diff --git a/experimental/Intersection/EdgeWalker.cpp b/experimental/Intersection/EdgeWalker.cpp index 4f4fc9b94..f3ae312a2 100644 --- a/experimental/Intersection/EdgeWalker.cpp +++ b/experimental/Intersection/EdgeWalker.cpp @@ -104,27 +104,208 @@ void contourBounds(const SkPath& path, SkTDArray& boundsArray) { } } -struct OutEdge { +static bool extendLine(const SkPoint line[2], const SkPoint& add) { + // FIXME: allow this to extend lines that have slopes that are nearly equal + SkScalar dx1 = line[1].fX - line[0].fX; + SkScalar dy1 = line[1].fY - line[0].fY; + SkScalar dx2 = add.fX - line[0].fX; + SkScalar dy2 = add.fY - line[0].fY; + return dx1 * dy2 == dx2 * dy1; +} +struct OutEdge { + bool operator<(const OutEdge& rh) const { + const SkPoint& first = fPts.begin()[0]; + const SkPoint& rhFirst = rh.fPts.begin()[0]; + return first.fY == rhFirst.fY + ? first.fX < rhFirst.fX + : first.fY < rhFirst.fY; + } + SkTDArray fPts; SkTDArray fVerbs; }; +// for sorting only +class OutBottomEdge : public OutEdge { +public: + bool operator<(const OutBottomEdge& rh) const { + const SkPoint& last = fPts.end()[-1]; + const SkPoint& rhLast = rh.fPts.end()[-1]; + return last.fY == rhLast.fY + ? last.fX < rhLast.fX + : last.fY < rhLast.fY; + } + +}; + class OutEdgeBuilder { public: - void addLine(SkPoint pts[2]) { - ; - OutEdge* edge; - - edge = fEdges.append(); - - if (empty) { - *edge->fPts.append() = pts[0]; + OutEdgeBuilder(bool fill) + : fFill(fill) { + } + + void addLine(const SkPoint line[2]) { + size_t count = fEdges.count(); + for (size_t index = 0; index < count; ++index) { + SkTDArray& pts = fEdges[index].fPts; + SkPoint* last = pts.end() - 1; + if (last[0] == line[0]) { + if (extendLine(&last[-1], line[1])) { + last[0] = line[1]; + } else { + *pts.append() = line[1]; + } + return; + } + } + OutEdge& edge = fEdges.push_back(); + *edge.fPts.append() = line[0]; + *edge.fPts.append() = line[1]; + } + + void assemble(SkPath& simple) { + size_t index = 0; + do { + SkTDArray& downArray = fEdges[index].fPts; + SkPoint* pts = downArray.begin(); + SkPoints* end = downArray.end(); + SkPoint firstPt = pts[0]; + simple.moveTo(pts[0].fX, pts[0].fY); + while (++pts < end) { + simple.lineTo(pts->fX, pts->fY); + } + index = fBottoms[index]; + SkTDArray& upArray = fEdges[index].fPts; + pts = upArray.end(); + SkPoints* begin = upArray.begin(); + while (--pts > begin) { + simple.lineTo(pts->fX, pts->fY); + } + if (pts[0] == firstPt) { + simple.close(); + closed = true; + + } else { + simple.lineTo(pts->fX, pts->fY); + } + index = advance > 0 ? fBottoms[index] : fTops[index]; + advance = -advance; + } while (true); + + } else { + if (firstAdded.fY == pts[0].fY) { + advance = -1; + pts = ptArray.end(); + } + } + size_t count2 = ptArray.count(); + for (size_t inner = 1; inner < count2; ++inner) { + pts += advance; + simple.lineTo(pts->fX, pts->fY); + } + if (*pts == *ptArray.begin()) { +// lastAdded = *pts; + simple.close(); + newContour = true; + } + } + } + + static bool lessThan(const SkTArray& edges, const int* onePtr, + const int* twoPtr) { + int one = *onePtr; + const OutEdge& oneEdge = edges[(one < 0 ? -one : one) - 1]; + const SkPoint* onePt = one < 0 ? oneEdge.fPts.begin() + : oneEdge.fPts.end() - 1; + int two = *twoPtr; + const OutEdge& twoEdge = edges[(two < 0 ? -two : two) - 1]; + const SkPoint* twoPt = two < 0 ? twoEdge.fPts.begin() + : twoEdge.fPts.end() - 1; + return onePt.fY == twoPt.fY ? onePt.fX < twoPt.fX : onePt.fY < twoPt.fY; + } + + void