From a970a611928a5c7e421431c6df59eda22ebfd705 Mon Sep 17 00:00:00 2001
From: Joseph Gerardot <indyJAG@gmail.com>
Date: Wed, 20 Nov 2019 13:31:36 -0500
Subject: [PATCH] Add energy comsumption on rolling and charging, and
 accelerating regeneration when idle.

---
 common/src/comp/energy.rs |  3 +++
 common/src/comp/mod.rs    |  2 +-
 common/src/comp/stats.rs  |  5 +----
 common/src/sys/stats.rs   | 44 +++++++++++++++++++++++++++++++++++----
 4 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/common/src/comp/energy.rs b/common/src/comp/energy.rs
index 88164813e0..23d4d9535d 100644
--- a/common/src/comp/energy.rs
+++ b/common/src/comp/energy.rs
@@ -5,6 +5,7 @@ use specs_idvs::IDVStorage;
 pub struct Energy {
     current: u32,
     maximum: u32,
+    pub regen_rate: i32,
     pub last_change: Option<(i32, f64, EnergySource)>,
 }
 
@@ -12,6 +13,7 @@ pub struct Energy {
 pub enum EnergySource {
     CastSpell,
     LevelUp,
+    Regen,
     Unknown,
 }
 
@@ -20,6 +22,7 @@ impl Energy {
         Energy {
             current: amount,
             maximum: amount,
+            regen_rate: 0,
             last_change: None,
         }
     }
diff --git a/common/src/comp/mod.rs b/common/src/comp/mod.rs
index 5f2a631c89..21f6114608 100644
--- a/common/src/comp/mod.rs
+++ b/common/src/comp/mod.rs
@@ -26,7 +26,7 @@ pub use controller::{
     ControlEvent, Controller, ControllerInputs, Input, InputState, InventoryManip, MountState,
     Mounting,
 };
-pub use energy::Energy;
+pub use energy::{Energy, EnergySource};
 pub use inputs::CanBuild;
 pub use inventory::{item, Inventory, InventoryUpdate, Item, ItemKind};
 pub use last::Last;
diff --git a/common/src/comp/stats.rs b/common/src/comp/stats.rs
index 532f6cb8be..117f064f04 100644
--- a/common/src/comp/stats.rs
+++ b/common/src/comp/stats.rs
@@ -164,10 +164,7 @@ impl Stats {
                 current: 0,
                 maximum: 50,
             },
-            equipment: Equipment {
-                main: main,
-                alt: None,
-            },
+            equipment: Equipment { main, alt: None },
             is_dead: false,
         };
 
diff --git a/common/src/sys/stats.rs b/common/src/sys/stats.rs
index f4ac03e576..6e668a98fc 100644
--- a/common/src/sys/stats.rs
+++ b/common/src/sys/stats.rs
@@ -1,9 +1,13 @@
 use crate::{
-    comp::{HealthSource, Stats},
+    comp::{ActionState, CharacterState, Energy, EnergySource, HealthSource, Stats},
     event::{EventBus, ServerEvent},
     state::DeltaTime,
 };
-use specs::{Entities, Join, Read, System, WriteStorage};
+use specs::{Entities, Join, Read, ReadStorage, System, WriteStorage};
+
+const ENERGY_REGEN_ACCEL: i32 = 1;
+const BLOCK_COST: i32 = 50;
+const ROLL_CHARGE_COST: i32 = 200;
 
 /// This system kills players
 /// and handles players levelling up
@@ -13,10 +17,15 @@ impl<'a> System<'a> for Sys {
         Entities<'a>,
         Read<'a, DeltaTime>,
         Read<'a, EventBus<ServerEvent>>,
+        ReadStorage<'a, CharacterState>,
         WriteStorage<'a, Stats>,
+        WriteStorage<'a, Energy>,
     );
 
-    fn run(&mut self, (entities, dt, server_event_bus, mut stats): Self::SystemData) {
+    fn run(
+        &mut self,
+        (entities, dt, server_event_bus, character_states, mut stats,mut energies): Self::SystemData,
+    ) {
         let mut server_event_emitter = server_event_bus.emitter();
 
         // Increment last change timer
@@ -27,7 +36,14 @@ impl<'a> System<'a> for Sys {
         stats.set_event_emission(true);
 
         // Mutates all stats every tick causing the server to resend this component for every entity every tick
-        for (entity, mut stats) in (&entities, &mut stats.restrict_mut()).join() {
+        for (entity, character_state, mut stats, energy) in (
+            &entities,
+            &character_states,
+            &mut stats.restrict_mut(),
+            &mut energies,
+        )
+            .join()
+        {
             let (set_dead, level_up) = {
                 let stat = stats.get_unchecked();
                 (
@@ -58,6 +74,26 @@ impl<'a> System<'a> for Sys {
                 stat.health
                     .set_to(stat.health.maximum(), HealthSource::LevelUp)
             }
+
+            // Recharge energy if not wielding, and accelerate.
+            match character_state.action {
+                ActionState::Wield { .. } | ActionState::Attack { .. } => energy.regen_rate = 0,
+                ActionState::Block { .. } => {
+                    energy.change_by(framerate_dt(-BLOCK_COST, dt.0), EnergySource::CastSpell)
+                }
+                ActionState::Roll { .. } | ActionState::Charge { .. } => energy.change_by(
+                    framerate_dt(-ROLL_CHARGE_COST, dt.0),
+                    EnergySource::CastSpell,
+                ),
+                ActionState::Idle => {
+                    energy.regen_rate += ENERGY_REGEN_ACCEL;
+                    energy.change_by(energy.regen_rate, EnergySource::Regen);
+                }
+            }
         }
     }
 }
+/// Convience method to scale an integer by dt
+fn framerate_dt(a: i32, dt: f32) -> i32 {
+    (a as f32 * (dt)) as i32
+}