Nimgobus example without package global variables

nimgobus-example.go

package main

import (
	_ "image/png"
	"time"

	"github.com/adamstimb/nimgobus"
	"github.com/hajimehoshi/ebiten"
)

func main() {
	ebiten.SetWindowSize(670, 540)
	ebiten.SetWindowResizable(true)
	ebiten.SetWindowTitle("Nimgobus Example (resizeable)")

	game := NewGame(ebiten.WindowSize())

	game.Setup()

	ebiten.RunGame(game)
}

type Game struct {
	width  int
	height int

	nimgobus.Nimbus
}

func NewGame(width, height int) *Game {
	game := &Game{width: width, height: height}

	game.Init()

	return game
}

func (g *Game) Setup() {
	g.SetMode(40)
	g.SetBorder(LowGreyDark)
	g.SetPaper(LowGrey)
}

func (g *Game) Update(screen *ebiten.Image) error {
	if ebiten.IsKeyPressed(ebiten.KeyEscape) {
		return Error{"done"}
	}

	g.width = screen.Bounds().Dx()
	g.height = screen.Bounds().Dy()

	g.Cls()

	op := nimgobus.PlotOptions{
		SizeX: 2,
		SizeY: 3,
		Brush: LowGreenDark,
	}

	g.Plot(op, "Nimgobus Example", 35, 150)

	op.Brush = LowGreen

	g.Plot(op, "Nimgobus Example", 37, 152)

	op.SizeX = 1
	op.SizeY = 1
	op.Brush = LowBlueDark

	g.Plot(op, "No package global variables!", 50, 90)

	g.PlonkLogo(8, 30)

	op.Brush = LowWhite
	g.Plot(op, time.Now().Format(time.Stamp), 200, 0)

	g.Nimbus.Update()

	return nil
}

func (g *Game) Draw(screen *ebiten.Image) {
	mw, mh := g.Monitor.Size()

	mr := float64(mw) / float64(mh)

	var scale, offsetX, offsetY float64

	r := g.ratio()

	switch {
	case r > mr:
		scale = float64(g.height) / float64(mh)
		offsetX = (float64(g.width) - float64(mw)*scale) / 2
		offsetY = 0
	case r <= mr:
		scale = float64(g.width) / float64(mw)
		offsetX = 0
		offsetY = (float64(g.height) - float64(mh)*scale) / 2
	}

	op := &ebiten.DrawImageOptions{}

	op.GeoM.Scale(scale, scale)
	op.GeoM.Translate(offsetX, offsetY)
	op.Filter = ebiten.FilterLinear

	screen.DrawImage(g.Monitor, op)
}

func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
	return outsideWidth, outsideHeight
}

func (g *Game) ratio() float64 {
	return float64(g.width) / float64(g.height)
}

type Error struct {
	Message string
}

func (e Error) Error() string {
	return e.Message
}

// Low resolution colors
var (
	LowBlack      = 0
	LowBlueDark   = 1
	LowRedDark    = 2
	LowPurpleDark = 3
	LowGreenDark  = 4
	LowCyanDark   = 5
	LowBrown      = 6
	LowGrey       = 7
	LowGreyDark   = 8
	LowBlue       = 9
	LowRed        = 10
	LowPurple     = 11
	LowGreen      = 12
	LowCyan       = 13
	LowYellow     = 14
	LowWhite      = 15
)