feat: add gravity and gravity-movement plugins

Add CHGravityPlugin to manage the global gravity resource and
CHGravityMovementGluePlugin to apply gravity to movement velocity
each fixed update. Update workspace dependencies and include the
new crates in the main app.

8 files changed, 110 insertions, 3 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 76b093d..707d3c9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1969,6 +1969,23 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
 
 [[package]]
+name = "ch-gravity"
+version = "0.1.0"
+dependencies = [
+ "bevy",
+ "ch-macro-rules",
+]
+
+[[package]]
+name = "ch-gravity-movement"
+version = "0.1.0"
+dependencies = [
+ "bevy",
+ "ch-gravity",
+ "ch-movement",
+]
+
+[[package]]
 name = "ch-macro-rules"
 version = "0.1.0"
 
@@ -1994,6 +2011,8 @@ name = "cigarette_hacker_bevy"
 version = "0.1.0"
 dependencies = [
  "bevy",
+ "ch-gravity",
+ "ch-gravity-movement",
  "ch-movement",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 9d073ca..ce898e3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,7 +5,9 @@ edition.workspace = true
 
 [dependencies]
 bevy.workspace = true
-ch-movement = { path = "plugins/movement" }
+ch-movement.workspace = true
+ch-gravity.workspace = true
+ch-gravity-movement.workspace = true
 
 [workspace.dependencies]
 # Core
@@ -16,6 +18,11 @@ proc-macro2 = "1.0.107"
 quote = "1.0.47"
 syn = "3.0.3"
 
+# Plugins
+ch-movement = { path = "plugins/movement" }
+ch-gravity = { path = "plugins/gravity" }
+ch-gravity-movement = { path = "plugins/glues/gravity_movement" }
+
 # Utils
 ch-macros = { path = "utils/macros" }
 ch-macro-rules = { path = "utils/macro_rules" }
@@ -25,7 +32,9 @@ version = "0.1.0"
 edition = "2024"
 
 [workspace]
-members = [
-    "plugins/movement", "utils/macro_rules",
+members = ["plugins/glues/gravity_movement",
+    "plugins/gravity",
+    "plugins/movement",
+    "utils/macro_rules",
     "utils/macros"
 ]
diff --git a/plugins/glues/gravity_movement/Cargo.toml b/plugins/glues/gravity_movement/Cargo.toml
new file mode 100644
index 0000000..4b5790c
--- /dev/null
+++ b/plugins/glues/gravity_movement/Cargo.toml
@@ -0,0 +1,9 @@
+[package]
+name = "ch-gravity-movement"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+bevy.workspace = true
+ch-movement.workspace = true
+ch-gravity.workspace = true
diff --git a/plugins/glues/gravity_movement/src/lib.rs b/plugins/glues/gravity_movement/src/lib.rs
new file mode 100644
index 0000000..da31061
--- /dev/null
+++ b/plugins/glues/gravity_movement/src/lib.rs
@@ -0,0 +1,29 @@
+//! CH Glue - Gravity & Movement
+//!
+//! This module provides the glue layer for the Gravity and Movement modules.
+
+#![deny(missing_docs)]
+
+use bevy::{
+    app::{FixedUpdate, Plugin},
+    ecs::system::{Query, Res},
+};
+use ch_gravity::Gravity;
+use ch_movement::{Movement, Velocity};
+
+/// Cigarette Hacker gravity movement glue
+pub struct CHGravityMovementGluePlugin;
+
+impl Plugin for CHGravityMovementGluePlugin {
+    fn build(&self, app: &mut bevy::app::App) {
+        app.add_systems(FixedUpdate, apply_gravity_to_movement);
+    }
+}
+
+fn apply_gravity_to_movement(mut query: Query<(&mut Velocity, &Movement)>, gravity: Res<Gravity>) {
+    for (mut velocity, _movement) in query.iter_mut() {
+        velocity.x += gravity.x;
+        velocity.y += gravity.y;
+        velocity.z += gravity.z;
+    }
+}
diff --git a/plugins/gravity/Cargo.toml b/plugins/gravity/Cargo.toml
new file mode 100644
index 0000000..1221f40
--- /dev/null
+++ b/plugins/gravity/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "ch-gravity"
+version.workspace = true
+edition.workspace = true
+
+[dependencies]
+bevy.workspace = true
+ch-macro-rules.workspace = true
diff --git a/plugins/gravity/src/gravity.rs b/plugins/gravity/src/gravity.rs
new file mode 100644
index 0000000..6d7030c
--- /dev/null
+++ b/plugins/gravity/src/gravity.rs
@@ -0,0 +1,12 @@
+use bevy::{
+    ecs::resource::Resource,
+    math::Vec3,
+    prelude::{Deref, DerefMut},
+};
+
+/// Represents the global gravity
+#[derive(Resource, Deref, DerefMut, PartialEq, Default, Clone)]
+pub struct Gravity {
+    #[deref]
+    pub(crate) gravity: Vec3,
+}
diff --git a/plugins/gravity/src/lib.rs b/plugins/gravity/src/lib.rs
new file mode 100644
index 0000000..4282256
--- /dev/null
+++ b/plugins/gravity/src/lib.rs
@@ -0,0 +1,19 @@
+//! CH Modules - Gravity
+//!
+//! CH Gravity provides the basic in-game representation of gravity
+
+use bevy::{app::Plugin, math::Vec3};
+use ch_macro_rules::import;
+
+import!(gravity);
+
+/// Cigarette Hacker gravity plugin
+pub struct CHGravityPlugin;
+
+impl Plugin for CHGravityPlugin {
+    fn build(&self, app: &mut bevy::app::App) {
+        app.insert_resource(Gravity {
+            gravity: Vec3::new(0., 1., 0.) * -9.8,
+        });
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index 4906590..df08db9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,5 +9,7 @@ fn main() {
     let mut app = App::new();
     app.add_plugins(DefaultPlugins);
     app.add_plugins(ch_movement::CHMovementPlugin);
+    app.add_plugins(ch_gravity::CHGravityPlugin);
+    app.add_plugins(ch_gravity_movement::CHGravityMovementGluePlugin);
     app.run();
 }