mtsatellite/tilemapper/colors.go

// 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.

package main

import (
	"bufio"
	"fmt"
	"image/color"
	"os"
	"strings"
)

type Colors struct {
	Colors    []color.RGBA
	NameIndex map[string]int
}

func ParseColors(filename string) (colors *Colors, err error) {

	var file *os.File
	if file, err = os.Open(filename); err != nil {
		return
	}
	defer file.Close()

	nameIndex := make(map[string]int)
	cols := make([]color.RGBA, 0, 2200)

	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 {
			idx := len(cols)
			cols = append(cols, c)
			nameIndex[name] = idx
		}
	}
	err = scanner.Err()
	colors = &Colors{Colors: cols, NameIndex: nameIndex}
	return
}