Merge pull request #7564 from levzzz5154/modapi/level-world

Native mods: a level's seed, difficulty, game rules and weather through LevelRef (#7387)

crates/horizon-client/src/game.rs

@@ -252,6 +252,7 @@ mod native_item_container;
 mod native_item_energy;
 mod native_item_fluids;
 mod native_level_refs;
+mod native_level_world;
 mod native_lifecycle;
 mod native_living_refs;
 mod native_machines;

crates/horizon-client/src/game/native_level_refs.rs

@@ -9,7 +9,7 @@ use horizon_client::world::World;
 
 impl Game<'_> {
     /// The world a handle names now, or None for a stale or foreign one.
-    fn native_level_world(&self, level: LevelRef) -> Option<&World> {
+    pub(super) fn native_level_world(&self, level: LevelRef) -> Option<&World> {
         if self.remote.is_some() || self.native_lifecycle.epoch() != Some(level.epoch()) {
             return None;
         }

crates/horizon-client/src/game/native_level_world.rs

@@ -0,0 +1,68 @@
+//! A level's world settings for native server mods, through a `LevelRef`
+//! (docs/native-mods.md, "Entity and level handles", #7387): the seed, the
+//! difficulty, game rules and weather. They return `None` on a client or for
+//! a handle of an earlier open.
+use super::Game;
+use horizon_client::command::vanilla::DIFFICULTIES;
+use horizon_client::mod_api::{GameRuleValue, LevelRef};
+
+/// `Level.isRaining` and `isThundering` from the rain and thunder levels.
+fn weather_flags((rain, thunder): (f32, f32)) -> (bool, bool) {
+    (rain > 0.2, thunder > 0.9)
+}
+
+impl Game<'_> {
+    /// The world's seed (`WorldOptions.seed`), as `/seed` shows it. API
+    /// @API:level_world@.
+    pub(super) fn native_level_seed(&self, level: LevelRef) -> Option<i64> {
+        self.native_level_world(level)?;
+        Some(self.level.seed)
+    }
+    /// The difficulty (`Level.getDifficulty`): `peaceful`, `easy`, `normal`
+    /// or `hard`, as `/difficulty` names it. API @API:level_world@.
+    pub(super) fn native_level_difficulty(&self, level: LevelRef) -> Option<&'static str> {
+        self.native_level_world(level)?;
+        DIFFICULTIES.get(usize::from(self.ui.difficulty)).copied()
+    }
+    /// Game rule `rule` (`minecraft:keep_inventory` or `keep_inventory`), as
+    /// `/gamerule` queries it: None for an unknown rule. API @API:level_world@.
+    pub(super) fn native_level_game_rule(
+        &self,
+        level: LevelRef,
+        rule: &str,
+    ) -> Option<GameRuleValue> {
+        self.native_level_world(level)?;
+        let r = horizon_client::gamerules::rule(rule)?;
+        self.ui.rules.get(r.name)
+    }
+    /// The rain and thunder levels, each 0.0 to 1.0 (`Level.getRainLevel`,
+    /// `getThunderLevel`): both 0 in a level with no weather, as the Nether
+    /// and the End. API @API:level_world@.
+    pub(super) fn native_level_weather(&self, level: LevelRef) -> Option<(f32, f32)> {
+        let world = self.native_level_world(level)?;
+        if level.dimension() != super::Dim::Overworld.id() {
+            return Some((0.0, 0.0));
+        }
+        Some(world.weather.levels(1.0))
+    }
+    /// Whether it rains (`Level.isRaining`: a rain level above 0.2). API
+    /// @API:level_world@.
+    pub(super) fn native_level_is_raining(&self, level: LevelRef) -> Option<bool> {
+        Some(weather_flags(self.native_level_weather(level)?).0)
+    }
+    /// Whether it thunders (`Level.isThundering`: a thunder level above 0.9).
+    /// API @API:level_world@.
+    pub(super) fn native_level_is_thundering(&self, level: LevelRef) -> Option<bool> {
+        Some(weather_flags(self.native_level_weather(level)?).1)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn rain_and_thunder_start_above_vanillas_thresholds() {
+        assert_eq!(super::weather_flags((0.2, 0.0)), (false, false));
+        assert_eq!(super::weather_flags((0.21, 0.9)), (true, false));
+        assert_eq!(super::weather_flags((1.0, 0.95)), (true, true));
+    }
+}

