Add particle effects for Melee combat

src/components.rs

@@ -174,6 +174,11 @@ pub struct DefenseBonus {
     pub defense: i32,
 }
 
+#[derive(Component, Serialize, Deserialize, Clone)]
+pub struct ParticleLifetime {
+    pub lifetime_ms: f32,
+}
+
 // Serialization helper code. We need to implement ConvertSaveLoad for each type that contains an
 // Entity.
 

src/main.rs

@@ -12,6 +12,7 @@ mod map;
 mod map_indexing_system;
 mod melee_combat_system;
 mod monster_ai_system;
+mod particle_system;
 mod player;
 pub mod random_table;
 mod rect;
@@ -101,6 +102,9 @@ impl State {
         let mut item_remove = ItemRemoveSystem {};
         item_remove.run_now(&self.ecs);
 
+        let mut particles = particle_system::ParticleSpawnSystem {};
+        particles.run_now(&self.ecs);
+
         self.ecs.maintain();
     }
 }
@@ -114,6 +118,7 @@ impl GameState for State {
         }
 
         ctx.cls();
+        particle_system::cull_dead_particles(&mut self.ecs, ctx);
 
         match newrunstate {
             RunState::MainMenu { .. } => {}
@@ -485,6 +490,7 @@ fn main() -> rltk::BError {
         MeleePowerBonus,
         DefenseBonus,
         WantsToRemoveItem,
+        ParticleLifetime,
     );
 
     gs.ecs.insert(SimpleMarkerAllocator::<SerializeMe>::new());
@@ -506,6 +512,7 @@ fn main() -> rltk::BError {
         menu_selection: gui::MainMenuSelection::NewGame,
     });
     gs.ecs.insert(GameLog::new("Welcome to Rusty Roguelike"));
+    gs.ecs.insert(particle_system::ParticleBuilder::new());
 
     rltk::main_loop(context, gs)
 }

src/melee_combat_system.rs

@@ -1,7 +1,8 @@
 use crate::components::{
     CombatStats, DefenseBonus, Equipped, MeleePowerBonus, Name, SufferDamage, WantsToMelee,
 };
-use crate::game_log::GameLog;
+use crate::{game_log::GameLog, particle_system::ParticleBuilder, Position};
+use rltk::RGB;
 use specs::prelude::*;
 
 pub struct MeleeCombatSystem {}
@@ -18,6 +19,8 @@ impl<'a> System<'a> for MeleeCombatSystem {
         ReadStorage<'a, MeleePowerBonus>,
         ReadStorage<'a, DefenseBonus>,
         ReadStorage<'a, Equipped>,
+        WriteExpect<'a, ParticleBuilder>,
+        ReadStorage<'a, Position>,
     );
 
     fn run(&mut self, data: Self::SystemData) {
@@ -31,6 +34,8 @@ impl<'a> System<'a> for MeleeCombatSystem {
             melee_power_bonuses,
             defense_bonuses,
             equipped,
+            mut particle_builder,
+            positions,
         ) = data;
 
         for (entity, wants_melee, name, stats) in
@@ -59,6 +64,17 @@ impl<'a> System<'a> for MeleeCombatSystem {
                         }
                     }
 
+                    if let Some(pos) = positions.get(wants_melee.target) {
+                        particle_builder.request(
+                            pos.x,
+                            pos.y,
+                            RGB::named(rltk::ORANGE),
+                            RGB::named(rltk::BLACK),
+                            rltk::to_cp437('‼'),
+                            200.0,
+                        );
+                    }
+
                     let damage = i32::max(
                         0,
                         (stats.power + offensive_bonus) - (target_stats.defense + defensive_bonus),

