Use consuming builder pattern for SpritesheetBuilder

CHANGELOG.md

@@ -5,6 +5,7 @@
 - Text in SVG `<text>` elements now rendered in PNG sprites (see [#102])
 - Support loading SVG files compressed with gzip (`*.svgz`; see [#107])
 - Propagate errors in `get_svg_input_paths` (see [#108])
+- Use consuming builder pattern for `SpritesheetBuilder` (see [#109])
 - Update Oxipng dependency from v9 to v10 (see [#106])
 - Update thiserror dependency from v1 to v2 (see [#106])
 
@@ -14,6 +15,7 @@ The minimum supported version of Rust is now 1.85.1 (released March 2025).
 [#106]: https://github.com/flother/spreet/pull/106
 [#107]: https://github.com/flother/spreet/pull/107
 [#108]: https://github.com/flother/spreet/pull/108
+[#109]: https://github.com/flother/spreet/pull/109
 
 ## v0.13.1 (2025-12-24)
 

src/bin/spreet/main.rs

@@ -48,15 +48,13 @@ fn main() {
         std::process::exit(exitcode::NOINPUT);
     }
 
-    let mut spritesheet_builder = Spritesheet::build();
-    spritesheet_builder.sprites(sprites);
-    spritesheet_builder.spacing(args.spacing);
+    let mut spritesheet_builder = Spritesheet::build().sprites(sprites).spacing(args.spacing);
     if args.unique {
-        spritesheet_builder.make_unique();
-    };
+        spritesheet_builder = spritesheet_builder.make_unique();
+    }
     if args.sdf {
-        spritesheet_builder.make_sdf();
-    };
+        spritesheet_builder = spritesheet_builder.make_sdf();
+    }
 
     // Generate sprite sheet
     let Some(spritesheet) = spritesheet_builder.generate() else {

src/sprite/mod.rs

@@ -311,6 +311,7 @@ impl SpriteDescription {
 /// Builder pattern for `Spritesheet`: construct a `Spritesheet` object using calls to a builder
 /// helper.
 #[derive(Default, Clone)]
+#[must_use = "builder does nothing unless you call .generate()"]
 pub struct SpritesheetBuilder {
     sprites: Option<BTreeMap<String, Sprite>>,
     references: Option<MultiMap<String, String>>,
@@ -328,20 +329,20 @@ impl SpritesheetBuilder {
         }
     }
 
-    pub fn sprites(&mut self, sprites: BTreeMap<String, Sprite>) -> &mut Self {
+    pub fn sprites(mut self, sprites: BTreeMap<String, Sprite>) -> Self {
         self.sprites = Some(sprites);
         self
     }
 
     /// Set the spacing (in pixels) to add to the right and bottom of each sprite.
-    pub fn spacing(&mut self, spacing: u8) -> &mut Self {
+    pub fn spacing(mut self, spacing: u8) -> Self {
         self.spacing = spacing;
         self
     }
 
     // Remove any duplicate sprites from the spritesheet's sprites. This is used to let spritesheets
     // include only unique sprites, with multiple references to the same sprite in the index file.
-    pub fn make_unique(&mut self) -> &mut Self {
+    pub fn make_unique(mut self) -> Self {
         match self.sprites.take() {
             Some(sprites) => {
                 let mut unique_sprites = BTreeMap::new();
@@ -373,7 +374,7 @@ impl SpritesheetBuilder {
     ///
     /// You have to ensure that the sprites are created as an SDF file beforehand. See
     /// [`Sprite::new_sdf`] for further context.
-    pub fn make_sdf(&mut self) -> &mut Self {
+    pub fn make_sdf(mut self) -> Self {
         self.sdf = true;
         self
     }