bridge() { + size_t index; + size_t count = fEdges.count(); + if (!count) { + return; + } + SkASSERT(!fFill || (count & 1) == 0); + fTops.setCount(count); + sk_bzero(fTops.begin(), sizeof(fTops[0]) * count); + fBottoms.setCount(count); + sk_bzero(fBottoms.begin(), sizeof(fBottoms[0]) * count); + for (index = 0; index < count; ++index) { + *fList.append() = index + 1; + *fList.append() = -index - 1; + } + Context context; + QSort&, int>(fEdges, fList.begin(), count, lessThan); + connectTops(); + // sort bottoms + SkTDArray bottomList; + for (index = 0; index < count; ++index) { + *bottomList.append() = static_cast(&fEdges[index]); + fBottoms[index] = -1; + } + QSort(bottomList.begin(), count); + connectBottoms(bottomList); + } + +protected: + void connectTops() { + int* lastPtr = fList.end() - 1; + int* leftPtr = fList.begin(); + for (; leftPtr < lastPtr; ++leftPtr) { + OutEdge* left = edges[(*leftPtr < 0 ? -*leftPtr : *leftPtr) - 1]; + int* rightPtr = leftPtr + 1; + OutEdge* right = edges[(*rightPtr < 0 ? -*rightPtr : *rightPtr) - 1]; + start here; + // i'm a bit confused right now -- but i'm trying to sort indices + // of paired points and then create more indices so assemble() can + // look up the next edge and whether to connect the top or bottom + int leftIndex = leftPtr - bottomList.begin(); + int rightIndex = rightPtr - bottomList.begin(); + SkASSERT(!fFill || left->fPts[0].fY == right->fPts[0].fY); + if (fFill || left->fPts[0] == right->fPts[0]) { + int leftIndex = leftPtr - topList.begin(); + int rightIndex = rightPtr - topList.begin(); + fTops[leftIndex] = rightIndex; + fTops[rightIndex] = leftIndex; + ++rightPtr; + } + leftPtr = rightPtr; + } + } + + void connectBottoms(SkTDArray& bottomList) { + OutBottomEdge** lastPtr = bottomList.end() - 1; + OutBottomEdge** leftPtr = bottomList.begin(); + size_t leftCount = (*leftPtr)->fPts.count(); + for (; leftPtr < lastPtr; ++leftPtr) { + OutBottomEdge** rightPtr = leftPtr + 1; + size_t rightCount = (*rightPtr)->fPts.count(); + SkASSERT(!fFill || (*leftPtr)->fPts[leftCount].fY + == (*rightPtr)->fPts[rightCount].fY); + if (fFill || (*leftPtr)->fPts[leftCount] + == (*rightPtr)->fPts[rightCount]) { + int leftIndex = leftPtr - bottomList.begin(); + int rightIndex = rightPtr - bottomList.begin(); + fBottoms[leftIndex] = rightIndex; + fBottoms[rightIndex] = leftIndex; + if (++rightPtr < lastPtr) { + rightCount = (*rightPtr)->fPts.count(); + } + } + leftPtr = rightPtr; + leftCount = rightCount; } - *edge->fPts.append() = pts[1]; } SkTArray fEdges; + SkTDArray fList; + bool fFill; }; // Bounds, unlike Rect, does not consider a vertical line to be empty. @@ -239,6 +420,7 @@ InEdgeBuilder(const SkPath& path, bool ignoreHorizontal, SkTArray& edges protected: void addEdge() { + SkASSERT(fCurrentEdge); fCurrentEdge->fPts.append(fPtCount - fPtOffset, &fPts[fPtOffset]); fPtOffset = 1; *fCurrentEdge->fVerbs.append() = fVerb; @@ -291,8 +473,10 @@ void walk() { winding = direction(4); break; case SkPath::kClose_Verb: + SkASSERT(fCurrentEdge); if (fCurrentEdge->fVerbs.count()) { fCurrentEdge->complete(fWinding); + fCurrentEdge = NULL; } continue; default: @@ -305,13 +489,16 @@ void walk() { if (fWinding + winding == 0) { // FIXME: if prior verb or this verb is a horizontal line, reverse // it instead of starting a new edge + SkASSERT(fCurrentEdge); fCurrentEdge->complete(fWinding); startEdge(); } fWinding = winding; addEdge(); } - fCurrentEdge->complete(fWinding); + if (fCurrentEdge) { + fCurrentEdge->complete(fWinding); + } } private: @@ -405,7 +592,7 @@ static void addToActive(SkTDArray& activeEdges, const InEdge* edge) // FIXME: in the pathological case where there is a ton of intercepts, binary search? size_t count = activeEdges.count(); for (size_t index = 0; index < count; ++index) { - if (edge < activeEdges[index].fWorkEdge.fEdge) { + if (*edge < *activeEdges[index].fWorkEdge.fEdge) { ActiveEdge* active = activeEdges.insert(index); active->init(edge); return; @@ -418,192 +605,233 @@ static void addToActive(SkTDArray& activeEdges, const InEdge* edge) active->init(edge); } + // find any intersections in the range of active edges +static void addBottomT(InEdge** currentPtr, InEdge** lastPtr, SkScalar bottom) { + InEdge** testPtr = currentPtr; + InEdge* test = *testPtr; + while (testPtr != lastPtr) { + if (test->fBounds.fBottom > bottom) { + WorkEdge wt; + wt.init(test); + do { + // FIXME: add all curve types + // OPTIMIZATION: if bottom intersection does not change + // the winding on either side of the split, don't intersect + if (wt.verb() == SkPath::kLine_Verb) { + double wtTs[2]; + int pts = LineIntersect(wt.fPts, bottom, wtTs); + if (pts) { + test->add(wtTs, pts, wt.verbIndex()); + } + } + } while (wt.next()); + } + test = *++testPtr; + } +} + +static void addIntersectingTs(InEdge** currentPtr, InEdge** lastPtr) { + InEdge** testPtr = currentPtr; + InEdge* test = *testPtr; + while (testPtr != lastPtr - 1) { + InEdge* next = *++testPtr; + if (!test->cached(next) + && Bounds::Intersects(test->fBounds, next->fBounds)) { + WorkEdge wt, wn; + wt.init(test); + wn.init(next); + do { + // FIXME: add all combinations of curve types + if (wt.verb() == SkPath::kLine_Verb + && wn.verb() == SkPath::kLine_Verb) { + double wtTs[2], wnTs[2]; + int pts = LineIntersect(wt.fPts, wn.fPts, wtTs, wnTs); + if (pts) { + test->add(wtTs, pts, wt.verbIndex()); + test->fContainsIntercepts = true; + next->add(wnTs, pts, wn.verbIndex()); + next->fContainsIntercepts = true; + } + } + } while (wt.bottom() <= wn.bottom() ? wt.next() : wn.next()); + } + test = next; + } +} + +// compute bottom taking into account any intersected edges +static void computeInterceptBottom(SkTDArray& activeEdges, + SkScalar& bottom) { + ActiveEdge* activePtr = activeEdges.begin() - 1; + ActiveEdge* lastActive = activeEdges.end(); + while (++activePtr != lastActive) { + const InEdge* test = activePtr->fWorkEdge.fEdge; + if (!test->fContainsIntercepts) { + continue; + } + WorkEdge wt; + wt.init(test); + do { + // FIXME: add all curve types + const Intercepts& intercepts = test->fIntercepts[wt.verbIndex()]; + const SkTDArray& fTs = intercepts.fTs; + size_t count = fTs.count(); + for (size_t index = 0; index < count; ++index) { + if (wt.verb() == SkPath::kLine_Verb) { + SkScalar yIntercept = LineYAtT(wt.fPts, fTs[index]); + if (bottom > yIntercept) { + bottom = yIntercept; + } + } + } + } while (wt.next()); + } +} + +static SkScalar findBottom(InEdge** currentPtr, + InEdge** edgeListEnd, SkTDArray& activeEdges, SkScalar y, + bool asFill, InEdge**& lastPtr) { + InEdge* current = *currentPtr; + SkScalar bottom = current->fBounds.fBottom; + + // find the list of edges that cross y + InEdge* last = *lastPtr; + while (lastPtr != edgeListEnd) { + if (bottom <= last->fBounds.fTop) { + break; + } + SkScalar lastTop = last->fBounds.fTop; + // OPTIMIZATION: Shortening the bottom is only interesting when filling + // and when the edge is to the left of a longer edge. If it's a framing + // edge, or part of