From db238c3248938eda6463c75ceae7a82ff3bb1237 Mon Sep 17 00:00:00 2001
From: hheik <4469778+hheik@users.noreply.github.com>
Date: Sat, 23 Aug 2025 00:38:10 +0300
Subject: [PATCH] Added piece collision

---
 src/game.rs                    |   5 +-
 src/game/systems.rs            |   4 +
 src/game/systems/game_scene.rs | 150 +++++----------------------------
 src/game/systems/input.rs      |  53 ++++++++++++
 src/game/systems/movement.rs   |  99 ++++++++++++++++++++++
 src/game/tetris.rs             |  75 ++++++++++-------
 src/game/tetris/input.rs       |  57 +++++++++++++
 7 files changed, 285 insertions(+), 158 deletions(-)
 create mode 100644 src/game/systems/input.rs
 create mode 100644 src/game/systems/movement.rs
 create mode 100644 src/game/tetris/input.rs

diff --git a/src/game.rs b/src/game.rs
index f6fb94b..c412392 100644
--- a/src/game.rs
+++ b/src/game.rs
@@ -17,16 +17,19 @@ pub fn init(app: &mut App) {
 
     app.add_event::<tetris::OnPiecePlaced>()
         .register_type::<tetris::GameArea>()
+        .register_type::<tetris::GameGravity>()
+        .register_type::<tetris::BlockSet>()
         .register_type::<tetris::NextPiece>()
         .register_type::<tetris::Piece>()
         .register_type::<tetris::PieceControls>()
         .register_type::<tetris::ControllablePiece>()
+        .register_type::<tetris::Gravity>()
         .register_type::<tetris::Block>()
         .register_type::<prefab::PieceType>()
         .register_type::<grid::Grid>()
         .register_type::<grid::GridTransform>()
         .add_systems(Startup, systems::setup_game_scene)
-        .add_systems(PreUpdate, (systems::block_control, systems::apply_gravity))
+        .add_systems(PreUpdate, (systems::repeat_inputs, systems::apply_gravity))
         .add_systems(Update, (systems::demo_2d, systems::apply_piece_movement))
         .add_systems(PostUpdate, systems::grid_positioning);
 }
diff --git a/src/game/systems.rs b/src/game/systems.rs
index 09618bd..f93944a 100644
--- a/src/game/systems.rs
+++ b/src/game/systems.rs
@@ -1,7 +1,11 @@
 mod demo;
 mod game_scene;
 mod grid;
+mod input;
+mod movement;
 
 pub use demo::*;
 pub use game_scene::*;
 pub use grid::*;
+pub use input::*;
+pub use movement::*;
diff --git a/src/game/systems/game_scene.rs b/src/game/systems/game_scene.rs
index afb6005..284c96f 100644
--- a/src/game/systems/game_scene.rs
+++ b/src/game/systems/game_scene.rs
@@ -2,11 +2,7 @@ use std::collections::{HashMap, HashSet};
 
 use bevy::prelude::*;
 
-use crate::game::{
-    grid::*,
-    prefab::*,
-    tetris::{piece_input, *},
-};
+use crate::game::{grid::*, prefab::*, tetris::*};
 
 pub fn setup_game_scene(world: &mut World) {
     let game_area = GameArea::default();
@@ -35,127 +31,6 @@ pub fn setup_game_scene(world: &mut World) {
     world.flush();
 }
 
