From 367cc9e1ac6cdfd7f5c8c09eb6b3010a4b6e932e Mon Sep 17 00:00:00 2001
From: Stephen <webmaster@scd31.com>
Date: Sun, 23 Apr 2023 21:16:02 -0300
Subject: [PATCH] better image resizing logic
---
src/img.rs | 36 +++++++++++++++++++++++++++++++++---
1 file changed, 33 insertions(+), 3 deletions(-)
diff --git a/src/img.rs b/src/img.rs
index 16efd83..bada3c3 100644
--- a/src/img.rs
+++ b/src/img.rs
@@ -1,5 +1,5 @@
use image::{imageops::FilterType, io::Reader as ImageReader, ImageOutputFormat};
-use std::{fs, io::Cursor, path::PathBuf, sync::mpsc::Receiver};
+use std::{cmp::max, fs, io::Cursor, path::PathBuf, sync::mpsc::Receiver};
const IMG_DIM: u32 = 1024;
const IMG_MAX_SIZE: u32 = 2048;
@@ -20,8 +20,13 @@ impl ImgInfo {
// want a imagine that's 512 on one side
// resize so that the larger dimension is 512
- // TODO make this better. needs to be smaller than IMG_DIM but still % 16 on both sides
- let img = img.resize(IMG_DIM, IMG_DIM, FilterType::Triangle);
+ let (mut w, mut h) = resize_dimensions(img.width(), img.height(), IMG_DIM, IMG_DIM, false);
+
+ // make both dimensions divisible by 16 (SSDV requirement)
+ w -= w % 16;
+ h -= h % 16;
+
+ let img = img.resize_exact(w, h, FilterType::Triangle);
let mut bytes = vec![];
@@ -210,3 +215,28 @@ impl ImgManager {
Ok(())
}
}
+
+// shamelessly stolen from the image crate
+fn resize_dimensions(width: u32, height: u32, nwidth: u32, nheight: u32, fill: bool) -> (u32, u32) {
+ let wratio = nwidth as f64 / width as f64;
+ let hratio = nheight as f64 / height as f64;
+
+ let ratio = if fill {
+ f64::max(wratio, hratio)
+ } else {
+ f64::min(wratio, hratio)
+ };
+
+ let nw = max((width as f64 * ratio).round() as u64, 1);
+ let nh = max((height as f64 * ratio).round() as u64, 1);
+
+ if nw > u64::from(u32::MAX) {
+ let ratio = u32::MAX as f64 / width as f64;
+ (u32::MAX, max((height as f64 * ratio).round() as u32, 1))
+ } else if nh > u64::from(u32::MAX) {
+ let ratio = u32::MAX as f64 / height as f64;
+ (max((width as f64 * ratio).round() as u32, 1), u32::MAX)
+ } else {
+ (nw as u32, nh as u32)
+ }
+}
--
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