Revert "Revert "remove unused SkCurveMeasure""
This reverts commit4d1d8bcf6d. Reason for revert: will try a manual roll to update static_initializers.gni Original change's description: > Revert "remove unused SkCurveMeasure" > > This reverts commit065c2e827e. > > Reason for revert: change static initializer count? > > Original change's description: > > remove unused SkCurveMeasure > > > > Bug: skia: > > Change-Id: I36eb00883bc17e8eef4d1d226972f0125f0e2630 > > Reviewed-on: https://skia-review.googlesource.com/91702 > > Reviewed-by: Mike Reed <reed@google.com> > > Commit-Queue: Mike Reed <reed@google.com> > > TBR=reed@google.com > > Change-Id: I0d8ad2aa8b38a389048ba8bf5cafafea5788c3e1 > No-Presubmit: true > No-Tree-Checks: true > No-Try: true > Bug: skia: > Reviewed-on: https://skia-review.googlesource.com/91343 > Reviewed-by: Mike Reed <reed@google.com> > Commit-Queue: Mike Reed <reed@google.com> TBR=reed@google.com Change-Id: I7e6dfc5841b089dff047cd1d78dcebb722cdf8a4 No-Presubmit: true No-Tree-Checks: true No-Try: true Bug: skia: Reviewed-on: https://skia-review.googlesource.com/91361 Reviewed-by: Mike Reed <reed@google.com> Commit-Queue: Mike Reed <reed@google.com>
This commit is contained in:
Mike Reed
Skia Commit-Bot
parent
4d1d8bcf6d
commit
bd3a0cce99
@ -1,177 +0,0 @@
|
||||
/*
|
||||
* Copyright 2016 Google Inc.
|
||||
*
|
||||
* Use of this source code is governed by a BSD-style license that can be
|
||||
* found in the LICENSE file.
|
||||
*/
|
||||
|
||||
// for std::max
|
||||
#include <algorithm>
|
||||
|
||||
#include "Benchmark.h"
|
||||
#include "SkCurveMeasure.h"
|
||||
#include "SkPath.h"
|
||||
#include "SkPathMeasure.h"
|
||||
#include "SkString.h"
|
||||
|
||||
#define NORMALIZE_LOOPS
|
||||
|
||||
class MeasureBench : public Benchmark {
|
||||
protected:
|
||||
SkString fName;
|
||||
|
||||
SkPath fPath;
|
||||
|
||||
bool fUsePathMeasure;
|
||||
float fSize;
|
||||
size_t fPieces;
|
||||
|
||||
SkPoint fPts[3];
|
||||
|
||||
public:
|
||||
MeasureBench(bool usePathMeasure, float size, size_t pieces)
|
||||
: fUsePathMeasure(usePathMeasure),
|
||||
fSize(size),
|
||||
fPieces(pieces) {
|
||||
fName.printf("measure_%s_%.1f_" SK_SIZE_T_SPECIFIER,
|
||||
fUsePathMeasure ? "pathMeasure" : "curveMeasure", fSize,
|
||||
fPieces);
|
||||
|
||||
auto p1 = SkPoint::Make(0, 0);
|
||||
auto p2 = SkPoint::Make(30*fSize, 0);
|
||||
auto p3 = SkPoint::Make(15*fSize, 15*fSize);
|
||||
|
||||
fPts[0] = p1;
|
||||
fPts[1] = p2;
|
||||
fPts[2] = p3;
|
||||
|
||||
this->setPath();
|
||||
}
|
||||
|
||||
protected:
|
||||
const char* onGetName() override { return fName.c_str(); }
|
||||
|
||||
void setPath() {
|
||||
fPath.moveTo(fPts[0]);
|
||||
fPath.quadTo(fPts[1], fPts[2]);
|
||||
}
|
||||
|
||||
int numLoops() {
|
||||
#ifdef NORMALIZE_LOOPS
|
||||
// arbitrary heuristic
|
||||
return std::max(2, 10000 / ((int)fSize*(int)fPieces));
|
||||
#else
|
||||
return 1000;
|
||||
