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Some more SkPolyUtils optimizations and clean up.

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Bug: skia:
Change-Id: I7c03d8fd9557102a95fa3e784ad1d0ca1ee89786
Reviewed-on: https://skia-review.googlesource.com/142328
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
This commit is contained in:
Jim Van Verth 2018-07-24 09:30:37 -04:00 committed by Skia Commit-Bot
parent 804f817861
commit a631683cc5
1 changed files with 75 additions and 60 deletions
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135
src/utils/SkPolyUtils.cpp
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@ -19,14 +19,13 @@
struct OffsetSegment {
SkPoint fP0;
SkPoint fP1;
SkVector fV;
};
// Computes perpDot for point compared to segment.
// Computes perpDot for point p compared to segment defined by origin s0 and vector v0.
// A positive value means the point is to the left of the segment,
// negative is to the right, 0 is collinear.
static int compute_side(const SkPoint& s0, const SkPoint& s1, const SkPoint& p) {
SkVector v0 = s1 - s0;
static int compute_side(const SkPoint& s0, const SkVector& v0, const SkPoint& p) {
SkVector v1 = p - s0;
SkScalar perpDot = v0.cross(v1);
if (!SkScalarNearlyZero(perpDot)) {
@ -133,22 +132,8 @@ static inline SkScalar compute_param(const SkVector& v, const SkVector& d) {
// Returns false if there is no intersection.
static bool compute_intersection(const OffsetSegment& s0, const OffsetSegment& s1,
SkPoint* p, SkScalar* s, SkScalar* t) {
// Common cases for polygon chains -- check if endpoints are touching
if (SkPointPriv::EqualsWithinTolerance(s0.fP1, s1.fP0)) {
*p = s0.fP1;
*s = SK_Scalar1;
*t = 0;
return true;
}
if (SkPointPriv::EqualsWithinTolerance(s1.fP1, s0.fP0)) {
*p = s1.fP1;
*s = 0;
*t = SK_Scalar1;
return true;
}
SkVector v0 = s0.fP1 - s0.fP0;
SkVector v1 = s1.fP1 - s1.fP0;
const SkVector& v0 = s0.fV;
const SkVector& v1 = s1.fV;
SkVector d = s1.fP0 - s0.fP0;
SkScalar perpDot = v0.cross(v1);
SkScalar localS, localT;
@ -191,7 +176,7 @@ static bool compute_intersection(const OffsetSegment& s0, const OffsetSegment& s
// Otherwise try the other one
SkScalar oldLocalS = localS;
localS = compute_param(v0, s1.fP1 - s0.fP0);
localS = compute_param(v0, d + v1);
localT = SK_Scalar1;
if (localS < 0 || localS > SK_Scalar1) {
// it's possible that segment1's interval surrounds segment0
@ -225,8 +210,8 @@ static bool compute_intersection(const OffsetSegment& s0, const OffsetSegment& s
// computes the line intersection and then the distance to s0's endpoint
static SkScalar compute_crossing_distance(const OffsetSegment& s0, const OffsetSegment& s1) {
SkVector v0 = s0.fP1 - s0.fP0;
SkVector v1 = s1.fP1 - s1.fP0;
const SkVector& v0 = s0.fV;
const SkVector& v1 = s1.fV;
SkScalar perpDot = v0.cross(v1);
if (SkScalarNearlyZero(perpDot)) {
@ -305,14 +290,30 @@ struct OffsetEdge {
OffsetSegment fInset;
SkPoint fIntersection;
SkScalar fTValue;
uint16_t fEnd;
uint16_t fIndex;
uint16_t fEnd;
void init(uint16_t start = 0, uint16_t end = 0) {
fIntersection = fInset.fP0;
fTValue = SK_ScalarMin;
fEnd = end;
fIndex = start;
fEnd = end;
}
// special intersection check that looks for endpoint intersection
bool checkIntersection(const OffsetEdge* that,
SkPoint* p, SkScalar* s, SkScalar* t) {
if (this->fEnd == that->fIndex) {
SkPoint p1 = this->fInset.fP0 + this->fInset.fV;
