Broke GrTessellatingPathRenderer's tessellator out into a separate file.
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1557083002
Committed: https://skia.googlesource.com/skia/+/8b05cb8a00bdb82e100f1ba74bf4de4a504cceea
Review URL: https://codereview.chromium.org/1557083002
diff --git a/gyp/gpu.gypi b/gyp/gpu.gypi
index 7312ff4..a760580 100644
--- a/gyp/gpu.gypi
+++ b/gyp/gpu.gypi
@@ -161,6 +161,8 @@
'<(skia_src_path)/gpu/GrStencilAttachment.h',
'<(skia_src_path)/gpu/GrStrokeInfo.cpp',
'<(skia_src_path)/gpu/GrStrokeInfo.h',
+ '<(skia_src_path)/gpu/GrTessellator.cpp',
+ '<(skia_src_path)/gpu/GrTessellator.h',
'<(skia_src_path)/gpu/GrTraceMarker.cpp',
'<(skia_src_path)/gpu/GrTraceMarker.h',
'<(skia_src_path)/gpu/GrTracing.h',
diff --git a/src/gpu/GrTessellator.cpp b/src/gpu/GrTessellator.cpp
new file mode 100644
index 0000000..ea130cf
--- /dev/null
+++ b/src/gpu/GrTessellator.cpp
@@ -0,0 +1,1470 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrTessellator.h"
+
+#include "GrBatchFlushState.h"
+#include "GrBatchTest.h"
+#include "GrDefaultGeoProcFactory.h"
+#include "GrPathUtils.h"
+#include "GrVertices.h"
+#include "GrResourceCache.h"
+#include "GrResourceProvider.h"
+#include "SkGeometry.h"
+#include "SkChunkAlloc.h"
+
+#include "batches/GrVertexBatch.h"
+
+#include <stdio.h>
+
+/*
+ * There are six stages to the algorithm:
+ *
+ * 1) Linearize the path contours into piecewise linear segments (path_to_contours()).
+ * 2) Build a mesh of edges connecting the vertices (build_edges()).
+ * 3) Sort the vertices in Y (and secondarily in X) (merge_sort()).
+ * 4) Simplify the mesh by inserting new vertices at intersecting edges (simplify()).
+ * 5) Tessellate the simplified mesh into monotone polygons (tessellate()).
+ * 6) Triangulate the monotone polygons directly into a vertex buffer (polys_to_triangles()).
+ *
+ * The vertex sorting in step (3) is a merge sort, since it plays well with the linked list
+ * of vertices (and the necessity of inserting new vertices on intersection).
+ *
+ * Stages (4) and (5) use an active edge list, which a list of all edges for which the
+ * sweep line has crossed the top vertex, but not the bottom vertex. It's sorted
+ * left-to-right based on the point where both edges are active (when both top vertices
+ * have been seen, so the "lower" top vertex of the two). If the top vertices are equal
+ * (shared), it's sorted based on the last point where both edges are active, so the
+ * "upper" bottom vertex.
+ *
+ * The most complex step is the simplification (4). It's based on the Bentley-Ottman
+ * line-sweep algorithm, but due to floating point inaccuracy, the intersection points are
+ * not exact and may violate the mesh topology or active edge list ordering. We
+ * accommodate this by adjusting the topology of the mesh and AEL to match the intersection
+ * points. This occurs in three ways:
+ *
+ * A) Intersections may cause a shortened edge to no longer be ordered with respect to its
+ * neighbouring edges at the top or bottom vertex. This is handled by merging the
+ * edges (merge_collinear_edges()).
+ * B) Intersections may cause an edge to violate the left-to-right ordering of the
+ * active edge list. This is handled by splitting the neighbour edge on the
+ * intersected vertex (cleanup_active_edges()).
+ * C) Shortening an edge may cause an active edge to become inactive or an inactive edge
+ * to become active. This is handled by removing or inserting the edge in the active
+ * edge list (fix_active_state()).
+ *
+ * The tessellation steps (5) and (6) are based on "Triangulating Simple Polygons and
+ * Equivalent Problems" (Fournier and Montuno); also a line-sweep algorithm. Note that it
+ * currently uses a linked list for the active edge list, rather than a 2-3 tree as the
+ * paper describes. The 2-3 tree gives O(lg N) lookups, but insertion and removal also
+ * become O(lg N). In all the test cases, it was found that the cost of frequent O(lg N)
+ * insertions and removals was greater than the cost of infrequent O(N) lookups with the
+ * linked list implementation. With the latter, all removals are O(1), and most insertions
+ * are O(1), since we know the adjacent edge in the active edge list based on the topology.
+ * Only type 2 vertices (see paper) require the O(N) lookups, and these are much less
+ * frequent. There may be other data structures worth investigating, however.
+ *
+ * Note that the orientation of the line sweep algorithms is determined by the aspect ratio of the
+ * path bounds. When the path is taller than it is wide, we sort vertices based on increasing Y
+ * coordinate, and secondarily by increasing X coordinate. When the path is wider than it is tall,
+ * we sort by increasing X coordinate, but secondarily by *decreasing* Y coordinate. This is so
+ * that the "left" and "right" orientation in the code remains correct (edges to the left are
+ * increasing in Y; edges to the right are decreasing in Y). That is, the setting rotates 90
+ * degrees counterclockwise, rather that transposing.
+ */
+
+#define LOGGING_ENABLED 0
+
+#if LOGGING_ENABLED
+#define LOG printf
+#else
+#define LOG(...)
+#endif
+
+#define ALLOC_NEW(Type, args, alloc) new (alloc.allocThrow(sizeof(Type))) Type args
+
+namespace {
+
+struct Vertex;
+struct Edge;
+struct Poly;
+
+template <class T, T* T::*Prev, T* T::*Next>
+void insert(T* t, T* prev, T* next, T** head, T** tail) {
+ t->*Prev = prev;
+ t->*Next = next;
+ if (prev) {
+ prev->*Next = t;
+ } else if (head) {
+ *head = t;
+ }
+ if (next) {
+ next->*Prev = t;
+ } else if (tail) {
+ *tail = t;
+ }
+}
+
+template <class T, T* T::*Prev, T* T::*Next>
+void remove(T* t, T** head, T** tail) {
+ if (t->*Prev) {
+ t->*Prev->*Next = t->*Next;
+ } else if (head) {
+ *head = t->*Next;
+ }
+ if (t->*Next) {
+ t->*Next->*Prev = t->*Prev;
+ } else if (tail) {
+ *tail = t->*Prev;
+ }
+ t->*Prev = t->*Next = nullptr;
+}
+
+/**
+ * Vertices are used in three ways: first, the path contours are converted into a
+ * circularly-linked list of Vertices for each contour. After edge construction, the same Vertices
+ * are re-ordered by the merge sort according to the sweep_lt comparator (usually, increasing
+ * in Y) using the same fPrev/fNext pointers that were used for the contours, to avoid
+ * reallocation. Finally, MonotonePolys are built containing a circularly-linked list of
+ * Vertices. (Currently, those Vertices are newly-allocated for the MonotonePolys, since
+ * an individual Vertex from the path mesh may belong to multiple
+ * MonotonePolys, so the original Vertices cannot be re-used.
+ */
+
+struct Vertex {
+ Vertex(const SkPoint& point)
+ : fPoint(point), fPrev(nullptr), fNext(nullptr)
+ , fFirstEdgeAbove(nullptr), fLastEdgeAbove(nullptr)
+ , fFirstEdgeBelow(nullptr), fLastEdgeBelow(nullptr)
+ , fProcessed(false)
+#if LOGGING_ENABLED
+ , fID (-1.0f)
+#endif
+ {}
+ SkPoint fPoint; // Vertex position
+ Vertex* fPrev; // Linked list of contours, then Y-sorted vertices.
+ Vertex* fNext; // "
+ Edge* fFirstEdgeAbove; // Linked list of edges above this vertex.
+ Edge* fLastEdgeAbove; // "
+ Edge* fFirstEdgeBelow; // Linked list of edges below this vertex.
+ Edge* fLastEdgeBelow; // "
+ bool fProcessed; // Has this vertex been seen in simplify()?
+#if LOGGING_ENABLED
+ float fID; // Identifier used for logging.
+#endif
+};
+
+/***************************************************************************************/
+
+typedef bool (*CompareFunc)(const SkPoint& a, const SkPoint& b);
+
+struct Comparator {
+ CompareFunc sweep_lt;
+ CompareFunc sweep_gt;
+};
+
+bool sweep_lt_horiz(const SkPoint& a, const SkPoint& b) {
+ return a.fX == b.fX ? a.fY > b.fY : a.fX < b.fX;
+}
+
+bool sweep_lt_vert(const SkPoint& a, const SkPoint& b) {
+ return a.fY == b.fY ? a.fX < b.fX : a.fY < b.fY;
+}
+
+bool sweep_gt_horiz(const SkPoint& a, const SkPoint& b) {
+ return a.fX == b.fX ? a.fY < b.fY : a.fX > b.fX;
+}
+
+bool sweep_gt_vert(const SkPoint& a, const SkPoint& b) {
+ return a.fY == b.fY ? a.fX > b.fX : a.fY > b.fY;
+}
+
+inline SkPoint* emit_vertex(Vertex* v, SkPoint* data) {
+ *data++ = v->fPoint;
+ return data;
+}
+
+SkPoint* emit_triangle(Vertex* v0, Vertex* v1, Vertex* v2, SkPoint* data) {
+#if WIREFRAME
+ data = emit_vertex(v0, data);
+ data = emit_vertex(v1, data);
+ data = emit_vertex(v1, data);
+ data = emit_vertex(v2, data);
+ data = emit_vertex(v2, data);
+ data = emit_vertex(v0, data);
+#else
+ data = emit_vertex(v0, data);
+ data = emit_vertex(v1, data);
+ data = emit_vertex(v2, data);
+#endif
+ return data;
+}
+
+struct EdgeList {
+ EdgeList() : fHead(nullptr), fTail(nullptr) {}
+ Edge* fHead;
+ Edge* fTail;
+};
+
+/**
+ * An Edge joins a top Vertex to a bottom Vertex. Edge ordering for the list of "edges above" and
+ * "edge below" a vertex as well as for the active edge list is handled by isLeftOf()/isRightOf().
+ * Note that an Edge will give occasionally dist() != 0 for its own endpoints (because floating
+ * point). For speed, that case is only tested by the callers which require it (e.g.,
+ * cleanup_active_edges()). Edges also handle checking for intersection with other edges.
+ * Currently, this converts the edges to the parametric form, in order to avoid doing a division
+ * until an intersection has been confirmed. This is slightly slower in the "found" case, but
+ * a lot faster in the "not found" case.
+ *
+ * The coefficients of the line equation stored in double precision to avoid catastrphic
+ * cancellation in the isLeftOf() and isRightOf() checks. Using doubles ensures that the result is
+ * correct in float, since it's a polynomial of degree 2. The intersect() function, being
+ * degree 5, is still subject to catastrophic cancellation. We deal with that by assuming its
+ * output may be incorrect, and adjusting the mesh topology to match (see comment at the top of
+ * this file).
+ */
+
+struct Edge {
+ Edge(Vertex* top, Vertex* bottom, int winding)
+ : fWinding(winding)
+ , fTop(top)
+ , fBottom(bottom)
+ , fLeft(nullptr)
+ , fRight(nullptr)
+ , fPrevEdgeAbove(nullptr)
+ , fNextEdgeAbove(nullptr)
+ , fPrevEdgeBelow(nullptr)
+ , fNextEdgeBelow(nullptr)
+ , fLeftPoly(nullptr)
+ , fRightPoly(nullptr) {
+ recompute();
+ }
+ int fWinding; // 1 == edge goes downward; -1 = edge goes upward.
+ Vertex* fTop; // The top vertex in vertex-sort-order (sweep_lt).
+ Vertex* fBottom; // The bottom vertex in vertex-sort-order.
+ Edge* fLeft; // The linked list of edges in the active edge list.
+ Edge* fRight; // "
+ Edge* fPrevEdgeAbove; // The linked list of edges in the bottom Vertex's "edges above".
+ Edge* fNextEdgeAbove; // "
+ Edge* fPrevEdgeBelow; // The linked list of edges in the top Vertex's "edges below".
+ 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.
+ double fDX; // The line equation for this edge, in implicit form.
+ double fDY; // fDY * x + fDX * y + fC = 0, for point (x, y) on the line.
+ double fC;
+ double dist(const SkPoint& p) const {
+ return fDY * p.fX - fDX * p.fY + fC;
+ }
+ bool isRightOf(Vertex* v) const {
+ return dist(v->fPoint) < 0.0;
+ }
+ bool isLeftOf(Vertex* v) const {
+ return dist(v->fPoint) > 0.0;
+ }
+ void recompute() {
+ fDX = static_cast<double>(fBottom->fPoint.fX) - fTop->fPoint.fX;
+ fDY = static_cast<double>(fBottom->fPoint.fY) - fTop->fPoint.fY;
+ fC = static_cast<double>(fTop->fPoint.fY) * fBottom->fPoint.fX -
+ static_cast<double>(fTop->fPoint.fX) * fBottom->fPoint.fY;
+ }
+ bool intersect(const Edge& other, SkPoint* p) {
+ LOG("intersecting %g -> %g with %g -> %g\n",
+ fTop->fID, fBottom->fID,
+ other.fTop->fID, other.fBottom->fID);
+ if (fTop == other.fTop || fBottom == other.fBottom) {
+ return false;
+ }
+ double denom = fDX * other.fDY - fDY * other.fDX;
+ if (denom == 0.0) {
+ return false;
+ }
+ double dx = static_cast<double>(fTop->fPoint.fX) - other.fTop->fPoint.fX;
+ double dy = static_cast<double>(fTop->fPoint.fY) - other.fTop->fPoint.fY;
+ double sNumer = dy * other.fDX - dx * other.fDY;
+ double tNumer = dy * fDX - dx * fDY;
+ // If (sNumer / denom) or (tNumer / denom) is not in [0..1], exit early.
+ // This saves us doing the divide below unless absolutely necessary.
