veloren/common/systems/src/shockwave.rs
juliancoffee 4766450258 Avoid negative bounds in harm checks
* disallow_harm -> allow_harm to avoid negative reasoning since it mostly
requires double negation in code
* allow_harm -> may_harm to specify side-effect free
2021-08-03 18:57:53 +03:00

357 lines
13 KiB
Rust

use common::{
combat::{self, AttackOptions, AttackSource, AttackerInfo, TargetInfo},
comp::{
agent::{Sound, SoundKind},
Body, CharacterState, Combo, Energy, Group, Health, HealthSource, Inventory, Ori,
PhysicsState, Player, Pos, Scale, Shockwave, ShockwaveHitEntities, Stats,
},
event::{EventBus, ServerEvent},
outcome::Outcome,
resources::{DeltaTime, Time},
uid::{Uid, UidAllocator},
util::Dir,
GroupTarget,
};
use common_ecs::{Job, Origin, Phase, System};
use rand::{thread_rng, Rng};
use specs::{
saveload::MarkerAllocator, shred::ResourceId, Entities, Join, Read, ReadStorage, SystemData,
World, Write, WriteStorage,
};
use vek::*;
#[derive(SystemData)]
pub struct ReadData<'a> {
entities: Entities<'a>,
server_bus: Read<'a, EventBus<ServerEvent>>,
time: Read<'a, Time>,
players: ReadStorage<'a, Player>,
dt: Read<'a, DeltaTime>,
uid_allocator: Read<'a, UidAllocator>,
uids: ReadStorage<'a, Uid>,
positions: ReadStorage<'a, Pos>,
orientations: ReadStorage<'a, Ori>,
scales: ReadStorage<'a, Scale>,
bodies: ReadStorage<'a, Body>,
healths: ReadStorage<'a, Health>,
inventories: ReadStorage<'a, Inventory>,
groups: ReadStorage<'a, Group>,
physics_states: ReadStorage<'a, PhysicsState>,
energies: ReadStorage<'a, Energy>,
stats: ReadStorage<'a, Stats>,
combos: ReadStorage<'a, Combo>,
character_states: ReadStorage<'a, CharacterState>,
}
/// This system is responsible for handling accepted inputs like moving or
/// attacking
#[derive(Default)]
pub struct Sys;
impl<'a> System<'a> for Sys {
type SystemData = (
ReadData<'a>,
WriteStorage<'a, Shockwave>,
WriteStorage<'a, ShockwaveHitEntities>,
Write<'a, Vec<Outcome>>,
);
const NAME: &'static str = "shockwave";
const ORIGIN: Origin = Origin::Common;
const PHASE: Phase = Phase::Create;
fn run(
_job: &mut Job<Self>,
(read_data, mut shockwaves, mut shockwave_hit_lists, mut outcomes): Self::SystemData,
) {
let mut server_emitter = read_data.server_bus.emitter();
let time = read_data.time.0;
let dt = read_data.dt.0;
// Shockwaves
for (entity, pos, ori, shockwave, shockwave_hit_list) in (
&read_data.entities,
&read_data.positions,
&read_data.orientations,
&shockwaves,
&mut shockwave_hit_lists,
)
.join()
{
let creation_time = match shockwave.creation {
Some(time) => time,
// Skip newly created shockwaves
None => continue,
};
let end_time = creation_time + shockwave.duration.as_secs_f64();
let shockwave_owner = shockwave
.owner
.and_then(|uid| read_data.uid_allocator.retrieve_entity_internal(uid.into()));
let mut rng = thread_rng();
if rng.gen_bool(0.05) {
server_emitter.emit(ServerEvent::Sound {
sound: Sound::new(SoundKind::Shockwave, pos.0, 16.0, time),
});
}
// If shockwave is out of time emit destroy event but still continue since it
// may have traveled and produced effects a bit before reaching it's end point
if time > end_time {
server_emitter.emit(ServerEvent::Destroy {
entity,
cause: HealthSource::World,
});
continue;
}
// Determine area that was covered by the shockwave in the last tick
let time_since_creation = (time - creation_time) as f32;
