1 /*
2 * Copyright 2012 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 #include "include/core/SkTypes.h"
9 #if defined(SK_BUILD_FOR_WIN)
10
11 #include "include/core/SkPath.h"
12 #include "src/utils/SkFloatUtils.h"
13 #include "src/utils/win/SkDWriteGeometrySink.h"
14 #include "src/utils/win/SkObjBase.h"
15
16 #include <dwrite.h>
17 #include <d2d1.h>
18
SkDWriteGeometrySink(SkPath * path)19 SkDWriteGeometrySink::SkDWriteGeometrySink(SkPath* path) : fRefCount(1), fPath(path) { }
20
~SkDWriteGeometrySink()21 SkDWriteGeometrySink::~SkDWriteGeometrySink() { }
22
QueryInterface(REFIID iid,void ** object)23 SK_STDMETHODIMP SkDWriteGeometrySink::QueryInterface(REFIID iid, void **object) {
24 if (nullptr == object) {
25 return E_INVALIDARG;
26 }
27 if (iid == __uuidof(IUnknown) || iid == __uuidof(IDWriteGeometrySink)) {
28 *object = static_cast<IDWriteGeometrySink*>(this);
29 this->AddRef();
30 return S_OK;
31 } else {
32 *object = nullptr;
33 return E_NOINTERFACE;
34 }
35 }
36
SK_STDMETHODIMP_(ULONG)37 SK_STDMETHODIMP_(ULONG) SkDWriteGeometrySink::AddRef(void) {
38 return static_cast<ULONG>(InterlockedIncrement(&fRefCount));
39 }
40
SK_STDMETHODIMP_(ULONG)41 SK_STDMETHODIMP_(ULONG) SkDWriteGeometrySink::Release(void) {
42 ULONG res = static_cast<ULONG>(InterlockedDecrement(&fRefCount));
43 if (0 == res) {
44 delete this;
45 }
46 return res;
47 }
48
SK_STDMETHODIMP_(void)49 SK_STDMETHODIMP_(void) SkDWriteGeometrySink::SetFillMode(D2D1_FILL_MODE fillMode) {
50 switch (fillMode) {
51 case D2D1_FILL_MODE_ALTERNATE:
52 fPath->setFillType(SkPath::kEvenOdd_FillType);
53 break;
54 case D2D1_FILL_MODE_WINDING:
55 fPath->setFillType(SkPath::kWinding_FillType);
56 break;
57 default:
58 SkDEBUGFAIL("Unknown D2D1_FILL_MODE.");
59 break;
60 }
61 }
62
SK_STDMETHODIMP_(void)63 SK_STDMETHODIMP_(void) SkDWriteGeometrySink::SetSegmentFlags(D2D1_PATH_SEGMENT vertexFlags) {
64 if (vertexFlags == D2D1_PATH_SEGMENT_NONE || vertexFlags == D2D1_PATH_SEGMENT_FORCE_ROUND_LINE_JOIN) {
65 SkDEBUGFAIL("Invalid D2D1_PATH_SEGMENT value.");
66 }
67 }
68
SK_STDMETHODIMP_(void)69 SK_STDMETHODIMP_(void) SkDWriteGeometrySink::BeginFigure(D2D1_POINT_2F startPoint, D2D1_FIGURE_BEGIN figureBegin) {
70 fPath->moveTo(startPoint.x, startPoint.y);
71 if (figureBegin == D2D1_FIGURE_BEGIN_HOLLOW) {
72 SkDEBUGFAIL("Invalid D2D1_FIGURE_BEGIN value.");
73 }
74 }
75
SK_STDMETHODIMP_(void)76 SK_STDMETHODIMP_(void) SkDWriteGeometrySink::AddLines(const D2D1_POINT_2F *points, UINT pointsCount) {
77 for (const D2D1_POINT_2F *end = &points[pointsCount]; points < end; ++points) {
78 fPath->lineTo(points->x, points->y);
79 }
80 }
81
approximately_equal(float a,float b)82 static bool approximately_equal(float a, float b) {
83 const SkFloatingPoint<float, 10> lhs(a), rhs(b);
84 return lhs.AlmostEquals(rhs);
85 }
86
87 typedef struct {
88 float x;
89 float y;
90 } Cubic[4], Quadratic[3];
91
check_quadratic(const Cubic & cubic,Quadratic & reduction)92 static bool check_quadratic(const Cubic& cubic, Quadratic& reduction) {
93 float dx10 = cubic[1].x - cubic[0].x;
94 float dx23 = cubic[2].x - cubic[3].x;
95 float midX = cubic[0].x + dx10 * 3 / 2;
96 //NOTE: !approximately_equal(midX - cubic[3].x, dx23 * 3 / 2)
97 //does not work as subnormals get in between the left side and 0.
98 if (!approximately_equal(midX, (dx23 * 3 / 2) + cubic[3].x)) {
99 return false;
100 }
101 float dy10 = cubic[1].y - cubic[0].y;
102 float dy23 = cubic[2].y - cubic[3].y;
103 float midY = cubic[0].y + dy10 * 3 / 2;
104 if (!approximately_equal(midY, (dy23 * 3 / 2) + cubic[3].y)) {
105 return false;
106 }
107 reduction[0] = cubic[0];
108 reduction[1].x = midX;
109 reduction[1].y = midY;
110 reduction[2] = cubic[3];
111 return true;
112 }
113
SK_STDMETHODIMP_(void)114 SK_STDMETHODIMP_(void) SkDWriteGeometrySink::AddBeziers(const D2D1_BEZIER_SEGMENT *beziers, UINT beziersCount) {
115 SkPoint lastPt;
116 fPath->getLastPt(&lastPt);
117 D2D1_POINT_2F prevPt = { SkScalarToFloat(lastPt.fX), SkScalarToFloat(lastPt.fY) };
118
119 for (const D2D1_BEZIER_SEGMENT *end = &beziers[beziersCount]; beziers < end; ++beziers) {
120 Cubic cubic = { { prevPt.x, prevPt.y },
121 { beziers->point1.x, beziers->point1.y },
122 { beziers->point2.x, beziers->point2.y },
123 { beziers->point3.x, beziers->point3.y }, };
124 Quadratic quadratic;
125 if (check_quadratic(cubic, quadratic)) {
126 fPath->quadTo(quadratic[1].x, quadratic[1].y,
127 quadratic[2].x, quadratic[2].y);
128 } else {
129 fPath->cubicTo(beziers->point1.x, beziers->point1.y,
130 beziers->point2.x, beziers->point2.y,
131 beziers->point3.x, beziers->point3.y);
132 }
133 prevPt = beziers->point3;
134 }
135 }
136
SK_STDMETHODIMP_(void)137 SK_STDMETHODIMP_(void) SkDWriteGeometrySink::EndFigure(D2D1_FIGURE_END figureEnd) {
138 fPath->close();
139 }
140
Close()141 SK_STDMETHODIMP SkDWriteGeometrySink::Close() {
142 return S_OK;
143 }
144
Create(SkPath * path,IDWriteGeometrySink ** geometryToPath)145 HRESULT SkDWriteGeometrySink::Create(SkPath* path, IDWriteGeometrySink** geometryToPath) {
146 *geometryToPath = new SkDWriteGeometrySink(path);
147 return S_OK;
148 }
149
150 #endif//defined(SK_BUILD_FOR_WIN)
151