GrTessellator: improved straight skeleton implementation.
This patch improves the straight skeleton implementation used by
GrTessellator to collapse overlap regions in the alpha gradient border.
The resulting quality improvement can be seen in the
"thinconcavepaths" GM, for example, where the coverage values of
the "thin right angle", "thin rect and triangle" and "skinny snake"
are now lower and match the raster backend more closely. It also improves
correctness, such as on the linked Chromium bugs below.
Previously, the straight skeleton was performed using the same Vertex
and Edge classes used for tessellation, but this led to fragility in
maintaining the connectivity and ordering required by those classes.
Instead, that functionality has been moved to new SSEdge and SSVertex
classes. Their construction results in alternating SSVertex and
SSEdges around the boundary of the each overlap region, shrunk by one
SSEdge as the boundary collapses.
Applying events may now also create further events (chained events),
as intersections between newly-adjacent bisectors change the structure
of the skeleton. This is always calculated from the bisectors of
original boundary, not the shrunk boundary of the straight skeleton,
which is why each SSEdge points at its originating Edge. If the edges
are parallel or near-parallel, the bisector may be infinite. This is
handled by a new flavour of create_event(), which does a Line/Line
intersection (rather than an Edge/Edge intersection) to find the
intersection between the infinite bisector and an adjacent bisector.
Several ancillary bugs were fixed: the priority queue used to represent
edge events was sorting the inner edges incorrectly. These need to be
sorted in descending not ascending order of coverage. Its implementation
was moved from Skia's TDPQueue to std::priority_queue(), which is more
flexible in specifying a comparator.
check_for_intersection()'s partner synthesis code was moved into a new
function, compute_bisector(), also used by the chained skeleton events
code.
Degenerate edges are now removed during the simplify_boundary() pass.
They were previously detected but ignored, causing incorrect inner and
outer tangents to be computed in stroke_boundary().
An fSynthetic flag was added to Vertex, in order to detect vertices
which cannot be moved by an edge collapse event (e.g., intersections
with non-boundary edges, merged vertices, straight skeleton vertices).
More raw implementation notes:
Connect straight skeleton vertices as we find them, so we don't
have to use partnering (ss_connect()).
Only disconnect edges which are still alive after event application.
Add a check for near-parallel lines in compute_bisector().
Don't use edge type to determine direction to offset for bisectors.
The winding should already include this information.
Move Event ownership to SSEdge.
If we're down to the last two edges in a skeleton, don't check for events.
Add concave_arc_and_circle GM.
Add a collapsepaths GM.
Bug: 941429, 913349, 929915, 945853
Change-Id: Ib89e231d0e8611f8735fd3592db6391da096369d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/215094
Commit-Queue: Stephen White <senorblanco@chromium.org>
Reviewed-by: Robert Phillips <robertphillips@google.com>
diff --git a/src/gpu/GrTessellator.cpp b/src/gpu/GrTessellator.cpp
index 1ceed08..0a0cef9 100644
--- a/src/gpu/GrTessellator.cpp
+++ b/src/gpu/GrTessellator.cpp
@@ -15,10 +15,11 @@
#include "src/core/SkArenaAlloc.h"
#include "src/core/SkGeometry.h"
#include "src/core/SkPointPriv.h"
-#include "src/core/SkTDPQueue.h"
#include <algorithm>
#include <cstdio>
+#include <queue>
+#include <unordered_map>
#include <utility>
/*
@@ -153,6 +154,7 @@
, fLeftEnclosingEdge(nullptr), fRightEnclosingEdge(nullptr)
, fPartner(nullptr)
, fAlpha(alpha)
+ , fSynthetic(false)
#if LOGGING_ENABLED
, fID (-1.0f)
#endif
@@ -168,6 +170,7 @@
Edge* fRightEnclosingEdge; // Nearest edge in the AEL right of this vertex.
Vertex* fPartner; // Corresponding inner or outer vertex (for AA).
uint8_t fAlpha;
+ bool fSynthetic; // Is this a synthetic vertex?
#if LOGGING_ENABLED
float fID; // Identifier used for logging.
