Include images from raw pixmaps and more (#5632)

Co-authored-by: PgBiel <9021226+PgBiel@users.noreply.github.com>
Co-authored-by: Laurenz <laurmaedje@gmail.com>

1 files changed, 27 insertions, 13 deletions

diff --git a/crates/typst-render/src/image.rs b/crates/typst-render/src/image.rs
index 27b03911..7425bdd2 100644
--- a/crates/typst-render/src/image.rs
+++ b/crates/typst-render/src/image.rs
@@ -3,8 +3,9 @@ use std::sync::Arc;
 use image::imageops::FilterType;
 use image::{GenericImageView, Rgba};
 use tiny_skia as sk;
+use typst_library::foundations::Smart;
 use typst_library::layout::Size;
-use typst_library::visualize::{Image, ImageKind};
+use typst_library::visualize::{Image, ImageKind, ImageScaling};
 
 use crate::{AbsExt, State};
 
@@ -34,7 +35,7 @@ pub fn render_image(
     let w = (scale_x * view_width.max(aspect * view_height)).ceil() as u32;
     let h = ((w as f32) / aspect).ceil() as u32;
 
-    let pixmap = scaled_texture(image, w, h)?;
+    let pixmap = build_texture(image, w, h)?;
     let paint_scale_x = view_width / pixmap.width() as f32;
     let paint_scale_y = view_height / pixmap.height() as f32;
 
@@ -57,29 +58,42 @@ pub fn render_image(
 
 /// Prepare a texture for an image at a scaled size.
 #[comemo::memoize]
-fn scaled_texture(image: &Image, w: u32, h: u32) -> Option<Arc<sk::Pixmap>> {
-    let mut pixmap = sk::Pixmap::new(w, h)?;
+fn build_texture(image: &Image, w: u32, h: u32) -> Option<Arc<sk::Pixmap>> {
+    let mut texture = sk::Pixmap::new(w, h)?;
     match image.kind() {
         ImageKind::Raster(raster) => {
-            let downscale = w < raster.width();
-            let filter =
-                if downscale { FilterType::Lanczos3 } else { FilterType::CatmullRom };
-            let buf = raster.dynamic().resize(w, h, filter);
-            for ((_, _, src), dest) in buf.pixels().zip(pixmap.pixels_mut()) {
+            let w = texture.width();
+            let h = texture.height();
+
+            let buf;
+            let dynamic = raster.dynamic();
+            let resized = if (w, h) == (dynamic.width(), dynamic.height()) {
+                // Small optimization to not allocate in case image is not resized.
+                dynamic
+            } else {
+                let upscale = w > dynamic.width();
+                let filter = match image.scaling() {
+                    Smart::Custom(ImageScaling::Pixelated) => FilterType::Nearest,
+                    _ if upscale => FilterType::CatmullRom,
+                    _ => FilterType::Lanczos3, // downscale
+                };
+                buf = dynamic.resize_exact(w, h, filter);
+                &buf
+            };
+
+            for ((_, _, src), dest) in resized.pixels().zip(texture.pixels_mut()) {
                 let Rgba([r, g, b, a]) = src;
                 *dest = sk::ColorU8::from_rgba(r, g, b, a).premultiply();
             }
         }
-        // Safety: We do not keep any references to tree nodes beyond the scope
-        // of `with`.
         ImageKind::Svg(svg) => {
             let tree = svg.tree();
             let ts = tiny_skia::Transform::from_scale(
                 w as f32 / tree.size().width(),
                 h as f32 / tree.size().height(),
             );
-            resvg::render(tree, ts, &mut pixmap.as_mut())
+            resvg::render(tree, ts, &mut texture.as_mut());
         }
     }
-    Some(Arc::new(pixmap))
+    Some(Arc::new(texture))
 }