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comparison pkg/mesh/util.go @ 4827:f4abfd0ee8ad remove-octree-debris

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Renamed octree package to mesh as there is no octree any more.
author Sascha L. Teichmann <sascha.teichmann@intevation.de>
date Tue, 05 Nov 2019 14:30:22 +0100
parents pkg/octree/util.go@620038ade708
children
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4826:ec5afada70ec 4827:f4abfd0ee8ad
1 // Copyright (C) 2018 Michael Fogleman
2 //
3 // Permission is hereby granted, free of charge, to any person obtaining
4 // a copy of this software and associated documentation files (the "Software"),
5 // to deal in the Software without restriction, including without limitation
6 // the rights to use, copy, modify, merge, publish, distribute, sublicense,
7 // and/or sell copies of the Software, and to permit persons to whom the
8 // Software is furnished to do so, subject to the following conditions:
9 //
10 // The above copyright notice and this permission notice shall be included
11 // in all copies or substantial portions of the Software.
12 //
13 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
14 // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
16 // THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
19
20 package mesh
21
22 import "math"
23
24 var (
25 eps = math.Nextafter(1, 2) - 1
26 infinity = math.Inf(1)
27 )
28
29 func pseudoAngle(dx, dy float64) float64 {
30 p := dx / (math.Abs(dx) + math.Abs(dy))
31 if dy > 0 {
32 p = (3 - p) / 4
33 } else {
34 p = (1 + p) / 4
35 }
36 return math.Max(0, math.Min(1-eps, p))
37 }