--- /dev/null
+/*
+ * 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 "gm.h"
+#include "SkCanvas.h"
+
+#define WIDTH 400
+#define HEIGHT 600
+
+namespace {
+// Concave test
+void test_concave(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->translate(0, 0);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(30), SkIntToScalar(30));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+}
+
+// Reverse concave test
+void test_reverse_concave(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(100, 0);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(30), SkIntToScalar(30));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Bowtie (intersection)
+void test_bowtie(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(200, 0);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// "fake" bowtie (concave, but no intersection)
+void test_fake_bowtie(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(300, 0);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(40));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(60));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Fish test (intersection/concave)
+void test_fish(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(0, 100);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(70), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(0), SkIntToScalar(50));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Collinear edges
+void test_collinear_edges(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(100, 100);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Square polygon with a square hole.
+void test_hole(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(200, 100);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.moveTo(SkIntToScalar(30), SkIntToScalar(30));
+ path.lineTo(SkIntToScalar(30), SkIntToScalar(70));
+ path.lineTo(SkIntToScalar(70), SkIntToScalar(70));
+ path.lineTo(SkIntToScalar(70), SkIntToScalar(30));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Star test (self-intersecting)
+void test_star(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(300, 100);
+ path.moveTo(30, 20);
+ path.lineTo(50, 80);
+ path.lineTo(70, 20);
+ path.lineTo(20, 57);
+ path.lineTo(80, 57);
+ path.close();
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Stairstep with repeated vert (intersection)
+void test_stairstep(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(0, 200);
+ path.moveTo(SkIntToScalar(50), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+void test_stairstep2(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(100, 200);
+ path.moveTo(20, 60);
+ path.lineTo(35, 80);
+ path.lineTo(50, 60);
+ path.lineTo(65, 80);
+ path.lineTo(80, 60);
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Overlapping segments
+void test_overlapping(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(200, 200);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(30));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Monotone test 1 (point in the middle)
+void test_monotone_1(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(0, 300);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.quadTo(SkIntToScalar(20), SkIntToScalar(50),
+ SkIntToScalar(80), SkIntToScalar(50));
+ path.quadTo(SkIntToScalar(20), SkIntToScalar(50),
+ SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Monotone test 2 (point at the top)
+void test_monotone_2(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(100, 300);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(30));
+ path.quadTo(SkIntToScalar(20), SkIntToScalar(20),
+ SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Monotone test 3 (point at the bottom)
+void test_monotone_3(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(200, 300);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(70));
+ path.quadTo(SkIntToScalar(20), SkIntToScalar(80),
+ SkIntToScalar(20), SkIntToScalar(20));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Monotone test 4 (merging of two monotones)
+void test_monotone_4(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(300, 300);
+ path.moveTo(80, 25);
+ path.lineTo(50, 39);
+ path.lineTo(20, 25);
+ path.lineTo(40, 45);
+ path.lineTo(70, 50);
+ path.lineTo(80, 80);
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Monotone test 5 (aborted merging of two monotones)
+void test_monotone_5(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(0, 400);
+ path.moveTo(50, 20);
+ path.lineTo(80, 80);
+ path.lineTo(50, 50);
+ path.lineTo(20, 80);
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+// Degenerate intersection test
+void test_degenerate(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(100, 400);
+ path.moveTo(50, 20);
+ path.lineTo(70, 30);
+ path.lineTo(20, 50);
+ path.moveTo(50, 20);
+ path.lineTo(80, 80);
+ path.lineTo(50, 80);
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+// Two triangles with a coincident edge.
+void test_coincident_edge(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(200, 400);
+
+ path.moveTo(80, 20);
+ path.lineTo(80, 80);
+ path.lineTo(20, 80);
+
+ path.moveTo(20, 20);
+ path.lineTo(80, 80);
+ path.lineTo(20, 80);
+
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+// Bowtie with a coincident triangle (one triangle vertex coincident with the
+// bowtie's intersection).
+void test_bowtie_coincident_triangle(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(300, 400);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.moveTo(SkIntToScalar(50), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+// Coincident edges (big ones first, coincident vert on top).
+void test_coincident_edges_1(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(0, 500);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(50));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+// Coincident edges (small ones first, coincident vert on top).
+void test_coincident_edges_2(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(100, 500);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(50));
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(80));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+// Coincident edges (small ones first, coincident vert on bottom).
+void test_coincident_edges_3(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(200, 500);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(50));
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+// Coincident edges (big ones first, coincident vert on bottom).
+void test_coincident_edges_4(SkCanvas* canvas, const SkPaint& paint) {
+ SkPath path;
+ canvas->save();
+ canvas->translate(300, 500);
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(20));
+ path.lineTo(SkIntToScalar(80), SkIntToScalar(20));
+ path.moveTo(SkIntToScalar(20), SkIntToScalar(80));
+ path.lineTo(SkIntToScalar(20), SkIntToScalar(50));
+ path.lineTo(SkIntToScalar(50), SkIntToScalar(50));
+ canvas->drawPath(path, paint);
+ canvas->restore();
+}
+
+};
+
+class ConcavePathsGM : public skiagm::GM {
+public:
+ ConcavePathsGM() {}
+
+protected:
+ SkString onShortName() SK_OVERRIDE {
+ return SkString("concavepaths");
+ }
+
+ SkISize onISize() SK_OVERRIDE {
+ return SkISize::Make(WIDTH, HEIGHT);
+ }
+
+ void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+ SkPaint paint;
+
+ paint.setAntiAlias(true);
+ paint.setStyle(SkPaint::kFill_Style);
+
+ test_concave(canvas, paint);
+ test_reverse_concave(canvas, paint);
+ test_bowtie(canvas, paint);
+ test_fake_bowtie(canvas, paint);
+ test_fish(canvas, paint);
+ test_collinear_edges(canvas, paint);
+ test_hole(canvas, paint);
+ test_star(canvas, paint);
+ test_stairstep(canvas, paint);
+ test_stairstep2(canvas, paint);
+ test_overlapping(canvas, paint);
+ test_monotone_1(canvas, paint);
+ test_monotone_2(canvas, paint);
+ test_monotone_3(canvas, paint);
+ test_monotone_4(canvas, paint);
+ test_monotone_5(canvas, paint);
+ test_degenerate(canvas, paint);
+ test_coincident_edge(canvas, paint);
+ test_bowtie_coincident_triangle(canvas, paint);
+ test_coincident_edges_1(canvas, paint);
+ test_coincident_edges_2(canvas, paint);
+ test_coincident_edges_3(canvas, paint);
+ test_coincident_edges_4(canvas, paint);
+ }
+
+private:
+ typedef skiagm::GM INHERITED;
+};
+
+static skiagm::GM* F0(void*) { return new ConcavePathsGM; }
+static skiagm::GMRegistry R0(F0);
--- /dev/null
+/*
+ * 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 "GrTessellatingPathRenderer.h"
+
+#include "GrDefaultGeoProcFactory.h"
+#include "GrPathUtils.h"
+#include "SkChunkAlloc.h"
+#include "SkGeometry.h"
+
+#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
+ * 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 there is a compile-time flag (SWEEP_IN_X) which changes the orientation of the
+ * line sweep algorithms. When SWEEP_IN_X is unset, we sort vertices based on increasing
+ * Y coordinate, and secondarily by increasing X coordinate. When SWEEP_IN_X is set, 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.
