pts[2]);
                 } else {
                     SkChopQuadAt(pts, tmp0, stopT);
                     dst->quadTo(tmp0[1], tmp0[2]);
                 }
             } else {
                 SkChopQuadAt(pts, tmp0, startT);
                 if (SK_Scalar1 == stopT) {
                     dst->quadTo(tmp0[3], tmp0[4]);
                 } else {
                     SkChopQuadAt(&tmp0[2], tmp1, SkScalarDiv(stopT - startT,
                                                          SK_Scalar1 - startT));
                     dst->quadTo(tmp1[1], tmp1[2]);
                 }
             }
             break;
         case kCubic_SegType:
             if (0 == startT) {
                 if (SK_Scalar1 == stopT) {
                     dst->cubicTo(pts[1], pts[2], pts[3]);
                 } else {
                     SkChopCubicAt(pts, tmp0, stopT);
                     dst->cubicTo(tmp0[1], tmp0[2], tmp0[3]);
                 }
             } else {
                 SkChopCubicAt(pts, tmp0, startT);
                 if (SK_Scalar1 == stopT) {
                     dst->cubicTo(tmp0[4], tmp0[5], tmp0[6]);
                 } else {
                     SkChopCubicAt(&tmp0[3], tmp1, SkScalarDiv(stopT - startT,
                                                         SK_Scalar1 - startT));
                     dst->cubicTo(tmp1[1], tmp1[2], tmp1[3]);
                 }
             }
             break;
         default:
             SkDEBUGFAIL("unknown segType");
             sk_throw();
     }
 }
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
 SkPathMeasure::SkPathMeasure() {
     fPath = NULL;
     fLength = -1;   // signal we need to compute it
     fForceClosed = false;
     fFirstPtIndex = -1;
 }
 SkPathMeasure::SkPathMeasure(const SkPath& path, bool forceClosed) {
     fPath = &path;
     fLength = -1;   // signal we need to compute it
     fForceClosed = forceClosed;
     fFirstPtIndex = -1;
     fIter.setPath(path, forceClosed);
 }
 SkPathMeasure::~SkPathMeasure() {}
 /** Assign a new path, or null to have none.
 */
 void SkPathMeasure::setPath(const SkPath* path, bool forceClosed) {
     fPath = path;
     fLength = -1;   // signal we need to compute it
     fForceClosed = forceClosed;
     fFirstPtIndex = -1;
     if (path) {
         fIter.setPath(*path, forceClosed);
     }
     fSegments.reset();
     fPts.reset();
 }
 SkScalar SkPathMeasure::getLength() {
     if (fPath == NULL) {
         return 0;
     }
     if (fLength < 0) {
         this->buildSegments();
     }
     SkASSERT(fLength >= 0);
     return fLength;
 }
 const SkPathMeasure::Segment* SkPathMeasure::distanceToSegment(
                                             SkScalar distance, SkScalar* t) {
     SkDEBUGCODE(SkScalar length = ) this->getLength();
     SkASSERT(distance >= 0 && distance <= length);
     const Segment*  seg = fSegments.begin();
     int             count = fSegments.count();
     int index = SkTSearch<SkScalar>(&seg->fDistance, count, distance, sizeof(Segment));
     // don't care if we hit an exact match or not, so we xor index if it is negative
     index ^= (index >> 31);
     seg = &seg[index];
     // now interpolate t-values with the prev segment (if possible)
     SkScalar    startT = 0, startD = 0;
     // check if the prev segment is legal, and references the same set of points
     if (index > 0) {
         startD = seg[-1].fDistance;
         if (seg[-1].fPtIndex == seg->fPtIndex) {
             SkASSERT(seg[-1].fType == seg->fType);
             startT = seg[-1].getScalarT();
         }
     }
     SkASSERT(seg->getScalarT() > startT);
     SkASSERT(distance >= startD);
     SkASSERT(seg->fDistance > startD);
