Mercurial > gemma
view cmd/tin2octree/tin.go @ 904:e4b72a199258
New default bottleneck colors
Mainly to make the stroke color one actually selectable in the ui.
In addition the pink does better match the collors used on the ECDIS layer.
author | Sascha Wilde <wilde@intevation.de> |
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date | Tue, 02 Oct 2018 13:34:59 +0200 |
parents | b0bd242ff821 |
children |
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package main import ( "bytes" "encoding/binary" "errors" "fmt" "io" "log" "math" "gemma.intevation.de/gemma/pkg/octree" ) var ( errNoByteSlice = errors.New("Not a byte slice") errTooLessPoints = errors.New("Too less points") ) const ( wkbXDR byte = 0 wkbNDR byte = 1 wkbTinZ uint32 = 1000 + 16 wkbTriangleZ uint32 = 1000 + 17 ) const wgs84 = 4326 type tin struct { epsg uint32 vertices []octree.Vertex triangles [][]int32 min octree.Vertex max octree.Vertex } func (t *tin) FromWKB(data []byte) error { log.Printf("data length %d\n", len(data)) r := bytes.NewReader(data) endian, err := r.ReadByte() var order binary.ByteOrder switch { case err != nil: return err case endian == wkbNDR: order = binary.LittleEndian case endian == wkbXDR: order = binary.BigEndian default: return fmt.Errorf("unknown byte order %x", endian) } var geomType uint32 err = binary.Read(r, order, &geomType) switch { case err != nil: return err case geomType != wkbTinZ: return fmt.Errorf("unknown geometry type %x", geomType) } var num uint32 if err = binary.Read(r, order, &num); err != nil { return err } vertices := make([]octree.Vertex, 0, 100000) var v octree.Vertex v2i := make(map[octree.Vertex]int32, 100000) var indexPool []int32 allocIndices := func() []int32 { if len(indexPool) == 0 { indexPool = make([]int32, 3*8*1024) } ids := indexPool[:3] indexPool = indexPool[3:] return ids } var triangles [][]int32 min := octree.Vertex{math.MaxFloat64, math.MaxFloat64, math.MaxFloat64} max := octree.Vertex{-math.MaxFloat64, -math.MaxFloat64, -math.MaxFloat64} for i := uint32(0); i < num; i++ { endian, err = r.ReadByte() switch { case err != nil: return err case endian == wkbNDR: order = binary.LittleEndian case endian == wkbXDR: order = binary.BigEndian default: return fmt.Errorf("unknown byte order %x", endian) } err = binary.Read(r, order, &geomType) switch { case err != nil: return err case geomType != wkbTriangleZ: return fmt.Errorf("unknown geometry type %d", geomType) } var rings uint32 if err = binary.Read(r, order, &rings); err != nil { return err } triangle := allocIndices() for ring := uint32(0); ring < rings; ring++ { var npoints uint32 if err = binary.Read(r, order, &npoints); err != nil { return err } if npoints < 3 { return errTooLessPoints } for p := uint32(0); p < npoints; p++ { var x, y, z uint64 for _, addr := range []*uint64{&x, &y, &z} { if err = binary.Read(r, order, addr); err != nil { return err } } if p >= 3 || ring >= 1 { // Don't store the forth point. continue } // Do this conversion later to spare reflect calls // and allocs in binary.Read. v.X = math.Float64frombits(x) v.Y = math.Float64frombits(y) v.Z = math.Float64frombits(z) idx, found := v2i[v] if !found { idx = int32(len(vertices)) v2i[v] = idx vertices = append(vertices, v) min.Minimize(v) max.Maximize(v) } triangle[p] = idx } } triangles = append(triangles, triangle) } log.Printf("bbox: [[%f, %f], [%f, %f]]\n", min.X, min.Y, max.X, max.Y) *t = tin{ epsg: wgs84, vertices: vertices, triangles: triangles, min: min, max: max, } return nil } func (t *tin) Scan(raw interface{}) error { data, ok := raw.([]byte) if !ok { return errNoByteSlice } return t.FromWKB(data) } func (t *tin) Serialize(w io.Writer) error { if err := binary.Write(w, binary.LittleEndian, t.epsg); err != nil { return err } if err := t.min.Write(w); err != nil { return err } if err := t.max.Write(w); err != nil { return err } if err := binary.Write( w, binary.LittleEndian, uint32(len(t.vertices))); err != nil { return err } for _, v := range t.vertices { if err := v.Write(w); err != nil { return err } } log.Printf("vertices %d (%d)\n", len(t.vertices), len(t.vertices)*3*8) if err := binary.Write( w, binary.LittleEndian, uint32(len(t.triangles))); err != nil { return err } var buf [binary.MaxVarintLen32]byte var written int var last int32 for _, triangle := range t.triangles { for _, idx := range triangle { value := idx - last n := binary.PutVarint(buf[:], int64(value)) for p := buf[:n]; len(p) > 0; p = p[n:] { var err error if n, err = w.Write(p); err != nil { return err } written += n } last = idx } } log.Printf("compressed tin indices in bytes: %d (%d)\n", written, 3*4*len(t.triangles)) return nil }