#endif
@@ -352,12 +355,10 @@
, fNextEdgeBelow(nullptr)
, fLeftPoly(nullptr)
, fRightPoly(nullptr)
- , fEvent(nullptr)
, fLeftPolyPrev(nullptr)
, fLeftPolyNext(nullptr)
, fRightPolyPrev(nullptr)
, fRightPolyNext(nullptr)
- , fOverlap(false)
, fUsedInLeftPoly(false)
, fUsedInRightPoly(false)
, fLine(top, bottom) {
@@ -374,12 +375,10 @@
Edge* fNextEdgeBelow; // "
Poly* fLeftPoly; // The Poly to the left of this edge, if any.
Poly* fRightPoly; // The Poly to the right of this edge, if any.
- Event* fEvent;
Edge* fLeftPolyPrev;
Edge* fLeftPolyNext;
Edge* fRightPolyPrev;
Edge* fRightPolyNext;
- bool fOverlap; // True if there's an overlap region adjacent to this edge.
bool fUsedInLeftPoly;
bool fUsedInRightPoly;
Line fLine;
@@ -436,6 +435,28 @@
}
};
+struct SSEdge;
+
+struct SSVertex {
+ SSVertex(Vertex* v) : fVertex(v), fPrev(nullptr), fNext(nullptr) {}
+ Vertex* fVertex;
+ SSEdge* fPrev;
+ SSEdge* fNext;
+};
+
+struct SSEdge {
+ SSEdge(Edge* edge, SSVertex* prev, SSVertex* next)
+ : fEdge(edge), fEvent(nullptr), fPrev(prev), fNext(next) {
+ }
+ Edge* fEdge;
+ Event* fEvent;
+ SSVertex* fPrev;
+ SSVertex* fNext;
+};
+
+typedef std::unordered_map<Vertex*, SSVertex*> SSVertexMap;
+typedef std::vector<SSEdge*> SSEdgeList;
+
struct EdgeList {
EdgeList() : fHead(nullptr), fTail(nullptr) {}
Edge* fHead;
@@ -465,36 +486,70 @@
}
};
+struct EventList;
+
struct Event {
- Event(Edge* edge, bool isOuterBoundary, const SkPoint& point, uint8_t alpha)
- : fEdge(edge), fIsOuterBoundary(isOuterBoundary), fPoint(point), fAlpha(alpha)
- , fPrev(nullptr), fNext(nullptr) {
+ Event(SSEdge* edge, const SkPoint& point, uint8_t alpha)
+ : fEdge(edge), fPoint(point), fAlpha(alpha) {
}
- Edge* fEdge;
- bool fIsOuterBoundary;
+ SSEdge* fEdge;
SkPoint fPoint;
uint8_t fAlpha;
- Event* fPrev;
- Event* fNext;
- void apply(VertexList* mesh, Comparator& c, SkArenaAlloc& alloc);
+ void apply(VertexList* mesh, Comparator& c, EventList* events, SkArenaAlloc& alloc);
};
-bool compare(Event* const& e1, Event* const& e2) {
- return e1->fAlpha > e2->fAlpha;
-}
+struct EventComparator {
+ enum class Op { kLessThan, kGreaterThan };
+ EventComparator(Op op) : fOp(op) {}
+ bool operator() (Event* const &e1, Event* const &e2) {
+ return fOp == Op::kLessThan ? e1->fAlpha < e2->fAlpha
+ : e1->fAlpha > e2->fAlpha;
+ }
+ Op fOp;
+};
-struct EventList : public SkTDPQueue<Event*, &compare> {};
+typedef std::priority_queue<Event*, std::vector<Event*>, EventComparator> EventPQ;
-void create_event(Edge* e, bool isOuterBoundary, EventList* events, SkArenaAlloc& alloc) {
- Edge bisector1(e->fTop, e->fTop->fPartner, 1, Edge::Type::kConnector);
- Edge bisector2(e->fBottom, e->fBottom->fPartner, 1, Edge::Type::kConnector);
+struct EventList : EventPQ {
+ EventList(EventComparator comparison) : EventPQ(comparison) {
+ }
+};
+
+void create_event(SSEdge* e, EventList* events, SkArenaAlloc& alloc) {