+ *
+ * The choice is arbitrary, but most test cases are wider than they are tall, so the
+ * default is to sweep in X. In the future, we may want to make this a runtime parameter
+ * and base it on the aspect ratio of the clip bounds.
+ */
+#define LOGGING_ENABLED 0
+#define WIREFRAME 0
+#define SWEEP_IN_X 1
+
+#if LOGGING_ENABLED
+#define LOG printf
+#else
+#define LOG(...)
+#endif
+
+#define ALLOC_NEW(Type, args, alloc) \
+ SkNEW_PLACEMENT_ARGS(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 = NULL;
+}
+
+/**
+ * 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(NULL), fNext(NULL)
+ , fFirstEdgeAbove(NULL), fLastEdgeAbove(NULL)
+ , fFirstEdgeBelow(NULL), fLastEdgeBelow(NULL)
+ , 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
+};
+
+/***************************************************************************************/
+
+bool sweep_lt(const SkPoint& a, const SkPoint& b) {
+#if SWEEP_IN_X
+ return a.fX == b.fX ? a.fY > b.fY : a.fX < b.fX;
+#else
+ return a.fY == b.fY ? a.fX < b.fX : a.fY < b.fY;
+#endif
+}
+
+bool sweep_gt(const SkPoint& a, const SkPoint& b) {
+#if SWEEP_IN_X
+ return a.fX == b.fX ? a.fY < b.fY : a.fX > b.fX;
+#else
+ return a.fY == b.fY ? a.fX > b.fX : a.fY > b.fY;
+#endif
+}
+
+inline void* emit_vertex(Vertex* v, void* data) {
+ SkPoint* d = static_cast<SkPoint*>(data);
+ *d++ = v->fPoint;
+ return d;
+}
+
+void* emit_triangle(Vertex* v0, Vertex* v1, Vertex* v2, void* 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;
+}
+
+/**
+ * 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(NULL)
+ , fRight(NULL)
+ , fPrevEdgeAbove(NULL)
+ , fNextEdgeAbove(NULL)
+ , fPrevEdgeBelow(NULL)
+ , fNextEdgeBelow(NULL)
+ , fLeftPoly(NULL)
+ , fRightPoly(NULL) {
+ 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(Edge** activeEdges) const {
+ return activeEdges && (fLeft || fRight || *activeEdges == this);
+ }
+};
+
+/***************************************************************************************/
+
+struct Poly {
+ Poly(int winding)
+ : fWinding(winding)
+ , fHead(NULL)
+ , fTail(NULL)
+ , fActive(NULL)
+ , fNext(NULL)
+ , fPartner(NULL)
+ , 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(NULL)
+ , fTail(NULL)
+ , fPrev(NULL)
+ , fNext(NULL) {}
+ 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 == NULL) {
+ 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;
+ }
+
+ void* emit(void* data) {
+ Vertex* first = fHead;
+ Vertex* v = first->fNext;
+ while (v != fTail) {
+ SkASSERT(v && v->fPrev && v->fNext);
+#ifdef SK_DEBUG
+ validate();
+#endif
+ 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;
+ SkASSERT(v != fTail);
+ }
+ }
+ return data;
+ }
+
+#ifdef SK_DEBUG
+ void validate() {
+ int winding = sweep_lt(fHead->fPoint, fTail->fPoint) ? 1 : -1;
+ Vertex* top = winding < 0 ? fTail : fHead;
+ Vertex* bottom = winding < 0 ? fHead : fTail;
+ Edge e(top, bottom, winding);
+ for (Vertex* v = fHead->fNext; v != fTail; v = v->fNext) {
+ if (fSide == kRight_Side) {
+ SkASSERT(!e.isRightOf(v));
+ } else if (fSide == Poly::kLeft_Side) {
+ SkASSERT(!e.isLeftOf(v));
+ }
+ }
+ }
+#endif
+ };
+ 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 = NULL;
+ }
+ if (!fActive) {
+ fActive = ALLOC_NEW(MonotonePoly, (), alloc);
+ }
+ if (fActive->addVertex(v, side, alloc)) {
+#ifdef SK_DEBUG
+ fActive->validate();
+#endif
+ 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 = NULL;
+ }
+ addVertex(v, fActive->fSide == kLeft_Side ? kRight_Side : kLeft_Side, alloc);
+ }
+ void* emit(void *data) {
+ if (fCount < 3) {
+ return data;
+ }
+ LOG("emit() %d, size %d\n", fID, fCount);
+ for (MonotonePoly* m = fHead; m != NULL; 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;
+}
+
+#ifdef SK_DEBUG
+void validate_edges(Edge* head) {
+ for (Edge* e = head; e != NULL; e = e->fRight) {
+ SkASSERT(e->fTop != e->fBottom);
+ if (e->fLeft) {
+ SkASSERT(e->fLeft->fRight == e);
+ if (sweep_gt(e->fTop->fPoint, e->fLeft->fTop->fPoint)) {
+ SkASSERT(e->fLeft->isLeftOf(e->fTop));
+ }
+ if (sweep_lt(e->fBottom->fPoint, e->fLeft->fBottom->fPoint)) {
+ SkASSERT(e->fLeft->isLeftOf(e->fBottom));
+ }
+ } else {
+ SkASSERT(e == head);
+ }
+ if (e->fRight) {
+ SkASSERT(e->fRight->fLeft == e);
+ if (sweep_gt(e->fTop->fPoint, e->fRight->fTop->fPoint)) {
