func mouseButtonCallback(
window *glfw.Window,
button glfw.MouseButton,
action glfw.Action,
mod glfw.ModifierKey) {
if button == glfw.MouseButton1 {
down := action == glfw.Press
x, y := window.GetCursorPosition()
event <- ActionUpDownEvent{
Down: down,
X: float32(x),
Y: float32(y),
}
}
}