if (SkPointPriv::EqualsWithinTolerance(p1, that->fInset.fP0)) {
*p = p1;
*s = SK_Scalar1;
*t = 0;
return true;
}
}
return compute_intersection(this->fInset, that->fInset, p, s, t);
}
};
@ -346,6 +347,12 @@ bool SkInsetConvexPolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize
return false;
}
// restrict this to match other routines
// practically we don't want anything bigger than this anyway
if (inputPolygonSize >= (1 << 16)) {
return false;
}
// get winding direction
int winding = SkGetPolygonWinding(inputPolygonVerts, inputPolygonSize);
if (0 == winding) {
@ -361,19 +368,22 @@ bool SkInsetConvexPolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize
return false;
}
// check for convexity just to be sure
if (compute_side(inputPolygonVerts[prev], inputPolygonVerts[curr],
if (compute_side(inputPolygonVerts[prev], inputPolygonVerts[curr] - inputPolygonVerts[prev],
inputPolygonVerts[next])*winding < 0) {
return false;
}
edgeData[curr].fPrev = &edgeData[prev];
edgeData[curr].fNext = &edgeData[next];
SkPoint p0, p1;
if (!SkOffsetSegment(inputPolygonVerts[curr], inputPolygonVerts[next],
insetDistanceFunc(inputPolygonVerts[curr]),
insetDistanceFunc(inputPolygonVerts[next]),
winding,
&edgeData[curr].fInset.fP0, &edgeData[curr].fInset.fP1)) {
&p0, &p1)) {
return false;
}
edgeData[curr].fPrev = &edgeData[prev];
edgeData[curr].fNext = &edgeData[next];
edgeData[curr].fInset.fP0 = p0;
edgeData[curr].fInset.fV = p1 - p0;
edgeData[curr].init();
}
@ -418,11 +428,12 @@ bool SkInsetConvexPolygon(const SkPoint* inputPolygonVerts, int inputPolygonSize
} else {
// if prev to right side of curr
int side = winding*compute_side(currEdge->fInset.fP0,
currEdge->fInset.fP1,
prevEdge->fInset.fP1);
if (side < 0 && side == winding*compute_side(currEdge->fInset.fP0,
currEdge->fInset.fP1,
prevEdge->fInset.fP0)) {
currEdge->fInset.fV,
prevEdge->fInset.fP0);
if (side < 0 &&
side == winding*compute_side(currEdge->fInset.fP0,
currEdge->fInset.fV,
prevEdge->fInset.fP0 + prevEdge->fInset.fV)) {
// no point in considering this one again
remove_node(prevEdge, &head);
--insetVertexCount;
@ -526,8 +537,8 @@ enum VertexFlags {
};
struct ActiveEdge {
ActiveEdge(const SkPoint& p0, const SkPoint& p1, int32_t index0, int32_t index1)
: fSegment({p0, p1})
ActiveEdge(const SkPoint& p0, const SkPoint& p1, uint16_t index0, uint16_t index1)
: fSegment({p0, p1-p0})
, fIndex0(index0)
, fIndex1(index1) {}
@ -535,12 +546,12 @@ struct ActiveEdge {
bool above(const ActiveEdge& that) const {
SkASSERT(this->fSegment.fP0.fX <= that.fSegment.fP0.fX);
const SkScalar kTolerance = SK_ScalarNearlyZero * SK_ScalarNearlyZero;
SkVector u = this->fSegment.fP1 - this->fSegment.fP0;
const SkVector& u = this->fSegment.fV;
SkVector dv = that.fSegment.fP0 - this->fSegment.fP0;
// The idea here is that if the vector between the origins of the two segments (dv)
// rotates counterclockwise up to the vector representing the "this" segment (u),
// then we know that "this" is above that. If the result is clockwise we say it's below.
if (this->fIndex0 != that.fIndex0) {
SkVector dv = that.fSegment.fP0 - this->fSegment.fP0;
SkScalar cross = dv.cross(u);
if (cross > kTolerance) {
return true;
@ -554,7 +565,11 @@ struct ActiveEdge {
// At this point either the two origins are nearly equal or the origin of "that"
// lies on dv. So then we try the same for the vector from the tail of "this"
// to the head of "that". Again, ccw means "this" is above "that".
