mtsatellite/common/colors.go

84 lines
1.7 KiB
Go
Raw Normal View History

2014-09-09 15:22:29 +02:00
// Copyright 2014 by Sascha L. Teichmann
// Use of this source code is governed by the MIT license
// that can be found in the LICENSE file.
2014-09-14 00:02:04 +02:00
package common
2014-09-09 15:01:14 +02:00
import (
"bufio"
"fmt"
"image/color"
"os"
"sort"
2014-09-09 15:01:14 +02:00
"strings"
)
type Colors struct {
Colors []color.RGBA
NameIndex map[string]int32
Transparent int
}
type namedColor struct {
name string
color color.RGBA
}
type sortByAlpha []namedColor
func (colors sortByAlpha) Less(i, j int) bool {
return colors[i].color.A < colors[j].color.A
}
func (colors sortByAlpha) Len() int {
return len(colors)
}
func (colors sortByAlpha) Swap(i, j int) {
colors[i], colors[j] = colors[j], colors[i]
}
func ParseColors(filename string) (colors *Colors, err error) {
2014-09-09 15:01:14 +02:00
var file *os.File
if file, err = os.Open(filename); err != nil {
return
}
defer file.Close()
cols := make([]namedColor, 0, 2200)
2014-09-09 15:01:14 +02:00
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := scanner.Text()
if strings.HasPrefix(line, "#") {
continue
}
c := color.RGBA{A: 0xff}
var name string
if n, _ := fmt.Sscanf(
line, "%s %d %d %d %d", &name, &c.R, &c.G, &c.B, &c.A); n > 0 {
cols = append(cols, namedColor{name: name, color: c})
}
2014-09-09 15:01:14 +02:00
}
err = scanner.Err()
// Sort transparent colors to front. Makes it easier to figure out
// if an index corresponds to a transparent color (i < Transparent).
sort.Sort(sortByAlpha(cols))
cs := make([]color.RGBA, len(cols))
nameIndex := make(map[string]int32, len(cols))
transparent := 0
for i, nc := range cols {
if nc.color.A < 0xff {
transparent++
}
cs[i] = nc.color
nameIndex[nc.name] = int32(i)
}
colors = &Colors{Colors: cs, NameIndex: nameIndex, Transparent: transparent}
2014-09-09 15:01:14 +02:00
return
}