the right, it won't effect the longer edges. + if (lastTop > y) { + if (bottom > lastTop) { + bottom = lastTop; + break; + } + } else if (bottom > last->fBounds.fBottom) { + bottom = last->fBounds.fBottom; + } + addToActive(activeEdges, last); + last = *++lastPtr; + } + if (asFill && lastPtr - currentPtr <= 1) { + SkDebugf("expect 2 or more edges\n"); + SkASSERT(0); + } + return bottom; +} + +static void makeEdgeList(SkTArray& edges, InEdge& edgeSentinel, + SkTDArray& edgeList) { + size_t edgeCount = edges.count(); + if (edgeCount == 0) { + return; + } + for (size_t index = 0; index < edgeCount; ++index) { + *edgeList.append() = &edges[index]; + } + edgeSentinel.fBounds.set(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, SK_ScalarMax); + *edgeList.append() = &edgeSentinel; + ++edgeCount; + QSort(edgeList.begin(), edgeCount); +} + +static void removeEdge(SkTDArray& activeEdges, InEdge** currentPtr) { + InEdge* current = *currentPtr; + ActiveEdge* activePtr = activeEdges.begin() - 1; + ActiveEdge* lastActive = activeEdges.end(); + while (++activePtr != lastActive) { + if (activePtr->fWorkEdge.fEdge == current) { + activeEdges.remove(activePtr - activeEdges.begin()); + return; + } + } +} + +// stitch edge and t range that satisfies operation +static void stitchEdge(SkTDArray& activeEdges, SkScalar y, + SkScalar bottom, int windingMask, OutEdgeBuilder& outBuilder) { + int winding = 0; + ActiveEdge* activePtr = activeEdges.begin() - 1; + ActiveEdge* lastActive = activeEdges.end(); + SkDebugf("%s y=%g bottom=%g\n", __FUNCTION__, y, bottom); + while (++activePtr != lastActive) { + const WorkEdge& wt = activePtr->fWorkEdge; + int lastWinding = winding; + winding += wt.winding(); + if (!(lastWinding & windingMask) && !(winding & windingMask)) { + continue; + } + do { + double currentT = activePtr->t(); + const SkPoint* points = wt.fPts; + bool last; + do { + last = activePtr->nextT(); + double nextT = activePtr->t(); + // FIXME: add all combinations of curve types + if (wt.verb() == SkPath::kLine_Verb) { + SkPoint clippedPts[2]; + const SkPoint* clipped; + if (currentT * nextT != 0 || currentT + nextT != 1) { + LineSubDivide(points, currentT, nextT, clippedPts); + clipped = clippedPts; + } else { + clipped = points; + } + SkDebugf("%s line %g,%g %g,%g\n", __FUNCTION__, + clipped[0].fX, clipped[0].fY, + clipped[1].fX, clipped[1].fY); + outBuilder.addLine(clipped); + if (clipped[1].fY >= bottom) { + goto nextEdge; + } + } + currentT = nextT; + } while (!last); + } while (activePtr->next()); +nextEdge: + ; + } +} + void simplify(const SkPath& path, bool asFill, SkPath& simple) { + // returns 1 for evenodd, -1 for winding, regardless of inverse-ness + int windingMask = (path.getFillType() & 1) ? 1 : -1; + simple.reset(); + simple.setFillType(SkPath::kEvenOdd_FillType); // turn path into list of edges increasing in y // if an edge is a quad or a cubic with a y extrema, note it, but leave it unbroken // once we have a list, sort it, then walk the list (walk edges twice that have y extrema's on top) // and detect crossings -- look for raw bounds that cross over, then tight bounds that cross SkTArray edges; InEdgeBuilder builder(path, asFill, edges); - size_t edgeCount = edges.count(); - simple.reset(); - if (edgeCount == 0) { - return; - } - // returns 1 for evenodd, -1 for winding, regardless of inverse-ness - int windingMask = (path.getFillType() & 1) ? 