add jumping

7 files changed, 145 insertions, 4 deletions

diff --git a/azalea-block/src/behavior.rs b/azalea-block/src/behavior.rs
index db357632..18854fff 100644
--- a/azalea-block/src/behavior.rs
+++ b/azalea-block/src/behavior.rs
@@ -1,7 +1,17 @@
-#[derive(Default)]
 pub struct BlockBehavior {
     pub has_collision: bool,
     pub friction: f32,
+    pub jump_factor: f32,
+}
+
+impl Default for BlockBehavior {
+    fn default() -> Self {
+        Self {
+            has_collision: true,
+            friction: 0.6,
+            jump_factor: 1.0,
+        }
+    }
 }
 
 impl BlockBehavior {
@@ -16,4 +26,10 @@ impl BlockBehavior {
         self.friction = friction;
         self
     }
+
+    #[inline]
+    pub fn jump_factor(mut self, jump_factor: f32) -> Self {
+        self.jump_factor = jump_factor;
+        self
+    }
 }
diff --git a/azalea-client/src/client.rs b/azalea-client/src/client.rs
index cca932c0..2b721206 100644
--- a/azalea-client/src/client.rs
+++ b/azalea-client/src/client.rs
@@ -85,6 +85,12 @@ pub struct PhysicsState {
     pub move_direction: MoveDirection,
     pub forward_impulse: f32,
     pub left_impulse: f32,
+
+    /// Whether we will jump next tick. This is purely to help with bots,
+    /// realistic clients should change the `jumping` field in the player entity.
+    ///
+    /// TODO: have a convenient way to change the `jumping` field in the player entity.
+    pub jumping_once: bool,
 }
 
 /// Whether we should ignore errors when decoding packets.
diff --git a/azalea-client/src/movement.rs b/azalea-client/src/movement.rs
index 193f2017..ab324370 100644
--- a/azalea-client/src/movement.rs
+++ b/azalea-client/src/movement.rs
@@ -166,9 +166,16 @@ impl Client {
 
         // server ai step
         {
-            let physics_state = self.physics_state.lock().unwrap();
+            let mut physics_state = self.physics_state.lock().unwrap();
             player_entity.xxa = physics_state.left_impulse;
             player_entity.zza = physics_state.forward_impulse;
+
+            // handle jumping_once
+            if physics_state.jumping_once {
+                player_entity.jumping = true;
+            } else if player_entity.jumping {
+                physics_state.jumping_once = false;
+            }
         }
 
         player_entity.ai_step();
@@ -210,10 +217,33 @@ impl Client {
         }
     }
 
+    /// Start walking in the given direction.
     pub fn walk(&mut self, direction: MoveDirection) {
         let mut physics_state = self.physics_state.lock().unwrap();
         physics_state.move_direction = direction;
     }
+
+    /// Jump once next tick. This acts as if you pressed space for one tick in
+    /// vanilla. If you want to jump continuously, use `set_jumping`.
+    pub fn jump(&mut self) {
+        let mut physics_state = self.physics_state.lock().unwrap();
+        physics_state.jumping_once = true;
+    }
+
+    /// Toggle whether we're jumping. This acts as if you held space in
+    /// vanilla. If you want to jump once, use the `jump` function.
+    ///
+    /// If you're making a realistic client, calling this function every tick is
+    /// recommended.
+    pub fn set_jumping(&mut self, jumping: bool) {
+        let player_lock = self.player.lock().unwrap();
+        let mut dimension_lock = self.dimension.lock().unwrap();
+        let mut player_entity = player_lock
+            .entity_mut(&mut dimension_lock)
+            .expect("Player must exist");
+
+        player_entity.jumping = jumping;
+    }
 }
 
 #[derive(Clone, Copy, Debug, Default)]
diff --git a/azalea-physics/src/collision/mod.rs b/azalea-physics/src/collision/mod.rs
index a18440b7..f08e48e3 100644
--- a/azalea-physics/src/collision/mod.rs
+++ b/azalea-physics/src/collision/mod.rs
@@ -133,7 +133,7 @@ impl MovableEntity for EntityMut<'_> {
         let horizontal_collision = x_collision || z_collision;
         let vertical_collision = movement.y != collide_result.y;
         let on_ground = vertical_collision && movement.y < 0.;
-        // self.on_ground = on_ground;
+        self.on_ground = on_ground;
 
         // TODO: minecraft checks for a "minor" horizontal collision here
 
diff --git a/azalea-physics/src/lib.rs b/azalea-physics/src/lib.rs
index 56923577..fe75c71e 100644
--- a/azalea-physics/src/lib.rs
+++ b/azalea-physics/src/lib.rs
@@ -11,6 +11,8 @@ use collision::{MovableEntity, MoverType};
 pub trait HasPhysics {
     fn travel(&mut self, acceleration: &Vec3);
     fn ai_step(&mut self);
+
+    fn jump_from_ground(&mut self);
 }
 
 impl HasPhysics for EntityMut<'_> {
@@ -85,6 +87,14 @@ impl HasPhysics for EntityMut<'_> {
             self.delta.z = 0.;
         }
 