+ SkASSERT(e->fRight->isRightOf(e->fTop));
+ }
+ if (sweep_lt(e->fBottom->fPoint, e->fRight->fBottom->fPoint)) {
+ SkASSERT(e->fRight->isRightOf(e->fBottom));
+ }
+ }
+ }
+}
+
+void validate_connectivity(Vertex* v) {
+ for (Edge* e = v->fFirstEdgeAbove; e != NULL; e = e->fNextEdgeAbove) {
+ SkASSERT(e->fBottom == v);
+ if (e->fPrevEdgeAbove) {
+ SkASSERT(e->fPrevEdgeAbove->fNextEdgeAbove == e);
+ SkASSERT(e->fPrevEdgeAbove->isLeftOf(e->fTop));
+ } else {
+ SkASSERT(e == v->fFirstEdgeAbove);
+ }
+ if (e->fNextEdgeAbove) {
+ SkASSERT(e->fNextEdgeAbove->fPrevEdgeAbove == e);
+ SkASSERT(e->fNextEdgeAbove->isRightOf(e->fTop));
+ } else {
+ SkASSERT(e == v->fLastEdgeAbove);
+ }
+ }
+ for (Edge* e = v->fFirstEdgeBelow; e != NULL; e = e->fNextEdgeBelow) {
+ SkASSERT(e->fTop == v);
+ if (e->fPrevEdgeBelow) {
+ SkASSERT(e->fPrevEdgeBelow->fNextEdgeBelow == e);
+ SkASSERT(e->fPrevEdgeBelow->isLeftOf(e->fBottom));
+ } else {
+ SkASSERT(e == v->fFirstEdgeBelow);
+ }
+ if (e->fNextEdgeBelow) {
+ SkASSERT(e->fNextEdgeBelow->fPrevEdgeBelow == e);
+ SkASSERT(e->fNextEdgeBelow->isRightOf(e->fBottom));
+ } else {
+ SkASSERT(e == v->fLastEdgeBelow);
+ }
+ }
+}
+#endif
+
+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) {
+
+ SkScalar toleranceSqd = tolerance * tolerance;
+
+ SkPoint pts[4];
+ bool done = false;
+ SkPath::Iter iter(path, false);
+ Vertex* prev = NULL;
+ Vertex* head = NULL;
+ 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 = NULL;
+ }
+ 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, toleranceSqd);
+ prev = generate_quadratic_points(quadPts[0], quadPts[1], quadPts[2],
+ toleranceSqd, prev, &head, pointsLeft, alloc);
+ quadPts += 2;
+ }
+ break;
+ }
+ case SkPath::kMove_Verb:
+ if (head) {
+ head->fPrev = prev;
+ prev->fNext = head;
+ *contours++ = head;
+ }
+ head = prev = NULL;
+ 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, toleranceSqd);
+ prev = generate_quadratic_points(pts[0], pts[1], pts[2], toleranceSqd, prev,
+ &head, pointsLeft, alloc);
+ break;
+ }
+ case SkPath::kCubic_Verb: {
+ int pointsLeft = GrPathUtils::cubicPointCount(pts, toleranceSqd);
+ prev = generate_cubic_points(pts[0], pts[1], pts[2], pts[3],
+ toleranceSqd, prev, &head, pointsLeft, alloc);
+ break;
+ }
+ case SkPath::kClose_Verb:
+ if (head) {
+ head->fPrev = prev;
+ prev->fNext = head;
+ *contours++ = head;
+ }
+ head = prev = NULL;
+ 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) {
+ int winding = 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, Edge** head) {
+ LOG("removing edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID);
+ SkASSERT(edge->isActive(head));
+ remove<Edge, &Edge::fLeft, &Edge::fRight>(edge, head, NULL);
+}
+
+void insert_edge(Edge* edge, Edge* prev, Edge** head) {
+ LOG("inserting edge %g -> %g\n", edge->fTop->fID, edge->fBottom->fID);
+ SkASSERT(!edge->isActive(head));
+ Edge* next = prev ? prev->fRight : *head;
+ insert<Edge, &Edge::fLeft, &Edge::fRight>(edge, prev, next, head, NULL);
+}
+
+void find_enclosing_edges(Vertex* v, Edge* head, Edge** left, Edge** right) {
+ if (v->fFirstEdgeAbove) {
+ *left = v->fFirstEdgeAbove->fLeft;
+ *right = v->fLastEdgeAbove->fRight;
+ return;
+ }
+ Edge* prev = NULL;
+ Edge* next;
+ for (next = head; next != NULL; next = next->fRight) {
+ if (next->isRightOf(v)) {
+ break;
+ }
+ prev = next;
+ }
+ *left = prev;
+ *right = next;
+ return;
+}
+
+void find_enclosing_edges(Edge* edge, Edge* head, Edge** left, Edge** right) {
+ Edge* prev = NULL;
+ Edge* next;
+ for (next = head; next != NULL; next = next->fRight) {
+ if ((sweep_gt(edge->fTop->fPoint, next->fTop->fPoint) && next->isRightOf(edge->fTop)) ||
+ (sweep_gt(next->fTop->fPoint, edge->fTop->fPoint) && edge->isLeftOf(next->fTop)) ||
+ (sweep_lt(edge->fBottom->fPoint, next->fBottom->fPoint) &&
+ next->isRightOf(edge->fBottom)) ||
+ (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, Edge** activeEdges) {
+ 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, &left, &right);
+ insert_edge(edge, left, activeEdges);
+ }
+}
+
+void insert_edge_above(Edge* edge, Vertex* v) {
+ if (edge->fTop->fPoint == edge->fBottom->fPoint ||
+ sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) {
+ SkASSERT(false);
+ return;
