use crate::comp::Body; use serde::{Deserialize, Serialize}; use specs::{Component, DerefFlaggedStorage}; use specs_idvs::IdvStorage; use std::cmp; pub const ENERGY_PER_LEVEL: u32 = 50; #[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)] pub struct Energy { current: u32, base_max: u32, maximum: u32, pub regen_rate: f32, pub last_change: Option<(i32, f64, EnergySource)>, } #[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)] pub enum EnergySource { Ability, Climb, LevelUp, HitEnemy, Regen, Revive, Unknown, } #[derive(Debug)] pub enum StatChangeError { Underflow, Overflow, } impl Energy { pub fn new(body: Body, level: u16) -> Energy { let mut energy = Energy::empty(); energy.update_max_energy(Some(body), level); energy.set_to(energy.maximum(), EnergySource::Revive); energy } pub fn empty() -> Self { Energy { current: 0, maximum: 0, base_max: 0, regen_rate: 0.0, last_change: None, } } pub fn current(&self) -> u32 { self.current } pub fn base_max(&self) -> u32 { self.base_max } pub fn maximum(&self) -> u32 { self.maximum } pub fn set_to(&mut self, amount: u32, cause: EnergySource) { let amount = amount.min(self.maximum); self.last_change = Some((amount as i32 - self.current as i32, 0.0, cause)); self.current = amount; } pub fn change_by(&mut self, change: EnergyChange) { self.current = ((self.current as i32 + change.amount).max(0) as u32).min(self.maximum); self.last_change = Some((change.amount, 0.0, change.source)); } /// This function changes the modified max energy value, not the base energy /// value. The modified energy value takes into account buffs and other /// temporary changes to max energy. pub fn set_maximum(&mut self, amount: u32) { self.maximum = amount; self.current = self.current.min(self.maximum); } /// Scales the temporary max energy by a modifier. pub fn scale_maximum(&mut self, scaled: f32) { let scaled_max = (self.base_max as f32 * scaled) as u32; self.set_maximum(scaled_max); } pub fn try_change_by( &mut self, amount: i32, cause: EnergySource, ) -> Result<(), StatChangeError> { if self.current as i32 + amount < 0 { Err(StatChangeError::Underflow) } else if self.current as i32 + amount > self.maximum as i32 { Err(StatChangeError::Overflow) } else { self.change_by(EnergyChange { amount, source: cause, }); Ok(()) } } pub fn update_max_energy(&mut self, body: Option, level: u16) { if let Some(body) = body { // Checks the current difference between maximum and base max let current_difference = self.maximum as i32 - self.base_max as i32; // Sets base max to new value based off of new level provided self.base_max = body.base_energy() + ENERGY_PER_LEVEL * level as u32; // Calculates new maximum by adding difference to new base max let new_maximum = (self.base_max as i32 + current_difference).max(0) as u32; // Sets maximum to calculated value self.set_maximum(new_maximum); // Awards energy self.change_by(EnergyChange { amount: ENERGY_PER_LEVEL as i32, source: EnergySource::LevelUp, }); } } /// Returns the fraction of energy an entity has remaining pub fn fraction(&self) -> f32 { self.current as f32 / cmp::max(self.maximum, 1) as f32 } } pub struct EnergyChange { pub amount: i32, pub source: EnergySource, } impl Component for Energy { type Storage = DerefFlaggedStorage>; }