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 #include "SkPathOpsPoint.h"
8 #include "SkPathWriter.h"
9
10 // wrap path to keep track of whether the contour is initialized and non-empty
SkPathWriter(SkPath & path)11 SkPathWriter::SkPathWriter(SkPath& path)
12 : fPathPtr(&path)
13 , fCloses(0)
14 , fMoves(0)
15 {
16 init();
17 }
18
close()19 void SkPathWriter::close() {
20 if (!fHasMove) {
21 return;
22 }
23 bool callClose = isClosed();
24 lineTo();
25 if (fEmpty) {
26 return;
27 }
28 if (callClose) {
29 #if DEBUG_PATH_CONSTRUCTION
30 SkDebugf("path.close();\n");
31 #endif
32 fPathPtr->close();
33 fCloses++;
34 }
35 init();
36 }
37
conicTo(const SkPoint & pt1,const SkPoint & pt2,SkScalar weight)38 void SkPathWriter::conicTo(const SkPoint& pt1, const SkPoint& pt2, SkScalar weight) {
39 lineTo();
40 if (fEmpty && AlmostEqualUlps(fDefer[0], pt1) && AlmostEqualUlps(pt1, pt2)) {
41 deferredLine(pt2);
42 return;
43 }
44 moveTo();
45 fDefer[1] = pt2;
46 nudge();
47 fDefer[0] = fDefer[1];
48 #if DEBUG_PATH_CONSTRUCTION
49 SkDebugf("path.conicTo(%1.9g,%1.9g, %1.9g,%1.9g, %1.9g);\n",
50 pt1.fX, pt1.fY, fDefer[1].fX, fDefer[1].fY, weight);
51 #endif
52 fPathPtr->conicTo(pt1.fX, pt1.fY, fDefer[1].fX, fDefer[1].fY, weight);
53 fEmpty = false;
54 }
55
cubicTo(const SkPoint & pt1,const SkPoint & pt2,const SkPoint & pt3)56 void SkPathWriter::cubicTo(const SkPoint& pt1, const SkPoint& pt2, const SkPoint& pt3) {
57 lineTo();
58 if (fEmpty && AlmostEqualUlps(fDefer[0], pt1) && AlmostEqualUlps(pt1, pt2)
59 && AlmostEqualUlps(pt2, pt3)) {
60 deferredLine(pt3);
61 return;
62 }
63 moveTo();
64 fDefer[1] = pt3;
65 nudge();
66 fDefer[0] = fDefer[1];
67 #if DEBUG_PATH_CONSTRUCTION
68 SkDebugf("path.cubicTo(%1.9g,%1.9g, %1.9g,%1.9g, %1.9g,%1.9g);\n",
69 pt1.fX, pt1.fY, pt2.fX, pt2.fY, fDefer[1].fX, fDefer[1].fY);
70 #endif
71 fPathPtr->cubicTo(pt1.fX, pt1.fY, pt2.fX, pt2.fY, fDefer[1].fX, fDefer[1].fY);
72 fEmpty = false;
73 }
74
deferredLine(const SkPoint & pt)75 void SkPathWriter::deferredLine(const SkPoint& pt) {
76 if (pt == fDefer[1]) {
77 return;
78 }
79 if (changedSlopes(pt)) {
80 lineTo();
81 fDefer[0] = fDefer[1];
82 }
83 fDefer[1] = pt;
84 }
85
deferredMove(const SkPoint & pt)86 void SkPathWriter::deferredMove(const SkPoint& pt) {
87 fMoved = true;
88 fHasMove = true;
89 fEmpty = true;
90 fDefer[0] = fDefer[1] = pt;
91 }
92
deferredMoveLine(const SkPoint & pt)93 void SkPathWriter::deferredMoveLine(const SkPoint& pt) {
94 if (!fHasMove) {
95 deferredMove(pt);
96 }
97 deferredLine(pt);
98 }
99
hasMove() const100 bool SkPathWriter::hasMove() const {
101 return fHasMove;
102 }
103
init()104 void SkPathWriter::init() {
105 fEmpty = true;
106 fHasMove = false;
107 fMoved = false;
108 }
109
isClosed() const110 bool SkPathWriter::isClosed() const {
111 return !fEmpty && SkDPoint::ApproximatelyEqual(fFirstPt, fDefer[1]);
112 }
113
lineTo()114 void SkPathWriter::lineTo() {
115 if (fDefer[0] == fDefer[1]) {
116 return;
117 }
118 moveTo();
119 nudge();
120 fEmpty = false;
121 #if DEBUG_PATH_CONSTRUCTION
122 SkDebugf("path.lineTo(%1.9g,%1.9g);\n", fDefer[1].fX, fDefer[1].fY);
123 #endif
124 fPathPtr->lineTo(fDefer[1].fX, fDefer[1].fY);
125 fDefer[0] = fDefer[1];
126 }
127
nativePath() const128 const SkPath* SkPathWriter::nativePath() const {
129 return fPathPtr;
130 }
131
nudge()132 void SkPathWriter::nudge() {
133 if (fEmpty || !AlmostEqualUlps(fDefer[1].fX, fFirstPt.fX)
134 || !AlmostEqualUlps(fDefer[1].fY, fFirstPt.fY)) {
135 return;
136 }
137 fDefer[1] = fFirstPt;
138 }
139
quadTo(const SkPoint & pt1,const SkPoint & pt2)140 void SkPathWriter::quadTo(const SkPoint& pt1, const SkPoint& pt2) {
141 lineTo();
142 if (fEmpty && AlmostEqualUlps(fDefer[0], pt1) && AlmostEqualUlps(pt1, pt2)) {
143 deferredLine(pt2);
144 return;
145 }
146 moveTo();
147 fDefer[1] = pt2;
148 nudge();
149 fDefer[0] = fDefer[1];
150 #if DEBUG_PATH_CONSTRUCTION
151 SkDebugf("path.quadTo(%1.9g,%1.9g, %1.9g,%1.9g);\n",
152 pt1.fX, pt1.fY, fDefer[1].fX, fDefer[1].fY);
153 #endif
154 fPathPtr->quadTo(pt1.fX, pt1.fY, fDefer[1].fX, fDefer[1].fY);
155 fEmpty = false;
156 }
157
someAssemblyRequired() const158 bool SkPathWriter::someAssemblyRequired() const {
159 return fCloses < fMoves;
160 }
161
changedSlopes(const SkPoint & pt) const162 bool SkPathWriter::changedSlopes(const SkPoint& pt) const {
163 if (fDefer[0] == fDefer[1]) {
164 return false;
165 }
166 SkScalar deferDx = fDefer[1].fX - fDefer[0].fX;
167 SkScalar deferDy = fDefer[1].fY - fDefer[0].fY;
168 SkScalar lineDx = pt.fX - fDefer[1].fX;
169 SkScalar lineDy = pt.fY - fDefer[1].fY;
170 return deferDx * lineDy != deferDy * lineDx;
171 }
172
moveTo()173 void SkPathWriter::moveTo() {
174 if (!fMoved) {
175 return;
176 }
177 fFirstPt = fDefer[0];
178 #if DEBUG_PATH_CONSTRUCTION
179 SkDebugf("path.moveTo(%1.9g,%1.9g);\n", fDefer[0].fX, fDefer[0].fY);
180 #endif
181 fPathPtr->moveTo(fDefer[0].fX, fDefer[0].fY);
182 fMoved = false;
183 fMoves++;
184 }
185