+ }
+ LOG("insert edge (%g -> %g) above vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID);
+ Edge* prev = NULL;
+ 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) {
+ if (edge->fTop->fPoint == edge->fBottom->fPoint ||
+ sweep_gt(edge->fTop->fPoint, edge->fBottom->fPoint)) {
+ SkASSERT(false);
+ return;
+ }
+ LOG("insert edge (%g -> %g) below vertex %g\n", edge->fTop->fID, edge->fBottom->fID, v->fID);
+ Edge* prev = NULL;
+ 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, Edge** head) {
+ 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(head)) {
+ remove_edge(edge, head);
+ }
+}
+
+void merge_collinear_edges(Edge* edge, Edge** activeEdges);
+
+void set_top(Edge* edge, Vertex* v, Edge** activeEdges) {
+ remove_edge_below(edge);
+ edge->fTop = v;
+ edge->recompute();
+ insert_edge_below(edge, v);
+ fix_active_state(edge, activeEdges);
+ merge_collinear_edges(edge, activeEdges);
+}
+
+void set_bottom(Edge* edge, Vertex* v, Edge** activeEdges) {
+ remove_edge_above(edge);
+ edge->fBottom = v;
+ edge->recompute();
+ insert_edge_above(edge, v);
+ fix_active_state(edge, activeEdges);
+ merge_collinear_edges(edge, activeEdges);
+}
+
+void merge_edges_above(Edge* edge, Edge* other, Edge** activeEdges) {
+ 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 (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);
+ } else {
+ edge->fWinding += other->fWinding;
+ erase_edge_if_zero_winding(edge, activeEdges);
+ set_bottom(other, edge->fTop, activeEdges);
+ }
+}
+
+void merge_edges_below(Edge* edge, Edge* other, Edge** activeEdges) {
+ 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 (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);
+ } else {
+ other->fWinding += edge->fWinding;
+ erase_edge_if_zero_winding(other, activeEdges);
+ set_top(edge, other->fBottom, activeEdges);
+ }
+}
+
+void merge_collinear_edges(Edge* edge, Edge** activeEdges) {
+ if (edge->fPrevEdgeAbove && (edge->fTop == edge->fPrevEdgeAbove->fTop ||
+ !edge->fPrevEdgeAbove->isLeftOf(edge->fTop))) {
+ merge_edges_above(edge, edge->fPrevEdgeAbove, activeEdges);
+ } else if (edge->fNextEdgeAbove && (edge->fTop == edge->fNextEdgeAbove->fTop ||
+ !edge->isLeftOf(edge->fNextEdgeAbove->fTop))) {
+ merge_edges_above(edge, edge->fNextEdgeAbove, activeEdges);
+ }
+ if (edge->fPrevEdgeBelow && (edge->fBottom == edge->fPrevEdgeBelow->fBottom ||
+ !edge->fPrevEdgeBelow->isLeftOf(edge->fBottom))) {
+ merge_edges_below(edge, edge->fPrevEdgeBelow, activeEdges);
+ } else if (edge->fNextEdgeBelow && (edge->fBottom == edge->fNextEdgeBelow->fBottom ||
+ !edge->isLeftOf(edge->fNextEdgeBelow->fBottom))) {
+ merge_edges_below(edge, edge->fNextEdgeBelow, activeEdges);
+ }
+}
+
+void split_edge(Edge* edge, Vertex* v, Edge** activeEdges, SkChunkAlloc& alloc);
+
+void cleanup_active_edges(Edge* edge, Edge** activeEdges, SkChunkAlloc& alloc) {
+ Vertex* top = edge->fTop;
+ Vertex* bottom = edge->fBottom;
+ if (edge->fLeft) {
+ Vertex* leftTop = edge->fLeft->fTop;
+ Vertex* leftBottom = edge->fLeft->fBottom;
+ if (sweep_gt(top->fPoint, leftTop->fPoint) && !edge->fLeft->isLeftOf(top)) {
+ split_edge(edge->fLeft, edge->fTop, activeEdges, alloc);
+ } else if (sweep_gt(leftTop->fPoint, top->fPoint) && !edge->isRightOf(leftTop)) {
+ split_edge(edge, leftTop, activeEdges, alloc);
+ } else if (sweep_lt(bottom->fPoint, leftBottom->fPoint) && !edge->fLeft->isLeftOf(bottom)) {
+ split_edge(edge->fLeft, bottom, activeEdges, alloc);
+ } else if (sweep_lt(leftBottom->fPoint, bottom->fPoint) && !edge->isRightOf(leftBottom)) {
+ split_edge(edge, leftBottom, activeEdges, alloc);
+ }
+ }
+ if (edge->fRight) {
+ Vertex* rightTop = edge->fRight->fTop;
+ Vertex* rightBottom = edge->fRight->fBottom;
+ if (sweep_gt(top->fPoint, rightTop->fPoint) && !edge->fRight->isRightOf(top)) {
+ split_edge(edge->fRight, top, activeEdges, alloc);
+ } else if (sweep_gt(rightTop->fPoint, top->fPoint) && !edge->isLeftOf(rightTop)) {
+ split_edge(edge, rightTop, activeEdges, alloc);
+ } else if (sweep_lt(bottom->fPoint, rightBottom->fPoint) &&
+ !edge->fRight->isRightOf(bottom)) {
+ split_edge(edge->fRight, bottom, activeEdges, alloc);
+ } else if (sweep_lt(rightBottom->fPoint, bottom->fPoint) &&
+ !edge->isLeftOf(rightBottom)) {
