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