+ if (denom > 0.0 ? (sNumer < 0.0 || sNumer > denom || tNumer < 0.0 || tNumer > denom)
+ : (sNumer > 0.0 || sNumer < denom || tNumer > 0.0 || tNumer < denom)) {
+ return false;
+ }
+ double s = sNumer / denom;
+ SkASSERT(s >= 0.0 && s <= 1.0);
+ p->fX = SkDoubleToScalar(fTop->fPoint.fX + s * fDX);
+ p->fY = SkDoubleToScalar(fTop->fPoint.fY + s * fDY);
+ return true;
+ }
+ bool isActive(EdgeList* activeEdges) const {
+ return activeEdges && (fLeft || fRight || activeEdges->fHead == this);
+ }
+};
+
+/***************************************************************************************/
+
+struct Poly {
+ Poly(int winding)
+ : fWinding(winding)
+ , fHead(nullptr)
+ , fTail(nullptr)
+ , fActive(nullptr)
+ , fNext(nullptr)
+ , fPartner(nullptr)
+ , fCount(0)
+ {
+#if LOGGING_ENABLED
+ static int gID = 0;
+ fID = gID++;
+ LOG("*** created Poly %d\n", fID);
+#endif
+ }
+ typedef enum { kNeither_Side, kLeft_Side, kRight_Side } Side;
+ struct MonotonePoly {
+ MonotonePoly()
+ : fSide(kNeither_Side)
+ , fHead(nullptr)
+ , fTail(nullptr)
+ , fPrev(nullptr)
+ , fNext(nullptr) {}
+ Side fSide;
+ Vertex* fHead;
+ Vertex* fTail;
+ MonotonePoly* fPrev;
+ MonotonePoly* fNext;
+ bool addVertex(Vertex* v, Side side, SkChunkAlloc& alloc) {
+ Vertex* newV = ALLOC_NEW(Vertex, (v->fPoint), alloc);
+ bool done = false;
+ if (fSide == kNeither_Side) {
+ fSide = side;
+ } else {
+ done = side != fSide;
+ }
+ if (fHead == nullptr) {
+ fHead = fTail = newV;
+ } else if (fSide == kRight_Side) {
+ newV->fPrev = fTail;
+ fTail->fNext = newV;
+ fTail = newV;
+ } else {
+ newV->fNext = fHead;
+ fHead->fPrev = newV;
+ fHead = newV;
+ }
+ return done;
+ }
+
+ SkPoint* emit(SkPoint* data) {
+ Vertex* first = fHead;
+ Vertex* v = first->fNext;
+ while (v != fTail) {
+ SkASSERT(v && v->fPrev && v->fNext);
+ Vertex* prev = v->fPrev;
+ Vertex* curr = v;
+ Vertex* next = v->fNext;
+ double ax = static_cast<double>(curr->fPoint.fX) - prev->fPoint.fX;
+ double ay = static_cast<double>(curr->fPoint.fY) - prev->fPoint.fY;
+ double bx = static_cast<double>(next->fPoint.fX) - curr->fPoint.fX;
+ double by = static_cast<double>(next->fPoint.fY) - curr->fPoint.fY;
+ if (ax * by - ay * bx >= 0.0) {
+ data = emit_triangle(prev, curr, next, data);
+ v->fPrev->fNext = v->fNext;
+ v->fNext->fPrev = v->fPrev;
+ if (v->fPrev == first) {
+ v = v->fNext;
+ } else {
+ v = v->fPrev;
+ }
+ } else {
+ v = v->fNext;
+ }
+ }
+ return data;
+ }
+ };
+ Poly* addVertex(Vertex* v, Side side, SkChunkAlloc& alloc) {
+ LOG("addVertex() to %d at %g (%g, %g), %s side\n", fID, v->fID, v->fPoint.fX, v->fPoint.fY,
+ side == kLeft_Side ? "left" : side == kRight_Side ? "right" : "neither");
+ Poly* partner = fPartner;
+ Poly* poly = this;
+ if (partner) {
+ fPartner = partner->fPartner = nullptr;
+ }
+ if (!fActive) {
+ fActive = ALLOC_NEW(MonotonePoly, (), alloc);
+ }
+ if (fActive->addVertex(v, side, alloc)) {
+ if (fTail) {
+ fActive->fPrev = fTail;
+ fTail->fNext = fActive;
+ fTail = fActive;
+ } else {
+ fHead = fTail = fActive;
+ }
+ if (partner) {
+ partner->addVertex(v, side, alloc);
+ poly = partner;
+ } else {
+ Vertex* prev = fActive->fSide == Poly::kLeft_Side ?
+ fActive->fHead->fNext : fActive->fTail->fPrev;
+ fActive = ALLOC_NEW(MonotonePoly, , alloc);
+ fActive->addVertex(prev, Poly::kNeither_Side, alloc);
+ fActive->addVertex(v, side, alloc);
+ }
+ }
+ fCount++;
+ return poly;
+ }
+ void end(Vertex* v, SkChunkAlloc& alloc) {
+ LOG("end() %d at %g, %g\n", fID, v->fPoint.fX, v->fPoint.fY);
+ if (fPartner) {
+ fPartner = fPartner->fPartner = nullptr;
+ }
+ addVertex(v, fActive->fSide == kLeft_Side ? kRight_Side : kLeft_Side, alloc);
+ }
+ SkPoint* emit(SkPoint *data) {
+ if (fCount < 3) {
+ return data;
+ }
+ LOG("emit() %d, size %d\n", fID, fCount);
+ for (MonotonePoly* m = fHead; m != nullptr; m = m->fNext) {
+ data = m->emit(data);
+ }
+ return data;
+ }
+ int fWinding;
+ MonotonePoly* fHead;
+ MonotonePoly* fTail;
+ MonotonePoly* fActive;
+ Poly* fNext;
+ Poly* fPartner;
+ int fCount;
+#if LOGGING_ENABLED
+ int fID;
+#endif
+};
+
+/***************************************************************************************/
+
+bool coincident(const SkPoint& a, const SkPoint& b) {
+ return a == b;
+}
+
+Poly* new_poly(Poly** head, Vertex* v, int winding, SkChunkAlloc& alloc) {
+ Poly* poly = ALLOC_NEW(Poly, (winding), alloc);
+ poly->addVertex(v, Poly::kNeither_Side, alloc);
+ poly->fNext = *head;
+ *head = poly;
+ return poly;
+}
+
+Vertex* append_point_to_contour(const SkPoint& p, Vertex* prev, Vertex** head,
+ SkChunkAlloc& alloc) {
+ Vertex* v = ALLOC_NEW(Vertex, (p), alloc);
+#if LOGGING_ENABLED
+ static float gID = 0.0f;
+ v->fID = gID++;
+#endif
+ if (prev) {
+ prev->fNext = v;
+ v->fPrev = prev;
+ } else {
+ *head = v;
+ }
+ return v;
+}
+
+Vertex* generate_quadratic_points(const SkPoint& p0,
+ const SkPoint& p1,
+ const SkPoint& p2,
+ SkScalar tolSqd,
+ Vertex* prev,
+ Vertex** head,
+ int pointsLeft,
+ SkChunkAlloc& alloc) {
+ SkScalar d = p1.distanceToLineSegmentBetweenSqd(p0, p2);
+ if (pointsLeft < 2 || d < tolSqd || !SkScalarIsFinite(d)) {
+ return append_point_to_contour(p2, prev, head, alloc);
+ }
+
+ const SkPoint q[] = {
+ { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) },
+ { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) },
+ };
+ const SkPoint r = { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) };
+
+ pointsLeft >>= 1;
+ prev = generate_quadratic_points(p0, q[0], r, tolSqd, prev, head, pointsLeft, alloc);
+ prev = generate_quadratic_points(r, q[1], p2, tolSqd, prev, head, pointsLeft, alloc);
+ return prev;
+}
+
+Vertex* generate_cubic_points(const SkPoint& p0,
+ const SkPoint& p1,
+ const SkPoint& p2,
+ const SkPoint& p3,
+ SkScalar tolSqd,
+ Vertex* prev,
+ Vertex** head,
+ int pointsLeft,
+ SkChunkAlloc& alloc) {
+ SkScalar d1 = p1.distanceToLineSegmentBetweenSqd(p0, p3);
+ SkScalar d2 = p2.distanceToLineSegmentBetweenSqd(p0, p3);
+ if (pointsLeft < 2 || (d1 < tolSqd && d2 < tolSqd) ||
+ !SkScalarIsFinite(d1) || !SkScalarIsFinite(d2)) {
+ return append_point_to_contour(p3, prev, head, alloc);
+ }
+ const SkPoint q[] = {
+ { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) },
+ { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) },
+ { SkScalarAve(p2.fX, p3.fX), SkScalarAve(p2.fY, p3.fY) }
+ };
+ const SkPoint r[] = {
+ { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) },
+ { SkScalarAve(q[1].fX, q[2].fX), SkScalarAve(q[1].fY, q[2].fY) }
+ };
+ const SkPoint s = { SkScalarAve(r[0].fX, r[1].fX), SkScalarAve(r[0].fY, r[1].fY) };
+ pointsLeft >>= 1;
+ prev = generate_cubic_points(p0, q[0], r[0], s, tolSqd, prev, head, pointsLeft, alloc);
+ prev = generate_cubic_points(s, r[1], q[2], p3, tolSqd, prev, head, pointsLeft, alloc);
+ return prev;
+}
+
+// Stage 1: convert the input path to a set of linear contours (linked list of Vertices).
+
+void path_to_contours(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
+ Vertex** contours, SkChunkAlloc& alloc, bool *isLinear) {
+ SkScalar toleranceSqd = tolerance * tolerance;
+
+ SkPoint pts[4];
+ bool done = false;
+ *isLinear = true;
+ SkPath::Iter iter(path, false);
+ Vertex* prev = nullptr;
+ Vertex* head = nullptr;
+ if (path.isInverseFillType()) {
+ SkPoint quad[4];
+ clipBounds.toQuad(quad);
+ for (int i = 3; i >= 0; i--) {
+ prev = append_point_to_contour(quad[i], prev, &head, alloc);
+ }
+ head->fPrev = prev;
+ prev->fNext = head;
+ *contours++ = head;
+ head = prev = nullptr;
+ }
+ SkAutoConicToQuads converter;
+ while (!done) {
+ SkPath::Verb verb = iter.next(pts);
+ switch (verb) {
+ case SkPath::kConic_Verb: {
+ SkScalar weight = iter.conicWeight();
+ const SkPoint* quadPts = converter.computeQuads(pts, weight, toleranceSqd);
+ for (int i = 0; i < converter.countQuads(); ++i) {
+ int pointsLeft = GrPathUtils::quadraticPointCount(quadPts, tolerance);
+ prev = generate_quadratic_points(quadPts[0], quadPts[1], quadPts[2],
+ toleranceSqd, prev, &head, pointsLeft, alloc);
+ quadPts += 2;
+ }
+ *isLinear = false;
+ break;
+ }
+ case SkPath::kMove_Verb:
+ if (head) {
+ head->fPrev = prev;
+ prev->fNext = head;
+ *contours++ = head;
+ }
+ head = prev = nullptr;
+ prev = append_point_to_contour(pts[0], prev, &head, alloc);
+ break;
+ case SkPath::kLine_Verb: {
+ prev = append_point_to_contour(pts[1], prev, &head, alloc);
+ break;
+ }
+ case SkPath::kQuad_Verb: {
+ int pointsLeft = GrPathUtils::quadraticPointCount(pts, tolerance);
+ prev = generate_quadratic_points(pts[0], pts[1], pts[2], toleranceSqd, prev,
+ &head, pointsLeft, alloc);
+ *isLinear = false;
+ break;
+ }
+ case SkPath::kCubic_Verb: {
+ int pointsLeft = GrPathUtils::cubicPointCount(pts, tolerance);
+ prev = generate_cubic_points(pts[0], pts[1], pts[2], pts[3],
+ toleranceSqd, prev, &head, pointsLeft, alloc);
+ *isLinear = false;
+ break;
+ }
+ case SkPath::kClose_Verb:
+ if (head) {
+ head->fPrev = prev;
+ prev->fNext = head;
+ *contours++ = head;
+ }
+ head = prev = nullptr;
+ break;
+ case SkPath::kDone_Verb:
+ if (head) {
+ head->fPrev = prev;
+ prev->fNext = head;
+ *contours++ = head;
+ }
+ done = true;
+ break;
+ }
+ }
+}
+
+inline bool apply_fill_type(SkPath::FillType fillType, int winding) {
+ switch (fillType) {
+ case SkPath::kWinding_FillType:
+ return winding != 0;
+ case SkPath::kEvenOdd_FillType:
+ return (winding & 1) != 0;
+ case SkPath::kInverseWinding_FillType:
+ return winding == 1;
+ case SkPath::kInverseEvenOdd_FillType:
+ return (winding & 1) == 1;
+ default:
+ SkASSERT(false);
+ return false;
+ }
+}
+
+Edge* new_edge(Vertex* prev, Vertex* next, SkChunkAlloc& alloc, Comparator& c) {
+ int winding = c.sweep_lt(prev->fPoint, next->fPoint) ? 1 : -1;
+ Vertex* top = winding < 0 ? next : prev;
+ Vertex* bottom = winding < 0 ? prev : next;
+ return ALLOC_NEW(Edge, (top, bottom, winding), alloc);
+}
+
+void remove_edge(Edge* edge, EdgeList* edges) {
+ LOG("removing edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID);
+ SkASSERT(edge->isActive(edges));
+ remove<Edge, &Edge::fLeft, &Edge::fRight>(edge, &edges->fHead, &edges->fTail);
+}
+
+void insert_edge(Edge* edge, Edge* prev, EdgeList* edges) {
+ LOG("inserting edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID);
+ SkASSERT(!edge->isActive(edges));
+ Edge* next = prev ? prev->fRight : edges->fHead;
+ insert<Edge, &Edge::fLeft, &Edge::fRight>(edge, prev, next, &edges->fHead, &edges->fTail);
+}
+
+void find_enclosing_edges(Vertex* v, EdgeList* edges, Edge** left, Edge** right) {
+ if (v->fFirstEdgeAbove) {
+ *left = v->fFirstEdgeAbove->fLeft;
+ *right = v->fLastEdgeAbove->fRight;
+ return;
+ }
+ Edge* next = nullptr;
+ Edge* prev;
+ for (prev = edges->fTail; prev != nullptr; prev = prev->fLeft) {
+ if (prev->isLeftOf(v)) {
+ break;
+ }
+ next = prev;
+ }
+ *left = prev;
+ *right = next;
+ return;
+}
+
+void find_enclosing_edges(Edge* edge, EdgeList* edges, Comparator& c, Edge** left, Edge** right) {
+ Edge* prev = nullptr;
+ Edge* next;
+ for (next = edges->fHead; next != nullptr; next = next->fRight) {
+ if ((c.sweep_gt(edge->fTop->fPoint, next->fTop->fPoint) && next->isRightOf(edge->fTop)) ||
+ (c.sweep_gt(next->fTop->fPoint, edge->fTop->fPoint) && edge->isLeftOf(next->fTop)) ||
+ (c.sweep_lt(edge->fBottom->fPoint, next->fBottom->fPoint) &&
+ next->isRightOf(edge->fBottom)) ||
+ (c.sweep_lt(next->fBottom->fPoint, edge->fBottom->fPoint) &&
+ edge->isLeftOf(next->fBottom))) {
+ break;
+ }
+ prev = next;
+ }
+ *left = prev;
+ *right = next;
+ return;
+}
+
+void fix_active_state(Edge* edge, EdgeList* activeEdges, Comparator& c) {
+ if (edge->isActive(activeEdges)) {
+ if (edge->fBottom->fProcessed || !edge->fTop->fProcessed) {
+ remove_edge(edge, activeEdges);
+ }
+ } else if (edge->fTop->fProcessed && !edge->fBottom->fProcessed) {
+ Edge* left;
+ Edge* right;
