Drawing a circle, but cost over 1 second, it's normal?

[yangwenmai]

//! An example using the drawing functions. Writes to the user-provided target file.

use std::env;
use std::path::Path;
use std::fmt;
use std::time::{Duration, Instant};
use image::{Rgb, RgbImage};
use imageproc::rect::Rect;
use imageproc::drawing::{
    draw_cross_mut,
    draw_line_segment_mut,
    draw_hollow_rect_mut,
    draw_filled_rect_mut,
    draw_hollow_circle_mut,
    draw_filled_circle_mut
};
struct Elapsed(Duration);
impl Elapsed {
    fn from(start: &Instant) -> Self {
        Elapsed(start.elapsed())
    }
}

impl fmt::Display for Elapsed {
    fn fmt(&self, out: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        match (self.0.as_secs(), self.0.subsec_nanos()) {
            (0, n) if n < 1000 => write!(out, "{} ns", n),
            (0, n) if n < 1000_000 => write!(out, "{} µs", n / 1000),
            (0, n) => write!(out, "{} ms", n / 1000_000),
            (s, n) if s < 10 => write!(out, "{}.{:02} s", s, n / 10_000_000),
            (s, _) => write!(out, "{} s", s),
        }
    }
}

fn main() {
    let arg = if env::args().count() == 2 {
            env::args().nth(1).unwrap()
        } else {
            panic!("Please enter a target file path")
        };
    let timer = Instant::now();
    let path = Path::new(&arg);
    let white = Rgb([255u8, 255u8, 255u8]);

    let mut image = RgbImage::new(1000, 1000);
    // Draw a filled circle within bounds
    draw_filled_circle_mut(&mut image, (500, 500), 400, white);
    image.save(path).unwrap();
    println!("draw in {}", Elapsed::from(&timer));
}

Debug：
Output: draw in 1.22s

Release：
Output：draw in 20ms

env:

MacBookPro 2017
3.1 GHz Intel Core i7
16 GB 2133 MHz LPDDR3

rustc 1.36.0-nightly (33fe1131c 2019-04-20)
cargo 1.36.0-nightly (b6581d383 2019-04-16)

[theotherphil]

cargo run --release --example drawing circle.png
draw in 19 ms

cargo run --example drawing circle.png
draw in 1.59 s

What you're reporting matches what I see in debug mode. Do you care about debug mode performance specifically?

[theotherphil]

Closing as answered: this performance from debug builds is not surprising.

[yangwenmai]

Thanks.