Mercurial > gemma
view pkg/imports/wkb.go @ 2624:9dbaf69c7a66
Improve geoserver config to better calculate bounding boxes
* Disable the use of estimated extents for the postgis storage
configuration for geoserver, which is set via the gemma middleware.
This way we are able to get better bounding boxes for many layers
where the postgis function `ST_EstimatedExtent()` would be far off.
author | Bernhard Reiter <bernhard@intevation.de> |
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date | Wed, 13 Mar 2019 16:18:39 +0100 |
parents | 63475c8e710e |
children | 8b75ac5e243e |
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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 imports import ( "bytes" "encoding/binary" "fmt" "math" shp "github.com/jonas-p/go-shp" "gemma.intevation.de/gemma/pkg/wkb" ) type ( pointSlice []float64 lineSlice [][]float64 polygonSlice [][][]float64 ) func (l lineSlice) asWKB() []byte { size := 1 + 4 + 4 + len(l)*(2*8) buf := bytes.NewBuffer(make([]byte, 0, size)) binary.Write(buf, binary.LittleEndian, wkb.NDR) binary.Write(buf, binary.LittleEndian, wkb.LineString) binary.Write(buf, binary.LittleEndian, uint32(len(l))) for _, c := range l { var lat, lon float64 if len(c) > 0 { lat = c[0] } if len(c) > 1 { lon = c[1] } binary.Write(buf, binary.LittleEndian, math.Float64bits(lat)) binary.Write(buf, binary.LittleEndian, math.Float64bits(lon)) } return buf.Bytes() } func (p pointSlice) asWKB() []byte { size := 1 + 4 + 2*8 buf := bytes.NewBuffer(make([]byte, 0, size)) binary.Write(buf, binary.LittleEndian, wkb.NDR) binary.Write(buf, binary.LittleEndian, wkb.Point) var lat, lon float64 if len(p) > 0 { lat = p[0] } if len(p) > 1 { lon = p[1] } binary.Write(buf, binary.LittleEndian, math.Float64bits(lat)) binary.Write(buf, binary.LittleEndian, math.Float64bits(lon)) return buf.Bytes() } func (p polygonSlice) asWKB() []byte { if p == nil { return nil } // pre-calculate size to avoid reallocations. size := 1 + 4 + 4 for _, ring := range p { size += 4 + len(ring)*2*8 } buf := bytes.NewBuffer(make([]byte, 0, size)) binary.Write(buf, binary.LittleEndian, wkb.NDR) binary.Write(buf, binary.LittleEndian, wkb.Polygon) binary.Write(buf, binary.LittleEndian, uint32(len(p))) for _, ring := range p { binary.Write(buf, binary.LittleEndian, uint32(len(ring))) for _, v := range ring { var lat, lon float64 if len(v) > 0 { lat = v[0] } if len(v) > 1 { lon = v[1] } binary.Write(buf, binary.LittleEndian, math.Float64bits(lat)) binary.Write(buf, binary.LittleEndian, math.Float64bits(lon)) } } return buf.Bytes() } func shapeToPolygon(s shp.Shape) (polygonSlice, error) { switch p := s.(type) { case *shp.Polygon: return toPolygon(p.NumParts, p.Parts, p.Points), nil case *shp.PolygonZ: return toPolygon(p.NumParts, p.Parts, p.Points), nil case *shp.PolygonM: return toPolygon(p.NumParts, p.Parts, p.Points), nil } return nil, fmt.Errorf("Unsupported shape type %T", s) } func toPolygon(numParts int32, parts []int32, points []shp.Point) polygonSlice { out := make(polygonSlice, numParts) var pos int32 for i := range out { var howMany int32 if i+1 >= len(parts) { howMany = int32(len(points)) - pos } else { howMany = parts[i+1] - parts[i] } line := make([][]float64, howMany) vertices := make([]float64, 2*howMany) for j := int32(0); j < howMany; j, pos = j+1, pos+1 { p := &points[pos] vertex := vertices[j*2 : j*2+2] vertex[0], vertex[1] = p.X, p.Y line[j] = vertex } out[i] = line } return out }