+ Vertex* prev = e->fPrev->fVertex;
+ Vertex* next = e->fNext->fVertex;
+ if (prev == next || !prev->fPartner || !next->fPartner) {
+ return;
+ }
+ Edge bisector1(prev, prev->fPartner, 1, Edge::Type::kConnector);
+ Edge bisector2(next, next->fPartner, 1, Edge::Type::kConnector);
SkPoint p;
uint8_t alpha;
if (bisector1.intersect(bisector2, &p, &alpha)) {
- LOG("found overlap edge %g -> %g, will collapse to %g,%g alpha %d\n",
- e->fTop->fID, e->fBottom->fID, p.fX, p.fY, alpha);
- e->fEvent = alloc.make<Event>(e, isOuterBoundary, p, alpha);
- events->insert(e->fEvent);
+ LOG("found edge event for %g, %g (original %g -> %g), will collapse to %g,%g alpha %d\n",
+ prev->fID, next->fID, e->fEdge->fTop->fID, e->fEdge->fBottom->fID, p.fX, p.fY, alpha);
+ e->fEvent = alloc.make<Event>(e, p, alpha);
+ events->push(e->fEvent);
+ }
+}
+
+void create_event(SSEdge* edge, Vertex* v, SSEdge* other, Vertex* dest, EventList* events,
+ Comparator& c, SkArenaAlloc& alloc) {
+ if (!v->fPartner) {
+ return;
+ }
+ Line line = edge->fEdge->fLine;
+ line.fC = -(dest->fPoint.fX * line.fA + dest->fPoint.fY * line.fB);
+ Edge bisector(v, v->fPartner, 1, Edge::Type::kConnector);
+ SkPoint p;
+ uint8_t alpha = dest->fAlpha;
+ if (line.intersect(bisector.fLine, &p) && !c.sweep_lt(p, edge->fEdge->fTop->fPoint) &&
+ c.sweep_lt(p, edge->fEdge->fBottom->fPoint)) {
+ LOG("found p edge event for %g, %g (original %g -> %g), will collapse to %g,%g alpha %d\n",
+ dest->fID, v->fID, edge->fEdge->fTop->fID, edge->fEdge->fBottom->fID, p.fX, p.fY,
+ alpha);
+ edge->fEvent = alloc.make<Event>(edge, p, alpha);
+ events->push(edge->fEvent);
}
}
@@ -1164,6 +1219,7 @@
set_top(edge, dst, nullptr, nullptr, c);
}
mesh->remove(src);
+ dst->fSynthetic = true;
}
Vertex* create_sorted_vertex(const SkPoint& p, uint8_t alpha, VertexList* mesh,
@@ -1217,6 +1273,25 @@
}
}
+void compute_bisector(Edge* edge1, Edge* edge2, Vertex* v, SkArenaAlloc& alloc) {
+ Line line1 = edge1->fLine;
+ Line line2 = edge2->fLine;
+ line1.normalize();
+ line2.normalize();
+ double cosAngle = line1.fA * line2.fA + line1.fB * line2.fB;
+ if (cosAngle > 0.999) {
+ return;
+ }
+ line1.fC += edge1->fWinding > 0 ? -1 : 1;
+ line2.fC += edge2->fWinding > 0 ? -1 : 1;
+ SkPoint p;
+ if (line1.intersect(line2, &p)) {
+ uint8_t alpha = edge1->fType == Edge::Type::kOuter ? 255 : 0;
+ v->fPartner = alloc.make<Vertex>(p, alpha);
+ LOG("computed bisector (%g,%g) alpha %d for vertex %g\n", p.fX, p.fY, alpha, v->fID);
+ }
+}
+
bool check_for_intersection(Edge* left, Edge* right, EdgeList* activeEdges, Vertex** current,
VertexList* mesh, Comparator& c, SkArenaAlloc& alloc) {
if (!left || !right) {
@@ -1250,17 +1325,8 @@
} else {
v = create_sorted_vertex(p, alpha, mesh, top, c, alloc);
if (left->fTop->fPartner) {
- Line line1 = left->fLine;
- Line line2 = right->fLine;
- int dir = left->fType == Edge::Type::kOuter ? -1 : 1;
