pushers

kiln-core/src/map_file.rs

@@ -101,21 +101,25 @@ pub enum PlayerStart {
 ///
 /// Each entry is keyed by a single character (e.g. `"#"` or `" "`).
 /// That character is used in the `[grid]` content string to place tiles.
-/// The entry defines both how the tile looks (`tile`, `fg`, `bg`) and which
-/// [`Archetype`] it uses for behavior.
+/// The entry defines which [`Archetype`] the cell uses for behavior; `tile`,
+/// `fg`, and `bg` are optional and fall back to [`Archetype::default_glyph`]
+/// when absent. On save, fields that match the archetype default are omitted.
 ///
 /// `tile` accepts either an integer (`tile = 35`) or a char (`tile = "#"`).
 #[derive(Deserialize, Serialize)]
 pub struct PaletteEntry {
     /// The archetype name for this tile, e.g. `"wall"` or `"empty"`.
     pub archetype: String,
-    /// The tile index into the board's bitmap font.
+    /// Tile index into the board's bitmap font. Omit to use the archetype default.
     /// Accepts either an integer or a single-character string.
-    tile: TileIndex,
-    /// Foreground color as an `"#RRGGBB"` hex string.
-    pub fg: String,
-    /// Background color as an `"#RRGGBB"` hex string.
-    pub bg: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    tile: Option<TileIndex>,
+    /// Foreground color as an `"#RRGGBB"` hex string. Omit to use the archetype default.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub fg: Option<String>,
+    /// Background color as an `"#RRGGBB"` hex string. Omit to use the archetype default.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub bg: Option<String>,
 }
 
 /// The `[grid]` section of a map file.
@@ -216,12 +220,16 @@ fn make_glyph(tile: u32, fg: &str, bg: &str) -> Glyph {
 }
 
 /// Constructs a serializable [`PaletteEntry`] from core board types.
+///
+/// Fields that match the archetype's [`default_glyph`](Archetype::default_glyph)
+/// are omitted (`None`) so saved files stay minimal and round-trip cleanly.
 fn make_palette_entry(glyph: Glyph, arch: Archetype) -> PaletteEntry {
+    let default = arch.default_glyph();
     PaletteEntry {
         archetype: arch.name().to_string(),
-        tile: TileIndex::Num(glyph.tile),
-        fg: color_to_hex(glyph.fg),
-        bg: color_to_hex(glyph.bg),
+        tile: (glyph.tile != default.tile).then_some(TileIndex::Num(glyph.tile)),
+        fg:   (glyph.fg   != default.fg  ).then_some(color_to_hex(glyph.fg)),
+        bg:   (glyph.bg   != default.bg  ).then_some(color_to_hex(glyph.bg)),
     }
 }
 
@@ -324,10 +332,14 @@ impl TryFrom<MapFile> for Board {
 
         for (key, entry) in mf.palette {
             let key_char = key.chars().next().unwrap_or(' ');
-            let tile = entry.tile.into_u32();
             match Archetype::try_from(entry.archetype.as_str()) {
                 Ok(archetype) => {
-                    let glyph = make_glyph(tile, &entry.fg, &entry.bg);
+                    // Fall back to default_glyph() for any absent visual field.
+                    let default = archetype.default_glyph();
+                    let tile = entry.tile.map(|t| t.into_u32()).unwrap_or(default.tile);
+                    let fg   = entry.fg.as_deref().map(parse_color).unwrap_or(default.fg);
+                    let bg   = entry.bg.as_deref().map(parse_color).unwrap_or(default.bg);
+                    let glyph = Glyph { tile, fg, bg };
                     palette.insert(key_char, (glyph, archetype));
                 }
                 Err(e) => {