polaris-mirror/src/thumbnails.rs
Antoine Gersant d894ae2783 Cleanup
2018-10-08 21:28:05 -07:00

75 lines
2.2 KiB
Rust

use image;
use image::DynamicImage;
use image::FilterType;
use image::GenericImage;
use image::GenericImageView;
use image::ImageBuffer;
use image::ImageOutputFormat;
use std::cmp;
use std::collections::hash_map::DefaultHasher;
use std::fs::{DirBuilder, File};
use std::hash::{Hash, Hasher};
use std::path::*;
use errors::*;
use utils;
const THUMBNAILS_PATH: &str = "thumbnails";
fn hash(path: &Path, dimension: u32) -> u64 {
let path_string = path.to_string_lossy();
let hash_input = format!("{}:{}", path_string, dimension.to_string());
let mut hasher = DefaultHasher::new();
hash_input.hash(&mut hasher);
hasher.finish()
}
pub fn get_thumbnail(real_path: &Path, max_dimension: u32) -> Result<PathBuf> {
let mut out_path = utils::get_data_root()?;
out_path.push(THUMBNAILS_PATH);
let mut dir_builder = DirBuilder::new();
dir_builder.recursive(true);
dir_builder.create(out_path.as_path())?;
let source_image = image::open(real_path)?;
let (source_width, source_height) = source_image.dimensions();
let largest_dimension = cmp::max(source_width, source_height);
let out_dimension = cmp::min(max_dimension, largest_dimension);
let hash = hash(real_path, out_dimension);
out_path.push(format!("{}.jpg", hash.to_string()));
if !out_path.exists() {
let quality = 80;
let source_aspect_ratio: f32 = source_width as f32 / source_height as f32;
let mut final_image;
if source_aspect_ratio < 0.8 || source_aspect_ratio > 1.2 {
let scaled_image =
source_image.resize(out_dimension, out_dimension, FilterType::Lanczos3);
let (scaled_width, scaled_height) = scaled_image.dimensions();
let background = image::Rgb {
data: [255 as u8, 255 as u8, 255 as u8],
};
final_image = DynamicImage::ImageRgb8(ImageBuffer::from_pixel(
out_dimension,
out_dimension,
background,
));
final_image.copy_from(
&scaled_image,
(out_dimension - scaled_width) / 2,
(out_dimension - scaled_height) / 2,
);
} else {
final_image =
source_image.resize_exact(out_dimension, out_dimension, FilterType::Lanczos3);
};
let mut out_file = File::create(&out_path)?;
final_image.write_to(&mut out_file, ImageOutputFormat::JPEG(quality))?;
}
Ok(out_path)
}