-pub fn block_control(
-    time: Res<Time>,
-    key_input: Res<ButtonInput<KeyCode>>,
-    mut piece_query: Query<&mut PieceControls, With<ControllablePiece>>,
-) {
-    const SOFT_DROP_SPEED: f32 = 10.0;
-    for mut piece in piece_query.iter_mut() {
-        piece.reset_inputs();
-        if key_input.pressed(KeyCode::ArrowDown) {
-            piece.cumulated_gravity += SOFT_DROP_SPEED * time.delta_secs();
-        }
-        if key_input.just_pressed(KeyCode::Space) {
-            piece.instant_drop = true;
-        }
-        if key_input.just_pressed(KeyCode::ArrowUp) {
-            piece.rotation = Some(piece_input::Rotation::Clockwise);
-        }
-        if key_input.just_pressed(KeyCode::ShiftLeft) {
-            piece.rotation = Some(piece_input::Rotation::CounterClockwise);
-        }
-        match (
-            key_input.pressed(KeyCode::ArrowLeft),
-            key_input.pressed(KeyCode::ArrowRight),
-        ) {
-            (true, false) => piece.movement = Some(piece_input::Move::Left),
-            (false, true) => piece.movement = Some(piece_input::Move::Right),
-            _ => (),
-        }
-    }
-}
-
-pub fn apply_gravity(
-    mut piece_query: Query<(&mut PieceControls, &ChildOf), With<ControllablePiece>>,
-    time: Res<Time>,
-    gravity_query: Query<&GameGravity>,
-) {
-    for (mut piece, parent) in piece_query.iter_mut() {
-        if let Ok(gravity) = gravity_query.get(parent.0) {
-            piece.cumulated_gravity += gravity.current * time.delta_secs();
-        }
-    }
-}
-
-pub struct InputRepeatState {
-    pub input_type: piece_input::Move,
-    pub cumulated_time: f32,
-    pub next_interval: f32,
-    pub interval_reduction: f32,
-    pub min_interval: f32,
-}
-
-pub fn apply_piece_movement(
-    mut piece_query: Query<(&mut PieceControls, Entity, &ChildOf, &Children)>,
-    mut transform_query: Query<(&mut GridTransform, Has<Block>)>,
-    mut input_repeat: Local<Option<InputRepeatState>>,
-    // mut on_piece_placed: EventWriter<OnPiecePlaced>,
-    time: Res<Time>,
-    mut commands: Commands,
-) {
-    // TODO: Handle piece collision
-    for (mut piece_controls, entity, parent, children) in piece_query.iter_mut() {
-        let (mut grid_transform, _) = transform_query.get_mut(entity).unwrap();
-        // TODO: replace with actual logic
-        if piece_controls.instant_drop {
-            grid_transform.translation.y = 0;
-            // on_piece_placed.write(OnPiecePlaced { piece: entity });
-            commands.trigger_targets(OnPiecePlaced { piece: entity }, parent.parent());
-            *input_repeat = None;
-            continue;
-        }
-        let can_move_down = grid_transform.translation.y > 0;
-        if can_move_down && piece_controls.cumulated_gravity >= 1.0 {
-            piece_controls.cumulated_gravity -= 1.0;
-            grid_transform.translation.y -= 1;
-        }
-        if !can_move_down && piece_controls.cumulated_gravity >= 3.0 {
-            // Force piece placement
-            // on_piece_placed.write(OnPiecePlaced { piece: entity });
-            commands.trigger_targets(OnPiecePlaced { piece: entity }, parent.parent());
-            *input_repeat = None;
-            continue;
-        }
-        if let Some(movement) = piece_controls.movement {
-            let mut move_piece = false;
-            if input_repeat
-                .as_ref()
-                .is_some_and(|state| state.input_type == movement)
-            {
-                if let Some(input_repeat) = input_repeat.as_mut() {
-                    input_repeat.cumulated_time += time.delta_secs();
-                    if input_repeat.cumulated_time >= input_repeat.next_interval {
-                        input_repeat.cumulated_time = 0.0;
-                        input_repeat.next_interval = (input_repeat.next_interval
-                            * input_repeat.interval_reduction)
-                            .max(input_repeat.min_interval);
-                        move_piece = true;
-                    }
-                }
-            } else {
-                *input_repeat = Some(InputRepeatState {
-                    input_type: movement,
-                    cumulated_time: 0.0,
-                    next_interval: 0.2,
-                    interval_reduction: 0.0,
-                    min_interval: 0.03,
-                });
-                move_piece = true;
-            }
-
-            if move_piece {
-                grid_transform.translation.x += match movement {
-                    piece_input::Move::Left => -1,
-                    piece_input::Move::Right => 1,
-                }
-            }
-        } else {
-            *input_repeat = None;
-        }
-    }
-}
-
 pub fn handle_placed_piece(trigger: Trigger<OnPiecePlaced>, world: &mut World) {
     let game_area = trigger.target();
     let event = *trigger.event();
@@ -178,6 +53,10 @@ pub fn handle_placed_piece(trigger: Trigger<OnPiecePlaced>, world: &mut World) {
         world.flush();
     }
 