let frame_start_dist = (shockwave.speed * (time_since_creation - dt)).max(0.0);
let frame_end_dist = (shockwave.speed * time_since_creation).max(frame_start_dist);
let pos2 = Vec2::from(pos.0);
let look_dir = ori.look_dir();
// From one frame to the next a shockwave travels over a strip of an arc
// This is used for collision detection
let arc_strip = ArcStrip {
origin: pos2,
// TODO: make sure this is not Vec2::new(0.0, 0.0)
dir: look_dir.xy(),
angle: shockwave.angle,
start: frame_start_dist,
end: frame_end_dist,
};
// Group to ignore collisions with
// Might make this more nuanced if shockwaves are used for non damage effects
let group = shockwave_owner.and_then(|e| read_data.groups.get(e));
// Go through all other effectable entities
for (target, uid_b, pos_b, health_b, body_b, physics_state_b) in (
&read_data.entities,
&read_data.uids,
&read_data.positions,
&read_data.healths,
&read_data.bodies,
&read_data.physics_states,
)
.join()
{
// Check to see if entity has already been hit
if shockwave_hit_list
.hit_entities
.iter()
.any(|&uid| uid == *uid_b)
{
continue;
}
// 2D versions
let pos_b2 = pos_b.0.xy();
// Scales
let scale_b = read_data.scales.get(target).map_or(1.0, |s| s.0);
let rad_b = body_b.radius() * scale_b;
// Angle checks
let pos_b_ground = Vec3::new(pos_b.0.x, pos_b.0.y, pos.0.z);
let max_angle = shockwave.vertical_angle.to_radians();
// See if entities are in the same group
let same_group = group
.map(|group_a| Some(group_a) == read_data.groups.get(target))
.unwrap_or(Some(*uid_b) == shockwave.owner);
let target_group = if same_group {
GroupTarget::InGroup
} else {
GroupTarget::OutOfGroup
};
// Check if it is a hit
let hit = entity != target
&& !health_b.is_dead
&& (pos_b.0 - pos.0).magnitude() < frame_end_dist + rad_b
// Collision shapes
&& {
// TODO: write code to collide rect with the arc strip so that we can do
// more complete collision detection for rapidly moving entities
arc_strip.collides_with_circle(Disk::new(pos_b2, rad_b))
}
&& (pos_b_ground - pos.0).angle_between(pos_b.0 - pos.0) < max_angle
&& (!shockwave.requires_ground || physics_state_b.on_ground.is_some());
if hit {
let dir = Dir::from_unnormalized(pos_b.0 - pos.0).unwrap_or(look_dir);
let attacker_info =
shockwave_owner
.zip(shockwave.owner)
.map(|(entity, uid)| AttackerInfo {
entity,
uid,
energy: read_data.energies.get(entity),
combo: read_data.combos.get(entity),
inventory: read_data.inventories.get(entity),
});
let target_info = TargetInfo {
entity: target,
uid: *uid_b,
inventory: read_data.inventories.get(target),
stats: read_data.stats.get(target),
health: read_data.healths.get(target),
pos: pos_b.0,
ori: read_data.orientations.get(target),
char_state: read_data.character_states.get(target),
};
let may_harm = combat::may_harm(
shockwave_owner.and_then(|owner| read_data.players.get(owner)),
read_data.players.get(target),
);
let attack_options = AttackOptions {
// Trying roll during earthquake isn't the best idea
target_dodging: false,
may_harm,
target_group,
};
shockwave.properties.attack.apply_attack(
attacker_info,
target_info,
dir,
attack_options,
1.0,
AttackSource::Shockwave,
|e| server_emitter.emit(e),
|o| outcomes.push(o),
);
shockwave_hit_list.hit_entities.push(*uid_b);
}
}
}
// Set start time on new shockwaves
// This change doesn't need to be recorded as it is not sent to the client
