Need clarification on events

[PiecePaperCode]

package main

import (
	"github.com/faiface/gui/win"
	"github.com/faiface/mainthread"
	"github.com/vova616/screenshot"
	"image"
	"image/draw"
	"time"
)

func run() {
	w, err := win.New(win.Title("faiface/gui"), win.Size(800, 600))
	if err != nil {
		panic(err)
	}
	redraw := func(drw draw.Image) image.Rectangle {
		r := image.Rect(0, 0, 2560, 1440)
		img2, _ := screenshot.CaptureScreen()
		myImg := image.Image(img2)
		draw.Draw(drw, r, myImg, image.ZP, draw.Src)
		return r
	}
	for event := range w.Events() {
		switch event.(type) {
		case win.WiClose:
			close(w.Draw())
		default:
			time.Sleep(17 * time.Millisecond)
			w.Draw() <- redraw
		}

	}
}

func main() {
	mainthread.Run(run)
}

I have coded this example. It grabs a screenshot of my screen and displays it just fine at around 60Hz. It runs for a coupe of seconds until it crashes with the message attached below. I assume im running out of somthing.

panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x20 pc=0x4e00a0]

goroutine 18 [running, locked to thread]:
image.(*RGBA).Bounds(0x54d8de)
        /snap/go/9360/src/image/image.go:98
image/draw.clip({0x60e608, 0xc000356000}, 0xc00497be08, {0x60db08, 0x0}, 0xc00497bdc8, {0x0, 0x0}, 0xc00497bde8)
        /snap/go/9360/src/image/draw/draw.go:86 +0xd3
image/draw.DrawMask({0x60e608, 0xc000356000}, {{0x0, 0x0}, {0x320, 0x258}}, {0x60db08, 0x0}, {0x0, 0x0}, ...)
        /snap/go/9360/src/image/draw/draw.go:117 +0xa5
image/draw.Draw(...)
        /snap/go/9360/src/image/draw/draw.go:111
main.run.func1({0x60e608, 0xc000356000})