feat: add sky backdrops with cloud decks, storms, and lightning

Adds a fourth backdrop family alongside the gradients, deep-space scenes,
and geometric patterns. A sky palette carries the colours and a SkyKind
carries the structure, so --palette and --sky compose the same way
--palette and --scene already do.

Ten conditions: blue-hour, golden-hour, overcast, cirrus, mackerel,
mammatus, storm, bolt, aurora, crepuscular. Seven palettes sampled from
photographs of the named conditions, the same way the space palettes are
sampled from astrophotography.

Everything is drawn from the style seed at render time on image + rand,
with no new dependencies and nothing shipped as a bitmap, so a sky
resolves at any card size and --style-seed reproduces one exactly.

Sky palettes stay out of the default random rotation, which filters to
space palettes, so existing seeds render exactly as before. They are
reachable by explicit --palette or by naming them in a pool, matching how
the gradient and pattern families already behave.

ConfigCommand::Set is boxed because the args struct now carries one field
per styling axis and tripped clippy::large_enum_variant.

Author: solomonneas

src/cli.rs

@@ -78,6 +78,10 @@ pub struct PolishArgs {
     /// omitted. Only applies to pattern palettes.
     #[arg(long, value_parser = motif_name_parser())]
     pub motif: Option<String>,
+    /// Pin the sky condition (e.g. `bolt`, `mammatus`, `aurora`); random when
+    /// omitted. Only applies to sky palettes.
+    #[arg(long, value_parser = sky_name_parser())]
+    pub sky: Option<String>,
     /// Seed for deterministic styling.
     #[arg(long)]
     pub style_seed: Option<u64>,
@@ -178,6 +182,10 @@ fn motif_name_parser() -> clap::builder::PossibleValuesParser {
     clap::builder::PossibleValuesParser::new(polish::motif_names())
 }
 
+fn sky_name_parser() -> clap::builder::PossibleValuesParser {
+    clap::builder::PossibleValuesParser::new(polish::sky_names())
+}
+
 #[derive(Debug, Args)]
 pub struct CaptureArgs {
     #[arg(long, value_enum, default_value = "active")]
@@ -209,6 +217,10 @@ pub struct CaptureArgs {
     /// to pattern palettes.
     #[arg(long, value_parser = motif_name_parser())]
     pub motif: Option<String>,
+    /// Pin the sky condition (e.g. `bolt`, `mammatus`, `aurora`). Only applies
+    /// to sky palettes.
+    #[arg(long, value_parser = sky_name_parser())]
+    pub sky: Option<String>,
     #[arg(long)]
     pub style_seed: Option<u64>,
     /// Copy the card (or the raw shot with --presentation raw) to the
@@ -305,7 +317,10 @@ pub enum ConfigCommand {
     /// Print every palette and scene the pickers accept.
     Options,
     /// Update the persisted preferences.
-    Set(ConfigSetArgs),
+    ///
+    /// Boxed because the args struct carries one field per styling axis and
+    /// dwarfs the unit variants, which trips `clippy::large_enum_variant`.
+    Set(Box<ConfigSetArgs>),
 }
 