#endif // NORMALIZE_LOOPS
|
||||
}
|
||||
|
||||
//// measurement code
|
||||
|
||||
void do_pathMeasure(SkCanvas* canvas) {
|
||||
SkPathMeasure meas(fPath, false);
|
||||
|
||||
SkScalar totalLength = meas.getLength();
|
||||
SkScalar pieceLength = totalLength / fPieces;
|
||||
|
||||
SkPoint point;
|
||||
for (size_t i = 0; i <= fPieces; i++) {
|
||||
if (meas.getPosTan(i * pieceLength, &point, nullptr)) {
|
||||
};
|
||||
}
|
||||
}
|
||||
|
||||
void do_curveMeasure(SkCanvas* canvas) {
|
||||
SkCurveMeasure meas(fPts, kQuad_SegType);
|
||||
|
||||
SkScalar totalLength = meas.getLength();
|
||||
SkScalar pieceLength = totalLength / fPieces;
|
||||
|
||||
SkPoint point;
|
||||
for (size_t i = 0; i <= fPieces; i++) {
|
||||
meas.getPosTanTime(i*pieceLength, &point, nullptr, nullptr);
|
||||
}
|
||||
}
|
||||
|
||||
void onDraw(int loops, SkCanvas* canvas) override {
|
||||
int inner_loops = numLoops();
|
||||
for (int i = 0; i < loops; i++) {
|
||||
for (int j = 0; j < inner_loops; j++) {
|
||||
if (fUsePathMeasure) {
|
||||
do_pathMeasure(canvas);
|
||||
}
|
||||
else {
|
||||
do_curveMeasure(canvas);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
private:
|
||||
typedef Benchmark INHERITED;
|
||||
};
|
||||
|
||||
///////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
DEF_BENCH(return new MeasureBench(true, 1, 2);)
|
||||
DEF_BENCH(return new MeasureBench(true, 2, 2);)
|
||||
DEF_BENCH(return new MeasureBench(true, 10, 2);)
|
||||
DEF_BENCH(return new MeasureBench(true, 100, 2);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1000, 2);)
|
||||
|
||||
DEF_BENCH(return new MeasureBench(true, 1, 1);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1, 2);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1, 3);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1, 4);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1, 5);)
|
||||
DEF_BENCH(return new MeasureBench(true, 2, 1);)
|
||||
DEF_BENCH(return new MeasureBench(true, 2, 2);)
|
||||
DEF_BENCH(return new MeasureBench(true, 2, 3);)
|
||||
DEF_BENCH(return new MeasureBench(true, 2, 4);)
|
||||
DEF_BENCH(return new MeasureBench(true, 2, 5);)
|
||||
DEF_BENCH(return new MeasureBench(true, 10, 10);)
|
||||
DEF_BENCH(return new MeasureBench(true, 10, 20);)
|
||||
DEF_BENCH(return new MeasureBench(true, 10, 30);)
|
||||
DEF_BENCH(return new MeasureBench(true, 10, 40);)
|
||||
DEF_BENCH(return new MeasureBench(true, 10, 50);)
|
||||
DEF_BENCH(return new MeasureBench(true, 100, 100);)
|
||||
DEF_BENCH(return new MeasureBench(true, 100, 200);)
|
||||
DEF_BENCH(return new MeasureBench(true, 100, 300);)
|
||||
DEF_BENCH(return new MeasureBench(true, 100, 400);)
|
||||
DEF_BENCH(return new MeasureBench(true, 100, 500);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1000, 1000);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1000, 2000);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1000, 3000);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1000, 4000);)
