ゲーム開発における Golang の課題と応用を探る

package main

import (
    "github.com/veandco/go-sdl2/sdl"
)

var (
    windowWidth  = 800
    windowHeight = 600
)

func main() {
    err := sdl.Init(sdl.INIT_EVERYTHING)
    if err != nil {
        panic(err)
    }
    defer sdl.Quit()

    window, err := sdl.CreateWindow("Simple Game", sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED,
        windowWidth, windowHeight, sdl.WINDOW_SHOWN)
    if err != nil {
        panic(err)
    }
    defer window.Destroy()

    renderer, err := sdl.CreateRenderer(window, -1, sdl.RENDERER_ACCELERATED)
    if err != nil {
        panic(err)
    }
    defer renderer.Destroy()

    ball := sdl.Rect{X: 0, Y: 0, W: 20, H: 20}
    ballVelX, ballVelY := 3, 3

    for {
        for event := sdl.PollEvent(); event != nil; event = sdl.PollEvent() {
            switch event.(type) {
            case *sdl.QuitEvent:
                return
            }
        }

        renderer.SetDrawColor(0, 0, 0, 255)
        renderer.Clear()

        ball.X += int32(ballVelX)
        ball.Y += int32(ballVelY

        if ball.X > int32(windowWidth) || ball.X < 0 {
            ballVelX = -ballVelX
        }
        if ball.Y > int32(windowHeight) || ball.Y < 0 {
            ballVelY = -ballVelY
        }

        renderer.SetDrawColor(255, 255, 255, 255)
        renderer.FillRect(&ball)

        renderer.Present()
        sdl.Delay(10)
    }
}