 #[derive(Debug, Args)]
@@ -323,6 +338,9 @@ pub struct ConfigSetArgs {
     /// Motif to pin. Pattern palettes only.
     #[arg(long, value_parser = motif_name_parser())]
     pub motif: Option<String>,
+    /// Sky to pin. Sky palettes only.
+    #[arg(long, value_parser = sky_name_parser())]
+    pub sky: Option<String>,
     /// Comma-separated palettes the random picker may choose from. Replaces the
     /// stored pool.
     #[arg(long, value_delimiter = ',', value_parser = palette_name_parser())]
@@ -335,6 +353,10 @@ pub struct ConfigSetArgs {
     /// stored pool.
     #[arg(long, value_delimiter = ',', value_parser = motif_name_parser())]
     pub motifs: Option<Vec<String>>,
+    /// Comma-separated skies the random picker may choose from. Replaces the
+    /// stored pool.
+    #[arg(long, value_delimiter = ',', value_parser = sky_name_parser())]
+    pub skies: Option<Vec<String>>,
     /// Reset a preference to its default. Repeatable.
     #[arg(long = "clear", value_enum)]
     pub clear: Vec<ClearTarget>,
@@ -357,12 +379,16 @@ pub enum ClearTarget {
     Scene,
     /// Drop the pinned motif.
     Motif,
+    /// Drop the pinned sky.
+    Sky,
     /// Empty the random palette pool, restoring every space palette.
     Palettes,
     /// Empty the random scene pool.
     Scenes,
     /// Empty the random motif pool.
     Motifs,
+    /// Empty the random sky pool.
+    Skies,
     /// Reset every polish preference.
     All,
 }
@@ -467,6 +493,7 @@ pub fn capture(args: CaptureArgs) -> Result<ExitCode, Box<dyn std::error::Error>
                                 args.palette.as_deref(),
                                 args.scene.as_deref(),
                                 args.motif.as_deref(),
+                                args.sky.as_deref(),
                                 &mut warnings,
                             );
                             match polish::render_codex_card(
@@ -966,6 +993,7 @@ fn run_polish(args: PolishArgs, config_path: &Path) -> crate::contract::PolishRe
             args.palette.as_deref(),
             args.scene.as_deref(),
             args.motif.as_deref(),
+            args.sky.as_deref(),
             &mut warnings,
         );
         let parent_ready = card_path
@@ -1220,9 +1248,11 @@ fn apply_config_set(prefs: &mut config::PolishPrefs, args: &ConfigSetArgs) {
             ClearTarget::Palette => prefs.palette = None,
             ClearTarget::Scene => prefs.scene = None,
             ClearTarget::Motif => prefs.motif = None,
+            ClearTarget::Sky => prefs.sky = None,
             ClearTarget::Palettes => prefs.palettes.clear(),
             ClearTarget::Scenes => prefs.scenes.clear(),
             ClearTarget::Motifs => prefs.motifs.clear(),
+            ClearTarget::Skies => prefs.skies.clear(),
             ClearTarget::All => *prefs = config::PolishPrefs::default(),
         }
     }
@@ -1241,6 +1271,9 @@ fn apply_config_set(prefs: &mut config::PolishPrefs, args: &ConfigSetArgs) {
     if let Some(motif) = args.motif.clone() {
         prefs.motif = Some(motif);
     }
+    if let Some(sky) = args.sky.clone() {
+        prefs.sky = Some(sky);
+    }
     if let Some(palettes) = args.palettes.clone() {
         prefs.palettes = palettes;
     }
@@ -1250,6 +1283,9 @@ fn apply_config_set(prefs: &mut config::PolishPrefs, args: &ConfigSetArgs) {
     if let Some(motifs) = args.motifs.clone() {
         prefs.motifs = motifs;
     }
+    if let Some(skies) = args.skies.clone() {
+        prefs.skies = skies;
+    }
 }
 
 /// A pinned scene only renders behind a space palette; pairing it with a
@@ -1285,6 +1321,10 @@ fn style_options() -> crate::contract::StyleOptions {
             .into_iter()
             .map(str::to_string)
             .collect(),
+        skies: polish::sky_names()
+            .into_iter()
+            .map(str::to_string)
+            .collect(),
     }
 }
 
@@ -1366,7 +1406,7 @@ mod tests {
     }
 
     fn config_set(args: ConfigSetArgs, path: &Path) -> crate::contract::ConfigResult {
-        run_config(ConfigCommand::Set(args), path)
+        run_config(ConfigCommand::Set(Box::new(args)), path)
     }
 