+ find_enclosing_edges(edge, activeEdges, c, &left, &right);
+ insert_edge(edge, left, activeEdges);
+ }
+}
+
+void insert_edge_above(Edge* edge, Vertex* v, Comparator& c) {
+ if (edge->fTop->fPoint == edge->fBottom->fPoint ||
+ c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) {
+ return;
+ }
+ LOG("insert edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID);
+ Edge* prev = nullptr;
+ Edge* next;
+ for (next = v->fFirstEdgeAbove; next; next = next->fNextEdgeAbove) {
+ if (next->isRightOf(edge->fTop)) {
+ break;
+ }
+ prev = next;
+ }
+ insert<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>(
+ edge, prev, next, &v->fFirstEdgeAbove, &v->fLastEdgeAbove);
+}
+
+void insert_edge_below(Edge* edge, Vertex* v, Comparator& c) {
+ if (edge->fTop->fPoint == edge->fBottom->fPoint ||
+ c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) {
+ return;
+ }
+ LOG("insert edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID);
+ Edge* prev = nullptr;
+ Edge* next;
+ for (next = v->fFirstEdgeBelow; next; next = next->fNextEdgeBelow) {
+ if (next->isRightOf(edge->fBottom)) {
+ break;
+ }
+ prev = next;
+ }
+ insert<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>(
+ edge, prev, next, &v->fFirstEdgeBelow, &v->fLastEdgeBelow);
+}
+
+void remove_edge_above(Edge* edge) {
+ LOG("removing edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID,
+ edge->fBottom->fID);
+ remove<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>(
+ edge, &edge->fBottom->fFirstEdgeAbove, &edge->fBottom->fLastEdgeAbove);
+}
+
+void remove_edge_below(Edge* edge) {
+ LOG("removing edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID,
+ edge->fTop->fID);
+ remove<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>(
+ edge, &edge->fTop->fFirstEdgeBelow, &edge->fTop->fLastEdgeBelow);
+}
+
+void erase_edge_if_zero_winding(Edge* edge, EdgeList* edges) {
+ if (edge->fWinding != 0) {
+ return;
+ }
+ LOG("erasing edge (%g -> %g)\n", edge->fTop->fID, edge->fBottom->fID);
+ remove_edge_above(edge);
+ remove_edge_below(edge);
+ if (edge->isActive(edges)) {
+ remove_edge(edge, edges);
+ }
+}
+
+void merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c);
+
+void set_top(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) {
+ remove_edge_below(edge);
+ edge->fTop = v;
+ edge->recompute();
+ insert_edge_below(edge, v, c);
+ fix_active_state(edge, activeEdges, c);
+ merge_collinear_edges(edge, activeEdges, c);
+}
+
+void set_bottom(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) {
+ remove_edge_above(edge);
+ edge->fBottom = v;
+ edge->recompute();
+ insert_edge_above(edge, v, c);
+ fix_active_state(edge, activeEdges, c);
+ merge_collinear_edges(edge, activeEdges, c);
+}
+
+void merge_edges_above(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) {
+ if (coincident(edge->fTop->fPoint, other->fTop->fPoint)) {
+ LOG("merging coincident above edges (%g, %g) -> (%g, %g)\n",
+ edge->fTop->fPoint.fX, edge->fTop->fPoint.fY,
+ edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY);
+ other->fWinding += edge->fWinding;
+ erase_edge_if_zero_winding(other, activeEdges);
+ edge->fWinding = 0;
+ erase_edge_if_zero_winding(edge, activeEdges);
+ } else if (c.sweep_lt(edge->fTop->fPoint, other->fTop->fPoint)) {
+ other->fWinding += edge->fWinding;
+ erase_edge_if_zero_winding(other, activeEdges);
+ set_bottom(edge, other->fTop, activeEdges, c);
+ } else {
+ edge->fWinding += other->fWinding;
+ erase_edge_if_zero_winding(edge, activeEdges);
+ set_bottom(other, edge->fTop, activeEdges, c);
+ }
+}
+
+void merge_edges_below(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) {
+ if (coincident(edge->fBottom->fPoint, other->fBottom->fPoint)) {
+ LOG("merging coincident below edges (%g, %g) -> (%g, %g)\n",
+ edge->fTop->fPoint.fX, edge->fTop->fPoint.fY,
+ edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY);
+ other->fWinding += edge->fWinding;
+ erase_edge_if_zero_winding(other, activeEdges);
+ edge->fWinding = 0;
+ erase_edge_if_zero_winding(edge, activeEdges);
+ } else if (c.sweep_lt(edge->fBottom->fPoint, other->fBottom->fPoint)) {
+ edge->fWinding += other->fWinding;
+ erase_edge_if_zero_winding(edge, activeEdges);
+ set_top(other, edge->fBottom, activeEdges, c);
+ } else {
+ other->fWinding += edge->fWinding;
+ erase_edge_if_zero_winding(other, activeEdges);
+ set_top(edge, other->fBottom, activeEdges, c);
+ }
+}
+
+void merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c) {
+ if (edge->fPrevEdgeAbove && (edge->fTop == edge->fPrevEdgeAbove->fTop ||
+ !edge->fPrevEdgeAbove->isLeftOf(edge->fTop))) {
+ merge_edges_above(edge, edge->fPrevEdgeAbove, activeEdges, c);
+ } else if (edge->fNextEdgeAbove && (edge->fTop == edge->fNextEdgeAbove->fTop ||
+ !edge->isLeftOf(edge->fNextEdgeAbove->fTop))) {
+ merge_edges_above(edge, edge->fNextEdgeAbove, activeEdges, c);
+ }
+ if (edge->fPrevEdgeBelow && (edge->fBottom == edge->fPrevEdgeBelow->fBottom ||
+ !edge->fPrevEdgeBelow->isLeftOf(edge->fBottom))) {
+ merge_edges_below(edge, edge->fPrevEdgeBelow, activeEdges, c);
+ } else if (edge->fNextEdgeBelow && (edge->fBottom == edge->fNextEdgeBelow->fBottom ||
+ !edge->isLeftOf(edge->fNextEdgeBelow->fBottom))) {
+ merge_edges_below(edge, edge->fNextEdgeBelow, activeEdges, c);
+ }
+}
+
+void split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc);
+
+void cleanup_active_edges(Edge* edge, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) {
+ Vertex* top = edge->fTop;
+ Vertex* bottom = edge->fBottom;
+ if (edge->fLeft) {
+ Vertex* leftTop = edge->fLeft->fTop;
+ Vertex* leftBottom = edge->fLeft->fBottom;
+ if (c.sweep_gt(top->fPoint, leftTop->fPoint) && !edge->fLeft->isLeftOf(top)) {
+ split_edge(edge->fLeft, edge->fTop, activeEdges, c, alloc);
+ } else if (c.sweep_gt(leftTop->fPoint, top->fPoint) && !edge->isRightOf(leftTop)) {
+ split_edge(edge, leftTop, activeEdges, c, alloc);
+ } else if (c.sweep_lt(bottom->fPoint, leftBottom->fPoint) &&
+ !edge->fLeft->isLeftOf(bottom)) {
+ split_edge(edge->fLeft, bottom, activeEdges, c, alloc);
+ } else if (c.sweep_lt(leftBottom->fPoint, bottom->fPoint) && !edge->isRightOf(leftBottom)) {
+ split_edge(edge, leftBottom, activeEdges, c, alloc);
+ }
+ }
+ if (edge->fRight) {
+ Vertex* rightTop = edge->fRight->fTop;
+ Vertex* rightBottom = edge->fRight->fBottom;
+ if (c.sweep_gt(top->fPoint, rightTop->fPoint) && !edge->fRight->isRightOf(top)) {
+ split_edge(edge->fRight, top, activeEdges, c, alloc);
+ } else if (c.sweep_gt(rightTop->fPoint, top->fPoint) && !edge->isLeftOf(rightTop)) {
+ split_edge(edge, rightTop, activeEdges, c, alloc);
+ } else if (c.sweep_lt(bottom->fPoint, rightBottom->fPoint) &&
+ !edge->fRight->isRightOf(bottom)) {
+ split_edge(edge->fRight, bottom, activeEdges, c, alloc);
+ } else if (c.sweep_lt(rightBottom->fPoint, bottom->fPoint) &&
+ !edge->isLeftOf(rightBottom)) {
+ split_edge(edge, rightBottom, activeEdges, c, alloc);
+ }
+ }
+}
+
+void split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) {
+ LOG("splitting edge (%g -> %g) at vertex %g (%g, %g)\n",
+ edge->fTop->fID, edge->fBottom->fID,
+ v->fID, v->fPoint.fX, v->fPoint.fY);
+ if (c.sweep_lt(v->fPoint, edge->fTop->fPoint)) {
+ set_top(edge, v, activeEdges, c);
+ } else if (c.sweep_gt(v->fPoint, edge->fBottom->fPoint)) {
+ set_bottom(edge, v, activeEdges, c);
+ } else {
+ Edge* newEdge = ALLOC_NEW(Edge, (v, edge->fBottom, edge->fWinding), alloc);
+ insert_edge_below(newEdge, v, c);
+ insert_edge_above(newEdge, edge->fBottom, c);
+ set_bottom(edge, v, activeEdges, c);
+ cleanup_active_edges(edge, activeEdges, c, alloc);
+ fix_active_state(newEdge, activeEdges, c);
+ merge_collinear_edges(newEdge, activeEdges, c);
+ }
+}
+
+void merge_vertices(Vertex* src, Vertex* dst, Vertex** head, Comparator& c, SkChunkAlloc& alloc) {
+ LOG("found coincident verts at %g, %g; merging %g into %g\n", src->fPoint.fX, src->fPoint.fY,
+ src->fID, dst->fID);
+ for (Edge* edge = src->fFirstEdgeAbove; edge;) {
+ Edge* next = edge->fNextEdgeAbove;
+ set_bottom(edge, dst, nullptr, c);
+ edge = next;
+ }
+ for (Edge* edge = src->fFirstEdgeBelow; edge;) {
+ Edge* next = edge->fNextEdgeBelow;
+ set_top(edge, dst, nullptr, c);
+ edge = next;
+ }
+ remove<Vertex, &Vertex::fPrev, &Vertex::fNext>(src, head, nullptr);
+}
+
+Vertex* check_for_intersection(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c,
+ SkChunkAlloc& alloc) {
+ SkPoint p;
+ if (!edge || !other) {
+ return nullptr;
+ }
+ if (edge->intersect(*other, &p)) {
+ Vertex* v;
+ LOG("found intersection, pt is %g, %g\n", p.fX, p.fY);
+ if (p == edge->fTop->fPoint || c.sweep_lt(p, edge->fTop->fPoint)) {
+ split_edge(other, edge->fTop, activeEdges, c, alloc);
+ v = edge->fTop;
+ } else if (p == edge->fBottom->fPoint || c.sweep_gt(p, edge->fBottom->fPoint)) {
+ split_edge(other, edge->fBottom, activeEdges, c, alloc);
+ v = edge->fBottom;
+ } else if (p == other->fTop->fPoint || c.sweep_lt(p, other->fTop->fPoint)) {
+ split_edge(edge, other->fTop, activeEdges, c, alloc);
+ v = other->fTop;
+ } else if (p == other->fBottom->fPoint || c.sweep_gt(p, other->fBottom->fPoint)) {
+ split_edge(edge, other->fBottom, activeEdges, c, alloc);
+ v = other->fBottom;
+ } else {
+ Vertex* nextV = edge->fTop;
+ while (c.sweep_lt(p, nextV->fPoint)) {
+ nextV = nextV->fPrev;
+ }
+ while (c.sweep_lt(nextV->fPoint, p)) {
+ nextV = nextV->fNext;
+ }
+ Vertex* prevV = nextV->fPrev;
+ if (coincident(prevV->fPoint, p)) {
+ v = prevV;
+ } else if (coincident(nextV->fPoint, p)) {
+ v = nextV;
+ } else {
+ v = ALLOC_NEW(Vertex, (p), alloc);
+ LOG("inserting between %g (%g, %g) and %g (%g, %g)\n",
+ prevV->fID, prevV->fPoint.fX, prevV->fPoint.fY,
+ nextV->fID, nextV->fPoint.fX, nextV->fPoint.fY);
+#if LOGGING_ENABLED
+ v->fID = (nextV->fID + prevV->fID) * 0.5f;
+#endif
+ v->fPrev = prevV;
+ v->fNext = nextV;
+ prevV->fNext = v;
+ nextV->fPrev = v;
+ }
+ split_edge(edge, v, activeEdges, c, alloc);
+ split_edge(other, v, activeEdges, c, alloc);
+ }
+ return v;
+ }
+ return nullptr;
+}
+
+void sanitize_contours(Vertex** contours, int contourCnt) {
+ for (int i = 0; i < contourCnt; ++i) {
+ SkASSERT(contours[i]);
+ for (Vertex* v = contours[i];;) {
+ if (coincident(v->fPrev->fPoint, v->fPoint)) {
+ LOG("vertex %g,%g coincident; removing\n", v->fPoint.fX, v->fPoint.fY);
+ if (v->fPrev == v) {
+ contours[i] = nullptr;
+ break;
+ }
+ v->fPrev->fNext = v->fNext;
+ v->fNext->fPrev = v->fPrev;
+ if (contours[i] == v) {
+ contours[i] = v->fNext;
+ }
+ v = v->fPrev;
+ } else {
+ v = v->fNext;
+ if (v == contours[i]) break;
+ }
+ }
+ }
+}
+
+void merge_coincident_vertices(Vertex** vertices, Comparator& c, SkChunkAlloc& alloc) {
+ for (Vertex* v = (*vertices)->fNext; v != nullptr; v = v->fNext) {
+ if (c.sweep_lt(v->fPoint, v->fPrev->fPoint)) {
+ v->fPoint = v->fPrev->fPoint;
+ }
+ if (coincident(v->fPrev->fPoint, v->fPoint)) {
+ merge_vertices(v->fPrev, v, vertices, c, alloc);
+ }
+ }
+}
+
+// Stage 2: convert the contours to a mesh of edges connecting the vertices.
+
+Vertex* build_edges(Vertex** contours, int contourCnt, Comparator& c, SkChunkAlloc& alloc) {
+ Vertex* vertices = nullptr;
+ Vertex* prev = nullptr;
+ for (int i = 0; i < contourCnt; ++i) {
+ for (Vertex* v = contours[i]; v != nullptr;) {
+ Vertex* vNext = v->fNext;
+ Edge* edge = new_edge(v->fPrev, v, alloc, c);
+ if (edge->fWinding > 0) {
+ insert_edge_below(edge, v->fPrev, c);
+ insert_edge_above(edge, v, c);
+ } else {
+ insert_edge_below(edge, v, c);
+ insert_edge_above(edge, v->fPrev, c);
+ }
+ merge_collinear_edges(edge, nullptr, c);
+ if (prev) {
+ prev->fNext = v;
+ v->fPrev = prev;
+ } else {
+ vertices = v;
+ }
+ prev = v;
+ v = vNext;
+ if (v == contours[i]) break;
+ }
+ }
+ if (prev) {
+ prev->fNext = vertices->fPrev = nullptr;
+ }
+ return vertices;
+}
+
+// Stage 3: sort the vertices by increasing sweep direction.