     *t = startT + SkScalarMulDiv(seg->getScalarT() - startT,
                                  distance - startD,
                                  seg->fDistance - startD);
     return seg;
 }
 bool SkPathMeasure::getPosTan(SkScalar distance, SkPoint* pos,
                               SkVector* tangent) {
     if (NULL == fPath) {
         return false;
     }
     SkScalar    length = this->getLength(); // call this to force computing it
     int         count = fSegments.count();
     if (count == 0 || length == 0) {
         return false;
     }
     // pin the distance to a legal range
     if (distance < 0) {
         distance = 0;
     } else if (distance > length) {
         distance = length;
     }
     SkScalar        t;
     const Segment*  seg = this->distanceToSegment(distance, &t);
     compute_pos_tan(&fPts[seg->fPtIndex], seg->fType, t, pos, tangent);
     return true;
 }
 bool SkPathMeasure::getMatrix(SkScalar distance, SkMatrix* matrix,
                               MatrixFlags flags) {
     if (NULL == fPath) {
         return false;
     }
     SkPoint     position;
     SkVector    tangent;
     if (this->getPosTan(distance, &position, &tangent)) {
         if (matrix) {
             if (flags & kGetTangent_MatrixFlag) {
                 matrix->setSinCos(tangent.fY, tangent.fX, 0, 0);
             } else {
                 matrix->reset();
             }
             if (flags & kGetPosition_MatrixFlag) {
                 matrix->postTranslate(position.fX, position.fY);
             }
         }
         return true;
     }
     return false;
 }
 bool SkPathMeasure::getSegment(SkScalar startD, SkScalar stopD, SkPath* dst,
                                bool startWithMoveTo) {
     SkASSERT(dst);
     SkScalar length = this->getLength();    // ensure we have built our segments
     if (startD < 0) {
         startD = 0;
     }
     if (stopD > length) {
         stopD = length;
     }
     if (startD >= stopD) {
         return false;
     }
     SkPoint  p;
     SkScalar startT, stopT;
     const Segment* seg = this->distanceToSegment(startD, &startT);
     const Segment* stopSeg = this->distanceToSegment(stopD, &stopT);
     SkASSERT(seg <= stopSeg);
     if (startWithMoveTo) {
         compute_pos_tan(&fPts[seg->fPtIndex], seg->fType, startT, &p, NULL);
         dst->moveTo(p);
     }
     if (seg->fPtIndex == stopSeg->fPtIndex) {
         seg_to(&fPts[seg->fPtIndex], seg->fType, startT, stopT, dst);
     } else {
         do {
             seg_to(&fPts[seg->fPtIndex], seg->fType, startT, SK_Scalar1, dst);
             seg = SkPathMeasure::NextSegment(seg);
             startT = 0;
         } while (seg->fPtIndex < stopSeg->fPtIndex);
         seg_to(&fPts[seg->fPtIndex], seg->fType, 0, stopT, dst);
     }
     return true;
 }
 bool SkPathMeasure::isClosed() {
     (void)this->getLength();
     return fIsClosed;
 }
 /** Move to the next contour in the path. Return true if one exists, or false if
     we're done with the path.
 */
 bool SkPathMeasure::nextContour() {
     fLength = -1;
     return this->getLength() > 0;
 }
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 #ifdef SK_DEBUG
 void SkPathMeasure::dump() {
     SkDebugf("pathmeas: length=%g, segs=%d\n", fLength, fSegments.count());
     for (int i = 0; i < fSegments.count(); i++) {
         const Segment* seg = &fSegments[i];
         SkDebugf("pathmeas: seg[%d] distance=%g, point=%d, t=%g, type=%d\n",
                 i, seg->fDistance, seg->fPtIndex, seg->getScalarT(),
                  seg->fType);
     }
 }
 #endif

The Tor Browser / annotate

gfx/skia/trunk/src/core/SkPathMeasure.cpp@129ffea94266 (annotated)

gfx/skia/trunk/src/core/SkPathMeasure.cpp