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comparison pkg/mesh/polygon.go @ 5601:1222b777f51f

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Made golint finally happy.
author Sascha L. Teichmann <sascha.teichmann@intevation.de>
date Sat, 06 Aug 2022 02:09:57 +0200
parents 5f47eeea988d
children 6270951dda28
comparison
equal deleted inserted replaced
5600:9967a78e43f4 5601:1222b777f51f
26 ) 26 )
27 27
28 type ( 28 type (
29 ring []float64 29 ring []float64
30 30
31 // Polygon has a border and holes.
32 // The line segments are spatially indexed.
31 Polygon struct { 33 Polygon struct {
32 rings []ring 34 rings []ring
33 indices []*rtree.RTree 35 indices []*rtree.RTree
34 } 36 }
35 37
38 // IntersectionType represents an enum
39 // of the type of intersection.
36 IntersectionType byte 40 IntersectionType byte
37 41
38 lineSegment []float64 42 lineSegment []float64
39 ) 43 )
40 44
41 const ( 45 const (
46 // IntersectionInside is inside the polygon.
42 IntersectionInside IntersectionType = iota 47 IntersectionInside IntersectionType = iota
48 // IntersectionOutSide is outside the polygon.
43 IntersectionOutSide 49 IntersectionOutSide
50 // IntersectionOverlaps overlaps the polygon.
44 IntersectionOverlaps 51 IntersectionOverlaps
45 ) 52 )
46 53
47 func (ls lineSegment) Rect() ([2]float64, [2]float64) { 54 func (ls lineSegment) Rect() ([2]float64, [2]float64) {
48 55
65 } 72 }
66 73
67 return min, max 74 return min, max
68 } 75 }
69 76
77 // Indexify creates a spatial index for thw polygon.
70 func (p *Polygon) Indexify() { 78 func (p *Polygon) Indexify() {
71 indices := make([]*rtree.RTree, len(p.rings)) 79 indices := make([]*rtree.RTree, len(p.rings))
72 80
73 for i := range indices { 81 for i := range indices {
74 index := new(rtree.RTree) 82 index := new(rtree.RTree)
210 // t := tNum / den 218 // t := tNum / den
211 // intersection at( p0[0] + (t * s10x), p0[1] + (t * s10y) ) 219 // intersection at( p0[0] + (t * s10x), p0[1] + (t * s10y) )
212 return true 220 return true
213 } 221 }
214 222
223 // IntersectionBox2D checks the type of intersection of the
224 // given box.
215 func (p *Polygon) IntersectionBox2D(box Box2D) IntersectionType { 225 func (p *Polygon) IntersectionBox2D(box Box2D) IntersectionType {
216 226
217 if len(p.rings) == 0 { 227 if len(p.rings) == 0 {
218 return IntersectionOutSide 228 return IntersectionOutSide
219 } 229 }
251 return IntersectionInside 261 return IntersectionInside
252 } 262 }
253 return IntersectionOutSide 263 return IntersectionOutSide
254 } 264 }
255 265
266 // IntersectionWithTriangle checks the intersection type
267 // for the given triangle.
256 func (p *Polygon) IntersectionWithTriangle(t *Triangle) IntersectionType { 268 func (p *Polygon) IntersectionWithTriangle(t *Triangle) IntersectionType {
257 box := t.BBox() 269 box := t.BBox()
258 min, max := box.Rect() 270 min, max := box.Rect()
259 for _, index := range p.indices { 271 for _, index := range p.indices {
260 var intersects bool 272 var intersects bool
385 diagSlope := (eY - sY) / (eX - sX) 397 diagSlope := (eY - sY) / (eX - sX)
386 398
387 return raySlope >= diagSlope 399 return raySlope >= diagSlope
388 } 400 }
389 401
402 // NumVertices returns the number of vertices of a given ring.
390 func (p *Polygon) NumVertices(ring int) int { 403 func (p *Polygon) NumVertices(ring int) int {
391 if ring < 0 || ring >= len(p.rings) { 404 if ring < 0 || ring >= len(p.rings) {
392 return 0 405 return 0
393 } 406 }
394 return len(p.rings[ring]) / 2 407 return len(p.rings[ring]) / 2
395 } 408 }
396 409
410 // Vertices passes the vertices of a given ring
411 // to the given fn function.
397 func (p *Polygon) Vertices(ring int, fn func(float64, float64)) { 412 func (p *Polygon) Vertices(ring int, fn func(float64, float64)) {
398 if ring < 0 || ring >= len(p.rings) { 413 if ring < 0 || ring >= len(p.rings) {
399 return 414 return
400 } 415 }
401 rng := p.rings[ring] 416 rng := p.rings[ring]
402 for i := 0; i < len(rng); i += 2 { 417 for i := 0; i < len(rng); i += 2 {
403 fn(rng[i+0], rng[i+1]) 418 fn(rng[i+0], rng[i+1])
404 } 419 }
405 } 420 }
406 421
422 // AsWKB serializes the polygon as WKB.
407 func (p *Polygon) AsWKB() []byte { 423 func (p *Polygon) AsWKB() []byte {
408 424
409 size := 1 + 4 + 4 425 size := 1 + 4 + 4
410 for _, r := range p.rings { 426 for _, r := range p.rings {
411 size += 4 + len(r)*8 427 size += 4 + len(r)*8
426 } 442 }
427 443
428 return buf.Bytes() 444 return buf.Bytes()
429 } 445 }
430 446
447 // FromWKB deserializes a polygon from WKB.
431 func (p *Polygon) FromWKB(data []byte) error { 448 func (p *Polygon) FromWKB(data []byte) error {
432 449
433 r := bytes.NewReader(data) 450 r := bytes.NewReader(data)
434 451
435 endian, err := r.ReadByte() 452 endian, err := r.ReadByte()
495 p.rings = rngs 512 p.rings = rngs
496 513
497 return nil 514 return nil
498 } 515 }
499 516
517 // FromLineStringZ creates a polygon from a given linestring z.
500 func (p *Polygon) FromLineStringZ(ls LineStringZ) { 518 func (p *Polygon) FromLineStringZ(ls LineStringZ) {
501 r := make([]float64, 2*len(ls)) 519 r := make([]float64, 2*len(ls))
502 var pos int 520 var pos int
503 for i := range ls { 521 for i := range ls {
504 r[pos+0] = ls[i].X 522 r[pos+0] = ls[i].X