+
+Vertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c);
+
+void front_back_split(Vertex* v, Vertex** pFront, Vertex** pBack) {
+ Vertex* fast;
+ Vertex* slow;
+ if (!v || !v->fNext) {
+ *pFront = v;
+ *pBack = nullptr;
+ } else {
+ slow = v;
+ fast = v->fNext;
+
+ while (fast != nullptr) {
+ fast = fast->fNext;
+ if (fast != nullptr) {
+ slow = slow->fNext;
+ fast = fast->fNext;
+ }
+ }
+
+ *pFront = v;
+ *pBack = slow->fNext;
+ slow->fNext->fPrev = nullptr;
+ slow->fNext = nullptr;
+ }
+}
+
+void merge_sort(Vertex** head, Comparator& c) {
+ if (!*head || !(*head)->fNext) {
+ return;
+ }
+
+ Vertex* a;
+ Vertex* b;
+ front_back_split(*head, &a, &b);
+
+ merge_sort(&a, c);
+ merge_sort(&b, c);
+
+ *head = sorted_merge(a, b, c);
+}
+
+inline void append_vertex(Vertex* v, Vertex** head, Vertex** tail) {
+ insert<Vertex, &Vertex::fPrev, &Vertex::fNext>(v, *tail, nullptr, head, tail);
+}
+
+inline void append_vertex_list(Vertex* v, Vertex** head, Vertex** tail) {
+ insert<Vertex, &Vertex::fPrev, &Vertex::fNext>(v, *tail, v->fNext, head, tail);
+}
+
+Vertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c) {
+ Vertex* head = nullptr;
+ Vertex* tail = nullptr;
+
+ while (a && b) {
+ if (c.sweep_lt(a->fPoint, b->fPoint)) {
+ Vertex* next = a->fNext;
+ append_vertex(a, &head, &tail);
+ a = next;
+ } else {
+ Vertex* next = b->fNext;
+ append_vertex(b, &head, &tail);
+ b = next;
+ }
+ }
+ if (a) {
+ append_vertex_list(a, &head, &tail);
+ }
+ if (b) {
+ append_vertex_list(b, &head, &tail);
+ }
+ return head;
+}
+
+// Stage 4: Simplify the mesh by inserting new vertices at intersecting edges.
+
+void simplify(Vertex* vertices, Comparator& c, SkChunkAlloc& alloc) {
+ LOG("simplifying complex polygons\n");
+ EdgeList activeEdges;
+ for (Vertex* v = vertices; v != nullptr; v = v->fNext) {
+ if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
+ continue;
+ }
+#if LOGGING_ENABLED
+ LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY);
+#endif
+ Edge* leftEnclosingEdge = nullptr;
+ Edge* rightEnclosingEdge = nullptr;
+ bool restartChecks;
+ do {
+ restartChecks = false;
+ find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
+ if (v->fFirstEdgeBelow) {
+ for (Edge* edge = v->fFirstEdgeBelow; edge != nullptr; edge = edge->fNextEdgeBelow) {
+ if (check_for_intersection(edge, leftEnclosingEdge, &activeEdges, c, alloc)) {
+ restartChecks = true;
+ break;
+ }
+ if (check_for_intersection(edge, rightEnclosingEdge, &activeEdges, c, alloc)) {
+ restartChecks = true;
+ break;
+ }
+ }
+ } else {
+ if (Vertex* pv = check_for_intersection(leftEnclosingEdge, rightEnclosingEdge,
+ &activeEdges, c, alloc)) {
+ if (c.sweep_lt(pv->fPoint, v->fPoint)) {
+ v = pv;
+ }
+ restartChecks = true;
+ }
+
+ }
+ } while (restartChecks);
+ for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) {
+ remove_edge(e, &activeEdges);
+ }
+ Edge* leftEdge = leftEnclosingEdge;
+ for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {
+ insert_edge(e, leftEdge, &activeEdges);
+ leftEdge = e;
+ }
+ v->fProcessed = true;
+ }
+}
+
+// Stage 5: Tessellate the simplified mesh into monotone polygons.
+
+Poly* tessellate(Vertex* vertices, SkChunkAlloc& alloc) {
+ LOG("tessellating simple polygons\n");
+ EdgeList activeEdges;
+ Poly* polys = nullptr;
+ for (Vertex* v = vertices; v != nullptr; v = v->fNext) {
+ if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
+ continue;
+ }
+#if LOGGING_ENABLED
+ LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY);
+#endif
+ Edge* leftEnclosingEdge = nullptr;
+ Edge* rightEnclosingEdge = nullptr;
+ find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
+ Poly* leftPoly = nullptr;
+ Poly* rightPoly = nullptr;
+ if (v->fFirstEdgeAbove) {
+ leftPoly = v->fFirstEdgeAbove->fLeftPoly;
+ rightPoly = v->fLastEdgeAbove->fRightPoly;
+ } else {
+ leftPoly = leftEnclosingEdge ? leftEnclosingEdge->fRightPoly : nullptr;
+ rightPoly = rightEnclosingEdge ? rightEnclosingEdge->fLeftPoly : nullptr;
+ }
+#if LOGGING_ENABLED
+ LOG("edges above:\n");
+ for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) {
+ LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID,
+ e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1);
+ }
+ LOG("edges below:\n");
+ for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {
+ LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID,
+ e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1);
+ }
+#endif
+ if (v->fFirstEdgeAbove) {
+ if (leftPoly) {
+ leftPoly = leftPoly->addVertex(v, Poly::kRight_Side, alloc);
+ }
+ if (rightPoly) {
+ rightPoly = rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
+ }
+ for (Edge* e = v->fFirstEdgeAbove; e != v->fLastEdgeAbove; e = e->fNextEdgeAbove) {
+ Edge* leftEdge = e;
+ Edge* rightEdge = e->fNextEdgeAbove;
+ SkASSERT(rightEdge->isRightOf(leftEdge->fTop));
+ remove_edge(leftEdge, &activeEdges);
+ if (leftEdge->fRightPoly) {
+ leftEdge->fRightPoly->end(v, alloc);
+ }
+ if (rightEdge->fLeftPoly && rightEdge->fLeftPoly != leftEdge->fRightPoly) {
+ rightEdge->fLeftPoly->end(v, alloc);
+ }
+ }
+ remove_edge(v->fLastEdgeAbove, &activeEdges);
+ if (!v->fFirstEdgeBelow) {
+ if (leftPoly && rightPoly && leftPoly != rightPoly) {
+ SkASSERT(leftPoly->fPartner == nullptr && rightPoly->fPartner == nullptr);
+ rightPoly->fPartner = leftPoly;
+ leftPoly->fPartner = rightPoly;
+ }
+ }
+ }
+ if (v->fFirstEdgeBelow) {
+ if (!v->fFirstEdgeAbove) {
+ if (leftPoly && leftPoly == rightPoly) {
+ // Split the poly.
+ if (leftPoly->fActive->fSide == Poly::kLeft_Side) {
+ leftPoly = new_poly(&polys, leftEnclosingEdge->fTop, leftPoly->fWinding,
+ alloc);
+ leftPoly->addVertex(v, Poly::kRight_Side, alloc);
+ rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
+ leftEnclosingEdge->fRightPoly = leftPoly;
+ } else {
+ rightPoly = new_poly(&polys, rightEnclosingEdge->fTop, rightPoly->fWinding,
+ alloc);
+ rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
+ leftPoly->addVertex(v, Poly::kRight_Side, alloc);
+ rightEnclosingEdge->fLeftPoly = rightPoly;
+ }
+ } else {
+ if (leftPoly) {
+ leftPoly = leftPoly->addVertex(v, Poly::kRight_Side, alloc);
+ }
+ if (rightPoly) {
+ rightPoly = rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
+ }
+ }
+ }
+ Edge* leftEdge = v->fFirstEdgeBelow;
+ leftEdge->fLeftPoly = leftPoly;
+ insert_edge(leftEdge, leftEnclosingEdge, &activeEdges);
+ for (Edge* rightEdge = leftEdge->fNextEdgeBelow; rightEdge;
+ rightEdge = rightEdge->fNextEdgeBelow) {
+ insert_edge(rightEdge, leftEdge, &activeEdges);
+ int winding = leftEdge->fLeftPoly ? leftEdge->fLeftPoly->fWinding : 0;
+ winding += leftEdge->fWinding;
+ if (winding != 0) {
+ Poly* poly = new_poly(&polys, v, winding, alloc);
+ leftEdge->fRightPoly = rightEdge->fLeftPoly = poly;
+ }
+ leftEdge = rightEdge;
+ }
+ v->fLastEdgeBelow->fRightPoly = rightPoly;
+ }
+#if LOGGING_ENABLED
+ LOG("\nactive edges:\n");
+ for (Edge* e = activeEdges.fHead; e != nullptr; e = e->fRight) {
+ LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID,
+ e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1);
+ }
+#endif
+ }
+ return polys;
+}
+
+// This is a driver function which calls stages 2-5 in turn.
+
+Poly* contours_to_polys(Vertex** contours, int contourCnt, const SkRect& pathBounds,
+ SkChunkAlloc& alloc) {
+ Comparator c;
+ if (pathBounds.width() > pathBounds.height()) {
+ c.sweep_lt = sweep_lt_horiz;
+ c.sweep_gt = sweep_gt_horiz;
+ } else {
+ c.sweep_lt = sweep_lt_vert;
+ c.sweep_gt = sweep_gt_vert;
+ }
+#if LOGGING_ENABLED
+ for (int i = 0; i < contourCnt; ++i) {
+ Vertex* v = contours[i];
+ SkASSERT(v);
+ LOG("path.moveTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY);
+ for (v = v->fNext; v != contours[i]; v = v->fNext) {
+ LOG("path.lineTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY);
+ }
+ }
+#endif
+ sanitize_contours(contours, contourCnt);
+ Vertex* vertices = build_edges(contours, contourCnt, c, alloc);
+ if (!vertices) {
+ return nullptr;
+ }
+
+ // Sort vertices in Y (secondarily in X).
+ merge_sort(&vertices, c);
+ merge_coincident_vertices(&vertices, c, alloc);
+#if LOGGING_ENABLED
+ for (Vertex* v = vertices; v != nullptr; v = v->fNext) {
+ static float gID = 0.0f;
+ v->fID = gID++;
+ }
+#endif
+ simplify(vertices, c, alloc);
+ return tessellate(vertices, alloc);
+}
+
+Poly* path_to_polys(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
+ int contourCnt, SkChunkAlloc& alloc, bool* isLinear) {
+ SkPath::FillType fillType = path.getFillType();
+ if (SkPath::IsInverseFillType(fillType)) {
+ contourCnt++;
+ }
+ SkAutoTDeleteArray<Vertex*> contours(new Vertex* [contourCnt]);
+
+ path_to_contours(path, tolerance, clipBounds, contours.get(), alloc, isLinear);
+ return contours_to_polys(contours.get(), contourCnt, path.getBounds(), alloc);
+}
+
+void get_contour_count_and_size_estimate(const SkPath& path, SkScalar tolerance, int* contourCnt,
+ int* sizeEstimate) {
+ int maxPts = GrPathUtils::worstCasePointCount(path, contourCnt, tolerance);
+ if (maxPts <= 0) {
+ *contourCnt = 0;
+ return;
+ }
+ if (maxPts > ((int)SK_MaxU16 + 1)) {
+ SkDebugf("Path not rendered, too many verts (%d)\n", maxPts);
+ *contourCnt = 0;
+ return;
+ }
+ // For the initial size of the chunk allocator, estimate based on the point count:
+ // one vertex per point for the initial passes, plus two for the vertices in the
+ // resulting Polys, since the same point may end up in two Polys. Assume minimal
+ // connectivity of one Edge per Vertex (will grow for intersections).
+ *sizeEstimate = maxPts * (3 * sizeof(Vertex) + sizeof(Edge));
+}
+
+int count_points(Poly* polys, SkPath::FillType fillType) {
+ int count = 0;
+ for (Poly* poly = polys; poly; poly = poly->fNext) {
+ if (apply_fill_type(fillType, poly->fWinding) && poly->fCount >= 3) {
+ count += (poly->fCount - 2) * (TESSELLATOR_WIREFRAME ? 6 : 3);
+ }
+ }
+ return count;
+}
+
+} // namespace
+
+namespace GrTessellator {
+
+// Stage 6: Triangulate the monotone polygons into a vertex buffer.
+
+int PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
+ GrResourceProvider* resourceProvider,
+ SkAutoTUnref<GrVertexBuffer>& vertexBuffer, bool canMapVB, bool* isLinear) {
+ int contourCnt;
+ int sizeEstimate;
+ get_contour_count_and_size_estimate(path, tolerance, &contourCnt, &sizeEstimate);
+ if (contourCnt <= 0) {
+ *isLinear = true;
+ return 0;
+ }
+ SkChunkAlloc alloc(sizeEstimate);
+ Poly* polys = path_to_polys(path, tolerance, clipBounds, contourCnt, alloc, isLinear);
+ SkPath::FillType fillType = path.getFillType();
+ int count = count_points(polys, fillType);
+ if (0 == count) {
+ return 0;
+ }
+
+ size_t size = count * sizeof(SkPoint);
+ if (!vertexBuffer.get() || vertexBuffer->gpuMemorySize() < size) {
+ vertexBuffer.reset(resourceProvider->createVertexBuffer(
+ size, GrResourceProvider::kStatic_BufferUsage, 0));
+ }
+ if (!vertexBuffer.get()) {
+ SkDebugf("Could not allocate vertices\n");
+ return 0;
+ }
+ SkPoint* verts;
+ if (canMapVB) {
+ verts = static_cast<SkPoint*>(vertexBuffer->map());
+ } else {
+ verts = new SkPoint[count];
+ }
+ SkPoint* end = verts;
+ for (Poly* poly = polys; poly; poly = poly->fNext) {
+ if (apply_fill_type(fillType, poly->fWinding)) {
+ end = poly->emit(end);
+ }
+ }
+ int actualCount = static_cast<int>(end - verts);
+ LOG("actual count: %d\n", actualCount);
+ SkASSERT(actualCount <= count);
+ if (canMapVB) {
+ vertexBuffer->unmap();
+ } else {
+ vertexBuffer->updateData(verts, actualCount * sizeof(SkPoint));
+ delete[] verts;
+ }
+
+ return actualCount;
+}
+
+int PathToVertices(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
+ GrTessellator::WindingVertex** verts) {
+ int contourCnt;
+ int sizeEstimate;
+ get_contour_count_and_size_estimate(path, tolerance, &contourCnt, &sizeEstimate);
+ if (contourCnt <= 0) {
+ return 0;
+ }
+ SkChunkAlloc alloc(sizeEstimate);
+ bool isLinear;
+ Poly* polys = path_to_polys(path, tolerance, clipBounds, contourCnt, alloc, &isLinear);
+ SkPath::FillType fillType = path.getFillType();
+ int count = count_points(polys, fillType);
+ if (0 == count) {
+ *verts = nullptr;
+ return 0;
+ }
+
+ *verts = new GrTessellator::WindingVertex[count];
+ GrTessellator::WindingVertex* vertsEnd = *verts;
+ SkPoint* points = new SkPoint[count];
+ SkPoint* pointsEnd = points;
+ for (Poly* poly = polys; poly; poly = poly->fNext) {
+ if (apply_fill_type(fillType, poly->fWinding)) {
+ SkPoint* start = pointsEnd;
+ pointsEnd = poly->emit(pointsEnd);
+ while (start != pointsEnd) {
+ vertsEnd->fPos = *start;
+ vertsEnd->fWinding = poly->fWinding;
+ ++start;
+ ++vertsEnd;
+ }
+ }
+ }
+ int actualCount = static_cast<int>(vertsEnd - *verts);
+ SkASSERT(actualCount <= count);
+ SkASSERT(pointsEnd - points == actualCount);
+ delete[] points;
+ return actualCount;
+}
+
+} // namespace
diff --git a/src/gpu/GrTessellator.h b/src/gpu/GrTessellator.h
new file mode 100644
index 0000000..4304920
--- /dev/null
+++ b/src/gpu/GrTessellator.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrTessellator_DEFINED
+#define GrTessellator_DEFINED
+
+#include "SkPath.h"
+#include "GrResourceProvider.h"
+
+/**
+ * Provides utility functions for converting paths to a collection of triangles.