+ split_edge(edge, rightBottom, activeEdges, alloc);
+ }
+ }
+}
+
+void split_edge(Edge* edge, Vertex* v, Edge** activeEdges, 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);
+ Edge* newEdge = ALLOC_NEW(Edge, (v, edge->fBottom, edge->fWinding), alloc);
+ insert_edge_below(newEdge, v);
+ insert_edge_above(newEdge, edge->fBottom);
+ set_bottom(edge, v, activeEdges);
+ cleanup_active_edges(edge, activeEdges, alloc);
+ fix_active_state(newEdge, activeEdges);
+ merge_collinear_edges(newEdge, activeEdges);
+}
+
+void merge_vertices(Vertex* src, Vertex* dst, Vertex** head, 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, NULL);
+ edge = next;
+ }
+ for (Edge* edge = src->fFirstEdgeBelow; edge;) {
+ Edge* next = edge->fNextEdgeBelow;
+ set_top(edge, dst, NULL);
+ edge = next;
+ }
+ remove<Vertex, &Vertex::fPrev, &Vertex::fNext>(src, head, NULL);
+}
+
+Vertex* check_for_intersection(Edge* edge, Edge* other, Edge** activeEdges, SkChunkAlloc& alloc) {
+ SkPoint p;
+ if (!edge || !other) {
+ return NULL;
+ }
+ if (edge->intersect(*other, &p)) {
+ Vertex* v;
+ LOG("found intersection, pt is %g, %g\n", p.fX, p.fY);
+ if (p == edge->fTop->fPoint || sweep_lt(p, edge->fTop->fPoint)) {
+ split_edge(other, edge->fTop, activeEdges, alloc);
+ v = edge->fTop;
+ } else if (p == edge->fBottom->fPoint || sweep_gt(p, edge->fBottom->fPoint)) {
+ split_edge(other, edge->fBottom, activeEdges, alloc);
+ v = edge->fBottom;
+ } else if (p == other->fTop->fPoint || sweep_lt(p, other->fTop->fPoint)) {
+ split_edge(edge, other->fTop, activeEdges, alloc);
+ v = other->fTop;
+ } else if (p == other->fBottom->fPoint || sweep_gt(p, other->fBottom->fPoint)) {
+ split_edge(edge, other->fBottom, activeEdges, alloc);
+ v = other->fBottom;
+ } else {
+ Vertex* nextV = edge->fTop;
+ while (sweep_lt(p, nextV->fPoint)) {
+ nextV = nextV->fPrev;
+ }
+ while (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, alloc);
+ split_edge(other, v, activeEdges, alloc);
+ }
+#ifdef SK_DEBUG
+ validate_connectivity(v);
+#endif
+ return v;
+ }
+ return NULL;
+}
+
+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] = NULL;
+ 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, SkChunkAlloc& alloc) {
+ for (Vertex* v = (*vertices)->fNext; v != NULL; v = v->fNext) {
+ if (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, alloc);
+ }
+ }
+}
+
+// Stage 2: convert the contours to a mesh of edges connecting the vertices.
+
+Vertex* build_edges(Vertex** contours, int contourCnt, SkChunkAlloc& alloc) {
+ Vertex* vertices = NULL;
+ Vertex* prev = NULL;
+ for (int i = 0; i < contourCnt; ++i) {
+ for (Vertex* v = contours[i]; v != NULL;) {
+ Vertex* vNext = v->fNext;
+ Edge* edge = new_edge(v->fPrev, v, alloc);
+ if (edge->fWinding > 0) {
+ insert_edge_below(edge, v->fPrev);
+ insert_edge_above(edge, v);
+ } else {
+ insert_edge_below(edge, v);
+ insert_edge_above(edge, v->fPrev);
+ }
+ merge_collinear_edges(edge, NULL);
+ 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 = NULL;
+ }
+ return vertices;
+}
+
+// Stage 3: sort the vertices by increasing Y (or X if SWEEP_IN_X is on).
+
+Vertex* sorted_merge(Vertex* a, Vertex* b);
+
+void front_back_split(Vertex* v, Vertex** pFront, Vertex** pBack) {
+ Vertex* fast;
+ Vertex* slow;
+ if (!v || !v->fNext) {
+ *pFront = v;
+ *pBack = NULL;
+ } else {
+ slow = v;
+ fast = v->fNext;
+
+ while (fast != NULL) {
+ fast = fast->fNext;
+ if (fast != NULL) {
+ slow = slow->fNext;
+ fast = fast->fNext;
+ }
+ }
+
+ *pFront = v;
+ *pBack = slow->fNext;
+ slow->fNext->fPrev = NULL;
+ slow->fNext = NULL;
+ }
+}
+
+void merge_sort(Vertex** head) {
+ if (!*head || !(*head)->fNext) {
+ return;
+ }
+
+ Vertex* a;
+ Vertex* b;
+ front_back_split(*head, &a, &b);
+
+ merge_sort(&a);
+ merge_sort(&b);
+
+ *head = sorted_merge(a, b);
+}
+
+Vertex* sorted_merge(Vertex* a, Vertex* b) {
+ if (!a) {
+ return b;
+ } else if (!b) {
+ return a;
+ }
+
+ Vertex* result = NULL;
+
+ if (sweep_lt(a->fPoint, b->fPoint)) {
+ result = a;
+ result->fNext = sorted_merge(a->fNext, b);
+ } else {
+ result = b;
+ result->fNext = sorted_merge(a, b->fNext);
+ }
+ result->fNext->fPrev = result;
+ return result;
+}
+
+// Stage 4: Simplify the mesh by inserting new vertices at intersecting edges.