- line1.fC += sqrt(left->fLine.magSq()) * (left->fWinding > 0 ? 1 : -1) * dir;
- line2.fC += sqrt(right->fLine.magSq()) * (right->fWinding > 0 ? 1 : -1) * dir;
- SkPoint p;
- if (line1.intersect(line2, &p)) {
- LOG("synthesizing partner (%g,%g) for intersection vertex %g\n",
- p.fX, p.fY, v->fID);
- v->fPartner = alloc.make<Vertex>(p, 255 - v->fAlpha);
- }
+ v->fSynthetic = true;
+ compute_bisector(left, right, v, alloc);
}
}
rewind(activeEdges, current, top ? top : v, c);
@@ -1433,6 +1499,21 @@
#endif
}
+void dump_skel(const SSEdgeList& ssEdges) {
+#if LOGGING_ENABLED
+ LOG("skeleton:\n");
+ for (SSEdge* edge : ssEdges) {
+ if (edge->fEdge) {
+ LOG("skel edge %g -> %g (original %g -> %g)\n",
+ edge->fPrev->fVertex->fID,
+ edge->fNext->fVertex->fID,
+ edge->fEdge->fTop->fID,
+ edge->fEdge->fBottom->fID);
+ }
+ }
+#endif
+}
+
#ifdef SK_DEBUG
void validate_edge_pair(Edge* left, Edge* right, Comparator& c) {
if (!left || !right) {
@@ -1470,12 +1551,16 @@
// Stage 4: Simplify the mesh by inserting new vertices at intersecting edges.
+bool connected(Vertex* v) {
+ return v->fFirstEdgeAbove || v->fFirstEdgeBelow;
+}
+
bool simplify(VertexList* mesh, Comparator& c, SkArenaAlloc& alloc) {
LOG("simplifying complex polygons\n");
EdgeList activeEdges;
bool found = false;
for (Vertex* v = mesh->fHead; v != nullptr; v = v->fNext) {
- if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
+ if (!connected(v)) {
continue;
}
Edge* leftEnclosingEdge;
@@ -1532,7 +1617,7 @@
EdgeList activeEdges;
Poly* polys = nullptr;
for (Vertex* v = vertices.fHead; v != nullptr; v = v->fNext) {
- if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
+ if (!connected(v)) {
continue;
}
#if LOGGING_ENABLED
@@ -1639,7 +1724,7 @@
LOG("removing non-boundary edges\n");
EdgeList activeEdges;
for (Vertex* v = mesh.fHead; v != nullptr; v = v->fNext) {
- if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
+ if (!connected(v)) {
continue;
}
Edge* leftEnclosingEdge;
@@ -1674,31 +1759,6 @@
SkDoubleToScalar(e->fLine.fB));
}
-void reconnect(Edge* edge, Vertex* src, Vertex* dst, Comparator& c) {
- disconnect(edge);
- if (src == edge->fTop) {
- edge->fTop = dst;
- } else {
- SkASSERT(src == edge->fBottom);
- edge->fBottom = dst;
- }
- if (edge->fEvent) {
- edge->fEvent->fEdge = nullptr;
- }
- if (edge->fTop == edge->fBottom) {
- return;
- }
- if (c.sweep_lt(edge->fBottom->fPoint, edge->fTop->fPoint)) {
- using std::swap;
- swap(edge->fTop, edge->fBottom);
- edge->fWinding *= -1;
- }
- edge->recompute();
- insert_edge_below(edge, edge->fTop, c);
- insert_edge_above(edge, edge->fBottom, c);
- merge_collinear_edges(edge, nullptr, nullptr, c);
-}
-
// Stage 5c: detect and remove "pointy" vertices whose edge normals point in opposite directions
// and whose adjacent vertices are less than a quarter pixel from an edge. These are guaranteed to
// invert on stroking.
