gemma: pkg/octree/polygon.go annotate

annotate pkg/octree/polygon.go @ 2490:c9164ff98871 octree-diff

Started with point in polygon check.

author	Sascha L. Teichmann <sascha.teichmann@intevation.de>
date	Sun, 03 Mar 2019 21:10:07 +0100
parents	4f292ff74d9e
children	10681749371d

rev	line source
2488 cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	1 // This is Free Software under GNU Affero General Public License v >= 3.0
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	2 // without warranty, see README.md and license for details.
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	3 //
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	4 // SPDX-License-Identifier: AGPL-3.0-or-later
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	5 // License-Filename: LICENSES/AGPL-3.0.txt
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	6 //
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	7 // Copyright (C) 2018 by via donau
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	8 // – Österreichische Wasserstraßen-Gesellschaft mbH
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	9 // Software engineering by Intevation GmbH
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	10 //
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	11 // Author(s):
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	12 // * Sascha L. Teichmann <sascha.teichmann@intevation.de>
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	13
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	14 package octree
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	15
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	16 import (
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	17 "bytes"
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	18 "encoding/binary"
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	19 "fmt"
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	20 "math"
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	21
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	22 "gemma.intevation.de/gemma/pkg/wkb"
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	23 )
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	24
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	25 type ring []float64
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	26
2488 cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	27 type Polygon struct {
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	28 // TODO: Implement me!
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	29 rings []ring
2488 cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	30 }
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	31
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	32 type IntersectionType byte
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	33
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	34 const (
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	35 IntersectionInside IntersectionType = iota
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	36 IntersectionOutSide
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	37 IntersectionOverlaps
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	38 )
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	39
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	40 func (p *Polygon) IntersectionBox2D(box Box2D) IntersectionType {
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	41 // TODO: Implement me
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	42 return IntersectionOutSide
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	43 }
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	44
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	45 func (p Polygon) IntersectionWithTriangle(t Triangle) IntersectionType {
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	46 // TODO: Implement me
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	47 return IntersectionOutSide
cb55d7eaaa36 Started with the idea to clip an octree by an bounding polygon. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: diff changeset	48 }
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	49
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	50 func (rng ring) isClosed() bool { return (len(rng) / 2) >= 3 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	51
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	52 func (rng ring) contains(point []float64) bool {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	53 if !rng.isClosed() {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	54 return false
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	55 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	56
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	57 contains := intersectsWithRaycast(point, rng[:2], rng[len(rng)-2:len(rng)])
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	58
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	59 for i := 2; i < len(rng); i += 2 {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	60 if intersectsWithRaycast(point, rng[i-2:i], rng[i:i+2]) {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	61 contains = !contains
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	62 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	63 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	64
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	65 return contains
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	66 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	67
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	68 // Using the raycast algorithm, this returns whether or not the passed in point
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	69 // Intersects with the edge drawn by the passed in start and end points.
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	70 // Original implementation: http://rosettacode.org/wiki/Ray-casting_algorithm#Go
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	71 func intersectsWithRaycast(point, start, end []float64) bool {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	72
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	73 // Always ensure that the the first point
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	74 // has a y coordinate that is less than the second point
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	75 if start[1] > end[1] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	76 // Switch the points if otherwise.
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	77 start, end = end, start
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	78 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	79
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	80 // Move the point's y coordinate
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	81 // outside of the bounds of the testing region
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	82 // so we can start drawing a ray
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	83 for point[1] == start[1] \|\| point[1] == end[1] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	84 y := math.Nextafter(point[1], math.Inf(1))
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	85 point = []float64{point[0], y}
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	86 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	87
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	88 // If we are outside of the polygon, indicate so.
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	89 if point[1] < start[1] \|\| point[1] > end[1] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	90 return false
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	91 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	92
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	93 if start[0] > end[0] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	94 if point[0] > start[0] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	95 return false
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	96 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	97 if point[0] < end[0] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	98 return true
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	99 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	100 } else {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	101 if point[0] > end[0] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	102 return false
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	103 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	104 if point[0] < start[0] {
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	105 return true
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	106 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	107 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	108
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	109 raySlope := (point[1] - start[1]) / (point[0] - start[0])
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	110 diagSlope := (end[1] - start[1]) / (end[0] - start[0])
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	111
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	112 return raySlope >= diagSlope
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	113 }
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	114
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	115 func (p *Polygon) FromWKB(data []byte) error {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	116
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	117 r := bytes.NewReader(data)
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	118
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	119 endian, err := r.ReadByte()
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	120
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	121 var order binary.ByteOrder
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	122
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	123 switch {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	124 case err != nil:
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	125 return err
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	126 case endian == wkb.NDR:
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	127 order = binary.LittleEndian
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	128 case endian == wkb.XDR:
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	129 order = binary.BigEndian
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	130 default:
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	131 return fmt.Errorf("unknown byte order %x", endian)
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	132 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	133
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	134 var geomType uint32
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	135 err = binary.Read(r, order, &geomType)
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	136
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	137 switch {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	138 case err != nil:
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	139 return err
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	140 case geomType != wkb.Polygon:
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	141 return fmt.Errorf("unknown geometry type %x", geomType)
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	142 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	143
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	144 var numRings uint32
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	145 if err = binary.Read(r, order, &numRings); err != nil {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	146 return err
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	147 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	148
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	149 rngs := make([]ring, numRings)
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	150
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	151 for rng := uint32(0); rng < numRings; rng++ {
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	152 var numVertices uint32
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	153 if err = binary.Read(r, order, &numVertices); err != nil {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	154 return err
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	155 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	156
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	157 numVertices *= 2
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	158 vertices := make([]float64, numVertices)
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	159
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	160 for v := uint32(0); v < numVertices; v += 2 {
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	161 var lat, lon uint64
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	162 if err = binary.Read(r, order, &lat); err != nil {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	163 return err
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	164 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	165 if err = binary.Read(r, order, &lon); err != nil {
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	166 return err
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	167 }
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	168 vertices[v] = math.Float64frombits(lat)
c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	169 vertices[v+1] = math.Float64frombits(lon)
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	170 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	171
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	172 rngs[rng] = vertices
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	173 }
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	174
2490 c9164ff98871 Started with point in polygon check. Sascha L. Teichmann <sascha.teichmann@intevation.de> parents: 2489 diff changeset	175 p.rings = rngs
2489 4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	176
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	177 return nil
4f292ff74d9e Added a WKB reader for clipping polygon. Sascha L. Teichmann <teichmann@intevation.de> parents: 2488 diff changeset	178 }

Mercurial > gemma

annotate pkg/octree/polygon.go @ 2490:c9164ff98871 octree-diff