SkVector dv = that.fSegment.fP1 - this->fSegment.fP0;
// dv = that.P1 - this.P0
// = that.fP0 + that.fV - this.fP0
// = that.fP0 - this.fP0 + that.fV
// = old_dv + that.fV
dv += that.fSegment.fV;
SkScalar cross = dv.cross(u);
if (cross > kTolerance) {
return true;
@ -571,10 +586,12 @@ struct ActiveEdge {
return false;
}
// The first endpoints are the same, so check the other endpoint
if (this->fSegment.fP1.fX < that.fSegment.fP1.fX) {
return (this->fSegment.fP1.fY >= that.fSegment.fP1.fY);
SkPoint thisP1 = this->fSegment.fP0 + this->fSegment.fV;
SkPoint thatP1 = that.fSegment.fP0 + that.fSegment.fV;
if (thisP1.fX < thatP1.fX) {
return (thisP1.fY >= thatP1.fY);
} else {
return (this->fSegment.fP1.fY > that.fSegment.fP1.fY);
return (thisP1.fY > thatP1.fY);
}
}
@ -589,14 +606,6 @@ struct ActiveEdge {
return compute_intersection(this->fSegment, that.fSegment, &intersection, &s, &t);
}
bool operator==(const ActiveEdge& that) const {
return (this->fIndex0 == that.fIndex0 && this->fIndex1 == that.fIndex1);
}
bool operator!=(const ActiveEdge& that) const {
return !operator==(that);
}
bool lessThan(const ActiveEdge& that) const {
if (this->fSegment.fP0.fX > that.fSegment.fP0.fX ||
(this->fSegment.fP0.fX == that.fSegment.fP0.fX &&
@ -614,15 +623,13 @@ struct ActiveEdge {
}
OffsetSegment fSegment;
int32_t fIndex0; // indices for previous and next vertex
int32_t fIndex1;
uint16_t fIndex0; // indices for previous and next vertex
uint16_t fIndex1;
};
class ActiveEdgeList {
public:
void reserve(int count) { }
bool insert(const SkPoint& p0, const SkPoint& p1, int32_t index0, int32_t index1) {
bool insert(const SkPoint& p0, const SkPoint& p1, uint16_t index0, uint16_t index1) {
std::pair<Iterator, bool> result = fEdgeTree.emplace(p0, p1, index0, index1);
if (!result.second) {
return false;
@ -674,6 +681,11 @@ bool SkIsSimplePolygon(const SkPoint* polygon, int polygonSize) {
return false;
}
// need to be able to represent all the vertices in the 16-bit indices
if (polygonSize >= (1 << 16)) {
return false;
}
SkTDPQueue <Vertex, Vertex::Left> vertexQueue(polygonSize);
for (int i = 0; i < polygonSize; ++i) {
Vertex newVertex;
@ -697,7 +709,6 @@ bool SkIsSimplePolygon(const SkPoint* polygon, int polygonSize) {
// pop each vertex from the queue and generate events depending on
// where it lies relative to its neighboring edges
ActiveEdgeList sweepLine;
sweepLine.reserve(polygonSize);
while (vertexQueue.count() > 0) {
const Vertex& v = vertexQueue.peek();
@ -738,7 +749,7 @@ static void setup_offset_edge(OffsetEdge* currEdge,
const SkPoint& endpoint0, const SkPoint& endpoint1,
int startIndex, int endIndex) {
currEdge->fInset.fP0 = endpoint0;
currEdge->fInset.fP1 = endpoint1;
currEdge->fInset.fV = endpoint1 - endpoint0;
currEdge->init(startIndex, endIndex);
}
@ -749,6 +760,11 @@ bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSiz
return false;
}
// need to be able to represent all the vertices in the 16-bit indices
if (inputPolygonSize >= (1 << 16)) {
return false;
}
// get winding direction
int winding = SkGetPolygonWinding(inputPolygonVerts, inputPolygonSize);
if (0 == winding) {
@ -786,7 +802,7 @@ bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSiz
int nextIndex = 1;
while (currIndex < inputPolygonSize) {
int side = compute_side(inputPolygonVerts[prevIndex],
inputPolygonVerts[currIndex],
inputPolygonVerts[currIndex] - inputPolygonVerts[prevIndex],
inputPolygonVerts[nextIndex]);
SkScalar offset = offsetDistanceFunc(inputPolygonVerts[currIndex]);
// if reflex point, fill in curve
@ -855,8 +871,7 @@ bool SkOffsetSimplePolygon(const SkPoint* inputPolygonVerts, int inputPolygonSiz
SkScalar s, t;
SkPoint intersection;
if (compute_intersection(prevEdge->fInset, currEdge->fInset,
&intersection, &s, &t)) {
if (prevEdge->checkIntersection(currEdge, &intersection, &s, &t)) {
// if new intersection is further back on previous inset from the prior intersection
if (s < prevEdge->fTValue) {
// no point in considering this one again