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pub mod collision;
use azalea_block::{Block, BlockState};
use azalea_core::{BlockPos, Vec3};
use azalea_world::entity::{EntityData, EntityMut};
use collision::{MovableEntity, MoverType};
pub trait HasPhysics {
fn travel(&mut self, acceleration: &Vec3);
fn ai_step(&mut self);
}
impl HasPhysics for EntityMut<'_> {
/// Move the entity with the given acceleration while handling friction,
/// gravity, collisions, and some other stuff.
fn travel(&mut self, acceleration: &Vec3) {
// if !self.is_effective_ai() && !self.is_controlled_by_local_instance() {
// // this.calculateEntityAnimation(this, this instanceof FlyingAnimal);
// return;
// }
let gravity: f64 = 0.08;
// TODO: slow falling effect
// let is_falling = self.delta.y <= 0.;
// TODO: fluids
// TODO: elytra
let block_pos_below = get_block_pos_below_that_affects_movement(self);
let block_state_below = self
.dimension
.get_block_state(&block_pos_below)
.unwrap_or(BlockState::Air);
let block_below: Box<dyn Block> = block_state_below.into();
let block_friction = block_below.behavior().friction;
let inertia = if self.on_ground {
block_friction * 0.91
} else {
0.91
};
// this applies the current delta
let mut movement =
handle_relative_friction_and_calculate_movement(self, acceleration, block_friction);
movement.y -= gravity;
// if (this.shouldDiscardFriction()) {
// this.setDeltaMovement(movement.x, yMovement, movement.z);
// } else {
// this.setDeltaMovement(movement.x * (double)inertia, yMovement * 0.9800000190734863D, movement.z * (double)inertia);
// }
// if should_discard_friction(self) {
if false {
self.delta = movement;
} else {
self.delta = Vec3 {
x: movement.x * inertia as f64,
y: movement.y * 0.98f64,
z: movement.z * inertia as f64,
};
}
}
/// applies air resistance, calls self.travel(), and some other random
/// stuff.
fn ai_step(&mut self) {
// vanilla does movement interpolation here, doesn't really matter much for a bot though
if self.delta.x.abs() < 0.003 {
self.delta.x = 0.;
}
if self.delta.y.abs() < 0.003 {
self.delta.y = 0.;
}
if self.delta.z.abs() < 0.003 {
self.delta.z = 0.;
}
self.xxa *= 0.98;
self.zza *= 0.98;
self.travel(&Vec3 {
x: self.xxa as f64,
y: self.yya as f64,
z: self.zza as f64,
});
// freezing
// pushEntities
// drowning damage
}
}
fn get_block_pos_below_that_affects_movement(entity: &EntityData) -> BlockPos {
BlockPos::new(
entity.pos().x.floor() as i32,
// TODO: this uses bounding_box.min_y instead of position.y
(entity.pos().y - 0.5f64).floor() as i32,
entity.pos().z.floor() as i32,
)
}
fn handle_relative_friction_and_calculate_movement(
entity: &mut EntityMut,
acceleration: &Vec3,
block_friction: f32,
) -> Vec3 {
entity.move_relative(get_speed(&*entity, block_friction), acceleration);
// entity.delta = entity.handle_on_climbable(entity.delta);
entity
.move_colliding(&MoverType::Own, &entity.delta.clone())
.expect("Entity should exist.");
// let delta_movement = entity.delta;
// if ((entity.horizontalCollision || entity.jumping) && (entity.onClimbable() || entity.getFeetBlockState().is(Blocks.POWDER_SNOW) && PowderSnowBlock.canEntityWalkOnPowderSnow(entity))) {
// var3 = new Vec3(var3.x, 0.2D, var3.z);
// }
// TODO: powdered snow
entity.delta
}
// private float getFrictionInfluencedSpeed(float friction) {
// return this.onGround ? this.getSpeed() * (0.21600002F / (friction * friction * friction)) : this.flyingSpeed;
// }
fn get_speed(entity: &EntityData, friction: f32) -> f32 {
// TODO: have speed & flying_speed fields in entity
if entity.on_ground {
let speed: f32 = 0.7;
speed * (0.216f32 / (friction * friction * friction))
} else {
// entity.flying_speed
0.02
}
}
#[cfg(test)]
mod tests {
use super::*;
use azalea_core::ChunkPos;
use azalea_world::{Chunk, Dimension};
use uuid::Uuid;
#[test]
fn test_gravity() {
let mut dim = Dimension::default();
dim.add_entity(
0,
EntityData::new(
Uuid::from_u128(0),
Vec3 {
x: 0.,
y: 70.,
z: 0.,
},
),
);
let mut entity = dim.entity_mut(0).unwrap();
// y should start at 70
assert_eq!(entity.pos().y, 70.);
entity.ai_step();
// delta is applied before gravity, so the first tick only sets the delta
assert_eq!(entity.pos().y, 70.);
assert!(entity.delta.y < 0.);
entity.ai_step();
// the second tick applies the delta to the position, so now it should go down
assert!(
entity.pos().y < 70.,
"Entity y ({}) didn't go down after physics steps",
entity.pos().y
);
}
#[test]
fn test_collision() {
let mut dim = Dimension::default();
dim.set_chunk(&ChunkPos { x: 0, z: 0 }, Some(Chunk::default()))
.unwrap();
dim.add_entity(
0,
EntityData::new(
Uuid::from_u128(0),
Vec3 {
x: 0.5,
y: 70.,
z: 0.5,
},
),
);
let old_block_state =
dim.set_block_state(&BlockPos { x: 0, y: 69, z: 0 }, BlockState::Stone);
assert!(
old_block_state.is_some(),
"Old block state should exist, if this fails that means the chunk wasn't loaded and the block didn't get placed"
);
let mut entity = dim.entity_mut(0).unwrap();
entity.ai_step();
// delta will change, but it won't move until next tick
assert_eq!(entity.pos().y, 70.);
assert!(entity.delta.y < 0.);
entity.ai_step();
// the second tick applies the delta to the position, but it also does collision
assert_eq!(entity.pos().y, 70.);
}
}
|
