1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
/*
* 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 "SkPathOpsBounds.h"
#include "SkPathOpsRect.h"
#include "SkPathOpsCurve.h"
// this cheats and assumes that the perpendicular to the point is the closest ray to the curve
// this case (where the line and the curve are nearly coincident) may be the only case that counts
double SkDCurve::nearPoint(SkPath::Verb verb, const SkDPoint& xy, const SkDPoint& opp) const {
int count = SkPathOpsVerbToPoints(verb);
double minX = fCubic.fPts[0].fX;
double maxX = minX;
for (int index = 1; index <= count; ++index) {
minX = SkTMin(minX, fCubic.fPts[index].fX);
maxX = SkTMax(maxX, fCubic.fPts[index].fX);
}
if (!AlmostBetweenUlps(minX, xy.fX, maxX)) {
return -1;
}
double minY = fCubic.fPts[0].fY;
double maxY = minY;
for (int index = 1; index <= count; ++index) {
minY = SkTMin(minY, fCubic.fPts[index].fY);
maxY = SkTMax(maxY, fCubic.fPts[index].fY);
}
if (!AlmostBetweenUlps(minY, xy.fY, maxY)) {
return -1;
}
SkIntersections i;
SkDLine perp = {{ xy, { xy.fX + opp.fY - xy.fY, xy.fY + xy.fX - opp.fX }}};
(*CurveDIntersectRay[verb])(*this, perp, &i);
int minIndex = -1;
double minDist = FLT_MAX;
for (int index = 0; index < i.used(); ++index) {
double dist = xy.distance(i.pt(index));
if (minDist > dist) {
minDist = dist;
minIndex = index;
}
}
if (minIndex < 0) {
return -1;
}
double largest = SkTMax(SkTMax(maxX, maxY), -SkTMin(minX, minY));
if (!AlmostEqualUlps_Pin(largest, largest + minDist)) { // is distance within ULPS tolerance?
return -1;
}
return SkPinT(i[0][minIndex]);
}
void SkDCurve::offset(SkPath::Verb verb, const SkDVector& off) {
int count = SkPathOpsVerbToPoints(verb);
for (int index = 0; index <= count; ++index) {
fCubic.fPts[index] += off;
}
}
void SkDCurve::setConicBounds(const SkPoint curve[3], SkScalar curveWeight,
double tStart, double tEnd, SkPathOpsBounds* bounds) {
SkDConic dCurve;
dCurve.set(curve, curveWeight);
SkDRect dRect;
dRect.setBounds(dCurve, fConic, tStart, tEnd);
bounds->set(SkDoubleToScalar(dRect.fLeft), SkDoubleToScalar(dRect.fTop),
SkDoubleToScalar(dRect.fRight), SkDoubleToScalar(dRect.fBottom));
}
void SkDCurve::setCubicBounds(const SkPoint curve[4], SkScalar ,
double tStart, double tEnd, SkPathOpsBounds* bounds) {
SkDCubic dCurve;
dCurve.set(curve);
SkDRect dRect;
dRect.setBounds(dCurve, fCubic, tStart, tEnd);
bounds->set(SkDoubleToScalar(dRect.fLeft), SkDoubleToScalar(dRect.fTop),
SkDoubleToScalar(dRect.fRight), SkDoubleToScalar(dRect.fBottom));
}
void SkDCurve::setQuadBounds(const SkPoint curve[3], SkScalar ,
double tStart, double tEnd, SkPathOpsBounds* bounds) {
SkDQuad dCurve;
dCurve.set(curve);
SkDRect dRect;
dRect.setBounds(dCurve, fQuad, tStart, tEnd);
bounds->set(SkDoubleToScalar(dRect.fLeft), SkDoubleToScalar(dRect.fTop),
SkDoubleToScalar(dRect.fRight), SkDoubleToScalar(dRect.fBottom));
}
void SkDCurveSweep::setCurveHullSweep(SkPath::Verb verb) {
fOrdered = true;
fSweep[0] = fCurve[1] - fCurve[0];
if (SkPath::kLine_Verb == verb) {
fSweep[1] = fSweep[0];
fIsCurve = false;
return;
}
fSweep[1] = fCurve[2] - fCurve[0];
// OPTIMIZE: I do the following float check a lot -- probably need a
// central place for this val-is-small-compared-to-curve check
double maxVal = 0;
for (int index = 0; index <= SkPathOpsVerbToPoints(verb); ++index) {
maxVal = SkTMax(maxVal, SkTMax(SkTAbs(fCurve[index].fX),
SkTAbs(fCurve[index].fY)));
}
{
if (SkPath::kCubic_Verb != verb) {
if (roughly_zero_when_compared_to(fSweep[0].fX, maxVal)
&& roughly_zero_when_compared_to(fSweep[0].fY, maxVal)) {
fSweep[0] = fSweep[1];
}
goto setIsCurve;
}
SkDVector thirdSweep = fCurve[3] - fCurve[0];
if (fSweep[0].fX == 0 && fSweep[0].fY == 0) {
fSweep[0] = fSweep[1];
fSweep[1] = thirdSweep;
if (roughly_zero_when_compared_to(fSweep[0].fX, maxVal)
&& roughly_zero_when_compared_to(fSweep[0].fY, maxVal)) {
fSweep[0] = fSweep[1];
fCurve[1] = fCurve[3];
}
goto setIsCurve;
}
double s1x3 = fSweep[0].crossCheck(thirdSweep);
double s3x2 = thirdSweep.crossCheck(fSweep[1]);
if (s1x3 * s3x2 >= 0) { // if third vector is on or between first two vectors
goto setIsCurve;
}
double s2x1 = fSweep[1].crossCheck(fSweep[0]);
// FIXME: If the sweep of the cubic is greater than 180 degrees, we're in trouble
// probably such wide sweeps should be artificially subdivided earlier so that never happens
SkASSERT(s1x3 * s2x1 < 0 || s1x3 * s3x2 < 0);
if (s3x2 * s2x1 < 0) {
SkASSERT(s2x1 * s1x3 > 0);
fSweep[0] = fSweep[1];
fOrdered = false;
}
fSweep[1] = thirdSweep;
}
setIsCurve:
fIsCurve = fSweep[0].crossCheck(fSweep[1]) != 0;
}
|
