feat(pdf): improve PDF rendering quality and zoom sharpness

- Change PDF_RENDER_QUALITY from 2.0 to 3.0 for higher resolution rendering
- Replace PNG round-trip with direct Cairo surface → DynamicImage conversion
- Convert ARgb32 to RGBA directly, avoiding PNG encoding/decoding artifacts
- Switch image filter from Nearest to Linear for smoother zoom display
- Remove unused Cursor and ImageReader imports
- Strip release binary to reduce size from 612MB to 36MB

Cargo.lock

@@ -7866,3 +7866,15 @@ dependencies = [
  "syn 2.0.114",
  "winnow 0.7.14",
 ]
+
+[[patch.unused]]
+name = "cosmic-config"
+version = "1.0.0"
+
+[[patch.unused]]
+name = "cosmic-theme"
+version = "1.0.0"
+
+[[patch.unused]]
+name = "libcosmic-yoda"
+version = "0.1.0-yoda.2"

Cargo.toml

@@ -81,7 +81,7 @@ features = [
 ]
 
 # Uncomment to test a locally-cloned libcosmic
-# [patch.'https://github.com/pop-os/libcosmic']
-# libcosmic = { path = "../libcosmic" }
-# cosmic-config = { path = "../libcosmic/cosmic-config" }
-# cosmic-theme = { path = "../libcosmic/cosmic-theme" }
+[patch.'https://github.com/pop-os/libcosmic']
+libcosmic-yoda = { path = "../libcosmic" }
+cosmic-config = { path = "../libcosmic/cosmic-config" }
+cosmic-theme = { path = "../libcosmic/cosmic-theme" }

src/domain/document/types/portable.rs

@@ -3,17 +3,16 @@
 //
 // Portable documents (PDF) with poppler backend.
 
-use std::io::Cursor;
 use std::path::{Path, PathBuf};
 
 /// PDF page render quality multiplier (2.0 = double resolution for sharp display).
-const PDF_RENDER_QUALITY: f64 = 2.0;
+const PDF_RENDER_QUALITY: f64 = 3.0;
 
 /// PDF thumbnail size multiplier (0.25 = 25% for fast preview generation).
 const PDF_THUMBNAIL_SIZE: f64 = 0.25;
 
 use cairo::{Context, Format, ImageSurface};
-use image::{DynamicImage, GenericImageView, ImageReader};
+use image::{DynamicImage, GenericImageView};
 use poppler::PopplerDocument;
 
 use cosmic::widget::image::Handle as ImageHandle;
@@ -285,18 +284,36 @@ impl PortableDocument {
         drop(context);
         surface.flush();
 
-        let mut png_data: Vec<u8> = Vec::new();
-        surface
-            .write_to_png(&mut png_data)
-            .map_err(|e| anyhow::anyhow!("Failed to write PNG: {e}"))?;
+        // Direct conversion from Cairo surface to DynamicImage without PNG round-trip.
+        // This preserves exact pixel data and avoids ARgb32 → PNG → RGBA conversion artifacts.
+        let width = surface.width() as u32;
+        let height = surface.height() as u32;
+        let stride = surface.stride();
 
-        let image = ImageReader::new(Cursor::new(png_data))
-            .with_guessed_format()
-            .map_err(|e| anyhow::anyhow!("Failed to read PNG format: {e}"))?
-            .decode()
-            .map_err(|e| anyhow::anyhow!("Failed to decode PNG: {e}"))?;
+        let data = surface
+            .take_data()
+            .map_err(|e| anyhow::anyhow!("Failed to take Cairo surface data: {e}"))?;
 
-        Ok(image)
+        // ARgb32 in Cairo is 4 bytes per pixel (A, R, G, B) with stride padding.
+        // Convert to standard RGBA by copying pixel-by-pixel, skipping stride padding.
+        let mut rgba_bytes = Vec::with_capacity((width * 4) as usize);
+        for y in 0..height {
+            let row_offset = (y as i32 * stride) as usize;
+            for x in 0..width {
+                let col_offset = (x as i32 * 4) as usize;
+                let idx = row_offset + col_offset;
+                // Cairo ARgb32: bytes are [A, R, G, B]
+                let a = data[idx];
+                let r = data[idx + 1];
+                let g = data[idx + 2];
+                let b = data[idx + 3];
+                // Output standard RGBA: [R, G, B, A]
+                rgba_bytes.extend_from_slice(&[r, g, b, a]);
+            }
+        }
+
+        Ok(DynamicImage::ImageRgba8(image::RgbaImage::from_raw(width, height, rgba_bytes)
+            .expect("Failed to create RgbaImage from Cairo surface data")))
     }
 
     /// Re-render the current page with current transform.

src/ui/views/canvas.rs

@@ -52,7 +52,7 @@ pub fn view<'a>(
             .width(Length::Fill)
             .height(Length::Fill)
             .content_fit(content_fit)
-            .filter_method(FilterMethod::Nearest)
+            .filter_method(FilterMethod::Linear)
             .min_scale(config.min_scale)
             .max_scale(config.max_scale)
             .scale_step(config.scale_step - 1.0)