1 : -1; SkTDArray edgeList; - for (size_t index = 0; index < edgeCount; ++index) { - *edgeList.append() = &edges[index]; - } InEdge edgeSentinel; - edgeSentinel.fBounds.set(SK_ScalarMax, SK_ScalarMax, SK_ScalarMax, SK_ScalarMax); - *edgeList.append() = &edgeSentinel; - ++edgeCount; - QSort(edgeList.begin(), edgeCount); + makeEdgeList(edges, edgeSentinel, edgeList); InEdge** currentPtr = edgeList.begin(); - InEdge* current = *currentPtr; - SkScalar y = current->fBounds.fTop; - SkScalar bottom = current->fBounds.fBottom; // walk the sorted edges from top to bottom, computing accumulated winding SkTDArray activeEdges; - OutEdgeBuilder outBuilder; + OutEdgeBuilder outBuilder(asFill); + SkScalar y = (*currentPtr)->fBounds.fTop; do { - // find the list of edges that cross y InEdge** lastPtr = currentPtr; // find the edge below the bottom of the first set - InEdge* last = *lastPtr; - while (lastPtr != edgeList.end()) { - if (bottom <= last->fBounds.fTop) { - break; - } - SkScalar lastTop = last->fBounds.fTop; - // OPTIMIZATION: Shortening the bottom is only interesting when filling - // and when the edge is to the left of a longer edge. If it's a framing - // edge, or part of the right, it won't effect the longer edges. - if (lastTop > y) { - if (bottom > lastTop) { - bottom = lastTop; - break; - } - } else if (bottom > last->fBounds.fBottom) { - bottom = last->fBounds.fBottom; - } - addToActive(activeEdges, last); - last = *++lastPtr; - } - if (asFill && lastPtr - currentPtr <= 1) { - SkDebugf("expect 2 or more edges\n"); - SkASSERT(0); - return; - } - - // find any intersections in the range of active edges - InEdge** testPtr = currentPtr; - InEdge* test = *testPtr; - while (testPtr != lastPtr) { - if (test->fBounds.fBottom > bottom) { - WorkEdge wt; - wt.init(test); - do { - // FIXME: add all curve types - // OPTIMIZATION: if bottom intersection does not change - // the winding on either side of the split, don't intersect - if (wt.verb() == SkPath::kLine_Verb) { - double wtTs[2]; - int pts = LineIntersect(wt.fPts, bottom, wtTs); - if (pts) { - test->add(wtTs, pts, wt.verbIndex()); - } - } - } while (wt.next()); - } - test = *++testPtr; - } - testPtr = currentPtr; - test = *testPtr; - while (testPtr != lastPtr - 1) { - InEdge* next = *++testPtr; - if (!test->cached(next) - && Bounds::Intersects(test->fBounds, next->fBounds)) { - WorkEdge wt, wn; - wt.init(test); - wn.init(next); - do { - // FIXME: add all combinations of curve types - if (wt.verb() == SkPath::kLine_Verb - && wn.verb() == SkPath::kLine_Verb) { - double wtTs[2], wnTs[2]; - int pts = LineIntersect(wt.fPts, wn.fPts, wtTs, wnTs); - if (pts) { - test->add(wtTs, pts, wt.verbIndex()); - test->fContainsIntercepts = true; - next->add(wnTs, pts, wn.verbIndex()); - next->fContainsIntercepts = true; - } - } - } while (wt.bottom() <= wn.bottom() ? wt.next() : wn.next()); - } - test = next; - } - - // compute bottom taking into account any intersected edges - ActiveEdge* activePtr = activeEdges.begin() - 1; - ActiveEdge* lastActive = activeEdges.end(); - while (++activePtr != lastActive) { - const InEdge* test = activePtr->fWorkEdge.fEdge; - if (!test->fContainsIntercepts) { - continue; - } - WorkEdge wt; - wt.init(test); - do { - // FIXME: add all curve types - const Intercepts& intercepts = test->fIntercepts[wt.verbIndex()]; - const SkTDArray& fTs = intercepts.fTs; - size_t count = fTs.count(); - for (size_t index = 0; index < count; ++index) { - if (wt.verb() == SkPath::kLine_Verb) { - SkScalar yIntercept = LineYAtT(wt.fPts, fTs[index]); - if (bottom > yIntercept) { - bottom = yIntercept; - } - } - } - } while (wt.next()); - } - - // stitch edge and t range that satisfies operation - int winding = 0; - activePtr = activeEdges.begin() - 1; - lastActive = activeEdges.end(); - SkDebugf("%s y=%g bottom=%g\n", __FUNCTION__, y, bottom); - while (++activePtr != lastActive) { - const WorkEdge& wt = activePtr->fWorkEdge; - int lastWinding = winding; - winding += wt.winding(); - if (!