Mercurial > gemma
view pkg/octree/tree.go @ 1234:1a5564655f2a
refac: Sidebar reorganized
In order to make context switches between administrative tasks
which are map related and those which are system related, we now have
a category "administration" and "systemadministration".
The Riverbedmorphology does nothing than display the map, so it is
renamed to that (map). In case the context of "systemadministration"
is chosen, the "map" brings you just back to the map.
author | Thomas Junk <thomas.junk@intevation.de> |
---|---|
date | Tue, 20 Nov 2018 09:54:53 +0100 |
parents | a244b18cb916 |
children | f4dcbe8941a1 |
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// This is Free Software under GNU Affero General Public License v >= 3.0 // without warranty, see README.md and license for details. // // SPDX-License-Identifier: AGPL-3.0-or-later // License-Filename: LICENSES/AGPL-3.0.txt // // Copyright (C) 2018 by via donau // – Österreichische Wasserstraßen-Gesellschaft mbH // Software engineering by Intevation GmbH // // Author(s): // * Sascha L. Teichmann <sascha.teichmann@intevation.de> package octree import ( "math" ) type Tree struct { EPSG uint32 vertices []Vertex triangles [][]int32 index []int32 Min Vertex Max Vertex } var scale = [4][4]float64{ {0.0, 0.0, 0.5, 0.5}, {0.5, 0.0, 1.0, 0.5}, {0.0, 0.5, 0.5, 1.0}, {0.5, 0.5, 1.0, 1.0}, } func (ot *Tree) Vertical(x1, y1, x2, y2 float64, fn func(*Triangle)) { box := Box2D{ X1: math.Min(x1, x2), Y1: math.Min(y1, y2), X2: math.Max(x1, x2), Y2: math.Max(y1, y2), } // out of bounding box if box.X2 < ot.Min.X || ot.Max.X < box.X1 || box.Y2 < ot.Min.Y || ot.Max.Y < box.Y1 { return } line := NewPlane2D(x1, y1, x2, y2) type frame struct { pos int32 Box2D } dupes := map[int32]struct{}{} all := Box2D{ot.Min.X, ot.Min.Y, ot.Max.X, ot.Max.Y} //log.Printf("area: %f\n", (box.x2-box.x1)*(box.y2-box.y1)) //log.Printf("all: %f\n", (all.x2-all.x1)*(all.y2-all.y1)) stack := []frame{{1, all}} for len(stack) > 0 { top := stack[len(stack)-1] stack = stack[:len(stack)-1] if top.pos > 0 { // node for i := int32(0); i < 4; i++ { a := ot.index[top.pos+i] b := ot.index[top.pos+i+4] if a == 0 && b == 0 { continue } dx := top.X2 - top.X1 dy := top.Y2 - top.Y1 nbox := Box2D{ dx*scale[i][0] + top.X1, dy*scale[i][1] + top.Y1, dx*scale[i][2] + top.X1, dy*scale[i][3] + top.Y1, } if nbox.Intersects(box) && nbox.IntersectsPlane(line) { if a != 0 { stack = append(stack, frame{a, nbox}) } if b != 0 { stack = append(stack, frame{b, nbox}) } } } } else { // leaf pos := -top.pos - 1 n := ot.index[pos] indices := ot.index[pos+1 : pos+1+n] for _, idx := range indices { if _, found := dupes[idx]; found { continue } tri := ot.triangles[idx] t := Triangle{ ot.vertices[tri[0]], ot.vertices[tri[1]], ot.vertices[tri[2]], } v0 := line.Eval(t[0].X, t[0].Y) v1 := line.Eval(t[1].X, t[1].Y) v2 := line.Eval(t[2].X, t[2].Y) if onPlane(v0) || onPlane(v1) || onPlane(v2) || sides(sides(sides(0, v0), v1), v2) == 3 { fn(&t) } dupes[idx] = struct{}{} } } } } func (ot *Tree) Horizontal(h float64, fn func(*Triangle)) { if h < ot.Min.Z || ot.Max.Z < h { return } type frame struct { pos int32 min float64 max float64 } dupes := map[int32]struct{}{} stack := []frame{{1, ot.Min.Z, ot.Max.Z}} for len(stack) > 0 { top := stack[len(stack)-1] stack = stack[:len(stack)-1] pos := top.pos if pos == 0 { continue } min, max := top.min, top.max if pos > 0 { // node if mid := (max-min)*0.5 + min; h >= mid { pos += 4 // nodes with z-bit set min = mid } else { max = mid } stack = append(stack, frame{ot.index[pos+0], min, max}, frame{ot.index[pos+1], min, max}, frame{ot.index[pos+2], min, max}, frame{ot.index[pos+3], min, max}) } else { // leaf pos = -pos - 1 n := ot.index[pos] //log.Printf("%d %d %d\n", pos, n, len(ot.index)) indices := ot.index[pos+1 : pos+1+n] for _, idx := range indices { if _, found := dupes[idx]; found { continue } tri := ot.triangles[idx] t := Triangle{ ot.vertices[tri[0]], ot.vertices[tri[1]], ot.vertices[tri[2]], } if !(math.Min(t[0].Z, math.Min(t[1].Z, t[2].Z)) > h || math.Max(t[0].Z, math.Max(t[1].Z, t[2].Z)) < h) { dupes[idx] = struct{}{} fn(&t) } } } } }