+        if self.jumping {
+            // TODO: jumping in liquids and jump delay
+
+            if self.on_ground {
+                self.jump_from_ground();
+            }
+        }
+
         self.xxa *= 0.98;
         self.zza *= 0.98;
 
@@ -97,6 +107,27 @@ impl HasPhysics for EntityMut<'_> {
         // pushEntities
         // drowning damage
     }
+
+    fn jump_from_ground(&mut self) {
+        let jump_power: f64 = jump_power(self) as f64 + jump_boost_power(self);
+        let old_delta_movement = self.delta;
+        self.delta = Vec3 {
+            x: old_delta_movement.x,
+            y: jump_power,
+            z: old_delta_movement.z,
+        };
+        // if self.sprinting {
+        //     let y_rot = self.y_rot * 0.017453292;
+        //     self.delta = self.delta
+        //         + Vec3 {
+        //             x: (-f32::sin(y_rot) * 0.2) as f64,
+        //             y: 0.,
+        //             z: (f32::cos(y_rot) * 0.2) as f64,
+        //         };
+        // }
+
+        // self.has_impulse = true;
+    }
 }
 
 fn get_block_pos_below_that_affects_movement(entity: &EntityData) -> BlockPos {
@@ -141,6 +172,54 @@ fn get_speed(entity: &EntityData, friction: f32) -> f32 {
     }
 }
 
+/// Returns the what the entity's jump should be multiplied by based on the
+/// block they're standing on.
+fn block_jump_factor(entity: &EntityMut) -> f32 {
+    let block_at_pos = entity.dimension.get_block_state(&entity.pos().into());
+    let block_below = entity
+        .dimension
+        .get_block_state(&get_block_pos_below_that_affects_movement(entity));
+
+    let block_at_pos_jump_factor = if let Some(block) = block_at_pos {
+        Box::<dyn Block>::from(block).behavior().jump_factor
+    } else {
+        1.
+    };
+    if block_at_pos_jump_factor != 1. {
+        return block_at_pos_jump_factor;
+    }
+
+    if let Some(block) = block_below {
+        Box::<dyn Block>::from(block).behavior().jump_factor
+    } else {
+        1.
+    }
+}
+
+// protected float getJumpPower() {
+//     return 0.42F * this.getBlockJumpFactor();
+// }
+// public double getJumpBoostPower() {
+//     return this.hasEffect(MobEffects.JUMP) ? (double)(0.1F * (float)(this.getEffect(MobEffects.JUMP).getAmplifier() + 1)) : 0.0D;
+// }
+fn jump_power(entity: &EntityMut) -> f32 {
+    0.42 * block_jump_factor(entity)
+}
+
+fn jump_boost_power(_entity: &EntityMut) -> f64 {
+    // TODO: potion effects
+    // if let Some(effects) = entity.effects() {
+    //     if let Some(jump_effect) = effects.get(&Effect::Jump) {
+    //         0.1 * (jump_effect.amplifier + 1) as f32
+    //     } else {
+    //         0.
+    //     }
+    // } else {
+    //     0.
+    // }
+    0.
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
diff --git a/azalea-world/src/entity/mod.rs b/azalea-world/src/entity/mod.rs
index b9c273f0..37474d1d 100644
--- a/azalea-world/src/entity/mod.rs
+++ b/azalea-world/src/entity/mod.rs
@@ -260,6 +260,10 @@ pub struct EntityData {
     pub dimensions: EntityDimensions,
     /// The bounding box of the entity. This is more than just width and height, unlike dimensions.
     pub bounding_box: AABB,
+
+    /// Whether the entity will try to jump every tick
+    /// (equivalent to the space key being held down in vanilla).
+    pub jumping: bool,
 }
 
 impl EntityData {
@@ -291,6 +295,8 @@ impl EntityData {
             // TODO: have this be based on the entity type
             bounding_box: dimensions.make_bounding_box(&pos),
             dimensions,
+
+            jumping: false,
         }
     }
 
diff --git a/bot/src/main.rs b/bot/src/main.rs
index 379b3af3..9b2eea1f 100644
--- a/bot/src/main.rs
+++ b/bot/src/main.rs
@@ -18,12 +18,16 @@ async fn handle_event(event: Event, mut bot: Client) -> anyhow::Result<()> {
     match event {
         Event::Login => {
             // tokio::time::sleep(std::time::Duration::from_secs(1)).await;
-            bot.walk(MoveDirection::Forward);
+            // bot.walk(MoveDirection::Forward);
+
             // loop {
             //     tokio::time::sleep(std::time::Duration::from_secs(2)).await;
             // }
             // bot.walk(MoveDirection::None);
         }
+        Event::GameTick => {
+            bot.set_jumping(true);
+        }
         Event::Packet(_packet) => {}
         _ => {}
     }