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SkLineParameters Class Reference

#include <SkLineParameters.h>

Public Member Functions

bool cubicEndPoints (const SkDCubic &pts)
 
void cubicEndPoints (const SkDCubic &pts, int s, int e)
 
double cubicPart (const SkDCubic &part)
 
void lineEndPoints (const SkDLine &pts)
 
bool quadEndPoints (const SkDQuad &pts)
 
void quadEndPoints (const SkDQuad &pts, int s, int e)
 
double quadPart (const SkDQuad &part)
 
double normalSquared () const
 
bool normalize ()
 
void cubicDistanceY (const SkDCubic &pts, SkDCubic &distance) const
 
void quadDistanceY (const SkDQuad &pts, SkDQuad &distance) const
 
double controlPtDistance (const SkDCubic &pts, int index) const
 
double controlPtDistance (const SkDQuad &pts) const
 
double pointDistance (const SkDPoint &pt) const
 
double dx () const
 
double dy () const
 

Detailed Description

Definition at line 28 of file SkLineParameters.h.

Member Function Documentation

◆ controlPtDistance() [1/2]

double SkLineParameters::controlPtDistance ( const SkDCubic &  pts,
int  index 
) const
inline

Definition at line 154 of file SkLineParameters.h.

154 {
155 SkASSERT(index == 1 || index == 2);
156 return fA * pts[index].fX + fB * pts[index].fY + fC;
157 }
SkASSERT
#define SkASSERT(cond)
Definition SkAssert.h:116

◆ controlPtDistance() [2/2]

double SkLineParameters::controlPtDistance ( const SkDQuad &  pts) const
inline

Definition at line 159 of file SkLineParameters.h.

159 {
160 return fA * pts[1].fX + fB * pts[1].fY + fC;
161 }

◆ cubicDistanceY()

void SkLineParameters::cubicDistanceY ( const SkDCubic &  pts,
SkDCubic &  distance 
) const
inline

Definition at line 138 of file SkLineParameters.h.

138 {
139 double oneThird = 1 / 3.0;
140 for (int index = 0; index < 4; ++index) {
141 distance[index].fX = index * oneThird;
142 distance[index].fY = fA * pts[index].fX + fB * pts[index].fY + fC;
143 }
144 }

◆ cubicEndPoints() [1/2]

bool SkLineParameters::cubicEndPoints ( const SkDCubic &  pts)
inline

Definition at line 31 of file SkLineParameters.h.

31 {
32 int endIndex = 1;
33 cubicEndPoints(pts, 0, endIndex);
34 if (dy() != 0) {
35 return true;
36 }
37 if (dx() == 0) {
38 cubicEndPoints(pts, 0, ++endIndex);
39 SkASSERT(endIndex == 2);
40 if (dy() != 0) {
41 return true;
42 }
43 if (dx() == 0) {
44 cubicEndPoints(pts, 0, ++endIndex); // line
45 SkASSERT(endIndex == 3);
46 return false;
47 }
48 }
49 // FIXME: after switching to round sort, remove bumping fA
50 if (dx() < 0) { // only worry about y bias when breaking cw/ccw tie
51 return true;
52 }
53 // if cubic tangent is on x axis, look at next control point to break tie
54 // control point may be approximate, so it must move significantly to account for error
55 if (NotAlmostEqualUlps(pts[0].fY, pts[++endIndex].fY)) {
56 if (pts[0].fY > pts[endIndex].fY) {
57 fA = DBL_EPSILON; // push it from 0 to slightly negative (y() returns -a)
58 }
59 return true;
60 }
61 if (endIndex == 3) {
62 return true;
63 }
64 SkASSERT(endIndex == 2);
65 if (pts[0].fY > pts[3].fY) {
66 fA = DBL_EPSILON; // push it from 0 to slightly negative (y() returns -a)
67 }
68 return true;
69 }
NotAlmostEqualUlps
bool NotAlmostEqualUlps(float a, float b)
Definition SkPathOpsTypes.cpp:153
SkLineParameters::cubicEndPoints
bool cubicEndPoints(const SkDCubic &pts)
Definition SkLineParameters.h:31
SkLineParameters::dx
double dx() const
Definition SkLineParameters.h:167
SkLineParameters::dy
double dy() const
Definition SkLineParameters.h:171

◆ cubicEndPoints() [2/2]

void SkLineParameters::cubicEndPoints ( const SkDCubic &  pts,
int  s,
int  e 
)
inline

Definition at line 71 of file SkLineParameters.h.

