Add scaling mode "Fill"

- Image covers the entire screen
- Aspect ratio preserved
- Excess image cropped (centered)

src/settings.rs

@@ -1,11 +1,11 @@
 use anyhow::Result;
 use std::path::PathBuf;
 
-use crate::{args, config};
+use crate::{args, config, wallpaper};
 
 pub struct WallpaperSettings {
     pub path: PathBuf,
-    pub mode: crate::wallpaper::ScalingMode,
+    pub mode: wallpaper::ScalingMode,
 }
 
 pub fn resolve_wallpaper(
@@ -50,7 +50,8 @@ pub fn resolve_wallpaper(
         _ => unreachable!(),
     };
 
-    let mode = crate::wallpaper::ScalingMode::Stretch; // Default for now. Fix later
+    //let mode = wallpaper::ScalingMode::Stretch; // 
+    let mode = wallpaper::ScalingMode::Fill; // Default
 
     Ok(WallpaperSettings { path, mode })
 }

src/wallpaper.rs

@@ -4,12 +4,11 @@ use std::path::Path;
 
 /// Supported wallpaper scaling modes.
 ///
-/// Only `Stretch` is implemented for now.
 /// Others are defined so the public API does not need to change later.
 #[derive(Debug, Clone, Copy)]
 pub enum ScalingMode {
     Stretch,
-    // Fill,
+    Fill,
     // Fit,
 }
 
@@ -38,6 +37,40 @@ fn rgba_to_bgra(mut pixels: Vec<u8>) -> Vec<u8> {
     pixels
 }
 
+/// Fill mode:
+/// - Image covers the entire screen
+/// - Aspect ratio is preserved
+/// - Excess image is cropped (centered)
+fn prepare_fill(img: &RgbaImage, screen_width: u32, screen_height: u32) -> PreparedWallpaper {
+    let img_w = img.width() as f32;
+    let img_h = img.height() as f32;
+
+    let screen_w = screen_width as f32;
+    let screen_h = screen_height as f32;
+
+    // Scale so that BOTH dimensions cover the screen
+    let scale = (screen_w / img_w).max(screen_h / img_h);
+
+    let scaled_w = (img_w * scale).round() as u32;
+    let scaled_h = (img_h * scale).round() as u32;
+
+    let resized = imageops::resize(img, scaled_w, scaled_h, imageops::FilterType::Lanczos3);
+
+    // Center the image; negative offsets cause cropping
+    let offset_x = (screen_width as i32 - scaled_w as i32) / 2;
+    let offset_y = (screen_height as i32 - scaled_h as i32) / 2;
+
+    let pixels = rgba_to_bgra(resized.into_raw());
+
+    PreparedWallpaper {
+        pixels,
+        width: scaled_w,
+        height: scaled_h,
+        offset_x,
+        offset_y,
+    }
+}
+
 /// Stretch mode:
 /// - Image is resized to exactly match screen dimensions
 /// - Aspect ratio is not preserved
@@ -85,6 +118,7 @@ pub fn prepare_wallpaper(
 
     let prepared = match mode {
         ScalingMode::Stretch => prepare_stretch(&img, screen_width, screen_height),
+        ScalingMode::Fill => prepare_fill(&img, screen_width, screen_height),
     };
 
     Ok(prepared)