+ */
+
+#define TESSELLATOR_WIREFRAME 0
+
+namespace GrTessellator {
+
+struct WindingVertex {
+ SkPoint fPos;
+ int fWinding;
+};
+
+// Triangulates a path to an array of vertices. Each triangle is represented as a set of three
+// WindingVertex entries, each of which contains the position and winding count (which is the same
+// for all three vertices of a triangle). The 'verts' out parameter is set to point to the resultant
+// vertex array. CALLER IS RESPONSIBLE for deleting this buffer to avoid a memory leak!
+int PathToVertices(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
+ WindingVertex** verts);
+
+int PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
+ GrResourceProvider* resourceProvider,
+ SkAutoTUnref<GrVertexBuffer>& vertexBuffer, bool canMapVB, bool* isLinear);
+
+}
+
+#endif
diff --git a/src/gpu/batches/GrTessellatingPathRenderer.cpp b/src/gpu/batches/GrTessellatingPathRenderer.cpp
index 27e287e..36b6d65 100644
--- a/src/gpu/batches/GrTessellatingPathRenderer.cpp
+++ b/src/gpu/batches/GrTessellatingPathRenderer.cpp
@@ -14,7 +14,7 @@
#include "GrVertices.h"
#include "GrResourceCache.h"
#include "GrResourceProvider.h"
-#include "SkChunkAlloc.h"
+#include "GrTessellator.h"
#include "SkGeometry.h"
#include "batches/GrVertexBatch.h"
@@ -22,1324 +22,29 @@
#include <stdio.h>
/*
- * This path renderer tessellates the path into triangles, uploads the triangles to a
- * vertex buffer, and renders them with a single draw call. It does not currently do
+ * This path renderer tessellates the path into triangles using GrTessellator, uploads the triangles
+ * to a vertex buffer, and renders them with a single draw call. It does not currently do
* antialiasing, so it must be used in conjunction with multisampling.
- *
- * There are six stages to the algorithm:
- *
- * 1) Linearize the path contours into piecewise linear segments (path_to_contours()).
- * 2) Build a mesh of edges connecting the vertices (build_edges()).
- * 3) Sort the vertices in Y (and secondarily in X) (merge_sort()).
- * 4) Simplify the mesh by inserting new vertices at intersecting edges (simplify()).
- * 5) Tessellate the simplified mesh into monotone polygons (tessellate()).
- * 6) Triangulate the monotone polygons directly into a vertex buffer (polys_to_triangles()).
- *
- * The vertex sorting in step (3) is a merge sort, since it plays well with the linked list
- * of vertices (and the necessity of inserting new vertices on intersection).
- *
- * Stages (4) and (5) use an active edge list, which a list of all edges for which the
- * sweep line has crossed the top vertex, but not the bottom vertex. It's sorted
- * left-to-right based on the point where both edges are active (when both top vertices
- * have been seen, so the "lower" top vertex of the two). If the top vertices are equal
- * (shared), it's sorted based on the last point where both edges are active, so the
- * "upper" bottom vertex.
- *
- * The most complex step is the simplification (4). It's based on the Bentley-Ottman
- * line-sweep algorithm, but due to floating point inaccuracy, the intersection points are
- * not exact and may violate the mesh topology or active edge list ordering. We
- * accommodate this by adjusting the topology of the mesh and AEL to match the intersection
- * points. This occurs in three ways:
- *
- * A) Intersections may cause a shortened edge to no longer be ordered with respect to its
- * neighbouring edges at the top or bottom vertex. This is handled by merging the
- * edges (merge_collinear_edges()).
- * B) Intersections may cause an edge to violate the left-to-right ordering of the
- * active edge list. This is handled by splitting the neighbour edge on the
- * intersected vertex (cleanup_active_edges()).
- * C) Shortening an edge may cause an active edge to become inactive or an inactive edge
- * to become active. This is handled by removing or inserting the edge in the active
- * edge list (fix_active_state()).
- *
- * The tessellation steps (5) and (6) are based on "Triangulating Simple Polygons and
- * Equivalent Problems" (Fournier and Montuno); also a line-sweep algorithm. Note that it
- * currently uses a linked list for the active edge list, rather than a 2-3 tree as the
- * paper describes. The 2-3 tree gives O(lg N) lookups, but insertion and removal also
- * become O(lg N). In all the test cases, it was found that the cost of frequent O(lg N)
- * insertions and removals was greater than the cost of infrequent O(N) lookups with the
- * linked list implementation. With the latter, all removals are O(1), and most insertions
- * are O(1), since we know the adjacent edge in the active edge list based on the topology.
- * Only type 2 vertices (see paper) require the O(N) lookups, and these are much less
- * frequent. There may be other data structures worth investigating, however.
- *
- * Note that the orientation of the line sweep algorithms is determined by the aspect ratio of the
- * path bounds. When the path is taller than it is wide, we sort vertices based on increasing Y
- * coordinate, and secondarily by increasing X coordinate. When the path is wider than it is tall,
- * we sort by increasing X coordinate, but secondarily by *decreasing* Y coordinate. This is so
- * that the "left" and "right" orientation in the code remains correct (edges to the left are
- * increasing in Y; edges to the right are decreasing in Y). That is, the setting rotates 90
- * degrees counterclockwise, rather that transposing.
*/
-#define LOGGING_ENABLED 0
-#define WIREFRAME 0
-
-#if LOGGING_ENABLED
-#define LOG printf
-#else
-#define LOG(...)
-#endif
-
-#define ALLOC_NEW(Type, args, alloc) new (alloc.allocThrow(sizeof(Type))) Type args
-
namespace {
-struct Vertex;
-struct Edge;
-struct Poly;
-
-template <class T, T* T::*Prev, T* T::*Next>
-void insert(T* t, T* prev, T* next, T** head, T** tail) {
- t->*Prev = prev;
- t->*Next = next;
- if (prev) {
- prev->*Next = t;
- } else if (head) {
- *head = t;
- }
- if (next) {
- next->*Prev = t;
- } else if (tail) {
- *tail = t;
- }
-}
-
-template <class T, T* T::*Prev, T* T::*Next>
-void remove(T* t, T** head, T** tail) {
- if (t->*Prev) {
- t->*Prev->*Next = t->*Next;
- } else if (head) {
- *head = t->*Next;
- }
- if (t->*Next) {
- t->*Next->*Prev = t->*Prev;
- } else if (tail) {
- *tail = t->*Prev;
- }
- t->*Prev = t->*Next = nullptr;
-}
-
-/**
- * Vertices are used in three ways: first, the path contours are converted into a
- * circularly-linked list of Vertices for each contour. After edge construction, the same Vertices
- * are re-ordered by the merge sort according to the sweep_lt comparator (usually, increasing
- * in Y) using the same fPrev/fNext pointers that were used for the contours, to avoid
- * reallocation. Finally, MonotonePolys are built containing a circularly-linked list of
- * Vertices. (Currently, those Vertices are newly-allocated for the MonotonePolys, since
- * an individual Vertex from the path mesh may belong to multiple
- * MonotonePolys, so the original Vertices cannot be re-used.
- */
-
-struct Vertex {
- Vertex(const SkPoint& point)
- : fPoint(point), fPrev(nullptr), fNext(nullptr)
- , fFirstEdgeAbove(nullptr), fLastEdgeAbove(nullptr)
- , fFirstEdgeBelow(nullptr), fLastEdgeBelow(nullptr)
- , fProcessed(false)
-#if LOGGING_ENABLED
- , fID (-1.0f)
-#endif
- {}
- SkPoint fPoint; // Vertex position
- Vertex* fPrev; // Linked list of contours, then Y-sorted vertices.
- Vertex* fNext; // "
- Edge* fFirstEdgeAbove; // Linked list of edges above this vertex.
- Edge* fLastEdgeAbove; // "
- Edge* fFirstEdgeBelow; // Linked list of edges below this vertex.
- Edge* fLastEdgeBelow; // "
- bool fProcessed; // Has this vertex been seen in simplify()?
-#if LOGGING_ENABLED
- float fID; // Identifier used for logging.
-#endif
-};
-
-/***************************************************************************************/
-
-typedef bool (*CompareFunc)(const SkPoint& a, const SkPoint& b);
-
-struct Comparator {
- CompareFunc sweep_lt;
- CompareFunc sweep_gt;
-};
-
-bool sweep_lt_horiz(const SkPoint& a, const SkPoint& b) {
- return a.fX == b.fX ? a.fY > b.fY : a.fX < b.fX;
-}
-
-bool sweep_lt_vert(const SkPoint& a, const SkPoint& b) {
- return a.fY == b.fY ? a.fX < b.fX : a.fY < b.fY;
-}
-
-bool sweep_gt_horiz(const SkPoint& a, const SkPoint& b) {
- return a.fX == b.fX ? a.fY < b.fY : a.fX > b.fX;
-}
-
-bool sweep_gt_vert(const SkPoint& a, const SkPoint& b) {
- return a.fY == b.fY ? a.fX > b.fX : a.fY > b.fY;
-}
-
-inline SkPoint* emit_vertex(Vertex* v, SkPoint* data) {
- *data++ = v->fPoint;
- return data;
-}
-
-SkPoint* emit_triangle(Vertex* v0, Vertex* v1, Vertex* v2, SkPoint* data) {
-#if WIREFRAME
- data = emit_vertex(v0, data);
- data = emit_vertex(v1, data);
- data = emit_vertex(v1, data);
- data = emit_vertex(v2, data);
- data = emit_vertex(v2, data);
- data = emit_vertex(v0, data);
-#else
- data = emit_vertex(v0, data);
- data = emit_vertex(v1, data);
- data = emit_vertex(v2, data);
-#endif
- return data;
-}
-
-struct EdgeList {
- EdgeList() : fHead(nullptr), fTail(nullptr) {}
- Edge* fHead;
- Edge* fTail;
-};
-
-/**
- * An Edge joins a top Vertex to a bottom Vertex. Edge ordering for the list of "edges above" and
- * "edge below" a vertex as well as for the active edge list is handled by isLeftOf()/isRightOf().
- * Note that an Edge will give occasionally dist() != 0 for its own endpoints (because floating
- * point). For speed, that case is only tested by the callers which require it (e.g.,
- * cleanup_active_edges()). Edges also handle checking for intersection with other edges.
- * Currently, this converts the edges to the parametric form, in order to avoid doing a division
- * until an intersection has been confirmed. This is slightly slower in the "found" case, but
- * a lot faster in the "not found" case.
- *
- * The coefficients of the line equation stored in double precision to avoid catastrphic
- * cancellation in the isLeftOf() and isRightOf() checks. Using doubles ensures that the result is
- * correct in float, since it's a polynomial of degree 2. The intersect() function, being
- * degree 5, is still subject to catastrophic cancellation. We deal with that by assuming its
- * output may be incorrect, and adjusting the mesh topology to match (see comment at the top of
- * this file).
- */
-
-struct Edge {
- Edge(Vertex* top, Vertex* bottom, int winding)
- : fWinding(winding)
- , fTop(top)
- , fBottom(bottom)
- , fLeft(nullptr)
- , fRight(nullptr)
- , fPrevEdgeAbove(nullptr)
- , fNextEdgeAbove(nullptr)
- , fPrevEdgeBelow(nullptr)
- , fNextEdgeBelow(nullptr)
- , fLeftPoly(nullptr)
- , fRightPoly(nullptr) {
- recompute();
- }
- int fWinding; // 1 == edge goes downward; -1 = edge goes upward.
- Vertex* fTop; // The top vertex in vertex-sort-order (sweep_lt).
- Vertex* fBottom; // The bottom vertex in vertex-sort-order.
- Edge* fLeft; // The linked list of edges in the active edge list.
- Edge* fRight; // "
- Edge* fPrevEdgeAbove; // The linked list of edges in the bottom Vertex's "edges above".
- Edge* fNextEdgeAbove; // "
- Edge* fPrevEdgeBelow; // The linked list of edges in the top Vertex's "edges below".
- 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.
- double fDX; // The line equation for this edge, in implicit form.
- double fDY; // fDY * x + fDX * y + fC = 0, for point (x, y) on the line.
- double fC;
- double dist(const SkPoint& p) const {
- return fDY * p.fX - fDX * p.fY + fC;
- }
- bool isRightOf(Vertex* v) const {
- return dist(v->fPoint) < 0.0;
- }
- bool isLeftOf(Vertex* v) const {
- return dist(v->fPoint) > 0.0;
- }
- void recompute() {
- fDX = static_cast<double>(fBottom->fPoint.fX) - fTop->fPoint.fX;
- fDY = static_cast<double>(fBottom->fPoint.fY) - fTop->fPoint.fY;
- fC = static_cast<double>(fTop->fPoint.fY) * fBottom->fPoint.fX -
- static_cast<double>(fTop->fPoint.fX) * fBottom->fPoint.fY;
- }
- bool intersect(const Edge& other, SkPoint* p) {
- LOG("intersecting %g -> %g with %g -> %g\n",
- fTop->fID, fBottom->fID,
- other.fTop->fID, other.fBottom->fID);
- if (fTop == other.fTop || fBottom == other.fBottom) {
- return false;
- }
- double denom = fDX * other.fDY - fDY * other.fDX;
- if (denom == 0.0) {
- return false;
- }
- double dx = static_cast<double>(fTop->fPoint.fX) - other.fTop->fPoint.fX;
- double dy = static_cast<double>(fTop->fPoint.fY) - other.fTop->fPoint.fY;
- double sNumer = dy * other.fDX - dx * other.fDY;
- double tNumer = dy * fDX - dx * fDY;
- // If (sNumer / denom) or (tNumer / denom) is not in [0..1], exit early.
- // This saves us doing the divide below unless absolutely necessary.
