add truecolor support

color.go

@@ -0,0 +1,73 @@
+package figlet4go
+
+import (
+	"fmt"
+	"errors"
+	"encoding/hex"
+)
+
+// Escape char
+const escape string = "\x1b"
+
+var (
+	ColorBlack   AnsiColor = AnsiColor{30}
+	ColorRed     AnsiColor = AnsiColor{31}
+	ColorGreen   AnsiColor = AnsiColor{32}
+	ColorYellow  AnsiColor = AnsiColor{33}
+	ColorBlue    AnsiColor = AnsiColor{34}
+	ColorMagenta AnsiColor = AnsiColor{35}
+	ColorCyan    AnsiColor = AnsiColor{36}
+	ColorWhite   AnsiColor = AnsiColor{37}
+)
+
+// Every color has a pre- and a suffix
+type Color interface {
+	getPrefix() string
+	getSuffix() string
+}
+
+// Ansi color
+type AnsiColor struct {
+	code int
+}
+
+// Truecolor with rgb Attributes
+type TrueColor struct {
+	r int
+	g int
+	b int
+}
+
+// Prefix for ansi color
+func (tc TrueColor) getPrefix() string {
+	return fmt.Sprintf("%v[38;2;%d;%d;%dm", escape, tc.r, tc.g, tc.b)
+}
+
+// Suffix for ansi color
+func (tc TrueColor) getSuffix() string {
+	return fmt.Sprintf("%v[0m", escape)
+}
+
+func GetTrueColorFromHexString(c string) (*TrueColor, error) {
+	rgb, err := hex.DecodeString(c)
+	if err != nil {
+		return nil, errors.New("Invalid color given (" + c + ")")
+	}
+
+	return &TrueColor{
+		int(rgb[0]),
+		int(rgb[1]),
+		int(rgb[2]),
+	}, nil
+}
+
+
+// Prefix for ansi color
+func (ac AnsiColor) getPrefix() string {
+	return fmt.Sprintf("%v[0;%dm", escape, ac.code)
+}
+
+// Suffix for ansi color
+func (ac AnsiColor) getSuffix() string {
+	return fmt.Sprintf("%v[0m", escape)
+}