     fn empty_set_args() -> ConfigSetArgs {
@@ -1378,6 +1418,8 @@ mod tests {
             scenes: None,
             motif: None,
             motifs: None,
+            sky: None,
+            skies: None,
             clear: Vec::new(),
             format: OutputFormat::Json,
         }
@@ -1455,6 +1497,7 @@ mod tests {
             palette: None,
             scene: None,
             motif: None,
+            sky: None,
             style_seed: Some(7),
             format: OutputFormat::Json,
         });
@@ -1485,6 +1528,7 @@ mod tests {
             palette: Some("aurora-teal".to_string()),
             scene: None,
             motif: None,
+            sky: None,
             style_seed: Some(11),
             format: OutputFormat::Json,
         });
@@ -1518,6 +1562,7 @@ mod tests {
                 palette: None,
                 scene: None,
                 motif: None,
+                sky: None,
                 style_seed: Some(4),
                 format: OutputFormat::Json,
             },
@@ -1552,6 +1597,7 @@ mod tests {
                 palette: Some("ember-glow".to_string()),
                 scene: None,
                 motif: None,
+                sky: None,
                 style_seed: Some(4),
                 format: OutputFormat::Json,
             },
@@ -1684,6 +1730,7 @@ mod tests {
             palette: None,
             scene: None,
             motif: None,
+            sky: None,
             style_seed: Some(3),
             format: OutputFormat::Json,
         });
@@ -1755,6 +1802,7 @@ mod tests {
             palette: None,
             scene: None,
             motif: None,
+            sky: None,
             style_seed: Some(13),
             format: OutputFormat::Json,
         });
@@ -1772,6 +1820,7 @@ mod tests {
             palette: None,
             scene: None,
             motif: None,
+            sky: None,
             style_seed: Some(5),
             format: OutputFormat::Json,
         });

src/config.rs

@@ -58,6 +58,8 @@ pub struct PolishPrefs {
     pub scene: Option<String>,
     /// Motif applied when `mode` is `pinned`. Pattern palettes only.
     pub motif: Option<String>,
+    /// Sky applied when `mode` is `pinned`. Sky palettes only.
+    pub sky: Option<String>,
     /// Palettes the random picker may choose from. Empty means the built-in
     /// pool (every space palette).
     pub palettes: Vec<String>,
@@ -67,6 +69,9 @@ pub struct PolishPrefs {
     /// Motifs the random picker may choose from. Empty leaves the motif to the
     /// seed's own pick inside the pattern renderer.
     pub motifs: Vec<String>,
+    /// Skies the random picker may choose from. Empty leaves the condition to
+    /// the seed's own pick inside the sky renderer.
+    pub skies: Vec<String>,
 }
 
 /// Where the preferences file lives on this machine.
@@ -158,13 +163,15 @@ pub fn resolve_style(
     palette: Option<&str>,
     scene: Option<&str>,
     motif: Option<&str>,
+    sky: Option<&str>,
     warnings: &mut Vec<String>,
 ) -> polish::PresentationStyle {
     let seed = seed.unwrap_or_else(polish::random_seed);
     let pinned = prefs.mode == PolishMode::Pinned;
     let palette = palette.or_else(|| pinned.then_some(prefs.palette.as_deref()).flatten());
     let scene = scene.or_else(|| pinned.then_some(prefs.scene.as_deref()).flatten());
     let motif = motif.or_else(|| pinned.then_some(prefs.motif.as_deref()).flatten());
+    let sky = sky.or_else(|| pinned.then_some(prefs.sky.as_deref()).flatten());
 
     let palettes = keep_known(
         &prefs.palettes,
@@ -174,13 +181,14 @@ pub fn resolve_style(
     );
     let scenes = keep_known(&prefs.scenes, &polish::scene_names(), "scene", warnings);
     let motifs = keep_known(&prefs.motifs, &polish::motif_names(), "motif", warnings);
+    let skies = keep_known(&prefs.skies, &polish::sky_names(), "sky", warnings);
 
     let mut style = match palette {
         Some(name) => polish::style_with_palette(seed, name).unwrap_or_else(|| {
             warnings.push(format!("unknown palette: {name}"));
-            polish::style_from_seed_in_pool(seed, &palettes, &scenes, &motifs)
+            polish::style_from_seed_in_pool(seed, &palettes, &scenes, &motifs, &skies)
         }),
-        None => polish::style_from_seed_in_pool(seed, &palettes, &scenes, &motifs),
+        None => polish::style_from_seed_in_pool(seed, &palettes, &scenes, &motifs, &skies),
     };
 
     if let Some(name) = scene {
@@ -204,6 +212,17 @@ pub fn resolve_style(
             None => warnings.push(format!("unknown motif: {name}")),
         }
     }
+
+    if let Some(name) = sky {
+        match polish::sky_from_name(name) {
+            Some(kind) if style.is_sky() => style.sky = Some(kind),
+            Some(_) => warnings.push(format!(
+                "sky {name} ignored: palette {} is not a sky",
+                style.palette_name
+            )),
+            None => warnings.push(format!("unknown sky: {name}")),
+        }
+    }
     style
 }
 
