Support images in HTML export (#6578)

2 files changed, 18 insertions, 10 deletions

diff --git a/crates/typst-svg/src/image.rs b/crates/typst-svg/src/image.rs
index 1868ca39..e6dd579f 100644
--- a/crates/typst-svg/src/image.rs
+++ b/crates/typst-svg/src/image.rs
@@ -18,21 +18,27 @@ impl SVGRenderer {
         self.xml.write_attribute("width", &size.x.to_pt());
         self.xml.write_attribute("height", &size.y.to_pt());
         self.xml.write_attribute("preserveAspectRatio", "none");
-        match image.scaling() {
-            Smart::Auto => {}
-            Smart::Custom(ImageScaling::Smooth) => {
-                // This is still experimental and not implemented in all major browsers.
-                // https://developer.mozilla.org/en-US/docs/Web/CSS/image-rendering#browser_compatibility
-                self.xml.write_attribute("style", "image-rendering: smooth")
-            }
-            Smart::Custom(ImageScaling::Pixelated) => {
-                self.xml.write_attribute("style", "image-rendering: pixelated")
-            }
+        if let Some(value) = convert_image_scaling(image.scaling()) {
+            self.xml
+                .write_attribute("style", &format_args!("image-rendering: {value}"))
         }
         self.xml.end_element();
     }
 }
 
+/// Converts an image scaling to a CSS `image-rendering` propery value.
+pub fn convert_image_scaling(scaling: Smart<ImageScaling>) -> Option<&'static str> {
+    match scaling {
+        Smart::Auto => None,
+        Smart::Custom(ImageScaling::Smooth) => {
+            // This is still experimental and not implemented in all major browsers.
+            // https://developer.mozilla.org/en-US/docs/Web/CSS/image-rendering#browser_compatibility
+            Some("smooth")
+        }
+        Smart::Custom(ImageScaling::Pixelated) => Some("pixelated"),
+    }
+}
+
 /// Encode an image into a data URL. The format of the URL is
 /// `data:image/{format};base64,`.
 #[comemo::memoize]
diff --git a/crates/typst-svg/src/lib.rs b/crates/typst-svg/src/lib.rs
index f4e81250..3931b67f 100644
--- a/crates/typst-svg/src/lib.rs
+++ b/crates/typst-svg/src/lib.rs
@@ -5,6 +5,8 @@ mod paint;
 mod shape;
 mod text;
 
+pub use image::{convert_image_scaling, convert_image_to_base64_url};
+
 use std::collections::HashMap;
 use std::fmt::{self, Display, Formatter, Write};