1/*
2 * Copyright 2015 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#ifndef GrTriangulator_DEFINED
9#define GrTriangulator_DEFINED
10
11#include "include/core/SkPoint.h"
12#include "include/private/SkColorData.h"
13#include "src/gpu/GrColor.h"
14
15class GrEagerVertexAllocator;
16class SkPath;
17struct SkRect;
18
19/**
20 * Provides utility functions for converting paths to a collection of triangles.
21 */
22
23#define TRIANGULATOR_WIREFRAME 0
24
25namespace GrTriangulator {
26
27struct WindingVertex {
28 SkPoint fPos;
29 int fWinding;
30};
31
32// Triangulates a path to an array of vertices. Each triangle is represented as a set of three
33// WindingVertex entries, each of which contains the position and winding count (which is the same
34// for all three vertices of a triangle). The 'verts' out parameter is set to point to the resultant
35// vertex array. CALLER IS RESPONSIBLE for deleting this buffer to avoid a memory leak!
36int PathToVertices(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
37 WindingVertex** verts);
38
39enum class Mode {
40 kNormal,
41
42 // Surround path edges with coverage ramps for antialiasing.
43 kEdgeAntialias,
44
45 // Triangulate only each contour's inner polygon. The inner polygons connect the endpoints of
46 // each verb. (i.e., they are the path that would result from collapsing all curves to single
47 // lines.)
48 //
49 // If the inner polygons are not simple (e.g., self intersection, double winding), then the
50 // tessellator aborts and returns 0.
51 kSimpleInnerPolygons
52};
53
54constexpr size_t GetVertexStride(Mode mode) {
55 return sizeof(SkPoint) + ((Mode::kEdgeAntialias == mode) ? sizeof(float) : 0);
56}
57
58int PathToTriangles(const SkPath& path, SkScalar tolerance, const SkRect& clipBounds,
59 GrEagerVertexAllocator*, Mode, int* numCountedCurves);
60} // namespace GrTriangulator
61
62#endif
63