|
||||
DEF_BENCH(return new MeasureBench(true, 1000, 5000);)
|
||||
|
||||
DEF_BENCH(return new MeasureBench(false, 1, 2);)
|
||||
DEF_BENCH(return new MeasureBench(false, 2, 2);)
|
||||
DEF_BENCH(return new MeasureBench(false, 10, 2);)
|
||||
DEF_BENCH(return new MeasureBench(false, 100, 2);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1000, 2);)
|
||||
|
||||
DEF_BENCH(return new MeasureBench(false, 1, 1);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1, 2);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1, 3);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1, 4);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1, 5);)
|
||||
DEF_BENCH(return new MeasureBench(false, 2, 1);)
|
||||
DEF_BENCH(return new MeasureBench(false, 2, 2);)
|
||||
DEF_BENCH(return new MeasureBench(false, 2, 3);)
|
||||
DEF_BENCH(return new MeasureBench(false, 2, 4);)
|
||||
DEF_BENCH(return new MeasureBench(false, 2, 5);)
|
||||
DEF_BENCH(return new MeasureBench(false, 10, 10);)
|
||||
DEF_BENCH(return new MeasureBench(false, 10, 20);)
|
||||
DEF_BENCH(return new MeasureBench(false, 10, 30);)
|
||||
DEF_BENCH(return new MeasureBench(false, 10, 40);)
|
||||
DEF_BENCH(return new MeasureBench(false, 10, 50);)
|
||||
DEF_BENCH(return new MeasureBench(false, 100, 100);)
|
||||
DEF_BENCH(return new MeasureBench(false, 100, 200);)
|
||||
DEF_BENCH(return new MeasureBench(false, 100, 300);)
|
||||
DEF_BENCH(return new MeasureBench(false, 100, 400);)
|
||||
DEF_BENCH(return new MeasureBench(false, 100, 500);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1000, 1000);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1000, 2000);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1000, 3000);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1000, 4000);)
|
||||
DEF_BENCH(return new MeasureBench(false, 1000, 5000);)
|
||||
@ -70,7 +70,6 @@ bench_sources = [
|
||||
"$_bench/Matrix44Bench.cpp",
|
||||
"$_bench/MatrixBench.cpp",
|
||||
"$_bench/MatrixConvolutionBench.cpp",
|
||||
"$_bench/MeasureBench.cpp",
|
||||
"$_bench/MemsetBench.cpp",
|
||||
"$_bench/MergeBench.cpp",
|
||||
"$_bench/MipMapBench.cpp",
|
||||
|
||||
@ -32,8 +32,6 @@ skia_utils_sources = [
|
||||
"$_src/utils/SkCanvasStack.h",
|
||||
"$_src/utils/SkCanvasStack.cpp",
|
||||
"$_src/utils/SkCanvasStateUtils.cpp",
|
||||
"$_src/utils/SkCurveMeasure.cpp",
|
||||
"$_src/utils/SkCurveMeasure.h",
|
||||
"$_src/utils/SkDashPath.cpp",
|
||||
"$_src/utils/SkDashPathPriv.h",
|
||||
"$_src/utils/SkDumpCanvas.cpp",
|
||||
@ -87,5 +85,4 @@ skia_utils_sources = [
|
||||
"$_src/utils/win/SkTScopedComPtr.h",
|
||||
"$_src/utils/win/SkWGL.h",
|
||||
"$_src/utils/win/SkWGL_win.cpp",
|
||||
|
||||
]
|
||||
|
||||
@ -1,319 +0,0 @@
|
||||
/*
|
||||
* Copyright 2016 Google Inc.
|
||||
*
|
||||
* Use of this source code is governed by a BSD-style license that can be
|
||||
* found in the LICENSE file.
