Beginning the conversion to an Effects system

src/effects/mod.rs

@@ -0,0 +1,105 @@
+use crate::spatial;
+use rltk::prelude::*;
+use specs::prelude::*;
+use std::collections::VecDeque;
+use std::sync::Mutex;
+
+mod damage;
+mod particles;
+mod targeting;
+
+lazy_static! {
+    pub static ref EFFECT_QUEUE: Mutex<VecDeque<EffectSpawner>> = Mutex::new(VecDeque::new());
+}
+
+pub enum EffectType {
+    Damage { amount: i32 },
+    Bloodstain,
+    Particle { glyph: FontCharType, fg: RGB, bg: RGB, lifespan: f32, delay: f32 },
+    EntityDeath,
+}
+
+#[derive(Clone)]
+pub enum Targets {
+    Entity { target: Entity },
+    EntityList { targets: Vec<Entity> },
+    Tile { target: usize },
+    TileList { targets: Vec<usize> },
+}
+
+pub struct EffectSpawner {
+    pub source: Option<Entity>,
+    pub effect_type: EffectType,
+    pub target: Targets,
+}
+
+/// Adds an effect to the effects queue
+pub fn add_effect(source: Option<Entity>, effect_type: EffectType, target: Targets) {
+    let mut lock = EFFECT_QUEUE.lock().unwrap();
+    lock.push_back(EffectSpawner { source, effect_type, target });
+}
+
+/// Iterates through the effects queue, applying each effect to their target.
+pub fn run_effects_queue(ecs: &mut World) {
+    loop {
+        let effect: Option<EffectSpawner> = EFFECT_QUEUE.lock().unwrap().pop_front();
+        if let Some(effect) = effect {
+            target_applicator(ecs, &effect);
+        } else {
+            break;
+        }
+    }
+}
+
+/// Applies an effect to the correct target(s).
+fn target_applicator(ecs: &mut World, effect: &EffectSpawner) {
+    match &effect.target {
+        Targets::Tile { target } => affect_tile(ecs, effect, *target),
+        Targets::TileList { targets } => targets.iter().for_each(|target| affect_tile(ecs, effect, *target)),
+        Targets::Entity { target } => affect_entity(ecs, effect, *target),
+        Targets::EntityList { targets } => targets.iter().for_each(|target| affect_entity(ecs, effect, *target)),
+    }
+}
+
+/// Checks if a given effect affects entities or not.
+fn tile_effect_hits_entities(effect: &EffectType) -> bool {
+    match effect {
+        EffectType::Damage { .. } => true,
+        _ => false,
+    }
+}
+
+/// Runs an effect on a given tile index
+fn affect_tile(ecs: &mut World, effect: &EffectSpawner, target: usize) {
+    if tile_effect_hits_entities(&effect.effect_type) {
+        spatial::for_each_tile_content(target, |entity| {
+            affect_entity(ecs, effect, entity);
+        });
+    }
+
+    match &effect.effect_type {
+        EffectType::Bloodstain => damage::bloodstain(ecs, target),
+        EffectType::Particle { .. } => particles::particle_to_tile(ecs, target as i32, &effect),
+        _ => {}
+    }
+    // Run the effect
+}
+
+/// Runs an effect on a given entity
+fn affect_entity(ecs: &mut World, effect: &EffectSpawner, target: Entity) {
+    match &effect.effect_type {
+        EffectType::Damage { .. } => damage::inflict_damage(ecs, effect, target),
+        EffectType::Bloodstain { .. } => {
+            if let Some(pos) = targeting::entity_position(ecs, target) {
+                damage::bloodstain(ecs, pos)
+            }
+        }
+        EffectType::Particle { .. } => {
+            if let Some(pos) = targeting::entity_position(ecs, target) {
+                particles::particle_to_tile(ecs, pos as i32, &effect)
+            }
+        }
+        EffectType::EntityDeath => damage::entity_death(ecs, effect, target),
+        _ => {}
+    }
+}