+
+void simplify(Vertex* vertices, SkChunkAlloc& alloc) {
+ LOG("simplifying complex polygons\n");
+ Edge* activeEdges = NULL;
+ for (Vertex* v = vertices; v != NULL; 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
+#ifdef SK_DEBUG
+ validate_connectivity(v);
+#endif
+ Edge* leftEnclosingEdge = NULL;
+ Edge* rightEnclosingEdge = NULL;
+ bool restartChecks;
+ do {
+ restartChecks = false;
+ find_enclosing_edges(v, activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
+ if (v->fFirstEdgeBelow) {
+ for (Edge* edge = v->fFirstEdgeBelow; edge != NULL; edge = edge->fNextEdgeBelow) {
+ if (check_for_intersection(edge, leftEnclosingEdge, &activeEdges, alloc)) {
+ restartChecks = true;
+ break;
+ }
+ if (check_for_intersection(edge, rightEnclosingEdge, &activeEdges, alloc)) {
+ restartChecks = true;
+ break;
+ }
+ }
+ } else {
+ if (Vertex* pv = check_for_intersection(leftEnclosingEdge, rightEnclosingEdge,
+ &activeEdges, alloc)) {
+ if (sweep_lt(pv->fPoint, v->fPoint)) {
+ v = pv;
+ }
+ restartChecks = true;
+ }
+
+ }
+ } while (restartChecks);
+ SkASSERT(!leftEnclosingEdge || leftEnclosingEdge->isLeftOf(v));
+ SkASSERT(!rightEnclosingEdge || rightEnclosingEdge->isRightOf(v));
+#ifdef SK_DEBUG
+ validate_edges(activeEdges);
+#endif
+ 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");
+ Edge* activeEdges = NULL;
+ Poly* polys = NULL;
+ for (Vertex* v = vertices; v != NULL; 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
+#ifdef SK_DEBUG
+ validate_connectivity(v);
+#endif
+ Edge* leftEnclosingEdge = NULL;
+ Edge* rightEnclosingEdge = NULL;
+ find_enclosing_edges(v, activeEdges, &leftEnclosingEdge, &rightEnclosingEdge);
+ SkASSERT(!leftEnclosingEdge || leftEnclosingEdge->isLeftOf(v));
+ SkASSERT(!rightEnclosingEdge || rightEnclosingEdge->isRightOf(v));
+#ifdef SK_DEBUG
+ validate_edges(activeEdges);
+#endif
+ Poly* leftPoly = NULL;
+ Poly* rightPoly = NULL;
+ if (v->fFirstEdgeAbove) {
+ leftPoly = v->fFirstEdgeAbove->fLeftPoly;
+ rightPoly = v->fLastEdgeAbove->fRightPoly;
+ } else {
+ leftPoly = leftEnclosingEdge ? leftEnclosingEdge->fRightPoly : NULL;
+ rightPoly = rightEnclosingEdge ? rightEnclosingEdge->fLeftPoly : NULL;
+ }
+#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 == NULL && rightPoly->fPartner == NULL);
+ 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;
+ }
+#ifdef SK_DEBUG
+ validate_edges(activeEdges);
+#endif
+#if LOGGING_ENABLED
+ LOG("\nactive edges:\n");
+ for (Edge* e = activeEdges; e != NULL; 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, 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, alloc);
+ if (!vertices) {
+ return NULL;
+ }
+
+ // Sort vertices in Y (secondarily in X).
+ merge_sort(&vertices);
+ merge_coincident_vertices(&vertices, alloc);
+#if LOGGING_ENABLED
+ for (Vertex* v = vertices; v != NULL; v = v->fNext) {
+ static float gID = 0.0f;
+ v->fID = gID++;
+ }
+#endif
+ simplify(vertices, alloc);
+ return tessellate(vertices, alloc);
+}
+
+// Stage 6: Triangulate the monotone polygons into a vertex buffer.
+
+void* polys_to_triangles(Poly* polys, SkPath::FillType fillType, void* data) {
+ void* d = data;
+ for (Poly* poly = polys; poly; poly = poly->fNext) {
+ if (apply_fill_type(fillType, poly->fWinding)) {
+ d = poly->emit(d);
+ }
+ }
+ return d;
+}
+
+};
+
+GrTessellatingPathRenderer::GrTessellatingPathRenderer() {
+}
+
+GrPathRenderer::StencilSupport GrTessellatingPathRenderer::onGetStencilSupport(
+ const GrDrawTarget*,
+ const GrPipelineBuilder*,
+ const SkPath&,
+ const SkStrokeRec&) const {
+ return GrPathRenderer::kNoSupport_StencilSupport;
+}
+
+bool GrTessellatingPathRenderer::canDrawPath(const GrDrawTarget* target,
+ const GrPipelineBuilder* pipelineBuilder,
+ const SkMatrix& viewMatrix,
+ const SkPath& path,
+ const SkStrokeRec& stroke,
+ bool antiAlias) const {
+ // This path renderer can draw all fill styles, but does not do antialiasing. It can do convex
+ // and concave paths, but we'll leave the convex ones to simpler algorithms.
+ return stroke.isFillStyle() && !antiAlias && !path.isConvex();
+}
+
+bool GrTessellatingPathRenderer::onDrawPath(GrDrawTarget* target,
+ GrPipelineBuilder* pipelineBuilder,
+ GrColor color,
+ const SkMatrix& viewM,
+ const SkPath& path,
+ const SkStrokeRec& stroke,
+ bool antiAlias) {
+ SkASSERT(!antiAlias);
+ const GrRenderTarget* rt = pipelineBuilder->getRenderTarget();
+ if (NULL == rt) {
+ return false;
+ }
+
+ SkScalar tol = GrPathUtils::scaleToleranceToSrc(SK_Scalar1, viewM, path.getBounds());
+
+ int contourCnt;
+ int maxPts = GrPathUtils::worstCasePointCount(path, &contourCnt, tol);
+ if (maxPts <= 0) {
+ return false;
+ }
+ if (maxPts > ((int)SK_MaxU16 + 1)) {
+ SkDebugf("Path not rendered, too many verts (%d)\n", maxPts);
+ return false;
+ }
+ SkPath::FillType fillType = path.getFillType();
+ if (SkPath::IsInverseFillType(fillType)) {
+ contourCnt++;
+ }
+
+ LOG("got %d pts, %d contours\n", maxPts, contourCnt);
+
+ SkAutoTDeleteArray<Vertex*> contours(SkNEW_ARRAY(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)));
+ SkIRect clipBoundsI;
+ pipelineBuilder->clip().getConservativeBounds(rt, &clipBoundsI);
+ SkRect clipBounds = SkRect::Make(clipBoundsI);
+ SkMatrix vmi;
+ if (!viewM.invert(&vmi)) {
+ return false;
+ }
+ vmi.mapRect(&clipBounds);
+ path_to_contours(path, tol, clipBounds, contours.get(), alloc);
+ Poly* polys;
+ uint32_t flags = GrDefaultGeoProcFactory::kPosition_GPType;
+ polys = contours_to_polys(contours.get(), contourCnt, alloc);
+ SkAutoTUnref<const GrGeometryProcessor> gp(
+ GrDefaultGeoProcFactory::Create(flags, color, viewM, SkMatrix::I()));
+ 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);
+ }
+ }
+
+ int stride = gp->getVertexStride();
+ GrDrawTarget::AutoReleaseGeometry arg;
+ if (!arg.set(target, count, stride, 0)) {
+ return false;
+ }
+ LOG("emitting %d verts\n", count);
+ void* end = polys_to_triangles(polys, fillType, arg.vertices());
+ int actualCount = (static_cast<char*>(end) - static_cast<char*>(arg.vertices())) / stride;
+ LOG("actual count: %d\n", actualCount);
+ SkASSERT(actualCount <= count);
+
+ GrPrimitiveType primitiveType = WIREFRAME ? kLines_GrPrimitiveType
+ : kTriangles_GrPrimitiveType;
+ target->drawNonIndexed(pipelineBuilder, gp, primitiveType, 0, actualCount);
+
+ return true;
+}
--- /dev/null
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#if SK_SUPPORT_GPU
+#include "GrContextFactory.h"
+#include "GrTessellatingPathRenderer.h"
+#include "GrTest.h"
+#include "Test.h"
+
+/*
+ * These tests pass by not crashing, hanging or asserting in Debug.