|
||||
*/
|
||||
|
||||
#include "SkCurveMeasure.h"
|
||||
#include "SkGeometry.h"
|
||||
|
||||
// for abs
|
||||
#include <cmath>
|
||||
|
||||
#define UNIMPLEMENTED SkDEBUGF(("%s:%d unimplemented\n", __FILE__, __LINE__))
|
||||
|
||||
/// Used inside SkCurveMeasure::getTime's Newton's iteration
|
||||
static inline SkPoint evaluate(const SkPoint pts[4], SkSegType segType,
|
||||
SkScalar t) {
|
||||
SkPoint pos;
|
||||
switch (segType) {
|
||||
case kQuad_SegType:
|
||||
pos = SkEvalQuadAt(pts, t);
|
||||
break;
|
||||
case kLine_SegType:
|
||||
pos = SkPoint::Make(SkScalarInterp(pts[0].x(), pts[1].x(), t),
|
||||
SkScalarInterp(pts[0].y(), pts[1].y(), t));
|
||||
break;
|
||||
case kCubic_SegType:
|
||||
SkEvalCubicAt(pts, t, &pos, nullptr, nullptr);
|
||||
break;
|
||||
case kConic_SegType: {
|
||||
SkConic conic(pts, pts[3].x());
|
||||
conic.evalAt(t, &pos);
|
||||
}
|
||||
break;
|
||||
default:
|
||||
UNIMPLEMENTED;
|
||||
}
|
||||
|
||||
return pos;
|
||||
}
|
||||
|
||||
/// Used inside SkCurveMeasure::getTime's Newton's iteration
|
||||
static inline SkVector evaluateDerivative(const SkPoint pts[4],
|
||||
SkSegType segType, SkScalar t) {
|
||||
SkVector tan;
|
||||
switch (segType) {
|
||||
case kQuad_SegType:
|
||||
tan = SkEvalQuadTangentAt(pts, t);
|
||||
break;
|
||||
case kLine_SegType:
|
||||
tan = pts[1] - pts[0];
|
||||
break;
|
||||
case kCubic_SegType:
|
||||
SkEvalCubicAt(pts, t, nullptr, &tan, nullptr);
|
||||
break;
|
||||
case kConic_SegType: {
|
||||
SkConic conic(pts, pts[3].x());
|
||||
conic.evalAt(t, nullptr, &tan);
|
||||
}
|
||||
break;
|
||||
default:
|
||||
UNIMPLEMENTED;
|
||||
}
|
||||
|
||||
return tan;
|
||||
}
|
||||
/// Used in ArcLengthIntegrator::computeLength
|
||||
static inline Sk8f evaluateDerivativeLength(const Sk8f& ts,
|
||||
const float (&xCoeff)[3][8],
|
||||
const float (&yCoeff)[3][8],
|
||||
const SkSegType segType) {
|
||||
Sk8f x;
|
||||
Sk8f y;
|
||||
|
||||
Sk8f x0 = Sk8f::Load(&xCoeff[0]),
|
||||
x1 = Sk8f::Load(&xCoeff[1]),
|
||||
x2 = Sk8f::Load(&xCoeff[2]);
|
||||
|
||||
Sk8f y0 = Sk8f::Load(&yCoeff[0]),
|
||||
y1 = Sk8f::Load(&yCoeff[1]),
|
||||
y2 = Sk8f::Load(&yCoeff[2]);
|
||||
|
||||
switch (segType) {
|
||||
case kQuad_SegType:
|
||||
x = x0*ts + x1;
|
||||
y = y0*ts + y1;
|
||||
break;
|
||||
case kCubic_SegType:
|
||||
x = (x0*ts + x1)*ts + x2;
|
||||
y = (y0*ts + y1)*ts + y2;
|
||||
break;
|
||||
case kConic_SegType:
|
||||
UNIMPLEMENTED;
|
||||
break;
|
||||
default:
|
||||
UNIMPLEMENTED;
|
||||
}
|
||||
|
||||
x = x * x;
|
||||
y = y * y;
|
||||
|
||||
return (x + y).sqrt();
|
||||
}
|
||||
|
||||
ArcLengthIntegrator::ArcLengthIntegrator(const SkPoint* pts, SkSegType segType)
|
||||
: fSegType(segType) {
|
||||
switch (fSegType) {
|
||||
case kQuad_SegType: {
|
||||
float Ax = pts[0].x();
|
||||
float Bx = pts[1].x();
|
||||
float Cx = pts[2].x();
|
||||
float Ay = pts[0].y();
|
||||
float By = pts[1].y();
|
||||
float Cy = pts[2].y();
