SDL2go.go

//This program draws fractal using SDL2 library binding for GOLANG

package main

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

var winTitle string = "SDL2 GFX"
var winWidth, winHeight int32 = 1280, 800

func NormClear(renderer *sdl.Renderer) error {
	r, g, b, a, _ := renderer.GetDrawColor()
	renderer.SetDrawColor(0, 0, 0, 255)
	err := renderer.Clear()
	renderer.SetDrawColor(r, g, b, a)
	renderer.Present()
	return err
}

func DrawTriangle(renderer *sdl.Renderer, x1, y1, x2, y2 int32) {
	x3 := x1+(x2-x1)/2
	y3 := y1+(x2-x1)
	renderer.DrawLine(x1, y1, x2, y2)
	renderer.DrawLine(x1, y1, x3, y3)
	renderer.DrawLine(x2, y2, x3, y3)
}

func Fractal(renderer *sdl.Renderer, len, x, y int32) {
	if (len > 5) {
		Fractal(renderer, len/2, x, y)
		Fractal(renderer, len/2, x + len/2, y)
		Fractal(renderer, len/2, x + len/4 + 1, y + len/2)
	} else {
		DrawTriangle(renderer, x, y, x+len, y)
	}
}

func main() {
	//--------------------INITIALIZATION----------------------------------------
	err := sdl.Init(sdl.INIT_EVERYTHING)
	if err != nil {
		fmt.Printf("Failed to initialize SDL: %s\n", err)
		return
	}
	defer sdl.Quit()

	var window *sdl.Window
	window, err = sdl.CreateWindow(winTitle, sdl.WINDOWPOS_UNDEFINED, sdl.WINDOWPOS_UNDEFINED, winWidth, winHeight, sdl.WINDOW_SHOWN)
	if err != nil {
		fmt.Printf("Failed to create window: %s\n", err)
		return
	}
	defer window.Destroy()

	var renderer *sdl.Renderer
	renderer, err = sdl.CreateRenderer(window, -1, sdl.RENDERER_ACCELERATED);
	if err != nil {
		fmt.Printf("Failed to create renderer: %s\n", err)
		return
	}
	defer renderer.Destroy()
	//-----------------------CODE-----------------------------------------------

	renderer.SetDrawColor(255, 255, 255, 255)

	sdl.Delay(20)
	NormClear(renderer)

	Fractal(renderer, 800, 0, 0)


	renderer.Present()

	sdl.Delay(30000)
}