+ */
+
+// Tests active edges made inactive by splitting.
+// Also tests active edge list forced into an invalid ordering by
+// splitting (mopped up in cleanup_active_edges()).
+static SkPath create_path_0() {
+ SkPath path;
+ path.moveTo(229.127044677734375f, 67.34100341796875f);
+ path.lineTo(187.8097381591796875f, -6.7729740142822265625f);
+ path.lineTo(171.411407470703125f, 50.94266510009765625f);
+ path.lineTo(245.5253753662109375f, 9.6253643035888671875f);
+ path.moveTo(208.4683990478515625f, 30.284009933471679688f);
+ path.lineTo(171.411407470703125f, 50.94266510009765625f);
+ path.lineTo(187.8097381591796875f, -6.7729740142822265625f);
+ return path;
+}
+
+// Intersections which fall exactly on the current vertex, and require
+// a restart of the intersection checking.
+static SkPath create_path_1() {
+ SkPath path;
+ path.moveTo(314.483551025390625f, 486.246002197265625f);
+ path.lineTo(385.41949462890625f, 532.8087158203125f);
+ path.lineTo(373.232879638671875f, 474.05938720703125f);
+ path.lineTo(326.670166015625f, 544.995361328125f);
+ path.moveTo(349.951507568359375f, 509.52734375f);
+ path.lineTo(373.232879638671875f, 474.05938720703125f);
+ path.lineTo(385.41949462890625f, 532.8087158203125f);
+ return path;
+}
+
+// Tests active edges which are removed by splitting.
+static SkPath create_path_2() {
+ SkPath path;
+ path.moveTo(343.107391357421875f, 613.62176513671875f);
+ path.lineTo(426.632415771484375f, 628.5740966796875f);
+ path.lineTo(392.3460693359375f, 579.33544921875f);
+ path.lineTo(377.39373779296875f, 662.86041259765625f);
+ path.moveTo(384.869873046875f, 621.097900390625f);
+ path.lineTo(392.3460693359375f, 579.33544921875f);
+ path.lineTo(426.632415771484375f, 628.5740966796875f);
+ return path;
+}
+
+// Collinear edges merged in set_top().
+// Also, an intersection between left and right enclosing edges which
+// falls above the current vertex.
+static SkPath create_path_3() {
+ SkPath path;
+ path.moveTo(545.95751953125f, 791.69854736328125f);
+ path.lineTo(612.05816650390625f, 738.494140625f);
+ path.lineTo(552.4056396484375f, 732.0460205078125f);
+ path.lineTo(605.61004638671875f, 798.14666748046875f);
+ path.moveTo(579.00787353515625f, 765.0963134765625f);
+ path.lineTo(552.4056396484375f, 732.0460205078125f);
+ path.lineTo(612.05816650390625f, 738.494140625f);
+ return path;
+}
+
+// Tests active edges which are made inactive by set_top().
+static SkPath create_path_4() {
+ SkPath path;
+ path.moveTo(819.2725830078125f, 751.77447509765625f);
+ path.lineTo(820.70904541015625f, 666.933837890625f);
+ path.lineTo(777.57049560546875f, 708.63592529296875f);
+ path.lineTo(862.4111328125f, 710.0723876953125f);
+ path.moveTo(819.99078369140625f, 709.3541259765625f);
+ path.lineTo(777.57049560546875f, 708.63592529296875f);
+ path.lineTo(820.70904541015625f, 666.933837890625f);
+ return path;
+}
+
+static SkPath create_path_5() {
+ SkPath path;
+ path.moveTo(823.33209228515625f, 749.052734375f);
+ path.lineTo(823.494873046875f, 664.20013427734375f);
+ path.lineTo(780.9871826171875f, 706.5450439453125f);
+ path.lineTo(865.8397216796875f, 706.70782470703125f);
+ path.moveTo(823.4134521484375f, 706.6263427734375f);
+ path.lineTo(780.9871826171875f, 706.5450439453125f);
+ path.lineTo(823.494873046875f, 664.20013427734375f);
+ return path;
+}
+
+static SkPath create_path_6() {
+ SkPath path;
+ path.moveTo(954.862548828125f, 562.8349609375f);
+ path.lineTo(899.32818603515625f, 498.679443359375f);
+ path.lineTo(895.017578125f, 558.52435302734375f);
+ path.lineTo(959.17315673828125f, 502.990081787109375f);
+ path.moveTo(927.0953369140625f, 530.7572021484375f);
+ path.lineTo(895.017578125f, 558.52435302734375f);
+ path.lineTo(899.32818603515625f, 498.679443359375f);
+ return path;
+}
+
+static SkPath create_path_7() {
+ SkPath path;
+ path.moveTo(958.5330810546875f, 547.35516357421875f);
+ path.lineTo(899.93109130859375f, 485.989013671875f);
+ path.lineTo(898.54901123046875f, 545.97308349609375f);
+ path.lineTo(959.9151611328125f, 487.37109375f);
+ path.moveTo(929.2320556640625f, 516.67205810546875f);
+ path.lineTo(898.54901123046875f, 545.97308349609375f);
+ path.lineTo(899.93109130859375f, 485.989013671875f);
+ return path;
+}
+
+static SkPath create_path_8() {
+ SkPath path;
+ path.moveTo(389.8609619140625f, 369.326873779296875f);
+ path.lineTo(470.6290283203125f, 395.33697509765625f);
+ path.lineTo(443.250030517578125f, 341.9478759765625f);
+ path.lineTo(417.239959716796875f, 422.7159423828125f);
+ path.moveTo(430.244964599609375f, 382.3319091796875f);
+ path.lineTo(443.250030517578125f, 341.9478759765625f);
+ path.lineTo(470.6290283203125f, 395.33697509765625f);
+ return path;
+}
+
+static SkPath create_path_9() {
+ SkPath path;
+ path.moveTo(20, 20);
+ path.lineTo(50, 80);
+ path.lineTo(20, 80);
+ path.moveTo(80, 50);
+ path.lineTo(50, 50);
+ path.lineTo(20, 50);
+ return path;
+}
+
+static SkPath create_path_10() {
+ SkPath path;
+ path.moveTo(257.19439697265625f, 320.876617431640625f);
+ path.lineTo(190.113037109375f, 320.58978271484375f);
+ path.lineTo(203.64404296875f, 293.8145751953125f);
+ path.moveTo(203.357177734375f, 360.896026611328125f);
+ path.lineTo(216.88824462890625f, 334.120819091796875f);
+ path.lineTo(230.41925048828125f, 307.345611572265625f);
+ return path;
+}
+
+// A degenerate segments case, where both upper and lower segments of
+// a split edge must remain active.
