func createNoise(win ui.Window, screen draw.Image) {
var rnd, rnd2 uint64
var rnd16a, rnd16b, rnd16c, rnd16d uint16
var img [240 * 320 * 4]byte
// Populate the image with pixel data
for {
for i := 0; i < len(img); i += 256 {
rnd = uint64(rand.Int63())
if (i % 63) == 0 {
rnd2 = uint64(rand.Int63())
}
rnd |= rnd2 & 1 << 63 // we have to set the 64'th bit from the rand.Int63() manualy
rnd16a = uint16(rnd & 0x000000000000FFFF)
rnd16b = uint16((rnd >> 16) & 0x000000000000FFFF)
rnd16c = uint16((rnd >> 32) & 0x000000000000FFFF)
rnd16d = uint16((rnd >> 48) & 0x000000000000FFFF)
copy(img[i:i+64], bw[rnd16a][:])
copy(img[i+64:i+128], bw[rnd16b][:])
copy(img[i+128:i+192], bw[rnd16c][:])
copy(img[i+192:i+256], bw[rnd16d][:])
rnd2 = rnd2 >> 1 // rotate to next random bit
}
// Copy pixel data to the screen
copy(screen.(*image.RGBA).Pix, img[:])
frameCount <- 1
win.FlushImage()
}
}
func flushFunc(ctxt ui.Window) func(r image.Rectangle) {
if fctxt, ok := ctxt.(RectFlusherContext); ok {
return func(r image.Rectangle) {
fctxt.FlushImageRect(r)
}
}
return func(_ image.Rectangle) {
ctxt.FlushImage()
}
}
func displayImage(buffer image.Image, window ui.Window) {
draw.Draw(window.Screen(), window.Screen().Bounds(), buffer, image.ZP, draw.Src)
window.FlushImage()
}