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// Copyright 2016 Florian Pigorsch. All rights reserved.
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package sm
import (
"fmt"
"image/color"
"math"
"strconv"
"strings"
"github.com/flopp/go-coordsparser"
"github.com/fogleman/gg"
"github.com/golang/geo/s2"
)
// Marker represents a marker on the map
type Marker struct {
MapObject
Position s2.LatLng
Color color.Color
Size float64
Label string
}
// NewMarker creates a new Marker
func NewMarker(pos s2.LatLng, col color.Color, size float64) *Marker {
m := new(Marker)
m.Position = pos
m.Color = col
m.Size = size
m.Label = ""
return m
}
func parseSizeString(s string) (float64, error) {
switch {
case s == "mid":
return 16.0, nil
case s == "small":
return 12.0, nil
case s == "tiny":
return 8.0, nil
}
if ss, err := strconv.ParseFloat(s, 64); err != nil && ss > 0 {
return ss, nil
}
return 0.0, fmt.Errorf("Cannot parse size string: %s", s)
}
// ParseMarkerString parses a string and returns an array of markers
func ParseMarkerString(s string) ([]*Marker, error) {
markers := make([]*Marker, 0, 0)
var color color.Color = color.RGBA{0xff, 0, 0, 0xff}
size := 16.0
label := ""
for _, ss := range strings.Split(s, "|") {
if ok, suffix := hasPrefix(ss, "color:"); ok {
var err error
color, err = ParseColorString(suffix)
if err != nil {
return nil, err
}
} else if ok, suffix := hasPrefix(ss, "label:"); ok {
label = suffix
} else if ok, suffix := hasPrefix(ss, "size:"); ok {
var err error
size, err = parseSizeString(suffix)
if err != nil {
return nil, err
}
} else {
lat, lng, err := coordsparser.Parse(ss)
if err != nil {
return nil, err
}
m := NewMarker(s2.LatLngFromDegrees(lat, lng), color, size)
m.Label = label
markers = append(markers, m)
}
}
return markers, nil
}
func (m *Marker) extraMarginPixels() float64 {
return 1.0 + 1.5*m.Size
}
func (m *Marker) bounds() s2.Rect {
r := s2.EmptyRect()
r = r.AddPoint(m.Position)
return r
}
func (m *Marker) draw(gc *gg.Context, trans *transformer) {
gc.ClearPath()
gc.SetLineJoin(gg.LineJoinRound)
gc.SetLineWidth(1.0)
radius := 0.5 * m.Size
x, y := trans.ll2p(m.Position)
gc.DrawArc(x, y-m.Size, radius, (90.0+60.0)*math.Pi/180.0, (360.0+90.0-60.0)*math.Pi/180.0)
gc.LineTo(x, y)
gc.ClosePath()
gc.SetColor(m.Color)
gc.FillPreserve()
gc.SetRGB(0, 0, 0)
gc.Stroke()
if m.Label != "" {
if Luminance(m.Color) >= 0.5 {
gc.SetColor(color.RGBA{0x00, 0x00, 0x00, 0xff})
} else {
gc.SetColor(color.RGBA{0xff, 0xff, 0xff, 0xff})
}
gc.DrawStringAnchored(m.Label, x, y-m.Size, 0.5, 0.5)
}
}
|