+static SkPath create_path_11() {
+ SkPath path;
+ path.moveTo(231.9331207275390625f, 306.2012939453125f);
+ path.lineTo(191.4859161376953125f, 306.04547119140625f);
+ path.lineTo(231.0659332275390625f, 300.2642822265625f);
+ path.moveTo(189.946807861328125f, 302.072265625f);
+ path.lineTo(179.79705810546875f, 294.859771728515625f);
+ path.lineTo(191.0016021728515625f, 296.165679931640625f);
+ path.moveTo(150.8942108154296875f, 304.900146484375f);
+ path.lineTo(179.708892822265625f, 297.849029541015625f);
+ path.lineTo(190.4742279052734375f, 299.11895751953125f);
+ return path;
+}
+
+// Handle the case where edge.dist(edge.fTop) != 0.0.
+static SkPath create_path_12() {
+ SkPath path;
+ path.moveTo( 0.0f, 400.0f);
+ path.lineTo( 138.0f, 202.0f);
+ path.lineTo( 0.0f, 202.0f);
+ path.moveTo( 12.62693023681640625f, 250.57464599609375f);
+ path.lineTo( 8.13896942138671875f, 254.556884765625f);
+ path.lineTo(-18.15641021728515625f, 220.40203857421875f);
+ path.lineTo(-15.986493110656738281f, 219.6513519287109375f);
+ path.moveTo( 36.931194305419921875f, 282.485504150390625f);
+ path.lineTo( 15.617521286010742188f, 261.2901611328125f);
+ path.lineTo( 10.3829498291015625f, 252.565765380859375f);
+ path.lineTo(-16.165292739868164062f, 222.646026611328125f);
+ return path;
+}
+
+// A degenerate segments case which exercises inactive edges being
+// made active by splitting.
+static SkPath create_path_13() {
+ SkPath path;
+ path.moveTo(690.62127685546875f, 509.25555419921875f);
+ path.lineTo(99.336181640625f, 511.71405029296875f);
+ path.lineTo(708.362548828125f, 512.4349365234375f);
+ path.lineTo(729.9940185546875f, 516.3114013671875f);
+ path.lineTo(738.708984375f, 518.76995849609375f);
+ path.lineTo(678.3463134765625f, 510.0819091796875f);
+ path.lineTo(681.21795654296875f, 504.81378173828125f);
+ path.moveTo(758.52764892578125f, 521.55963134765625f);
+ path.lineTo(719.1549072265625f, 514.50372314453125f);
+ path.lineTo(689.59063720703125f, 512.0628662109375f);
+ path.lineTo(679.78216552734375f, 507.447845458984375f);
+ return path;
+}
+
+// Tests vertices which become "orphaned" (ie., no connected edges)
+// after simplification.
+static SkPath create_path_14() {
+ SkPath path;
+ path.moveTo(217.326019287109375f, 166.4752960205078125f);
+ path.lineTo(226.279266357421875f, 170.929473876953125f);
+ path.lineTo(234.3973388671875f, 177.0623626708984375f);
+ path.lineTo(262.0921630859375f, 188.746124267578125f);
+ path.moveTo(196.23638916015625f, 174.0722198486328125f);
+ path.lineTo(416.15277099609375f, 180.138214111328125f);
+ path.lineTo(192.651947021484375f, 304.0228271484375f);
+ return path;
+}
+
+static void test_path(GrDrawTarget* dt, GrRenderTarget* rt, const SkPath& path) {
+ GrTessellatingPathRenderer tess;
+ GrPipelineBuilder pipelineBuilder;
+ pipelineBuilder.setRenderTarget(rt);
+ SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);
+ tess.drawPath(dt, &pipelineBuilder, SK_ColorWHITE, SkMatrix::I(), path, stroke, false);
+}
+
+DEF_GPUTEST(TessellatingPathRendererTests, reporter, factory) {
+ GrContext* context = factory->get(static_cast<GrContextFactory::GLContextType>(0));
+ GrSurfaceDesc desc;
+ desc.fFlags = kRenderTarget_GrSurfaceFlag;
+ desc.fWidth = 800;
+ desc.fHeight = 800;
+ desc.fConfig = kSkia8888_GrPixelConfig;
+ desc.fOrigin = kTopLeft_GrSurfaceOrigin;
+ SkAutoTUnref<GrTexture> texture(
+ context->refScratchTexture(desc, GrContext::kExact_ScratchTexMatch)
+ );
+ GrTestTarget tt;
+ context->getTestTarget(&tt);
+ GrRenderTarget* rt = texture->asRenderTarget();
+ GrDrawTarget* dt = tt.target();
+
+ test_path(dt, rt, create_path_0());
+ test_path(dt, rt, create_path_1());
+ test_path(dt, rt, create_path_2());
+ test_path(dt, rt, create_path_3());
+ test_path(dt, rt, create_path_4());
+ test_path(dt, rt, create_path_5());
+ test_path(dt, rt, create_path_6());
+ test_path(dt, rt, create_path_7());
+ test_path(dt, rt, create_path_8());
+ test_path(dt, rt, create_path_9());
+ test_path(dt, rt, create_path_10());
+ test_path(dt, rt, create_path_11());
+ test_path(dt, rt, create_path_12());
+ test_path(dt, rt, create_path_13());
+ test_path(dt, rt, create_path_14());
+}
+#endif
projects / platform / upstream / libSkiaSharp.git / commitdiff