@@ -1715,7 +1775,15 @@
SkVector normal;
get_edge_normal(e, &normal);
constexpr double kQuarterPixelSq = 0.25f * 0.25f;
- if (prev != next && prevNormal.dot(normal) < 0.0 &&
+ if (prev == next) {
+ remove_edge(prevEdge, boundary);
+ remove_edge(e, boundary);
+ prevEdge = boundary->fTail;
+ e = boundary->fHead;
+ if (prevEdge) {
+ get_edge_normal(prevEdge, &prevNormal);
+ }
+ } else if (prevNormal.dot(normal) < 0.0 &&
(distPrev * distPrev <= kQuarterPixelSq || distNext * distNext <= kQuarterPixelSq)) {
Edge* join = new_edge(prev, next, Edge::Type::kInner, c, alloc);
if (prev->fPoint != next->fPoint) {
@@ -1741,56 +1809,69 @@
}
}
-void reconnect_all_overlap_edges(Vertex* src, Vertex* dst, Edge* current, Comparator& c) {
- if (src->fPartner) {
- src->fPartner->fPartner = dst;
+void ss_connect(Vertex* v, Vertex* dest, Comparator& c, SkArenaAlloc& alloc) {
+ if (v == dest) {
+ return;
}
- for (Edge* e = src->fFirstEdgeAbove; e; ) {
- Edge* next = e->fNextEdgeAbove;
- if (e->fOverlap && e != current) {
- reconnect(e, src, dst, c);
- }
- e = next;
- }
- for (Edge* e = src->fFirstEdgeBelow; e; ) {
- Edge* next = e->fNextEdgeBelow;
- if (e->fOverlap && e != current) {
- reconnect(e, src, dst, c);
- }
- e = next;
+ LOG("ss_connecting vertex %g to vertex %g\n", v->fID, dest->fID);
+ if (v->fSynthetic) {
+ connect(v, dest, Edge::Type::kConnector, c, alloc, 0);
+ } else if (v->fPartner) {
+ LOG("setting %g's partner to %g ", v->fPartner->fID, dest->fID);
+ LOG("and %g's partner to null\n", v->fID);
+ v->fPartner->fPartner = dest;
+ v->fPartner = nullptr;
}
}
-void Event::apply(VertexList* mesh, Comparator& c, SkArenaAlloc& alloc) {
- if (!fEdge || !fEdge->fTop || !fEdge->fBottom) {
+void Event::apply(VertexList* mesh, Comparator& c, EventList* events, SkArenaAlloc& alloc) {
+ if (!fEdge) {
return;
}
- Vertex* top = fEdge->fTop;
- Vertex* bottom = fEdge->fBottom;
- Vertex* dest = create_sorted_vertex(fPoint, fAlpha, mesh, fEdge->fTop, c, alloc);
- LOG("collapsing edge %g -> %g to %g (%g, %g) alpha %d\n",
- top->fID, bottom->fID, dest->fID, fPoint.fX, fPoint.fY, fAlpha);
- reconnect_all_overlap_edges(top, dest, fEdge, c);
- reconnect_all_overlap_edges(bottom, dest, fEdge, c);
-
- // Since the destination has multiple partners, give it none.
- dest->fPartner = nullptr;
-
- // Disconnect all collapsed edges except outer boundaries.
- // Those are required to preserve shape coverage and winding correctness.
- if (!fIsOuterBoundary) {
- disconnect(fEdge);
- } else {
- LOG("edge %g -> %g is outer boundary; not disconnecting.\n",
- fEdge->fTop->fID, fEdge->fBottom->fID);
- fEdge->fWinding = fEdge->fWinding >= 0 ? 1 : -1;
+ Vertex* prev = fEdge->fPrev->fVertex;
+ Vertex* next = fEdge->fNext->fVertex;
+ SSEdge* prevEdge = fEdge->fPrev->fPrev;
+ SSEdge* nextEdge = fEdge->fNext->fNext;
+ if (!prevEdge || !nextEdge || !prevEdge->fEdge || !nextEdge->fEdge) {
+ return;
}
+ Vertex* dest = create_sorted_vertex(fPoint, fAlpha, mesh, prev, c, alloc);
+ dest->fSynthetic = true;
+ SSVertex* ssv = alloc.make<SSVertex>(dest);
+ LOG("collapsing %g, %g (original edge %g -> %g) to %g (%g, %g) alpha %d\n",
+ prev->fID, next->fID, fEdge->fEdge->fTop->fID, fEdge->fEdge->fBottom->fID,
+ dest->fID, fPoint.fX, fPoint.fY, fAlpha);
+ fEdge->fEdge = nullptr;
- // If top still has some connected edges, set its partner to dest.