71 {
72 fA = pts[s].fY - pts[e].fY;
73 fB = pts[e].fX - pts[s].fX;
74 fC = pts[s].fX * pts[e].fY - pts[e].fX * pts[s].fY;
75 }
s
struct MyStruct s
protoc_wrapper.e
e
Definition protoc_wrapper.py:226

◆ cubicPart()

double SkLineParameters::cubicPart ( const SkDCubic &  part)
inline

Definition at line 77 of file SkLineParameters.h.

77 {
78 cubicEndPoints(part);
79 if (part[0] == part[1] || ((const SkDLine& ) part[0]).nearRay(part[2])) {
80 return pointDistance(part[3]);
81 }
82 return pointDistance(part[2]);
83 }
SkLineParameters::pointDistance
double pointDistance(const SkDPoint &pt) const
Definition SkLineParameters.h:163

◆ dx()

double SkLineParameters::dx ( ) const
inline

Definition at line 167 of file SkLineParameters.h.

167 {
168 return fB;
169 }

◆ dy()

double SkLineParameters::dy ( ) const
inline

Definition at line 171 of file SkLineParameters.h.

171 {
172 return -fA;
173 }

◆ lineEndPoints()

void SkLineParameters::lineEndPoints ( const SkDLine &  pts)
inline

Definition at line 85 of file SkLineParameters.h.

85 {
86 fA = pts[0].fY - pts[1].fY;
87 fB = pts[1].fX - pts[0].fX;
88 fC = pts[0].fX * pts[1].fY - pts[1].fX * pts[0].fY;
89 }

◆ normalize()

bool SkLineParameters::normalize ( )
inline

Definition at line 125 of file SkLineParameters.h.

125 {
126 double normal = sqrt(normalSquared());
127 if (approximately_zero(normal)) {
128 fA = fB = fC = 0;
129 return false;
130 }
131 double reciprocal = 1 / normal;
132 fA *= reciprocal;
133 fB *= reciprocal;
134 fC *= reciprocal;
135 return true;
136 }
approximately_zero
static bool approximately_zero(double x)
Definition SkCubics.cpp:153
SkLineParameters::normalSquared
double normalSquared() const
Definition SkLineParameters.h:121
skvx::sqrt
SIN Vec< N, float > sqrt(const Vec< N, float > &x)
Definition SkVx.h:706

◆ normalSquared()

double SkLineParameters::normalSquared ( ) const
inline

Definition at line 121 of file SkLineParameters.h.

121 {
122 return fA * fA + fB * fB;
123 }

◆ pointDistance()

double SkLineParameters::pointDistance ( const SkDPoint &  pt) const
inline

Definition at line 163 of file SkLineParameters.h.

163 {
164 return fA * pt.fX + fB * pt.fY + fC;
165 }

◆ quadDistanceY()

void SkLineParameters::quadDistanceY ( const SkDQuad &  pts,
SkDQuad &  distance 
) const
inline

Definition at line 146 of file SkLineParameters.h.

146 {
147 double oneHalf = 1 / 2.0;
148 for (int index = 0; index < 3; ++index) {
149 distance[index].fX = index * oneHalf;
150 distance[index].fY = fA * pts[index].fX + fB * pts[index].fY + fC;
151 }
152 }

◆ quadEndPoints() [1/2]

bool SkLineParameters::quadEndPoints ( const SkDQuad &  pts)
inline

Definition at line 91 of file SkLineParameters.h.

91 {
92 quadEndPoints(pts, 0, 1);
93 if (dy() != 0) {
94 return true;
95 }
96 if (dx() == 0) {
97 quadEndPoints(pts, 0, 2);
98 return false;
99 }
100 if (dx() < 0) { // only worry about y bias when breaking cw/ccw tie
101 return true;
102 }
103 // FIXME: after switching to round sort, remove this
104 if (pts[0].fY > pts[2].fY) {
105 fA = DBL_EPSILON;
106 }
107 return true;
108 }
SkLineParameters::quadEndPoints
bool quadEndPoints(const SkDQuad &pts)
Definition SkLineParameters.h:91

◆ quadEndPoints() [2/2]

void SkLineParameters::quadEndPoints ( const SkDQuad &  pts,
int  s,
int  e 
)
inline

Definition at line 110 of file SkLineParameters.h.

110 {
111 fA = pts[s].fY - pts[e].fY;
112 fB = pts[e].fX - pts[s].fX;
113 fC = pts[s].fX * pts[e].fY - pts[e].fX * pts[s].fY;
114 }

◆ quadPart()

double SkLineParameters::quadPart ( const SkDQuad &  part)
inline

Definition at line 116 of file SkLineParameters.h.

116 {
117 quadEndPoints(part);
118 return pointDistance(part[2]);
119 }
The documentation for this class was generated from the following file:
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