scale.rs

use clap::Parser;
use image::imageops::FilterType;
use image::{imageops, GenericImage, Pixel};
use serde::{Deserialize, Serialize};
use crunch_cli::utils::TypedOutputFormat;

#[inline(always)]
fn one() -> f32 {
	1.0
}

/// Resize an image by a scale factor
#[derive(Debug, Clone, Parser, Serialize, Deserialize)]
#[clap(author, version = "0.3.0")]
pub struct Scale {
	/// The path to the image file
	#[serde(default)]
	pub input: String,
	/// The path to write the scaled image
	#[serde(default)]
	pub output: String,

	/// The scale factor to use; numbers between 0-1 shrink the image; numbers > 1 enlarge
	#[clap(short, long, default_value_t = 1.0)]
	#[serde(default = "one")]
	factor: f32,
}

impl Scale {
	pub fn run<T: GenericImage>(&self, image: &T) -> anyhow::Result<TypedOutputFormat<T>>
	where
		T::Pixel: 'static,
		<T::Pixel as Pixel>::Subpixel: 'static,
	{
		let width = (image.width() as f32 * self.factor) as u32;
		let height = (image.height() as f32 * self.factor) as u32;

		Ok(imageops::resize(image, width, height, FilterType::Nearest))
	}
}