@@ -284,9 +303,11 @@ mod tests {
                 palette: Some("violet-haze".to_string()),
                 scene: Some("jwst".to_string()),
                 motif: Some("plaid".to_string()),
+                sky: None,
                 palettes: vec!["orion-emission".to_string()],
                 scenes: vec!["alma".to_string()],
                 motifs: vec!["grid".to_string()],
+                skies: Vec::new(),
             },
         };
         save_to(&path, &config).expect("save");
@@ -336,6 +357,7 @@ mod tests {
             Some("aurora-teal"),
             None,
             None,
+            None,
             &mut warnings,
         );
         assert_eq!(style.palette_name, "aurora-teal");
@@ -351,6 +373,7 @@ mod tests {
             None,
             None,
             None,
+            None,
             &mut warnings,
         );
         assert_eq!(style.palette_name, "violet-haze");
@@ -364,7 +387,7 @@ mod tests {
             ..PolishPrefs::default()
         };
         let mut warnings = Vec::new();
-        let style = resolve_style(&prefs, Some(7), None, None, None, &mut warnings);
+        let style = resolve_style(&prefs, Some(7), None, None, None, None, &mut warnings);
         assert_eq!(style.palette_name, polish::style_from_seed(7).palette_name);
         assert!(warnings.is_empty(), "warnings: {warnings:?}");
     }
@@ -377,7 +400,7 @@ mod tests {
         };
         for seed in 0..40u64 {
             let mut warnings = Vec::new();
-            let style = resolve_style(&prefs, Some(seed), None, None, None, &mut warnings);
+            let style = resolve_style(&prefs, Some(seed), None, None, None, None, &mut warnings);
             assert!(
                 prefs.palettes.contains(&style.palette_name),
                 "seed {seed} escaped the pool with {}",
@@ -395,6 +418,7 @@ mod tests {
             None,
             None,
             None,
+            None,
             &mut warnings,
         );
         assert_eq!(space.scene, polish::scene_from_name("jwst"));
@@ -407,6 +431,7 @@ mod tests {
             None,
             None,
             None,
+            None,
             &mut warnings,
         );
         assert_eq!(gradient.scene, None);
@@ -422,7 +447,7 @@ mod tests {
             ..PolishPrefs::default()
         };
         let mut warnings = Vec::new();
-        let style = resolve_style(&prefs, Some(7), None, None, None, &mut warnings);
+        let style = resolve_style(&prefs, Some(7), None, None, None, None, &mut warnings);
         assert_eq!(style.palette_name, "orion-emission");
         assert_eq!(warnings.len(), 2, "warnings: {warnings:?}");
         assert!(warnings.iter().any(|w| w.contains("not-a-palette")));

src/contract.rs

@@ -98,14 +98,15 @@ pub struct StyleOptions {
     pub palettes: Vec<PaletteOption>,
     pub scenes: Vec<String>,
     pub motifs: Vec<String>,
+    pub skies: Vec<String>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, JsonSchema)]
 #[serde(rename_all = "camelCase")]
 pub struct PaletteOption {
     pub name: String,
-    /// `gradient`, `space`, or `pattern`. Scenes apply only to space palettes,
-    /// motifs only to pattern palettes.
+    /// `gradient`, `space`, `pattern`, or `sky`. Scenes apply only to space
+    /// palettes, motifs only to pattern palettes, skies only to sky palettes.
     pub kind: String,
 }
 

src/lib.rs

@@ -13,6 +13,7 @@ mod pattern;
 mod polish;
 mod reel_hyperframes;
 mod setup;
+mod sky;
 mod space;
 mod studio;
 mod text;