Physics (#11)

* Put physics module in azalea-entity

* port aabb

* add more stuff to PositionXYZ

* azalea-physics

* important collision things

* more physics stuff

* backup because i'm about to delete shapes

* more shape stuff

* CubeVoxelShape

* no compile errors???

insane

* impl VoxelShape for ArrayVoxelShape

* Shapes stuff

* collide_x but it doesn't work yet

* binary_search

* it compiles

* Entity has bounding box

* Update discrete_voxel_shape.rs

* Entity::make_bounding_box

* ok i'm about to merge az-entity and az-world

might be a terrible idea which is why i'm committing first

* ok so i moved entity to world

* on_pos and move_entity compiles

* add send_position

* move collision stuff to collision module in az-physics

* dimension is no longer an Option

* start trying to do collision for the client

* collision works :tada:

* start adding palette resizing

* get_and_set (pain)

* it compiles but probably won't work

* add a test

* remove printlns

* add more tests for palette stuff

* ClientboundMoveVec3Packet -> ClientboundMoveEntityPosPacket

i think i changed this on accident once

* palette resizing works

todo: remove the printlns

* Remove printlns in palette.rs

* fix issues from merge

* fixes + work a bit more on physics

* Better entities (#19)

* well it compiles

* add tests to entity storage

* add suggestions in azalea-brigadier

* this probably causes ub

* fix brigadiersuggestions

* get rid of entityid

* test From<EntityMut> for EntityRef

* don't mention other libraries since there's too many

* fix warnings

* do todos in brigadier suggestions

* work on physics

* more physics stuff

* remove trait feature on az-block

i think rust gets confused and compiles the macro without the feature

* bump ahash

* aes tests in az-crypto

* optimize aes's deps

* fix crashes

* fix section_index for negative numbers and test

* fix BlockPos protocol implementation

* remove some debug prints

* prepare to add ai_step

* make ai step work

* clippy

1 files changed, 72 insertions, 0 deletions

diff --git a/azalea-core/src/direction.rs b/azalea-core/src/direction.rs
index d3083922..96d20a10 100644
--- a/azalea-core/src/direction.rs
+++ b/azalea-core/src/direction.rs
@@ -1,5 +1,7 @@
 use azalea_buf::McBuf;
 
+use crate::floor_mod;
+
 #[derive(Clone, Copy, Debug, McBuf)]
 pub enum Direction {
     Down = 0,
@@ -9,3 +11,73 @@ pub enum Direction {
     West = 4,
     East = 5,
 }
+
+#[derive(Clone, Copy, Debug)]
+pub enum Axis {
+    X = 0,
+    Y = 1,
+    Z = 2,
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum AxisCycle {
+    None = 0,
+    Forward = 1,
+    Backward = 2,
+}
+
+impl Axis {
+    /// Pick x, y, or z from the arguments depending on the axis.
+    #[inline]
+    pub fn choose<T>(&self, x: T, y: T, z: T) -> T {
+        match self {
+            Axis::X => x,
+            Axis::Y => y,
+            Axis::Z => z,
+        }
+    }
+
+    pub fn from_ordinal(ordinal: u32) -> Self {
+        match ordinal {
+            0 => Axis::X,
+            1 => Axis::Y,
+            2 => Axis::Z,
+            _ => panic!("Invalid ordinal {}", ordinal),
+        }
+    }
+}
+
+impl AxisCycle {
+    pub fn from_ordinal(ordinal: u32) -> Self {
+        match ordinal {
+            0 => Self::None,
+            1 => Self::Forward,
+            2 => Self::Backward,
+            _ => panic!("invalid ordinal"),
+        }
+    }
+    pub fn between(axis0: Axis, axis1: Axis) -> Self {
+        Self::from_ordinal(floor_mod(axis1 as i32 - axis0 as i32, 3))
+    }
+    pub fn inverse(self) -> Self {
+        match self {
+            Self::None => Self::None,
+            Self::Forward => Self::Backward,
+            Self::Backward => Self::Forward,
+        }
+    }
+    pub fn cycle(self, axis: Axis) -> Axis {
+        match self {
+            Self::None => axis,
+            Self::Forward => Axis::from_ordinal(floor_mod(axis as i32 + 1, 3)),
+            Self::Backward => Axis::from_ordinal(floor_mod(axis as i32 - 1, 3)),
+        }
+    }
+    pub fn cycle_xyz(self, x: u32, y: u32, z: u32, axis: Axis) -> u32 {
+        match self {
+            Self::None => axis.choose(x, y, z),
+            Self::Forward => axis.choose(z, x, y),
+            Self::Backward => axis.choose(y, z, x),
+        }
+    }
+}