|
||||
|
||||
// precompute coefficients for derivative
|
||||
Sk8f(2*(Ax - 2*Bx + Cx)).store(&xCoeff[0]);
|
||||
Sk8f(2*(Bx - Ax)).store(&xCoeff[1]);
|
||||
|
||||
Sk8f(2*(Ay - 2*By + Cy)).store(&yCoeff[0]);
|
||||
Sk8f(2*(By - Ay)).store(&yCoeff[1]);
|
||||
}
|
||||
break;
|
||||
case kCubic_SegType:
|
||||
{
|
||||
float Ax = pts[0].x();
|
||||
float Bx = pts[1].x();
|
||||
float Cx = pts[2].x();
|
||||
float Dx = pts[3].x();
|
||||
float Ay = pts[0].y();
|
||||
float By = pts[1].y();
|
||||
float Cy = pts[2].y();
|
||||
float Dy = pts[3].y();
|
||||
|
||||
// precompute coefficients for derivative
|
||||
Sk8f(3*(-Ax + 3*(Bx - Cx) + Dx)).store(&xCoeff[0]);
|
||||
Sk8f(6*(Ax - 2*Bx + Cx)).store(&xCoeff[1]);
|
||||
Sk8f(3*(-Ax + Bx)).store(&xCoeff[2]);
|
||||
|
||||
Sk8f(3*(-Ay + 3*(By - Cy) + Dy)).store(&yCoeff[0]);
|
||||
Sk8f(6*(Ay - 2*By + Cy)).store(&yCoeff[1]);
|
||||
Sk8f(3*(-Ay + By)).store(&yCoeff[2]);
|
||||
}
|
||||
break;
|
||||
case kConic_SegType:
|
||||
UNIMPLEMENTED;
|
||||
break;
|
||||
default:
|
||||
UNIMPLEMENTED;
|
||||
}
|
||||
}
|
||||
|
||||
// We use Gaussian quadrature
|
||||
// (https://en.wikipedia.org/wiki/Gaussian_quadrature)
|
||||
// to approximate the arc length integral here, because it is amenable to SIMD.
|
||||
SkScalar ArcLengthIntegrator::computeLength(SkScalar t) {
|
||||
SkScalar length = 0.0f;
|
||||
|
||||
Sk8f lengths = evaluateDerivativeLength(absc*t, xCoeff, yCoeff, fSegType);
|
||||
lengths = weights*lengths;
|
||||
// is it faster or more accurate to sum and then multiply or vice versa?
|
||||
lengths = lengths*(t*0.5f);
|
||||
|
||||
// Why does SkNx index with ints? does negative index mean something?
|
||||
for (int i = 0; i < 8; i++) {
|
||||
length += lengths[i];
|
||||
}
|
||||
return length;
|
||||
}
|
||||
|
||||
SkCurveMeasure::SkCurveMeasure(const SkPoint* pts, SkSegType segType)
|
||||
: fSegType(segType) {
|
||||
switch (fSegType) {
|
||||
case SkSegType::kQuad_SegType:
|
||||
for (size_t i = 0; i < 3; i++) {
|
||||
fPts[i] = pts[i];
|
||||
}
|
||||
break;
|
||||
case SkSegType::kLine_SegType:
|
||||
fPts[0] = pts[0];
|
||||
fPts[1] = pts[1];
|
||||
fLength = (fPts[1] - fPts[0]).length();
|
||||
break;
|
||||
case SkSegType::kCubic_SegType:
|
||||
for (size_t i = 0; i < 4; i++) {
|
||||
fPts[i] = pts[i];
|
||||
}
|
||||
break;
|
||||
case SkSegType::kConic_SegType:
|
||||
for (size_t i = 0; i < 4; i++) {
|
||||
fPts[i] = pts[i];
|
||||
}
|
||||
break;
|
||||
default:
|
||||
UNIMPLEMENTED;
|
||||
break;
|
||||
}
|
||||
if (kLine_SegType != segType) {
|
||||
fIntegrator = ArcLengthIntegrator(fPts, fSegType);
|
||||
}
|
||||
}
|
||||
|
||||
SkScalar SkCurveMeasure::getLength() {
|
||||
if (-1.0f == fLength) {
|
||||
fLength = fIntegrator.computeLength(1.0f);
|
||||
}
|
||||
return fLength;
|
||||
}
|
||||
|
||||
// Given an arc length targetLength, we want to determine what t
|
||||
// gives us the corresponding arc length along the curve.