- if (denom > 0.0 ? (sNumer < 0.0 || sNumer > denom || tNumer < 0.0 || tNumer > denom)
- : (sNumer > 0.0 || sNumer < denom || tNumer > 0.0 || tNumer < denom)) {
- return false;
- }
- double s = sNumer / denom;
- SkASSERT(s >= 0.0 && s <= 1.0);
- p->fX = SkDoubleToScalar(fTop->fPoint.fX + s * fDX);
- p->fY = SkDoubleToScalar(fTop->fPoint.fY + s * fDY);
- return true;
- }
- bool isActive(EdgeList* activeEdges) const {
- return activeEdges && (fLeft || fRight || activeEdges->fHead == this);
- }
-};
-
-/***************************************************************************************/
-
-struct Poly {
- Poly(int winding)
- : fWinding(winding)
- , fHead(nullptr)
- , fTail(nullptr)
- , fActive(nullptr)
- , fNext(nullptr)
- , fPartner(nullptr)
- , fCount(0)
- {
-#if LOGGING_ENABLED
- static int gID = 0;
- fID = gID++;
- LOG("*** created Poly %d\n", fID);
-#endif
- }
- typedef enum { kNeither_Side, kLeft_Side, kRight_Side } Side;
- struct MonotonePoly {
- MonotonePoly()
- : fSide(kNeither_Side)
- , fHead(nullptr)
- , fTail(nullptr)
- , fPrev(nullptr)
- , fNext(nullptr) {}
- Side fSide;
- Vertex* fHead;
- Vertex* fTail;
- MonotonePoly* fPrev;
- MonotonePoly* fNext;
- bool addVertex(Vertex* v, Side side, SkChunkAlloc& alloc) {
- Vertex* newV = ALLOC_NEW(Vertex, (v->fPoint), alloc);
- bool done = false;
- if (fSide == kNeither_Side) {
- fSide = side;
- } else {
- done = side != fSide;
- }
- if (fHead == nullptr) {
- fHead = fTail = newV;
- } else if (fSide == kRight_Side) {
- newV->fPrev = fTail;
- fTail->fNext = newV;
- fTail = newV;
- } else {
- newV->fNext = fHead;
- fHead->fPrev = newV;
- fHead = newV;
- }
- return done;
- }
-
- SkPoint* emit(SkPoint* data) {
- Vertex* first = fHead;
- Vertex* v = first->fNext;
- while (v != fTail) {
- SkASSERT(v && v->fPrev && v->fNext);
- Vertex* prev = v->fPrev;
- Vertex* curr = v;
- Vertex* next = v->fNext;
- double ax = static_cast<double>(curr->fPoint.fX) - prev->fPoint.fX;
- double ay = static_cast<double>(curr->fPoint.fY) - prev->fPoint.fY;
- double bx = static_cast<double>(next->fPoint.fX) - curr->fPoint.fX;
- double by = static_cast<double>(next->fPoint.fY) - curr->fPoint.fY;
- if (ax * by - ay * bx >= 0.0) {
- data = emit_triangle(prev, curr, next, data);
- v->fPrev->fNext = v->fNext;
- v->fNext->fPrev = v->fPrev;
- if (v->fPrev == first) {
- v = v->fNext;
- } else {
- v = v->fPrev;
- }
- } else {
- v = v->fNext;
- }
- }
- return data;
- }
- };
- Poly* addVertex(Vertex* v, Side side, SkChunkAlloc& alloc) {
- LOG("addVertex() to %d at %g (%g, %g), %s side\n", fID, v->fID, v->fPoint.fX, v->fPoint.fY,
- side == kLeft_Side ? "left" : side == kRight_Side ? "right" : "neither");
- Poly* partner = fPartner;
- Poly* poly = this;
- if (partner) {
- fPartner = partner->fPartner = nullptr;
- }
- if (!fActive) {
- fActive = ALLOC_NEW(MonotonePoly, (), alloc);
- }
- if (fActive->addVertex(v, side, alloc)) {
- if (fTail) {
- fActive->fPrev = fTail;
- fTail->fNext = fActive;
- fTail = fActive;
- } else {
- fHead = fTail = fActive;
- }
- if (partner) {
- partner->addVertex(v, side, alloc);
- poly = partner;
- } else {
- Vertex* prev = fActive->fSide == Poly::kLeft_Side ?
- fActive->fHead->fNext : fActive->fTail->fPrev;
- fActive = ALLOC_NEW(MonotonePoly, , alloc);
- fActive->addVertex(prev, Poly::kNeither_Side, alloc);
- fActive->addVertex(v, side, alloc);
- }
- }
- fCount++;
- return poly;
- }
- void end(Vertex* v, SkChunkAlloc& alloc) {
- LOG("end() %d at %g, %g\n", fID, v->fPoint.fX, v->fPoint.fY);
- if (fPartner) {
- fPartner = fPartner->fPartner = nullptr;
- }
- addVertex(v, fActive->fSide == kLeft_Side ? kRight_Side : kLeft_Side, alloc);
- }
- SkPoint* emit(SkPoint *data) {
- if (fCount < 3) {
- return data;
- }
- LOG("emit() %d, size %d\n", fID, fCount);
- for (MonotonePoly* m = fHead; m != nullptr; m = m->fNext) {
- data = m->emit(data);
- }
- return data;
- }
- int fWinding;
- MonotonePoly* fHead;
- MonotonePoly* fTail;
- MonotonePoly* fActive;
- Poly* fNext;
- Poly* fPartner;
- int fCount;
-#if LOGGING_ENABLED
- int fID;
-#endif
-};
-
-/***************************************************************************************/
-
-bool coincident(const SkPoint& a, const SkPoint& b) {
- return a == b;
-}
-
-Poly* new_poly(Poly** head, Vertex* v, int winding, SkChunkAlloc& alloc) {
- Poly* poly = ALLOC_NEW(Poly, (winding), alloc);
- poly->addVertex(v, Poly::kNeither_Side, alloc);
- poly->fNext = *head;
- *head = poly;
- return poly;
-}
-
-Vertex* append_point_to_contour(const SkPoint& p, Vertex* prev, Vertex** head,
- SkChunkAlloc& alloc) {
- Vertex* v = ALLOC_NEW(Vertex, (p), alloc);
-#if LOGGING_ENABLED
- static float gID = 0.0f;
- v->fID = gID++;
-#endif
- if (prev) {
- prev->fNext = v;
- v->fPrev = prev;
- } else {
- *head = v;
- }
- return v;
-}
-
-Vertex* generate_quadratic_points(const SkPoint& p0,
- const SkPoint& p1,
- const SkPoint& p2,
- SkScalar tolSqd,
- Vertex* prev,
- Vertex** head,
- int pointsLeft,
- SkChunkAlloc& alloc) {
- SkScalar d = p1.distanceToLineSegmentBetweenSqd(p0, p2);
- if (pointsLeft < 2 || d < tolSqd || !SkScalarIsFinite(d)) {
- return append_point_to_contour(p2, prev, head, alloc);
- }
-
- const SkPoint q[] = {
- { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) },
- { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) },
- };
- const SkPoint r = { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) };
-
- pointsLeft >>= 1;
- prev = generate_quadratic_points(p0, q[0], r, tolSqd, prev, head, pointsLeft, alloc);
- prev = generate_quadratic_points(r, q[1], p2, tolSqd, prev, head, pointsLeft, alloc);
- return prev;
-}
-
-Vertex* generate_cubic_points(const SkPoint& p0,
- const SkPoint& p1,
- const SkPoint& p2,
- const SkPoint& p3,
- SkScalar tolSqd,
- Vertex* prev,
- Vertex** head,
- int pointsLeft,
- SkChunkAlloc& alloc) {
- SkScalar d1 = p1.distanceToLineSegmentBetweenSqd(p0, p3);
- SkScalar d2 = p2.distanceToLineSegmentBetweenSqd(p0, p3);
- if (pointsLeft < 2 || (d1 < tolSqd && d2 < tolSqd) ||
- !SkScalarIsFinite(d1) || !SkScalarIsFinite(d2)) {
- return append_point_to_contour(p3, prev, head, alloc);
- }
- const SkPoint q[] = {
- { SkScalarAve(p0.fX, p1.fX), SkScalarAve(p0.fY, p1.fY) },
- { SkScalarAve(p1.fX, p2.fX), SkScalarAve(p1.fY, p2.fY) },
- { SkScalarAve(p2.fX, p3.fX), SkScalarAve(p2.fY, p3.fY) }
- };
- const SkPoint r[] = {
- { SkScalarAve(q[0].fX, q[1].fX), SkScalarAve(q[0].fY, q[1].fY) },
- { SkScalarAve(q[1].fX, q[2].fX), SkScalarAve(q[1].fY, q[2].fY) }
- };
- const SkPoint s = { SkScalarAve(r[0].fX, r[1].fX), SkScalarAve(r[0].fY, r[1].fY) };
- pointsLeft >>= 1;
- prev = generate_cubic_points(p0, q[0], r[0], s, tolSqd, prev, head, pointsLeft, alloc);
- prev = generate_cubic_points(s, r[1], q[2], p3, tolSqd, prev, head, pointsLeft, alloc);
- return prev;
-}
-
-// Stage 1: convert the input path to a set of linear contours (linked list of Vertices).
-
-void path_to_contours(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
- Vertex** contours, SkChunkAlloc& alloc, bool *isLinear) {
-
- SkScalar toleranceSqd = tolerance * tolerance;
-
- SkPoint pts[4];
- bool done = false;
- *isLinear = true;
- SkPath::Iter iter(path, false);
- Vertex* prev = nullptr;
- Vertex* head = nullptr;
- if (path.isInverseFillType()) {
- SkPoint quad[4];
- clipBounds.toQuad(quad);
- for (int i = 3; i >= 0; i--) {
- prev = append_point_to_contour(quad[i], prev, &head, alloc);
- }
- head->fPrev = prev;
- prev->fNext = head;
- *contours++ = head;
- head = prev = nullptr;
- }
- SkAutoConicToQuads converter;
- while (!done) {
- SkPath::Verb verb = iter.next(pts);
- switch (verb) {
- case SkPath::kConic_Verb: {
- SkScalar weight = iter.conicWeight();
- const SkPoint* quadPts = converter.computeQuads(pts, weight, toleranceSqd);
- for (int i = 0; i < converter.countQuads(); ++i) {
- int pointsLeft = GrPathUtils::quadraticPointCount(quadPts, tolerance);
- prev = generate_quadratic_points(quadPts[0], quadPts[1], quadPts[2],
- toleranceSqd, prev, &head, pointsLeft, alloc);
- quadPts += 2;
- }
- *isLinear = false;
- break;
- }
- case SkPath::kMove_Verb:
- if (head) {
- head->fPrev = prev;
- prev->fNext = head;
- *contours++ = head;
- }
- head = prev = nullptr;
- prev = append_point_to_contour(pts[0], prev, &head, alloc);
- break;
- case SkPath::kLine_Verb: {
- prev = append_point_to_contour(pts[1], prev, &head, alloc);
- break;
- }
- case SkPath::kQuad_Verb: {
- int pointsLeft = GrPathUtils::quadraticPointCount(pts, tolerance);
- prev = generate_quadratic_points(pts[0], pts[1], pts[2], toleranceSqd, prev,
- &head, pointsLeft, alloc);
- *isLinear = false;
- break;
- }
- case SkPath::kCubic_Verb: {
- int pointsLeft = GrPathUtils::cubicPointCount(pts, tolerance);
- prev = generate_cubic_points(pts[0], pts[1], pts[2], pts[3],
- toleranceSqd, prev, &head, pointsLeft, alloc);
- *isLinear = false;
- break;
- }
- case SkPath::kClose_Verb:
- if (head) {
- head->fPrev = prev;
- prev->fNext = head;
- *contours++ = head;
- }
- head = prev = nullptr;
- break;
- case SkPath::kDone_Verb:
- if (head) {
- head->fPrev = prev;
- prev->fNext = head;
- *contours++ = head;
- }
- done = true;
- break;
- }
- }
-}
-
-inline bool apply_fill_type(SkPath::FillType fillType, int winding) {
- switch (fillType) {
- case SkPath::kWinding_FillType:
- return winding != 0;
- case SkPath::kEvenOdd_FillType:
- return (winding & 1) != 0;
- case SkPath::kInverseWinding_FillType:
- return winding == 1;
- case SkPath::kInverseEvenOdd_FillType:
- return (winding & 1) == 1;
- default:
- SkASSERT(false);
- return false;
- }
-}
-
-Edge* new_edge(Vertex* prev, Vertex* next, SkChunkAlloc& alloc, Comparator& c) {
- int winding = c.sweep_lt(prev->fPoint, next->fPoint) ? 1 : -1;
- Vertex* top = winding < 0 ? next : prev;
- Vertex* bottom = winding < 0 ? prev : next;
- return ALLOC_NEW(Edge, (top, bottom, winding), alloc);
-}
-
-void remove_edge(Edge* edge, EdgeList* edges) {
- LOG("removing edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID);
- SkASSERT(edge->isActive(edges));
- remove<Edge, &Edge::fLeft, &Edge::fRight>(edge, &edges->fHead, &edges->fTail);
-}
-
-void insert_edge(Edge* edge, Edge* prev, EdgeList* edges) {
- LOG("inserting edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID);
- SkASSERT(!edge->isActive(edges));
- Edge* next = prev ? prev->fRight : edges->fHead;
- insert<Edge, &Edge::fLeft, &Edge::fRight>(edge, prev, next, &edges->fHead, &edges->fTail);
-}
-
-void find_enclosing_edges(Vertex* v, EdgeList* edges, Edge** left, Edge** right) {
- if (v->fFirstEdgeAbove) {
- *left = v->fFirstEdgeAbove->fLeft;
- *right = v->fLastEdgeAbove->fRight;
- return;
- }
- Edge* next = nullptr;
- Edge* prev;
- for (prev = edges->fTail; prev != nullptr; prev = prev->fLeft) {
- if (prev->isLeftOf(v)) {
- break;
- }
- next = prev;
- }
- *left = prev;
- *right = next;
- return;
-}
-
-void find_enclosing_edges(Edge* edge, EdgeList* edges, Comparator& c, Edge** left, Edge** right) {
- Edge* prev = nullptr;
- Edge* next;
- for (next = edges->fHead; next != nullptr; next = next->fRight) {
- if ((c.sweep_gt(edge->fTop->fPoint, next->fTop->fPoint) && next->isRightOf(edge->fTop)) ||
- (c.sweep_gt(next->fTop->fPoint, edge->fTop->fPoint) && edge->isLeftOf(next->fTop)) ||
- (c.sweep_lt(edge->fBottom->fPoint, next->fBottom->fPoint) &&
- next->isRightOf(edge->fBottom)) ||
- (c.sweep_lt(next->fBottom->fPoint, edge->fBottom->fPoint) &&
- edge->isLeftOf(next->fBottom))) {
- break;
- }
- prev = next;
- }
- *left = prev;
- *right = next;
- return;
-}
-
-void fix_active_state(Edge* edge, EdgeList* activeEdges, Comparator& c) {
- if (edge->isActive(activeEdges)) {
- if (edge->fBottom->fProcessed || !edge->fTop->fProcessed) {
- remove_edge(edge, activeEdges);
- }
- } else if (edge->fTop->fProcessed && !edge->fBottom->fProcessed) {
- Edge* left;
- Edge* right;
- find_enclosing_edges(edge, activeEdges, c, &left, &right);
- insert_edge(edge, left, activeEdges);
- }
-}
-
-void insert_edge_above(Edge* edge, Vertex* v, Comparator& c) {
- if (edge->fTop->fPoint == edge->fBottom->fPoint ||
- c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) {
- return;
- }
- LOG("insert edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID);
- Edge* prev = nullptr;
- Edge* next;
- for (next = v->fFirstEdgeAbove; next; next = next->fNextEdgeAbove) {
- if (next->isRightOf(edge->fTop)) {
- break;
- }
- prev = next;
- }
- insert<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>(
- edge, prev, next, &v->fFirstEdgeAbove, &v->fLastEdgeAbove);
-}
-
-void insert_edge_below(Edge* edge, Vertex* v, Comparator& c) {
- if (edge->fTop->fPoint == edge->fBottom->fPoint ||
- c.sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) {