- top->fPartner = top->fFirstEdgeAbove || top->fFirstEdgeBelow ? dest : nullptr;
+ ss_connect(prev, dest, c, alloc);
+ ss_connect(next, dest, c, alloc);
- // If bottom still has some connected edges, set its partner to dest.
- bottom->fPartner = bottom->fFirstEdgeAbove || bottom->fFirstEdgeBelow ? dest : nullptr;
+ prevEdge->fNext = nextEdge->fPrev = ssv;
+ ssv->fPrev = prevEdge;
+ ssv->fNext = nextEdge;
+ if (!prevEdge->fEdge || !nextEdge->fEdge) {
+ return;
+ }
+ if (prevEdge->fEvent) {
+ prevEdge->fEvent->fEdge = nullptr;
+ }
+ if (nextEdge->fEvent) {
+ nextEdge->fEvent->fEdge = nullptr;
+ }
+ if (prevEdge->fPrev == nextEdge->fNext) {
+ ss_connect(prevEdge->fPrev->fVertex, dest, c, alloc);
+ prevEdge->fEdge = nextEdge->fEdge = nullptr;
+ } else {
+ compute_bisector(prevEdge->fEdge, nextEdge->fEdge, dest, alloc);
+ SkASSERT(prevEdge != fEdge && nextEdge != fEdge);
+ if (dest->fPartner) {
+ create_event(prevEdge, events, alloc);
+ create_event(nextEdge, events, alloc);
+ } else {
+ create_event(prevEdge, prevEdge->fPrev->fVertex, nextEdge, dest, events, c, alloc);
+ create_event(nextEdge, nextEdge->fNext->fVertex, prevEdge, dest, events, c, alloc);
+ }
+ }
}
bool is_overlap_edge(Edge* e) {
@@ -1805,51 +1886,82 @@
// This is a stripped-down version of tessellate() which computes edges which
// join two filled regions, which represent overlap regions, and collapses them.
-bool collapse_overlap_regions(VertexList* mesh, Comparator& c, SkArenaAlloc& alloc) {
+bool collapse_overlap_regions(VertexList* mesh, Comparator& c, SkArenaAlloc& alloc,
+ EventComparator comp) {
LOG("\nfinding overlap regions\n");
EdgeList activeEdges;
- EventList events;
+ EventList events(comp);
+ SSVertexMap ssVertices;
+ SSEdgeList ssEdges;
for (Vertex* v = mesh->fHead; v != nullptr; v = v->fNext) {
- if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
+ if (!connected(v)) {
continue;
}
Edge* leftEnclosingEdge;
Edge* rightEnclosingEdge;
find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
- for (Edge* e = v->fLastEdgeAbove; e; e = e->fPrevEdgeAbove) {
+ for (Edge* e = v->fLastEdgeAbove; e && e != leftEnclosingEdge;) {
Edge* prev = e->fPrevEdgeAbove ? e->fPrevEdgeAbove : leftEnclosingEdge;
remove_edge(e, &activeEdges);
+ bool leftOverlap = prev && is_overlap_edge(prev);
+ bool rightOverlap = is_overlap_edge(e);
+ bool isOuterBoundary = e->fType == Edge::Type::kOuter &&
+ (!prev || prev->fWinding == 0 || e->fWinding == 0);
if (prev) {
e->fWinding -= prev->fWinding;
}
+ if (leftOverlap && rightOverlap) {
+ LOG("found interior overlap edge %g -> %g, disconnecting\n",
+ e->fTop->fID, e->fBottom->fID);
+ disconnect(e);
+ } else if (leftOverlap || rightOverlap) {
+ LOG("found overlap edge %g -> %g%s\n", e->fTop->fID, e->fBottom->fID,
+ isOuterBoundary ? ", is outer boundary" : "");
+ Vertex* prevVertex = e->fWinding < 0 ? e->fBottom : e->fTop;
+ Vertex* nextVertex = e->fWinding < 0 ? e->fTop : e->fBottom;
