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|
use crate::color::Palette;
use crate::color::db32::{LIGHT_RED, PINK, PURPLE};
use crate::gfx;
use crate::math;
use crate::rng::Rng;
use crate::sprite::Sprite;
use crate::{GAME_H, GAME_W};
use std::f32::consts::TAU;
use aseprite::AsepriteFile;
use glam::Vec2;
const ROT_STEPS: f32 = 16.0;
#[derive(Default)]
enum State {
Dive {
path: [Vec2; 4],
fired: u32,
shots: u32,
t: f32,
},
#[default]
Formation,
}
pub struct Enemy {
base: Vec2,
flash: u32,
hp: u32,
pos: Vec2,
step: Vec2,
sprite: Sprite,
state: State,
}
impl Enemy {
pub fn new(sprites: &AsepriteFile, layer: &str, base: Vec2, hp: u32) -> Self {
let pos = base;
let step = Vec2::ZERO;
let sprite = Sprite::from_ase(sprites, layer);
let state = State::default();
Self {
base,
flash: 0,
hp,
pos,
step,
sprite,
state,
}
}
pub fn damage(&mut self) -> bool {
self.hp = self.hp.saturating_sub(1);
self.flash = 12;
self.hp == 0
}
pub fn center(&self) -> Vec2 {
self.pos + self.size() / 2.0
}
pub fn pos(&self) -> Vec2 {
self.pos
}
pub fn size(&self) -> Vec2 {
self.sprite.size.as_vec2()
}
pub fn start_dive(&mut self, player_x: f32, shots: u32, rng: &mut Rng) {
if matches!(self.state, State::Dive { .. }) {
return;
}
let side = if self.pos.x < 70.0 {
1.0
} else if self.pos.x > GAME_W as f32 - 70.0 {
-1.0
} else if rng.chance(0.5) {
1.0
} else {
-1.0
};
let min = Vec2::new(4.0, 4.0);
let max = Vec2::new(GAME_W as f32 - 20.0, GAME_H as f32 - 20.0);
let swing = (self.pos + Vec2::new(side * 70.0, -40.0)).clamp(min, max);
let plunge = Vec2::new(player_x, GAME_H as f32 - 20.0).clamp(min, max);
let path = [self.pos, swing, plunge, self.base];
self.state = State::Dive {
path,
fired: 0,
shots,
t: 0.0,
};
}
pub fn update(&mut self, sway: f32, player: Vec2) -> Option<Vec2> {
let before = self.pos;
let mut shot = None;
self.flash = self.flash.saturating_sub(1);
match &mut self.state {
State::Formation => {
let target = self.base.x + sway;
self.pos.x += (target - self.pos.x) * 0.2;
}
State::Dive {
path,
fired,
shots,
t,
} => {
*t += 1.0 / 240.0;
if *t >= 1.0 {
self.pos = self.base;
self.state = State::Formation;
} else {
self.pos = math::bezier(*path, *t);
let center = self.pos + self.sprite.size.as_vec2() / 2.0;
let facing = self.step.normalize_or_zero();
let to_player = (player - center).normalize_or_zero();
let next = 0.25 + 0.5 * *fired as f32 / *shots as f32;
if *fired < *shots && *t > next && facing.dot(to_player) > 0.8 {
*fired += 1;
shot = Some(center);
}
}
}
}
self.step = self.pos - before;
shot
}
pub fn draw(&self, frame: &mut [u32], palette: &Palette, a: f32, tick: u32) {
let pos = self.pos - self.step * (1.0 - a);
let tint = if self.flash > 0 && (tick / 2).is_multiple_of(2) {
LIGHT_RED
} else {
0
};
if matches!(self.state, State::Dive { .. }) && self.step.length_squared() > 0.001 {
let dir = self.step.normalize();
let angle = (-dir.x).atan2(dir.y);
let angle = (angle * ROT_STEPS / TAU).round() * (TAU / ROT_STEPS);
let center = pos + self.sprite.size.as_vec2() / 2.0;
self.sprite
.draw_rotated(frame, palette, center, angle, tint);
let half = self.sprite.size.y as f32 / 2.0;
for i in 0..3 {
let tail = center - dir * (half + 1.0 + i as f32 * 2.0);
let c = [PURPLE, PINK][(tick / 4 + i) as usize % 2];
gfx::blit(frame, palette, &[c], tail.round().as_ivec2(), 1, 0);
}
} else {
self.sprite
.draw_tinted(frame, palette, pos.round().as_ivec2(), tint);
}
}
}
|