- return;
- }
- LOG("insert edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID);
- Edge* prev = nullptr;
- Edge* next;
- for (next = v->fFirstEdgeBelow; next; next = next->fNextEdgeBelow) {
- if (next->isRightOf(edge->fBottom)) {
- break;
- }
- prev = next;
- }
- insert<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>(
- edge, prev, next, &v->fFirstEdgeBelow, &v->fLastEdgeBelow);
-}
-
-void remove_edge_above(Edge* edge) {
- LOG("removing edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID,
- edge->fBottom->fID);
- remove<Edge, &Edge::fPrevEdgeAbove, &Edge::fNextEdgeAbove>(
- edge, &edge->fBottom->fFirstEdgeAbove, &edge->fBottom->fLastEdgeAbove);
-}
-
-void remove_edge_below(Edge* edge) {
- LOG("removing edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID,
- edge->fTop->fID);
- remove<Edge, &Edge::fPrevEdgeBelow, &Edge::fNextEdgeBelow>(
- edge, &edge->fTop->fFirstEdgeBelow, &edge->fTop->fLastEdgeBelow);
-}
-
-void erase_edge_if_zero_winding(Edge* edge, EdgeList* edges) {
- if (edge->fWinding != 0) {
- return;
- }
- LOG("erasing edge (%g -> %g)\n", edge->fTop->fID, edge->fBottom->fID);
- remove_edge_above(edge);
- remove_edge_below(edge);
- if (edge->isActive(edges)) {
- remove_edge(edge, edges);
- }
-}
-
-void merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c);
-
-void set_top(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) {
- remove_edge_below(edge);
- edge->fTop = v;
- edge->recompute();
- insert_edge_below(edge, v, c);
- fix_active_state(edge, activeEdges, c);
- merge_collinear_edges(edge, activeEdges, c);
-}
-
-void set_bottom(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c) {
- remove_edge_above(edge);
- edge->fBottom = v;
- edge->recompute();
- insert_edge_above(edge, v, c);
- fix_active_state(edge, activeEdges, c);
- merge_collinear_edges(edge, activeEdges, c);
-}
-
-void merge_edges_above(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) {
- if (coincident(edge->fTop->fPoint, other->fTop->fPoint)) {
- LOG("merging coincident above edges (%g, %g) -> (%g, %g)\n",
- edge->fTop->fPoint.fX, edge->fTop->fPoint.fY,
- edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY);
- other->fWinding += edge->fWinding;
- erase_edge_if_zero_winding(other, activeEdges);
- edge->fWinding = 0;
- erase_edge_if_zero_winding(edge, activeEdges);
- } else if (c.sweep_lt(edge->fTop->fPoint, other->fTop->fPoint)) {
- other->fWinding += edge->fWinding;
- erase_edge_if_zero_winding(other, activeEdges);
- set_bottom(edge, other->fTop, activeEdges, c);
- } else {
- edge->fWinding += other->fWinding;
- erase_edge_if_zero_winding(edge, activeEdges);
- set_bottom(other, edge->fTop, activeEdges, c);
- }
-}
-
-void merge_edges_below(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c) {
- if (coincident(edge->fBottom->fPoint, other->fBottom->fPoint)) {
- LOG("merging coincident below edges (%g, %g) -> (%g, %g)\n",
- edge->fTop->fPoint.fX, edge->fTop->fPoint.fY,
- edge->fBottom->fPoint.fX, edge->fBottom->fPoint.fY);
- other->fWinding += edge->fWinding;
- erase_edge_if_zero_winding(other, activeEdges);
- edge->fWinding = 0;
- erase_edge_if_zero_winding(edge, activeEdges);
- } else if (c.sweep_lt(edge->fBottom->fPoint, other->fBottom->fPoint)) {
- edge->fWinding += other->fWinding;
- erase_edge_if_zero_winding(edge, activeEdges);
- set_top(other, edge->fBottom, activeEdges, c);
- } else {
- other->fWinding += edge->fWinding;
- erase_edge_if_zero_winding(other, activeEdges);
- set_top(edge, other->fBottom, activeEdges, c);
- }
-}
-
-void merge_collinear_edges(Edge* edge, EdgeList* activeEdges, Comparator& c) {
- if (edge->fPrevEdgeAbove && (edge->fTop == edge->fPrevEdgeAbove->fTop ||
- !edge->fPrevEdgeAbove->isLeftOf(edge->fTop))) {
- merge_edges_above(edge, edge->fPrevEdgeAbove, activeEdges, c);
- } else if (edge->fNextEdgeAbove && (edge->fTop == edge->fNextEdgeAbove->fTop ||
- !edge->isLeftOf(edge->fNextEdgeAbove->fTop))) {
- merge_edges_above(edge, edge->fNextEdgeAbove, activeEdges, c);
- }
- if (edge->fPrevEdgeBelow && (edge->fBottom == edge->fPrevEdgeBelow->fBottom ||
- !edge->fPrevEdgeBelow->isLeftOf(edge->fBottom))) {
- merge_edges_below(edge, edge->fPrevEdgeBelow, activeEdges, c);
- } else if (edge->fNextEdgeBelow && (edge->fBottom == edge->fNextEdgeBelow->fBottom ||
- !edge->isLeftOf(edge->fNextEdgeBelow->fBottom))) {
- merge_edges_below(edge, edge->fNextEdgeBelow, activeEdges, c);
- }
-}
-
-void split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc);
-
-void cleanup_active_edges(Edge* edge, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) {
- Vertex* top = edge->fTop;
- Vertex* bottom = edge->fBottom;
- if (edge->fLeft) {
- Vertex* leftTop = edge->fLeft->fTop;
- Vertex* leftBottom = edge->fLeft->fBottom;
- if (c.sweep_gt(top->fPoint, leftTop->fPoint) && !edge->fLeft->isLeftOf(top)) {
- split_edge(edge->fLeft, edge->fTop, activeEdges, c, alloc);
- } else if (c.sweep_gt(leftTop->fPoint, top->fPoint) && !edge->isRightOf(leftTop)) {
- split_edge(edge, leftTop, activeEdges, c, alloc);
- } else if (c.sweep_lt(bottom->fPoint, leftBottom->fPoint) &&
- !edge->fLeft->isLeftOf(bottom)) {
- split_edge(edge->fLeft, bottom, activeEdges, c, alloc);
- } else if (c.sweep_lt(leftBottom->fPoint, bottom->fPoint) && !edge->isRightOf(leftBottom)) {
- split_edge(edge, leftBottom, activeEdges, c, alloc);
- }
- }
- if (edge->fRight) {
- Vertex* rightTop = edge->fRight->fTop;
- Vertex* rightBottom = edge->fRight->fBottom;
- if (c.sweep_gt(top->fPoint, rightTop->fPoint) && !edge->fRight->isRightOf(top)) {
- split_edge(edge->fRight, top, activeEdges, c, alloc);
- } else if (c.sweep_gt(rightTop->fPoint, top->fPoint) && !edge->isLeftOf(rightTop)) {
- split_edge(edge, rightTop, activeEdges, c, alloc);
- } else if (c.sweep_lt(bottom->fPoint, rightBottom->fPoint) &&
- !edge->fRight->isRightOf(bottom)) {
- split_edge(edge->fRight, bottom, activeEdges, c, alloc);
- } else if (c.sweep_lt(rightBottom->fPoint, bottom->fPoint) &&
- !edge->isLeftOf(rightBottom)) {
- split_edge(edge, rightBottom, activeEdges, c, alloc);
- }
- }
-}
-
-void split_edge(Edge* edge, Vertex* v, EdgeList* activeEdges, Comparator& c, SkChunkAlloc& alloc) {
- LOG("splitting edge (%g -> %g) at vertex %g (%g, %g)\n",
- edge->fTop->fID, edge->fBottom->fID,
- v->fID, v->fPoint.fX, v->fPoint.fY);
- if (c.sweep_lt(v->fPoint, edge->fTop->fPoint)) {
- set_top(edge, v, activeEdges, c);
- } else if (c.sweep_gt(v->fPoint, edge->fBottom->fPoint)) {
- set_bottom(edge, v, activeEdges, c);
- } else {
- Edge* newEdge = ALLOC_NEW(Edge, (v, edge->fBottom, edge->fWinding), alloc);
- insert_edge_below(newEdge, v, c);
- insert_edge_above(newEdge, edge->fBottom, c);
- set_bottom(edge, v, activeEdges, c);
- cleanup_active_edges(edge, activeEdges, c, alloc);
- fix_active_state(newEdge, activeEdges, c);
- merge_collinear_edges(newEdge, activeEdges, c);
- }
-}
-
-void merge_vertices(Vertex* src, Vertex* dst, Vertex** head, Comparator& c, SkChunkAlloc& alloc) {
- LOG("found coincident verts at %g, %g; merging %g into %g\n", src->fPoint.fX, src->fPoint.fY,
- src->fID, dst->fID);
- for (Edge* edge = src->fFirstEdgeAbove; edge;) {
- Edge* next = edge->fNextEdgeAbove;
- set_bottom(edge, dst, nullptr, c);
- edge = next;
- }
- for (Edge* edge = src->fFirstEdgeBelow; edge;) {
- Edge* next = edge->fNextEdgeBelow;
- set_top(edge, dst, nullptr, c);
- edge = next;
- }
- remove<Vertex, &Vertex::fPrev, &Vertex::fNext>(src, head, nullptr);
-}
-
-Vertex* check_for_intersection(Edge* edge, Edge* other, EdgeList* activeEdges, Comparator& c,
- SkChunkAlloc& alloc) {
- SkPoint p;
- if (!edge || !other) {
- return nullptr;
- }
- if (edge->intersect(*other, &p)) {
- Vertex* v;
- LOG("found intersection, pt is %g, %g\n", p.fX, p.fY);
- if (p == edge->fTop->fPoint || c.sweep_lt(p, edge->fTop->fPoint)) {
- split_edge(other, edge->fTop, activeEdges, c, alloc);
- v = edge->fTop;
- } else if (p == edge->fBottom->fPoint || c.sweep_gt(p, edge->fBottom->fPoint)) {
- split_edge(other, edge->fBottom, activeEdges, c, alloc);
- v = edge->fBottom;
- } else if (p == other->fTop->fPoint || c.sweep_lt(p, other->fTop->fPoint)) {
- split_edge(edge, other->fTop, activeEdges, c, alloc);
- v = other->fTop;
- } else if (p == other->fBottom->fPoint || c.sweep_gt(p, other->fBottom->fPoint)) {
- split_edge(edge, other->fBottom, activeEdges, c, alloc);
- v = other->fBottom;
- } else {
- Vertex* nextV = edge->fTop;
- while (c.sweep_lt(p, nextV->fPoint)) {
- nextV = nextV->fPrev;
- }
- while (c.sweep_lt(nextV->fPoint, p)) {
- nextV = nextV->fNext;
- }
- Vertex* prevV = nextV->fPrev;
- if (coincident(prevV->fPoint, p)) {
- v = prevV;
- } else if (coincident(nextV->fPoint, p)) {
- v = nextV;
- } else {
- v = ALLOC_NEW(Vertex, (p), alloc);
- LOG("inserting between %g (%g, %g) and %g (%g, %g)\n",
- prevV->fID, prevV->fPoint.fX, prevV->fPoint.fY,
- nextV->fID, nextV->fPoint.fX, nextV->fPoint.fY);
-#if LOGGING_ENABLED
- v->fID = (nextV->fID + prevV->fID) * 0.5f;
-#endif
- v->fPrev = prevV;
- v->fNext = nextV;
- prevV->fNext = v;
- nextV->fPrev = v;
- }
- split_edge(edge, v, activeEdges, c, alloc);
- split_edge(other, v, activeEdges, c, alloc);
- }
- return v;
- }
- return nullptr;
-}
-
-void sanitize_contours(Vertex** contours, int contourCnt) {
- for (int i = 0; i < contourCnt; ++i) {
- SkASSERT(contours[i]);
- for (Vertex* v = contours[i];;) {
- if (coincident(v->fPrev->fPoint, v->fPoint)) {
- LOG("vertex %g,%g coincident; removing\n", v->fPoint.fX, v->fPoint.fY);
- if (v->fPrev == v) {
- contours[i] = nullptr;
- break;
- }
- v->fPrev->fNext = v->fNext;
- v->fNext->fPrev = v->fPrev;
- if (contours[i] == v) {
- contours[i] = v->fNext;
- }
- v = v->fPrev;
- } else {
- v = v->fNext;
- if (v == contours[i]) break;
- }
- }
- }
-}
-
-void merge_coincident_vertices(Vertex** vertices, Comparator& c, SkChunkAlloc& alloc) {
- for (Vertex* v = (*vertices)->fNext; v != nullptr; v = v->fNext) {
- if (c.sweep_lt(v->fPoint, v->fPrev->fPoint)) {
- v->fPoint = v->fPrev->fPoint;
- }
- if (coincident(v->fPrev->fPoint, v->fPoint)) {
- merge_vertices(v->fPrev, v, vertices, c, alloc);
- }
- }
-}
-
-// Stage 2: convert the contours to a mesh of edges connecting the vertices.
-
-Vertex* build_edges(Vertex** contours, int contourCnt, Comparator& c, SkChunkAlloc& alloc) {
- Vertex* vertices = nullptr;
- Vertex* prev = nullptr;
- for (int i = 0; i < contourCnt; ++i) {
- for (Vertex* v = contours[i]; v != nullptr;) {
- Vertex* vNext = v->fNext;
- Edge* edge = new_edge(v->fPrev, v, alloc, c);
- if (edge->fWinding > 0) {
- insert_edge_below(edge, v->fPrev, c);
- insert_edge_above(edge, v, c);
- } else {
- insert_edge_below(edge, v, c);
- insert_edge_above(edge, v->fPrev, c);
- }
- merge_collinear_edges(edge, nullptr, c);
- if (prev) {
- prev->fNext = v;
- v->fPrev = prev;
- } else {
- vertices = v;
- }
- prev = v;
- v = vNext;
- if (v == contours[i]) break;
- }
- }
- if (prev) {
- prev->fNext = vertices->fPrev = nullptr;
- }
- return vertices;
-}
-
-// Stage 3: sort the vertices by increasing sweep direction.
-
-Vertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c);
-
-void front_back_split(Vertex* v, Vertex** pFront, Vertex** pBack) {
- Vertex* fast;
- Vertex* slow;
- if (!v || !v->fNext) {
- *pFront = v;
- *pBack = nullptr;
- } else {
- slow = v;
- fast = v->fNext;
-
- while (fast != nullptr) {
- fast = fast->fNext;
- if (fast != nullptr) {
- slow = slow->fNext;
- fast = fast->fNext;
- }
- }
-
- *pFront = v;
- *pBack = slow->fNext;
- slow->fNext->fPrev = nullptr;
- slow->fNext = nullptr;
- }
-}
-
-void merge_sort(Vertex** head, Comparator& c) {
- if (!*head || !(*head)->fNext) {
- return;
- }
-
- Vertex* a;
- Vertex* b;
- front_back_split(*head, &a, &b);
-
- merge_sort(&a, c);
- merge_sort(&b, c);
-
- *head = sorted_merge(a, b, c);
-}
-
-inline void append_vertex(Vertex* v, Vertex** head, Vertex** tail) {
- insert<Vertex, &Vertex::fPrev, &Vertex::fNext>(v, *tail, nullptr, head, tail);
-}
-
-inline void append_vertex_list(Vertex* v, Vertex** head, Vertex** tail) {
- insert<Vertex, &Vertex::fPrev, &Vertex::fNext>(v, *tail, v->fNext, head, tail);
-}
-
-Vertex* sorted_merge(Vertex* a, Vertex* b, Comparator& c) {
- Vertex* head = nullptr;
- Vertex* tail = nullptr;
-
- while (a && b) {
- if (c.sweep_lt(a->fPoint, b->fPoint)) {
- Vertex* next = a->fNext;
- append_vertex(a, &head, &tail);
- a = next;
- } else {
- Vertex* next = b->fNext;
- append_vertex(b, &head, &tail);
- b = next;
- }
- }
- if (a) {
- append_vertex_list(a, &head, &tail);
- }
- if (b) {
- append_vertex_list(b, &head, &tail);
- }
- return head;
-}
-
-// Stage 4: Simplify the mesh by inserting new vertices at intersecting edges.