src/particle_system.rs

@@ -0,0 +1,118 @@
+use crate::components::{ParticleLifetime, Renderable};
+use crate::Position;
+use rltk::{Rltk, RGB};
+use specs::prelude::*;
+
+pub fn cull_dead_particles(ecs: &mut World, ctx: &Rltk) {
+    let mut dead_particles: Vec<Entity> = Vec::new();
+    {
+        // Age out particles
+        let mut particles = ecs.write_storage::<ParticleLifetime>();
+        let entities = ecs.entities();
+        for (entity, mut particle) in (&entities, &mut particles).join() {
+            particle.lifetime_ms -= ctx.frame_time_ms;
+
+            if particle.lifetime_ms < 0.0 {
+                dead_particles.push(entity);
+            }
+        }
+    }
+
+    for dead in dead_particles.iter() {
+        ecs.delete_entity(*dead)
+            .expect("Failed to delete dead particle entity");
+    }
+}
+
+struct ParticleRequest {
+    x: i32,
+    y: i32,
+    fg: RGB,
+    bg: RGB,
+    glyph: rltk::FontCharType,
+    lifetime: f32,
+}
+
+#[derive(Default)]
+pub struct ParticleBuilder {
+    requests: Vec<ParticleRequest>,
+}
+
+impl ParticleBuilder {
+    pub fn new() -> ParticleBuilder {
+        ParticleBuilder::default()
+    }
+
+    pub fn request(
+        &mut self,
+        x: i32,
+        y: i32,
+        fg: RGB,
+        bg: RGB,
+        glyph: rltk::FontCharType,
+        lifetime: f32,
+    ) {
+        self.requests.push(ParticleRequest {
+            x,
+            y,
+            fg,
+            bg,
+            glyph,
+            lifetime,
+        })
+    }
+}
+
+pub struct ParticleSpawnSystem {}
+
+impl<'a> System<'a> for ParticleSpawnSystem {
+    #[allow(clippy::type_complexity)]
+    type SystemData = (
+        Entities<'a>,
+        WriteStorage<'a, Position>,
+        WriteStorage<'a, Renderable>,
+        WriteStorage<'a, ParticleLifetime>,
+        WriteExpect<'a, ParticleBuilder>,
+    );
+
+    fn run(&mut self, data: Self::SystemData) {
+        let (entities, mut positions, mut renderables, mut particles, mut particle_builder) = data;
+
+        for new_particle in particle_builder.requests.iter() {
+            let p = entities.create();
+
+            positions
+                .insert(
+                    p,
+                    Position {
+                        x: new_particle.x,
+                        y: new_particle.y,
+                    },
+                )
+                .expect("Failed to insert Position of new particle");
+
+            renderables
+                .insert(
+                    p,
+                    Renderable {
+                        fg: new_particle.fg,
+                        bg: new_particle.bg,
+                        glyph: new_particle.glyph,
+                        render_order: 0,
+                    },
+                )
+                .expect("Failed to insert Renderable of new particle");
+
+            particles
+                .insert(
+                    p,
+                    ParticleLifetime {
+                        lifetime_ms: new_particle.lifetime,
+                    },
+                )
+                .expect("Failed to insert Lifetime of new particle");
+        }
+
+        particle_builder.requests.clear();
+    }
+}

src/player.rs

@@ -175,17 +175,8 @@ pub fn player_input(gs: &mut State, ctx: &mut Rltk) -> RunState {
                 try_move_player(-1, 1, &mut gs.ecs)
             }
 
-            // Pick up item
-            VirtualKeyCode::G => get_item(&mut gs.ecs),
-
-            // Show inventory
-            VirtualKeyCode::I => return RunState::ShowInventory,
-
-            // Show item drop screen
-            VirtualKeyCode::D => return RunState::ShowDropItem,
-
-            // Save and Quit
-            VirtualKeyCode::Escape => return RunState::SaveGame,
+            // Skip Turn
+            VirtualKeyCode::Numpad5 | VirtualKeyCode::Space => return skip_turn(&mut gs.ecs),
 
             // Level changes
             VirtualKeyCode::Period => {
@@ -194,12 +185,15 @@ pub fn player_input(gs: &mut State, ctx: &mut Rltk) -> RunState {
                 }
             }
 
-            // Skip Turn
-            VirtualKeyCode::Numpad5 | VirtualKeyCode::Space => return skip_turn(&mut gs.ecs),
-
-            // Remove item
+            // Item management
+            VirtualKeyCode::G => get_item(&mut gs.ecs),
+            VirtualKeyCode::I => return RunState::ShowInventory,
+            VirtualKeyCode::D => return RunState::ShowDropItem,
             VirtualKeyCode::R => return RunState::ShowRemoveItem,
 
+            // Save and Quit
+            VirtualKeyCode::Escape => return RunState::SaveGame,
+
             _ => return RunState::AwaitingInput,
         },
     }

src/saveload_system.rs

@@ -74,7 +74,8 @@ pub fn save_game(ecs: &mut World) {
             Equipped,
             MeleePowerBonus,
             DefenseBonus,
-            WantsToRemoveItem
+            WantsToRemoveItem,
+            ParticleLifetime
         );
     }
 
@@ -155,7 +156,8 @@ pub fn load_game(ecs: &mut World) {
             Equipped,
             MeleePowerBonus,
             DefenseBonus,
-            WantsToRemoveItem
+            WantsToRemoveItem,
+            ParticleLifetime
         );
     }