+ SSVertex* ssPrev = ssVertices[prevVertex];
+ if (!ssPrev) {
+ ssPrev = ssVertices[prevVertex] = alloc.make<SSVertex>(prevVertex);
+ }
+ SSVertex* ssNext = ssVertices[nextVertex];
+ if (!ssNext) {
+ ssNext = ssVertices[nextVertex] = alloc.make<SSVertex>(nextVertex);
+ }
+ SSEdge* ssEdge = alloc.make<SSEdge>(e, ssPrev, ssNext);
+ ssEdges.push_back(ssEdge);
+// SkASSERT(!ssPrev->fNext && !ssNext->fPrev);
+ ssPrev->fNext = ssNext->fPrev = ssEdge;
+ create_event(ssEdge, &events, alloc);
+ if (!isOuterBoundary) {
+ disconnect(e);
+ }
+ }
+ e = prev;
}
Edge* prev = leftEnclosingEdge;
for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {
if (prev) {
e->fWinding += prev->fWinding;
- e->fOverlap = e->fOverlap || is_overlap_edge(prev);
- }
- e->fOverlap = e->fOverlap || is_overlap_edge(e);
- if (e->fOverlap) {
- // If this edge borders a zero-winding area, it's a boundary; don't disconnect it.
- bool isOuterBoundary = e->fType == Edge::Type::kOuter &&
- (!prev || prev->fWinding == 0 || e->fWinding == 0);
- create_event(e, isOuterBoundary, &events, alloc);
}
insert_edge(e, prev, &activeEdges);
prev = e;
}
}
+ bool complex = events.size() > 0;
+
LOG("\ncollapsing overlap regions\n");
- if (events.count() == 0) {
- return false;
- }
- while (events.count() > 0) {
- Event* event = events.peek();
+ while (events.size() > 0) {
+ Event* event = events.top();
events.pop();
- event->apply(mesh, c, alloc);
+ event->apply(mesh, c, &events, alloc);
}
- return true;
+ dump_skel(ssEdges);
+ for (SSEdge* edge : ssEdges) {
+ if (Edge* e = edge->fEdge) {
+ connect(edge->fPrev->fVertex, edge->fNext->fVertex, e->fType, c, alloc, 0);
+ }
+ }
+ return complex;
}
bool inversion(Vertex* prev, Vertex* next, Edge* origEdge, Comparator& c) {
@@ -2118,6 +2230,8 @@
sort_mesh(&mesh, c, alloc);
merge_coincident_vertices(&mesh, c, alloc);
simplify(&mesh, c, alloc);
+ LOG("\nsimplified mesh:\n");
+ dump_mesh(mesh);
if (antialias) {
VertexList innerMesh;
extract_boundaries(mesh, &innerMesh, outerMesh, fillType, c, alloc);
@@ -2131,8 +2245,10 @@
dump_mesh(innerMesh);
LOG("\nouter mesh before:\n");
dump_mesh(*outerMesh);
- was_complex = collapse_overlap_regions(&innerMesh, c, alloc) || was_complex;
- was_complex = collapse_overlap_regions(outerMesh, c, alloc) || was_complex;
+ EventComparator eventLT(EventComparator::Op::kLessThan);
+ EventComparator eventGT(EventComparator::Op::kGreaterThan);
+ was_complex = collapse_overlap_regions(&innerMesh, c, alloc, eventLT) || was_complex;
+ was_complex = collapse_overlap_regions(outerMesh, c, alloc, eventGT) || was_complex;
if (was_complex) {
LOG("found complex mesh; taking slow path\n");
VertexList aaMesh;
@@ -2145,6 +2261,7 @@
sorted_merge(&innerMesh, outerMesh, &aaMesh, c);
merge_coincident_vertices(&aaMesh, c, alloc);
simplify(&aaMesh, c, alloc);
+ LOG("combined and simplified mesh:\n");
dump_mesh(aaMesh);
outerMesh->fHead = outerMesh->fTail = nullptr;
return tessellate(aaMesh, alloc);