[tetra] spritesheet off by 1 px

Cargo.toml

[package]
name = "spritesheet"
version = "0.1.0"
authors = ["taotao54321 <taotao54321@gmail.com>"]
edition = "2018"

[dependencies]
tetra = "0.4"

main.rs

use tetra::graphics::{self, DrawParams, Rectangle, Texture};
use tetra::math::Vec2;
use tetra::{Context, ContextBuilder, State};

const SPRITE_W: f32 = 128.0;
const SPRITE_H: f32 = 128.0;

struct GameState {
    tex: Texture,
}

impl GameState {
    fn new(ctx: &mut Context) -> tetra::Result<Self> {
        Ok(Self {
            tex: Texture::new(ctx, concat!(env!("CARGO_MANIFEST_DIR"), "/tile.png"))?,
        })
    }
}

impl State for GameState {
    fn draw(&mut self, ctx: &mut Context) -> tetra::Result {
        for i in 0..4 {
            let clip = Rectangle::new(0.0, i as f32 * SPRITE_H, SPRITE_W, SPRITE_H);

            graphics::draw(
                ctx,
                &self.tex,
                DrawParams::default()
                    .clip(clip)
                    .position(Vec2::new(40.0 + (SPRITE_W + 20.0) * i as f32, 39.5)),
            );
        }

        Ok(())
    }
}

fn main() -> tetra::Result {
    ContextBuilder::new("spritesheet", 640, 200)
        .quit_on_escape(true)
        .build()?
        .run(GameState::new)
}

tile.png.md