-
-void simplify(Vertex* vertices, Comparator& c, SkChunkAlloc& alloc) {
- LOG("simplifying complex polygons\n");
- EdgeList activeEdges;
- for (Vertex* v = vertices; v != nullptr; v = v->fNext) {
- if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
- continue;
- }
-#if LOGGING_ENABLED
- LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY);
-#endif
- Edge* leftEnclosingEdge = nullptr;
- Edge* rightEnclosingEdge = nullptr;
- bool restartChecks;
- do {
- restartChecks = false;
- find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
- if (v->fFirstEdgeBelow) {
- for (Edge* edge = v->fFirstEdgeBelow; edge != nullptr; edge = edge->fNextEdgeBelow) {
- if (check_for_intersection(edge, leftEnclosingEdge, &activeEdges, c, alloc)) {
- restartChecks = true;
- break;
- }
- if (check_for_intersection(edge, rightEnclosingEdge, &activeEdges, c, alloc)) {
- restartChecks = true;
- break;
- }
- }
- } else {
- if (Vertex* pv = check_for_intersection(leftEnclosingEdge, rightEnclosingEdge,
- &activeEdges, c, alloc)) {
- if (c.sweep_lt(pv->fPoint, v->fPoint)) {
- v = pv;
- }
- restartChecks = true;
- }
-
- }
- } while (restartChecks);
- for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) {
- remove_edge(e, &activeEdges);
- }
- Edge* leftEdge = leftEnclosingEdge;
- for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {
- insert_edge(e, leftEdge, &activeEdges);
- leftEdge = e;
- }
- v->fProcessed = true;
- }
-}
-
-// Stage 5: Tessellate the simplified mesh into monotone polygons.
-
-Poly* tessellate(Vertex* vertices, SkChunkAlloc& alloc) {
- LOG("tessellating simple polygons\n");
- EdgeList activeEdges;
- Poly* polys = nullptr;
- for (Vertex* v = vertices; v != nullptr; v = v->fNext) {
- if (!v->fFirstEdgeAbove && !v->fFirstEdgeBelow) {
- continue;
- }
-#if LOGGING_ENABLED
- LOG("\nvertex %g: (%g,%g)\n", v->fID, v->fPoint.fX, v->fPoint.fY);
-#endif
- Edge* leftEnclosingEdge = nullptr;
- Edge* rightEnclosingEdge = nullptr;
- find_enclosing_edges(v, &activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
- Poly* leftPoly = nullptr;
- Poly* rightPoly = nullptr;
- if (v->fFirstEdgeAbove) {
- leftPoly = v->fFirstEdgeAbove->fLeftPoly;
- rightPoly = v->fLastEdgeAbove->fRightPoly;
- } else {
- leftPoly = leftEnclosingEdge ? leftEnclosingEdge->fRightPoly : nullptr;
- rightPoly = rightEnclosingEdge ? rightEnclosingEdge->fLeftPoly : nullptr;
- }
-#if LOGGING_ENABLED
- LOG("edges above:\n");
- for (Edge* e = v->fFirstEdgeAbove; e; e = e->fNextEdgeAbove) {
- LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID,
- e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1);
- }
- LOG("edges below:\n");
- for (Edge* e = v->fFirstEdgeBelow; e; e = e->fNextEdgeBelow) {
- LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID,
- e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1);
- }
-#endif
- if (v->fFirstEdgeAbove) {
- if (leftPoly) {
- leftPoly = leftPoly->addVertex(v, Poly::kRight_Side, alloc);
- }
- if (rightPoly) {
- rightPoly = rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
- }
- for (Edge* e = v->fFirstEdgeAbove; e != v->fLastEdgeAbove; e = e->fNextEdgeAbove) {
- Edge* leftEdge = e;
- Edge* rightEdge = e->fNextEdgeAbove;
- SkASSERT(rightEdge->isRightOf(leftEdge->fTop));
- remove_edge(leftEdge, &activeEdges);
- if (leftEdge->fRightPoly) {
- leftEdge->fRightPoly->end(v, alloc);
- }
- if (rightEdge->fLeftPoly && rightEdge->fLeftPoly != leftEdge->fRightPoly) {
- rightEdge->fLeftPoly->end(v, alloc);
- }
- }
- remove_edge(v->fLastEdgeAbove, &activeEdges);
- if (!v->fFirstEdgeBelow) {
- if (leftPoly && rightPoly && leftPoly != rightPoly) {
- SkASSERT(leftPoly->fPartner == nullptr && rightPoly->fPartner == nullptr);
- rightPoly->fPartner = leftPoly;
- leftPoly->fPartner = rightPoly;
- }
- }
- }
- if (v->fFirstEdgeBelow) {
- if (!v->fFirstEdgeAbove) {
- if (leftPoly && leftPoly == rightPoly) {
- // Split the poly.
- if (leftPoly->fActive->fSide == Poly::kLeft_Side) {
- leftPoly = new_poly(&polys, leftEnclosingEdge->fTop, leftPoly->fWinding,
- alloc);
- leftPoly->addVertex(v, Poly::kRight_Side, alloc);
- rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
- leftEnclosingEdge->fRightPoly = leftPoly;
- } else {
- rightPoly = new_poly(&polys, rightEnclosingEdge->fTop, rightPoly->fWinding,
- alloc);
- rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
- leftPoly->addVertex(v, Poly::kRight_Side, alloc);
- rightEnclosingEdge->fLeftPoly = rightPoly;
- }
- } else {
- if (leftPoly) {
- leftPoly = leftPoly->addVertex(v, Poly::kRight_Side, alloc);
- }
- if (rightPoly) {
- rightPoly = rightPoly->addVertex(v, Poly::kLeft_Side, alloc);
- }
- }
- }
- Edge* leftEdge = v->fFirstEdgeBelow;
- leftEdge->fLeftPoly = leftPoly;
- insert_edge(leftEdge, leftEnclosingEdge, &activeEdges);
- for (Edge* rightEdge = leftEdge->fNextEdgeBelow; rightEdge;
- rightEdge = rightEdge->fNextEdgeBelow) {
- insert_edge(rightEdge, leftEdge, &activeEdges);
- int winding = leftEdge->fLeftPoly ? leftEdge->fLeftPoly->fWinding : 0;
- winding += leftEdge->fWinding;
- if (winding != 0) {
- Poly* poly = new_poly(&polys, v, winding, alloc);
- leftEdge->fRightPoly = rightEdge->fLeftPoly = poly;
- }
- leftEdge = rightEdge;
- }
- v->fLastEdgeBelow->fRightPoly = rightPoly;
- }
-#if LOGGING_ENABLED
- LOG("\nactive edges:\n");
- for (Edge* e = activeEdges.fHead; e != nullptr; e = e->fRight) {
- LOG("%g -> %g, lpoly %d, rpoly %d\n", e->fTop->fID, e->fBottom->fID,
- e->fLeftPoly ? e->fLeftPoly->fID : -1, e->fRightPoly ? e->fRightPoly->fID : -1);
- }
-#endif
- }
- return polys;
-}
-
-// This is a driver function which calls stages 2-5 in turn.
-
-Poly* contours_to_polys(Vertex** contours, int contourCnt, Comparator& c, SkChunkAlloc& alloc) {
-#if LOGGING_ENABLED
- for (int i = 0; i < contourCnt; ++i) {
- Vertex* v = contours[i];
- SkASSERT(v);
- LOG("path.moveTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY);
- for (v = v->fNext; v != contours[i]; v = v->fNext) {
- LOG("path.lineTo(%20.20g, %20.20g);\n", v->fPoint.fX, v->fPoint.fY);
- }
- }
-#endif
- sanitize_contours(contours, contourCnt);
- Vertex* vertices = build_edges(contours, contourCnt, c, alloc);
- if (!vertices) {
- return nullptr;
- }
-
- // Sort vertices in Y (secondarily in X).
- merge_sort(&vertices, c);
- merge_coincident_vertices(&vertices, c, alloc);
-#if LOGGING_ENABLED
- for (Vertex* v = vertices; v != nullptr; v = v->fNext) {
- static float gID = 0.0f;
- v->fID = gID++;
- }
-#endif
- simplify(vertices, c, alloc);
- return tessellate(vertices, alloc);
-}
-
-// Stage 6: Triangulate the monotone polygons into a vertex buffer.
-
-SkPoint* polys_to_triangles(Poly* polys, SkPath::FillType fillType, SkPoint* data) {
- SkPoint* d = data;
- for (Poly* poly = polys; poly; poly = poly->fNext) {
- if (apply_fill_type(fillType, poly->fWinding)) {
- d = poly->emit(d);
- }
- }
- return d;
-}
-
struct TessInfo {
SkScalar fTolerance;
int fCount;
};
+// When the SkPathRef genID changes, invalidate a corresponding GrResource described by key.
+class PathInvalidator : public SkPathRef::GenIDChangeListener {
+public:
+ explicit PathInvalidator(const GrUniqueKey& key) : fMsg(key) {}
+private:
+ GrUniqueKeyInvalidatedMessage fMsg;
+
+ void onChange() override {
+ SkMessageBus<GrUniqueKeyInvalidatedMessage>::Post(fMsg);
+ }
+};
+
bool cache_match(GrVertexBuffer* vertexBuffer, SkScalar tol, int* actualCount) {
if (!vertexBuffer) {
return false;
@@ -1354,27 +59,11 @@
return false;
}
-};
+} // namespace
GrTessellatingPathRenderer::GrTessellatingPathRenderer() {
}
-namespace {
-
-// When the SkPathRef genID changes, invalidate a corresponding GrResource described by key.
-class PathInvalidator : public SkPathRef::GenIDChangeListener {
-public:
- explicit PathInvalidator(const GrUniqueKey& key) : fMsg(key) {}
-private:
- GrUniqueKeyInvalidatedMessage fMsg;
-
- void onChange() override {
- SkMessageBus<GrUniqueKeyInvalidatedMessage>::Post(fMsg);
- }
-};
-
-} // namespace
-
bool GrTessellatingPathRenderer::onCanDrawPath(const CanDrawPathArgs& args) const {
// This path renderer can draw all fill styles, all stroke styles except hairlines, but does
// not do antialiasing. It can do convex and concave paths, but we'll leave the convex ones to
@@ -1435,90 +124,23 @@
}
stroke.setFillStyle();
}
- SkRect pathBounds = path.getBounds();
- Comparator c;
- if (pathBounds.width() > pathBounds.height()) {
- c.sweep_lt = sweep_lt_horiz;
- c.sweep_gt = sweep_gt_horiz;
- } else {
- c.sweep_lt = sweep_lt_vert;
- c.sweep_gt = sweep_gt_vert;
- }
SkScalar screenSpaceTol = GrPathUtils::kDefaultTolerance;
+ SkRect pathBounds = path.getBounds();
SkScalar tol = GrPathUtils::scaleToleranceToSrc(screenSpaceTol, fViewMatrix, pathBounds);
- int contourCnt;
- int maxPts = GrPathUtils::worstCasePointCount(path, &contourCnt, tol);
- if (maxPts <= 0) {
- return 0;
- }
- if (maxPts > ((int)SK_MaxU16 + 1)) {
- SkDebugf("Path not rendered, too many verts (%d)\n", maxPts);
- return 0;
- }
- SkPath::FillType fillType = path.getFillType();
- if (SkPath::IsInverseFillType(fillType)) {
- contourCnt++;
- }
- LOG("got %d pts, %d contours\n", maxPts, contourCnt);
- SkAutoTDeleteArray<Vertex*> contours(new Vertex* [contourCnt]);
-
- // For the initial size of the chunk allocator, estimate based on the point count:
- // one vertex per point for the initial passes, plus two for the vertices in the
- // resulting Polys, since the same point may end up in two Polys. Assume minimal
- // connectivity of one Edge per Vertex (will grow for intersections).
- SkChunkAlloc alloc(maxPts * (3 * sizeof(Vertex) + sizeof(Edge)));
bool isLinear;
- path_to_contours(path, tol, fClipBounds, contours.get(), alloc, &isLinear);
- Poly* polys;
- polys = contours_to_polys(contours.get(), contourCnt, c, alloc);
- int count = 0;
- for (Poly* poly = polys; poly; poly = poly->fNext) {
- if (apply_fill_type(fillType, poly->fWinding) && poly->fCount >= 3) {
- count += (poly->fCount - 2) * (WIREFRAME ? 6 : 3);
- }
- }
- if (0 == count) {
- return 0;
- }
-
- size_t size = count * sizeof(SkPoint);
- if (!vertexBuffer.get() || vertexBuffer->gpuMemorySize() < size) {
- vertexBuffer.reset(resourceProvider->createVertexBuffer(
- size, GrResourceProvider::kStatic_BufferUsage, 0));
- }
- if (!vertexBuffer.get()) {
- SkDebugf("Could not allocate vertices\n");
- return 0;
- }
- SkPoint* verts;
- if (canMapVB) {
- verts = static_cast<SkPoint*>(vertexBuffer->map());
- } else {
- verts = new SkPoint[count];
- }
- SkPoint* end = polys_to_triangles(polys, fillType, verts);
- int actualCount = static_cast<int>(end - verts);
- LOG("actual count: %d\n", actualCount);
- SkASSERT(actualCount <= count);
- if (canMapVB) {
- vertexBuffer->unmap();
- } else {
- vertexBuffer->updateData(verts, actualCount * sizeof(SkPoint));
- delete[] verts;
- }
-
-
+ int count = GrTessellator::PathToTriangles(path, tol, fClipBounds, resourceProvider,
+ vertexBuffer, canMapVB, &isLinear);
if (!fPath.isVolatile()) {
TessInfo info;
info.fTolerance = isLinear ? 0 : tol;
- info.fCount = actualCount;
+ info.fCount = count;
SkAutoTUnref<SkData> data(SkData::NewWithCopy(&info, sizeof(info)));
key->setCustomData(data.get());
resourceProvider->assignUniqueKeyToResource(*key, vertexBuffer.get());
SkPathPriv::AddGenIDChangeListener(fPath, new PathInvalidator(*key));
}
- return actualCount;
+ return count;
}
void onPrepareDraws(Target* target) const override {
@@ -1574,8 +196,8 @@
target->initDraw(gp, this->pipeline());
SkASSERT(gp->getVertexStride() == sizeof(SkPoint));
- GrPrimitiveType primitiveType = WIREFRAME ? kLines_GrPrimitiveType
- : kTriangles_GrPrimitiveType;
+ GrPrimitiveType primitiveType = TESSELLATOR_WIREFRAME ? kLines_GrPrimitiveType
+ : kTriangles_GrPrimitiveType;
GrVertices vertices;
vertices.init(primitiveType, vertexBuffer.get(), 0, actualCount);
target->draw(vertices);
