StackOverflow Piston problem

Cargo.toml

[package]
name = "stackoverflow-piston-example"
version = "0.0.0"
authors = ["Fred"]
description = "Note: This program can be used for both of the programs below. Simply use `cargo new` and save either of the below files as `src/main.rs`"
keywords = []

[dependencies]
piston = "0.35.0"
piston2d-opengl_graphics = "0.50.0"
piston2d-graphics = "0.24.0"
piston2d-touch_visualizer = "0.8.0"
pistoncore-sdl2_window = "0.47.0"

doesnt_flash.rs

extern crate piston;
extern crate opengl_graphics;
extern crate graphics;
extern crate touch_visualizer;
extern crate sdl2_window;

use opengl_graphics::{ GlGraphics, OpenGL };
use graphics::{ Context, Graphics };
use piston::input::*;
use piston::event_loop::*;
use sdl2_window::Sdl2Window as AppWindow;

static CURSOR_POS_COLOR: [f32; 4] = [0.0, 0.0, 0.0, 1.0];

fn main() {
    let opengl = OpenGL::V3_2;
    let mut window: AppWindow = piston::window::WindowSettings::new("Example for StackOverflow", [600, 600])
        .exit_on_esc(true).opengl(opengl).build().unwrap();

    let ref mut gl = GlGraphics::new(opengl);
    let (mut mx, mut my) = (0., 0.);
    let mut cursor_poses: Vec<(f64, f64)> = Vec::new();

    let mut events = Events::new(EventSettings::new().lazy(true));
    while let Some(e) = events.next(&mut window) {
        e.mouse_cursor(|x, y| {
            cursor_poses.push((x,y));
        });
        if let Some(args) = e.render_args() {
            gl.draw(args.viewport(), |c, g| {
                    graphics::clear([1.0; 4], g);
                    for &(x, y) in cursor_poses.iter() {
                        draw_cursor_pos([x, y], &c, g);
                    }
                }
            );
        }
    }
}

fn draw_cursor_pos<G: Graphics>(
    cursor: [f64; 2],
    c: &Context,
    g: &mut G,
) {
    graphics::ellipse(
        CURSOR_POS_COLOR,
        graphics::ellipse::circle(cursor[0], cursor[1], 4.0),
        c.transform,
        g
    );
}

flashes.rs

extern crate piston;
extern crate opengl_graphics;
extern crate graphics;
extern crate touch_visualizer;
extern crate sdl2_window;

use opengl_graphics::{ GlGraphics, OpenGL };
use graphics::{ Context, Graphics };
use piston::input::*;
use piston::event_loop::*;
use sdl2_window::Sdl2Window as AppWindow;

static CURSOR_POS_COLOR: [f32; 4] = [0.0, 0.0, 0.0, 1.0];

fn main() {
    let opengl = OpenGL::V3_2;
    let mut window: AppWindow = piston::window::WindowSettings::new("Example for StackOverflow", [600, 600])
        .exit_on_esc(true).opengl(opengl).build().unwrap();

    let ref mut gl = GlGraphics::new(opengl);
    let (mut mx, mut my) = (0., 0.);

    let mut i = 0;

    let mut events = Events::new(EventSettings::new().lazy(true));
    while let Some(e) = events.next(&mut window) {
        e.mouse_cursor(|x, y| {
            mx = x; my = y;
        });
        if let Some(args) = e.render_args() {
            gl.draw(args.viewport(), |c, g| {
                    if i == 0 {
                        graphics::clear([1.0; 4], g);
                    }
                    draw_cursor_pos([mx, my], &c, g);
                    i+=1;
                }
            );
        }
    }
}

fn draw_cursor_pos<G: Graphics>(
    cursor: [f64; 2],
    c: &Context,
    g: &mut G,
) {
    graphics::ellipse(
        CURSOR_POS_COLOR,
        graphics::ellipse::circle(cursor[0], cursor[1], 4.0),
        c.transform,
        g
    );
}