veloren/common/src/comp/energy.rs

129 lines
3.7 KiB
Rust

use crate::comp::Body;
use serde::{Deserialize, Serialize};
use specs::{Component, DerefFlaggedStorage};
use specs_idvs::IdvStorage;
#[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<Body>, level: u16) {
const ENERGY_PER_LEVEL: u32 = 50;
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,
});
}
}
}
pub struct EnergyChange {
pub amount: i32,
pub source: EnergySource,
}
impl Component for Energy {
type Storage = DerefFlaggedStorage<Self, IdvStorage<Self>>;
}