+    world
+        .run_system_cached_with(rebuild_collisions, game_area)
+        .expect("Rebuilding collisions");
+
     world
         .run_system_cached_with(check_lose_condition, game_area)
         .expect("Checking lose condition");
@@ -187,13 +66,28 @@ pub fn handle_placed_piece(trigger: Trigger<OnPiecePlaced>, world: &mut World) {
         .expect("Creating new piece");
     world.flush();
 
-    // TODO: Finish up clearing the piece / lines
     // TODO: Lose condition
 }
 
+fn rebuild_collisions(
+    In(game_entity): In<Entity>,
+    game_query: Query<&Children>,
+    block_query: Query<&GridTransform, With<Block>>,
+    mut commands: Commands,
+) {
+    if let Ok(children) = game_query.get(game_entity) {
+        let mut blocks = HashSet::new();
+        for child in children.iter() {
+            if let Ok(transform) = block_query.get(child) {
+                blocks.insert(transform.translation);
+            }
+        }
+        commands.entity(game_entity).insert(BlockSet::new(blocks));
+    }
+}
+
 /// Returns a vector of affected game area entities
 fn place_blocks(
-    // mut piece_placed_events: EventReader<OnPiecePlaced>,
     In((event, game_area)): In<(OnPiecePlaced, Entity)>,
     mut commands: Commands,
     child_query: Query<&Children>,
diff --git a/src/game/systems/input.rs b/src/game/systems/input.rs
new file mode 100644
index 0000000..a46285d
--- /dev/null
+++ b/src/game/systems/input.rs
@@ -0,0 +1,53 @@
+use bevy::prelude::*;
+
+use crate::game::tetris::*;
+
+pub fn repeat_inputs(
+    key_input: Res<ButtonInput<KeyCode>>,
+    mut repeat_move: Local<input::InputRepeat>,
+    mut repeat_rotate: Local<input::InputRepeat>,
+    time: Res<Time>,
+    mut controllable_query: Query<&mut PieceControls, With<ControllablePiece>>,
+) {
+    for mut controls in controllable_query.iter_mut() {
+        *controls = PieceControls::default();
+        let delta_secs = time.delta_secs();
+
+        let move_dir = match (
+            key_input.pressed(KeyCode::ArrowLeft),
+            key_input.pressed(KeyCode::ArrowRight),
+        ) {
+            (true, false) => Some(input::Move::Left),
+            (false, true) => Some(input::Move::Right),
+            _ => None,
+        };
+
+        controls.movement = if repeat_move.should_repeat(move_dir.is_some(), delta_secs) {
+            move_dir
+        } else {
+            None
+        };
+
+        let rotate_dir = match (
+            key_input.pressed(KeyCode::ArrowUp),
+            key_input.pressed(KeyCode::ShiftLeft),
+        ) {
+            (true, false) => Some(input::Rotation::Clockwise),
+            (false, true) => Some(input::Rotation::CounterClockwise),
+            _ => None,
+        };
+
+        controls.rotation = if repeat_rotate.should_repeat(rotate_dir.is_some(), delta_secs) {
+            rotate_dir
+        } else {
+            None
+        };
+
+        if key_input.pressed(KeyCode::ArrowDown) {
+            controls.fast_drop = true;
+        }
+        if key_input.just_pressed(KeyCode::Space) {
+            controls.instant_drop = true;
+        }
+    }
+}
diff --git a/src/game/systems/movement.rs b/src/game/systems/movement.rs
new file mode 100644
index 0000000..ba73e18
--- /dev/null
+++ b/src/game/systems/movement.rs
@@ -0,0 +1,99 @@
+use bevy::prelude::*;
+
+use crate::{
+    game::{grid::*, tetris::*},
+    util::Vector2I,
+};
+
+pub fn apply_gravity(