crates/horizon-client/src/mod_api.rs

@@ -40,6 +40,7 @@ pub use crate::game::{
     NativePlayer, NativePlayerRender, NativeReloadListener, NativeShake, NativeStructureBlock,
     NativeStructureTemplate, NativeWorldDraw,
 };
+pub use crate::gamerules::Value as GameRuleValue;
 pub use crate::gfx::native_render::{
     BlockSpriteArrays, RenderHooks, RenderNeeds, RenderNeedsEvent, WorldDrawn, WorldDrawnEvent,
     wgpu,

docs/native-mods.md

@@ -3711,6 +3711,9 @@ a dimension.
 - `level.block_state(host, pos)` (`minecraft:oak_stairs[facing=east,…]`, as `/setblock` takes it), `block` (the name
   alone), `block_property(host, pos, key)`, `is_loaded`, `height` (lowest `y` and height), `game_time` and `day_time`
   read any level the server has loaded, not only the one in place. A block in a chunk that isn't loaded reads as `None`.
+- `level.seed(host)`, `difficulty` (`"normal"`, as `/difficulty` names it), `game_rule(host, "keep_inventory")` (a
+  `GameRuleValue`, `Bool` or `Int`; None for an unknown rule), `weather` (rain and thunder levels, 0.0 to 1.0; both 0
+  where the level has no weather), `is_raining` and `is_thundering` read its world settings.
 - `host.living(entity)` gives a `LivingRef` for a mob, a player, an armor stand or the dragon (vanilla's
   `LivingEntity`); `living.entity()` goes back. `living.equipment(host, EquipmentSlot::Head)` and `hand_item(host,
   Hand::Main)` read its equipment (an empty slot reads as `None`); `set_equipment(host, slot, stack)` puts a stack in a

tools/native-hook-fragments/level_world.json

@@ -0,0 +1,40 @@
+{
+  "hooks": [],
+  "helpers": [
+    {
+      "name": "level_seed",
+      "target": "horizon_client::game::native_level_world::Game<'_>::native_level_seed",
+      "receiver": "level"
+    },
+    {
+      "name": "level_difficulty",
+      "target": "horizon_client::game::native_level_world::Game<'_>::native_level_difficulty",
+      "receiver": "level"
+    },
+    {
+      "name": "level_game_rule",
+      "target": "horizon_client::game::native_level_world::Game<'_>::native_level_game_rule",
+      "receiver": "level"
+    },
+    {
+      "name": "level_weather",
+      "target": "horizon_client::game::native_level_world::Game<'_>::native_level_weather",
+      "receiver": "level"
+    },
+    {
+      "name": "level_is_raining",
+      "target": "horizon_client::game::native_level_world::Game<'_>::native_level_is_raining",
+      "receiver": "level"
+    },
+    {
+      "name": "level_is_thundering",
+      "target": "horizon_client::game::native_level_world::Game<'_>::native_level_is_thundering",
+      "receiver": "level"
+    }
+  ],
+  "rust_summary": "a level's world settings through a `LevelRef`: the seed, the difficulty, game rules and weather.",
+  "doc_summary": "`level.seed(host)`, `difficulty`, `game_rule(host, name)` (`GameRuleValue`), `weather`, `is_raining` and `is_thundering`. Bundles need \"hooks\": @API:level_world@.",
+  "comments": [
+    "crates/horizon-client/src/game/native_level_world.rs"
+  ]
+}