package main

import (
	"image/png"
	"math"
	"os"

	"github.com/tfriedel6/canvas"
	"github.com/tfriedel6/canvas/backend/softwarebackend"
)

func main() {
	backend := softwarebackend.New(720, 720)
	cv := canvas.New(backend)

	w, h := float64(cv.Width()), float64(cv.Height())
	cv.SetFillStyle("#000")
	cv.FillRect(0, 0, w, h)

	for r := 0.0; r < math.Pi*2; r += math.Pi * 0.1 {
		cv.SetFillStyle(int(r*10), int(r*20), int(r*40))
		cv.BeginPath()
		cv.MoveTo(w*0.5, h*0.5)
		cv.Arc(w*0.5, h*0.5, math.Min(w, h)*0.4, r, r+0.1*math.Pi, false)
		cv.ClosePath()
		cv.Fill()
	}

	cv.SetStrokeStyle("#FFF")
	cv.SetLineWidth(10)
	cv.BeginPath()
	cv.Arc(w*0.5, h*0.5, math.Min(w, h)*0.4, 0, math.Pi*2, false)
	cv.Stroke()

	f, err := os.OpenFile("result.png", os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0777)
	if err != nil {
		panic(err)
	}
	err = png.Encode(f, backend.Image)
	if err != nil {
		panic(err)
	}
}