// Requires "go mod init main" and "go get github.com/holizz/terrapin" after
// You may need to install git first: https://git-scm.com/
package main

import (
	"github.com/holizz/terrapin"
	"image"
	"image/png"
	"math"
	"os"
)

func kochCurve(t *terrapin.Terrapin, lung float64, liv int) {
	if liv == 0 {
		t.Forward(lung)
	} else {
		kochCurve(t, lung / 3, liv - 1)
		t.Left(math.Pi / 3.0)
		kochCurve(t, lung / 3, liv - 1)
		t.Right(2.0 * math.Pi / 3.0)
		kochCurve(t, lung/ 3, liv - 1)
		t.Left(math.Pi / 3.0)
		kochCurve(t, lung / 3, liv - 1)
	}
}

func kochSnowflake(t *terrapin.Terrapin, lung float64, liv int) {
		kochCurve(t, lung, liv)
		t.Right(2.0 * math.Pi / 3.0)
		kochCurve(t, lung, liv)
		t.Right(2.0 * math.Pi / 3.0)
		kochCurve(t, lung, liv)
		t.Right(2.0 * math.Pi / 3.0)
}

func main() {
	i := image.NewRGBA(image.Rect(0, 0, 1000, 1000))
	t := terrapin.NewTerrapin(i, terrapin.Position{200.0, 800.0})
	kochSnowflake(t, 500.0, 5)
	png.Encode(os.Stdout, i)
}