+    mut piece_query: Query<(&mut Gravity, &PieceControls, &ChildOf)>,
+    time: Res<Time>,
+    game_gravity_query: Query<&GameGravity>,
+) {
+    const SOFT_DROP_SPEED: f32 = 10.0;
+    for (mut piece_gravity, controls, parent) in piece_query.iter_mut() {
+        if let Ok(game_gravity) = game_gravity_query.get(parent.0) {
+            piece_gravity.cumulated += game_gravity.current * time.delta_secs();
+        }
+        if controls.fast_drop {
+            piece_gravity.cumulated += SOFT_DROP_SPEED * time.delta_secs();
+        }
+    }
+}
+
+pub fn apply_piece_movement(
+    mut piece_query: Query<(
+        &PieceControls,
+        Option<&mut Gravity>,
+        Entity,
+        &ChildOf,
+        &Children,
+    )>,
+    game_query: Query<(&BlockSet, &GameArea)>,
+    mut transform_query: Query<(&mut GridTransform, Has<Block>)>,
+    mut commands: Commands,
+) {
+    for (controls, maybe_gravity, entity, parent, children) in piece_query.iter_mut() {
+        let game_entity = parent.parent();
+        let (collisions, game_area) = game_query.get(game_entity).unwrap();
+
+        let blocks: Vec<Vector2I> = {
+            let mut blocks = vec![];
+            for child in children.iter() {
+                let block = transform_query
+                    .get(child)
+                    .iter()
+                    .filter_map(|(transform, has_block)| {
+                        if *has_block {
+                            Some(transform.translation)
+                        } else {
+                            None
+                        }
+                    })
+                    .next();
+                if let Some(pos) = block {
+                    blocks.push(pos);
+                }
+            }
+            blocks
+        };
+
+        let cast_shape =
+            |pos| collisions.cast_shape(pos, &blocks) || !game_area.is_shape_inside(pos, &blocks);
+
+        let piece_pos = &mut transform_query.get_mut(entity).unwrap().0.translation;
+
+        if controls.instant_drop {
+            let mut drop_pos = *piece_pos;
+            while !cast_shape(drop_pos + Vector2I::DOWN) {
+                drop_pos = drop_pos + Vector2I::DOWN;
+            }
+            *piece_pos = drop_pos;
+            commands.trigger_targets(OnPiecePlaced { piece: entity }, game_entity);
+            continue;
+        }
+
+        let can_move_down = !cast_shape(*piece_pos + Vector2I::DOWN);
+
+        if let Some(mut gravity) = maybe_gravity {
+            if gravity.cumulated >= 1.0 && can_move_down {
+                gravity.cumulated -= 1.0;
+                *piece_pos = *piece_pos + Vector2I::DOWN;
+            }
+            if gravity.cumulated >= 3.0 && !can_move_down {
+                commands.trigger_targets(OnPiecePlaced { piece: entity }, game_entity);
+                continue;
+            }
+        }
+
+        if let Some(movement) = controls.movement {
+            let dir = match movement {
+                input::Move::Left => Vector2I::LEFT,
+                input::Move::Right => Vector2I::RIGHT,
+            };
+            if !cast_shape(*piece_pos + dir) {
+                *piece_pos = *piece_pos + dir;
+            }
+        }
+    }
+}
diff --git a/src/game/tetris.rs b/src/game/tetris.rs
index 00c77ab..80d62ca 100644
--- a/src/game/tetris.rs
+++ b/src/game/tetris.rs
@@ -1,15 +1,42 @@
+use std::collections::HashSet;
+
 use bevy::prelude::*;
 
