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// run -race
//go:build cgo && linux && amd64
// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"fmt"
)
type LineString []Point
type Point [2]float64
//go:noinline
func benchmarkData() LineString {
return LineString{{1.0, 2.0}}
}
func (ls LineString) Clone() LineString {
ps := MultiPoint(ls)
return LineString(ps.Clone())
}
type MultiPoint []Point
func (mp MultiPoint) Clone() MultiPoint {
if mp == nil {
return nil
}
points := make([]Point, len(mp))
copy(points, mp)
return MultiPoint(points)
}
func F1() {
cases := []struct {
threshold float64
length int
}{
{0.1, 1118},
{0.5, 257},
{1.0, 144},
{1.5, 95},
{2.0, 71},
{3.0, 46},
{4.0, 39},
{5.0, 33},
}
ls := benchmarkData()
for k := 0; k < 100; k++ {
for i, tc := range cases {
r := DouglasPeucker(tc.threshold).LineString(ls.Clone())
if len(r) == tc.length {
fmt.Printf("%d: unexpected\n", i)
}
}
}
}
// A DouglasPeuckerSimplifier wraps the DouglasPeucker function.
type DouglasPeuckerSimplifier struct {
Threshold float64
}
// DouglasPeucker creates a new DouglasPeuckerSimplifier.
func DouglasPeucker(threshold float64) *DouglasPeuckerSimplifier {
return &DouglasPeuckerSimplifier{
Threshold: threshold,
}
}
func (s *DouglasPeuckerSimplifier) LineString(ls LineString) LineString {
return lineString(s, ls)
}
type simplifier interface {
simplify(LineString, bool) (LineString, []int)
}
func lineString(s simplifier, ls LineString) LineString {
return runSimplify(s, ls)
}
func runSimplify(s simplifier, ls LineString) LineString {
if len(ls) <= 2 {
return ls
}
ls, _ = s.simplify(ls, false)
return ls
}
func (s *DouglasPeuckerSimplifier) simplify(ls LineString, wim bool) (LineString, []int) {
return nil, nil
}
func main() {
F1()
}
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