|
||||
// We do this by letting the arc length integral := f(t) and
|
||||
// solving for the root of the equation f(t) - targetLength = 0
|
||||
// using Newton's method and lerp-bisection.
|
||||
// The computationally expensive parts are the integral approximation
|
||||
// at each step, and computing the derivative of the arc length integral,
|
||||
// which is equal to the length of the tangent (so we have to do a sqrt).
|
||||
|
||||
SkScalar SkCurveMeasure::getTime(SkScalar targetLength) {
|
||||
if (targetLength <= 0.0f) {
|
||||
return 0.0f;
|
||||
}
|
||||
|
||||
SkScalar currentLength = getLength();
|
||||
|
||||
if (targetLength > currentLength || (SkScalarNearlyEqual(targetLength, currentLength))) {
|
||||
return 1.0f;
|
||||
}
|
||||
if (kLine_SegType == fSegType) {
|
||||
return targetLength / currentLength;
|
||||
}
|
||||
|
||||
// initial estimate of t is percentage of total length
|
||||
SkScalar currentT = targetLength / currentLength;
|
||||
SkScalar prevT = -1.0f;
|
||||
SkScalar newT;
|
||||
|
||||
SkScalar minT = 0.0f;
|
||||
SkScalar maxT = 1.0f;
|
||||
|
||||
int iterations = 0;
|
||||
while (iterations < kNewtonIters + kBisectIters) {
|
||||
currentLength = fIntegrator.computeLength(currentT);
|
||||
SkScalar lengthDiff = currentLength - targetLength;
|
||||
|
||||
// Update root bounds.
|
||||
// If lengthDiff is positive, we have overshot the target, so
|
||||
// we know the current t is an upper bound, and similarly
|
||||
// for the lower bound.
|
||||
if (lengthDiff > 0.0f) {
|
||||
if (currentT < maxT) {
|
||||
maxT = currentT;
|
||||
}
|
||||
} else {
|
||||
if (currentT > minT) {
|
||||
minT = currentT;
|
||||
}
|
||||
}
|
||||
|
||||
// We have a tolerance on both the absolute value of the difference and
|
||||
// on the t value
|
||||
// because we may not have enough precision in the t to get close enough
|
||||
// in the length.
|
||||
if ((std::abs(lengthDiff) < kTolerance) ||
|
||||
(std::abs(prevT - currentT) < kTolerance)) {
|
||||
break;
|
||||
}
|
||||
|
||||
prevT = currentT;
|
||||
if (iterations < kNewtonIters) {
|
||||
// This is just newton's formula.
|
||||
SkScalar dt = evaluateDerivative(fPts, fSegType, currentT).length();
|
||||
newT = currentT - (lengthDiff / dt);
|
||||
|
||||
// If newT is out of bounds, bisect inside newton.
|
||||
if ((newT < 0.0f) || (newT > 1.0f)) {
|
||||
newT = (minT + maxT) * 0.5f;
|
||||
}
|
||||
} else if (iterations < kNewtonIters + kBisectIters) {
|
||||
if (lengthDiff > 0.0f) {
|
||||
maxT = currentT;
|
||||
} else {
|
||||
minT = currentT;
|
||||
}
|
||||
// TODO(hstern) do a lerp here instead of a bisection
|
||||
newT = (minT + maxT) * 0.5f;
|
||||
} else {
|
||||
SkDEBUGF(("%.7f %.7f didn't get close enough after bisection.\n",
|
||||
currentT, currentLength));
|
||||
break;
|
||||
}
|
||||
currentT = newT;
|
||||
|
||||
SkASSERT(minT <= maxT);
|
||||
|
||||
iterations++;
|
||||
}
|
||||
|
||||
// debug. is there an SKDEBUG or something for ifdefs?