shockwaves.set_event_emission(false);
(&mut shockwaves).join().for_each(|mut shockwave| {
if shockwave.creation.is_none() {
shockwave.creation = Some(time);
}
});
shockwaves.set_event_emission(true);
}
}
#[derive(Clone, Copy)]
struct ArcStrip {
origin: Vec2<f32>,
/// Normalizable direction
dir: Vec2<f32>,
/// Angle in degrees
angle: f32,
/// Start radius
start: f32,
/// End radius
end: f32,
}
impl ArcStrip {
fn collides_with_circle(self, d: Disk<f32, f32>) -> bool {
// Quit if aabb's don't collide
if (self.origin.x - d.center.x).abs() > self.end + d.radius
|| (self.origin.y - d.center.y).abs() > self.end + d.radius
{
return false;
}
let dist = self.origin.distance(d.center);
let half_angle = self.angle.to_radians() / 2.0;
if dist > self.end + d.radius || dist + d.radius < self.start {
// Completely inside or outside full ring
return false;
}
let inside_edge = Disk::new(self.origin, self.start);
let outside_edge = Disk::new(self.origin, self.end);
let inner_corner_in_circle = || {
let midpoint = self.dir.normalized() * self.start;
d.contains_point(midpoint.rotated_z(half_angle) + self.origin)
|| d.contains_point(midpoint.rotated_z(-half_angle) + self.origin)
};
let arc_segment_in_circle = || {
let midpoint = self.dir.normalized();
let segment_in_circle = |angle| {
let dir = midpoint.rotated_z(angle);
let side = LineSegment2 {
start: dir * self.start + self.origin,
end: dir * self.end + self.origin,
};
d.contains_point(side.projected_point(d.center))
};
segment_in_circle(half_angle) || segment_in_circle(-half_angle)
};
if dist > self.end {
// Circle center is outside ring
// Check intersection with line segments
arc_segment_in_circle() || {
// Check angle of intersection points on outside edge of ring
let (p1, p2) = intersection_points(outside_edge, d, dist);
self.dir.angle_between(p1 - self.origin) < half_angle
|| self.dir.angle_between(p2 - self.origin) < half_angle
}
} else if dist < self.start {
// Circle center is inside ring
// Check angle of intersection points on inside edge of ring
// Check if circle contains one of the inner points of the arc
inner_corner_in_circle()
|| (
// Check that the circles aren't identical
inside_edge != d && {
let (p1, p2) = intersection_points(inside_edge, d, dist);
self.dir.angle_between(p1 - self.origin) < half_angle
|| self.dir.angle_between(p2 - self.origin) < half_angle
}
)
} else if d.radius > dist {
// Circle center inside ring
// but center of ring is inside the circle so we can't calculate the angle
inner_corner_in_circle()
} else {
// Circle center inside ring
// Calculate extra angle to account for circle radius
let extra_angle = (d.radius / dist).asin();
self.dir.angle_between(d.center - self.origin) < half_angle + extra_angle
}
}
}
// Assumes an intersection is occuring at 2 points
// Uses precalculated distance
// https://www.xarg.org/2016/07/calculate-the-intersection-points-of-two-circles/
fn intersection_points(
disk1: Disk<f32, f32>,
disk2: Disk<f32, f32>,
dist: f32,
) -> (Vec2<f32>, Vec2<f32>) {
let e = (disk2.center - disk1.center) / dist;
let x = (disk1.radius.powi(2) - disk2.radius.powi(2) + dist.powi(2)) / (2.0 * dist);
let y = (disk1.radius.powi(2) - x.powi(2)).sqrt();
let pxe = disk1.center + x * e;
let eyx = e.yx();
let p1 = pxe + Vec2::new(-y, y) * eyx;
let p2 = pxe + Vec2::new(y, -y) * eyx;
(p1, p2)
}