(lastWinding & windingMask) && !(winding & windingMask)) { - continue; - } - do { - double currentT = activePtr->t(); - const SkPoint* points = wt.fPts; - bool last; - do { - last = activePtr->nextT(); - double nextT = activePtr->t(); - // FIXME: add all combinations of curve types - if (wt.verb() == SkPath::kLine_Verb) { - SkPoint clippedPts[2]; - const SkPoint* clipped; - if (currentT * nextT != 0 || currentT + nextT != 1) { - LineSubDivide(points, currentT, nextT, clippedPts); - clipped = clippedPts; - } else { - clipped = points; - } - SkDebugf("%s line %g,%g %g,%g\n", __FUNCTION__, - clipped[0].fX, clipped[0].fY, - clipped[1].fX, clipped[1].fY); - outBuilder->addLine(clipped); - if (clipped[1].fY >= bottom) { - goto nextEdge; - } - } - currentT = nextT; - } while (!last); - } while (activePtr->next()); - nextEdge: - ; - } - + SkScalar bottom = findBottom(currentPtr, edgeList.end(), + activeEdges, y, asFill, lastPtr); + addBottomT(currentPtr, lastPtr, bottom); + addIntersectingTs(currentPtr, lastPtr); + computeInterceptBottom(activeEdges, bottom); + stitchEdge(activeEdges, y, bottom, windingMask, outBuilder); y = bottom; while ((*currentPtr)->fBounds.fBottom <= y) { + removeEdge(activeEdges, currentPtr); ++currentPtr; } } while (*currentPtr != &edgeSentinel); - // assemble output path from string of pts, verbs - ; + outBuilder.bridge(); + outBuilder.assemble(simple); } void testSimplify(); diff --git a/experimental/Intersection/TSearch.h b/experimental/Intersection/TSearch.h index 53242c345..c1ba59c67 100644 --- a/experimental/Intersection/TSearch.h +++ b/experimental/Intersection/TSearch.h @@ -39,17 +39,18 @@ void QSort(T** base, size_t count) QSort_Partition(base, base + (count - 1)); } -template -static void QSort_Partition(T* first, T* last, bool (*lessThan)(const T*, const T*)) +template +static void QSort_Partition(const S& context, T* first, T* last, + bool (*lessThan)(const S&, const T*, const T*)) { T* left = first; T* rite = last; T* pivot = left; while (left <= rite) { - while (left < last && lessThan(left, pivot) < 0) + while (left < last && lessThan(context, left, pivot) < 0) left += 1; - while (first < rite && lessThan(rite, pivot) > 0) + while (first < rite && lessThan(context, rite, pivot) > 0) rite -= 1; if (left <= rite) { if (left < rite) { @@ -60,13 +61,14 @@ static void QSort_Partition(T* first, T* last, bool (*lessThan)(const T*, const } } if (first < rite) - QSort_Partition(first, rite, lessThan); + QSort_Partition(context, first, rite, lessThan); if (left < last) - QSort_Partition(left, last, lessThan); + QSort_Partition(context, left, last, lessThan); } -template -void QSort(T* base, size_t count, bool (*lessThan)(const T*, const T*)) +template +void QSort(const S& context, T* base, size_t count, + bool (*lessThan)(const S& , const T*, const T*)) { SkASSERT(base); SkASSERT(lessThan); @@ -74,5 +76,5 @@ void QSort(T* base, size_t count, bool (*lessThan)(const T*, const T*)) if (count <= 1) { return; } - QSort_Partition(base, base + (count - 1), lessThan); + QSort_Partition(context, base, base + (count - 1), lessThan); }