// +build example

package main

import (
        "image/color"
        _ "image/png"
        "log"

        "github.com/hajimehoshi/ebiten"
        "github.com/hajimehoshi/ebiten/ebitenutil"
)

const (
        screenWidth  = 320
        screenHeight = 240
)

var (
        ebitenImage *ebiten.Image
        colors      = []color.RGBA{
                {0xff, 0xff, 0xff, 0xff},
                {0xff, 0xff, 0x0, 0xff},
                {0xff, 0x0, 0xff, 0xff},
                {0xff, 0x0, 0x0, 0xff},
                {0x0, 0xff, 0xff, 0xff},
                {0x0, 0xff, 0x0, 0xff},
                {0x0, 0x0, 0xff, 0xff},
                {0x0, 0x0, 0x0, 0xff},
        }
)

func update(screen *ebiten.Image) error {
        if ebiten.IsRunningSlowly() {
                return nil
        }

        const (
                ox = 10
                oy = 10
                dx = 60
                dy = 50
        )
        screen.Fill(color.NRGBA{0x00, 0x40, 0x80, 0xff})

        op := &ebiten.DrawImageOptions{}
        op.GeoM.Translate(ox, oy)
        screen.DrawImage(ebitenImage, op)

        // Fill with solid colors
        for i, c := range colors {
                op := &ebiten.DrawImageOptions{}
                x := i % 4
                y := i/4 + 1
                op.GeoM.Translate(ox+float64(dx*x), oy+float64(dy*y))

                // Reset RGB (not Alpha) 0 forcibly
                op.ColorM.Scale(0, 0, 0, 1)

                // Set color
                r := float64(c.R) / 0xff
                g := float64(c.G) / 0xff
                b := float64(c.B) / 0xff
                op.ColorM.Translate(r, g, b, 0)
                screen.DrawImage(ebitenImage, op)
        }
        return nil
}

func main() {
        var err error
        ebitenImage, _, err = ebitenutil.NewImageFromFile("_resources/images/ebiten.png", ebiten.FilterDefault)
        if err != nil {
                log.Fatal(err)
        }
        if err := ebiten.Run(update, screenWidth, screenHeight, 2, "Flood fill with solid colors (Ebiten Demo)"); err != nil {
                log.Fatal(err)
        }
}