Go/Golang + Ebiten/Ebitengine

main.go

package main

import (
	"image/color"
	"log"

	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
)

const (
	ScreenWidth  = 480
	ScreenHeight = 640
)

var (
	backgroundColor = color.RGBA{0xff, 0xff, 0xff, 0xff}
)

type Game struct{}

func (g *Game) Update() error {
	return nil
}

func (g *Game) Draw(screen *ebiten.Image) {
	screen.Fill(backgroundColor)
	ebitenutil.DrawRect(screen, 0.0, 0.0, 32.0, 32.0, color.RGBA{0xff, 0, 0, 0xff})
}

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

func main() {
	ebiten.SetWindowSize(ScreenWidth, ScreenHeight)
	ebiten.SetWindowTitle("Hello, World!")
	if err := ebiten.RunGame(&Game{}); err != nil {
		log.Fatal(err)
	}
}