 use crate::util::Vector2I;
 
 use super::{grid::*, prefab::*};
 
+pub mod input;
+
 pub type YPos = i32;
 pub type XPos = i32;
 
+#[derive(Component, Debug, Default, Reflect)]
+#[reflect(Component)]
+pub struct BlockSet {
+    blocks: HashSet<Vector2I>,
+}
+
+impl BlockSet {
+    pub fn new(blocks: HashSet<Vector2I>) -> Self {
+        Self { blocks }
+    }
+
+    pub fn cast_point(&self, pos: &Vector2I) -> bool {
+        self.blocks.contains(pos)
+    }
+
+    pub fn cast_shape(&self, shape_pos: Vector2I, local_blocks: &[Vector2I]) -> bool {
+        local_blocks
+            .iter()
+            .map(|local_pos| shape_pos + *local_pos)
+            .any(|global_pos| self.cast_point(&global_pos))
+    }
+}
+
 #[derive(Component, Clone, Debug, Reflect)]
 #[reflect(Component)]
-#[require(Grid, NextPiece)]
+#[require(Grid, NextPiece, BlockSet)]
 pub struct GameArea {
     pub bottom_boundary: i32,
     pub kill_height: i32,
@@ -54,6 +81,13 @@ impl GameArea {
             && point.x <= self.right_boundary
             && point.y >= self.bottom_boundary
     }
+
+    pub fn is_shape_inside(&self, shape_pos: Vector2I, local_blocks: &[Vector2I]) -> bool {
+        local_blocks
+            .iter()
+            .map(|local_pos| shape_pos + *local_pos)
+            .all(|global_pos| self.is_point_inside(global_pos))
+    }
 }
 
 #[derive(Component, Debug, Reflect)]
@@ -68,22 +102,6 @@ impl Default for GameGravity {
     }
 }
 
-pub mod piece_input {
-    use bevy::prelude::*;
-
-    #[derive(Clone, Copy, Debug, PartialEq, Eq, Reflect)]
-    pub enum Rotation {
-        Clockwise,
-        CounterClockwise,
-    }
-
-    #[derive(Clone, Copy, Debug, PartialEq, Eq, Reflect)]
-    pub enum Move {
-        Left,
-        Right,
-    }
-}
-
 #[derive(Component, Debug, Default, Reflect)]
 #[reflect(Component)]
 #[require(Grid, GridTransform)]
@@ -91,20 +109,19 @@ pub struct Piece;
 
 #[derive(Component, Debug, Default, Reflect)]
 #[reflect(Component)]
-#[require(Piece)]
-pub struct PieceControls {
-    pub cumulated_gravity: f32,
-    pub instant_drop: bool,
-    pub movement: Option<piece_input::Move>,
-    pub rotation: Option<piece_input::Rotation>,
+pub struct Gravity {
+    pub cumulated: f32,
 }
 
-impl PieceControls {
-    pub fn reset_inputs(&mut self) {
-        self.instant_drop = false;
-        self.movement = None;
-        self.rotation = None;
-    }
+/// Dictates the intention of piece's movement
+#[derive(Component, Debug, Default, Reflect)]
+#[reflect(Component)]
+#[require(Piece, Gravity)]
+pub struct PieceControls {
+    pub instant_drop: bool,
+    pub fast_drop: bool,
+    pub movement: Option<input::Move>,
+    pub rotation: Option<input::Rotation>,
 }
 
 #[derive(Component, Debug, Reflect)]
diff --git a/src/game/tetris/input.rs b/src/game/tetris/input.rs
new file mode 100644
index 0000000..d57299b
--- /dev/null
+++ b/src/game/tetris/input.rs
@@ -0,0 +1,57 @@
+use bevy::prelude::*;
+
+#[derive(Debug, Clone, Reflect)]
+pub struct InputRepeat {
+    pub currently_pressed: bool,
+    pub cumulated_time: f32,
+    pub next_interval: f32,
+    pub interval_mult: f32,
+    pub min_interval: f32,
+}
+
+impl Default for InputRepeat {
+    fn default() -> Self {
+        Self {
+            currently_pressed: false,
+            cumulated_time: 0.0,
+            next_interval: 0.2,
+            interval_mult: 0.0,
+            min_interval: 0.03,
+        }
+    }
+}
+
+impl InputRepeat {
+    /// Returns if the input should be repeated this frame.
+    pub fn should_repeat(&mut self, pressed: bool, delta_seconds: f32) -> bool {
+        if !pressed {
+            *self = Self::default();
+            return false;
+        }
+        if !self.currently_pressed {
+            self.currently_pressed = true;
+            true
+        } else {
+            self.cumulated_time += delta_seconds;
+            if self.cumulated_time >= self.next_interval {
+                self.cumulated_time = 0.0;
+                self.next_interval =
+                    (self.next_interval * self.interval_mult).max(self.min_interval);
+                return true;
+            }
+            false
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Reflect)]
+pub enum Rotation {
+    Clockwise,
+    CounterClockwise,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Reflect)]
+pub enum Move {
+    Left,
+    Right,
+}