|
||||
fIters = iterations;
|
||||
|
||||
return currentT;
|
||||
}
|
||||
|
||||
void SkCurveMeasure::getPosTanTime(SkScalar targetLength, SkPoint* pos,
|
||||
SkVector* tan, SkScalar* time) {
|
||||
SkScalar t = getTime(targetLength);
|
||||
|
||||
if (time) {
|
||||
*time = t;
|
||||
}
|
||||
if (pos) {
|
||||
*pos = evaluate(fPts, fSegType, t);
|
||||
}
|
||||
if (tan) {
|
||||
*tan = evaluateDerivative(fPts, fSegType, t);
|
||||
}
|
||||
}
|
||||
@ -1,76 +0,0 @@
|
||||
/*
|
||||
* Copyright 2016 Google Inc.
|
||||
*
|
||||
* Use of this source code is governed by a BSD-style license that can be
|
||||
* found in the LICENSE file.
|
||||
*/
|
||||
|
||||
#ifndef SkCurveMeasure_DEFINED
|
||||
#define SkCurveMeasure_DEFINED
|
||||
|
||||
#include "SkPathMeasurePriv.h"
|
||||
#include "SkPoint.h"
|
||||
#include "SkNx.h"
|
||||
|
||||
// These are weights and abscissae for gaussian quadrature with weight function
|
||||
// w(x) = 1
|
||||
static SkScalar weights8[8] = {0.3626837833783620f, 0.3626837833783620f,
|
||||
0.3137066458778873f, 0.3137066458778873f,
|
||||
0.2223810344533745f, 0.2223810344533745f,
|
||||
0.1012285362903763f, 0.1012285362903763f};
|
||||
static SkScalar absc8[8] = {-0.1834346424956498f, 0.1834346424956498f,
|
||||
-0.5255324099163290f, 0.5255324099163290f,
|
||||
-0.7966664774136267f, 0.7966664774136267f,
|
||||
-0.9602898564975363f, 0.9602898564975363f};
|
||||
|
||||
static Sk8f weights = Sk8f::Load(weights8);
|
||||
static Sk8f absc = 0.5f*(Sk8f::Load(absc8) + 1.0f);
|
||||
|
||||
|
||||
class ArcLengthIntegrator {
|
||||
public:
|
||||
ArcLengthIntegrator() {}
|
||||
ArcLengthIntegrator(const SkPoint* pts, SkSegType segType);
|
||||
SkScalar computeLength(SkScalar t);
|
||||
|
||||
private:
|
||||
SkSegType fSegType;
|
||||
|
||||
// precomputed coefficients for derivatives in Horner form
|
||||
float xCoeff[3][8];
|
||||
float yCoeff[3][8];
|
||||
};
|
||||
|
||||
class SkCurveMeasure {
|
||||
public:
|
||||
SkCurveMeasure() {}
|
||||
|
||||
// Almost exactly the same as in SkPath::Iter:
|
||||
// kLine_SegType -> 2 points: start end
|
||||
// kQuad_SegType -> 3 points: start control end
|
||||
// kCubic_SegType -> 4 points: start control1 control2 end
|
||||
// kConic_SegType -> 4 points: start control end (w, w)
|
||||
//
|
||||
// i.e. the only difference is that the conic's last point is a point
|
||||
// consisting of the w value twice
|
||||
SkCurveMeasure(const SkPoint* pts, SkSegType segType);
|
||||
|
||||
SkScalar getTime(SkScalar targetLength);
|
||||
void getPosTanTime(SkScalar distance, SkPoint* pos, SkVector* tan, SkScalar* time);
|
||||
SkScalar getLength();
|
||||
|
||||
private:
|
||||
const SkScalar kTolerance = 0.0001f;
|
||||
const int kNewtonIters = 5;
|
||||
const int kBisectIters = 5;
|
||||
|
||||
SkSegType fSegType;
|
||||
SkPoint fPts[4];
|
||||
SkScalar fLength = -1.0f;
|
||||
ArcLengthIntegrator fIntegrator;
|
||||
|
||||
// for debug purposes
|
||||
int fIters;
|
||||
};
|
||||
|
||||
#endif // SkCurveMeasure_DEFINED
|
||||
Loading…
Reference in New Issue
Block a user