azalea/azalea-physics/src/collision/discrete_voxel_shape.rs

use super::mergers::IndexMerger;
use azalea_core::{Axis, AxisCycle, BitSet};

pub trait IntLineConsumer = FnMut(u32, u32, u32, u32, u32, u32);

#[derive(Clone, PartialEq, Eq, Debug)]
pub enum DiscreteVoxelShape {
    BitSet(BitSetDiscreteVoxelShape),
}

impl DiscreteVoxelShape {
    pub fn size(&self, axis: Axis) -> u32 {
        match self {
            DiscreteVoxelShape::BitSet(shape) => shape.size(axis),
        }
    }

    pub fn first_full(&self, axis: Axis) -> i32 {
        match self {
            DiscreteVoxelShape::BitSet(shape) => shape.first_full(axis),
        }
    }

    pub fn last_full(&self, axis: Axis) -> i32 {
        match self {
            DiscreteVoxelShape::BitSet(shape) => shape.last_full(axis),
        }
    }

    pub fn is_empty(&self) -> bool {
        if self.first_full(Axis::X) >= self.last_full(Axis::X) {
            return true;
        }
        if self.first_full(Axis::Y) >= self.last_full(Axis::Y) {
            return true;
        }
        if self.first_full(Axis::Z) >= self.last_full(Axis::Z) {
            return true;
        }
        false
    }

    pub fn is_full_wide(&self, x: i32, y: i32, z: i32) -> bool {
        if x < 0 || y < 0 || z < 0 {
            return false;
        }
        let (x, y, z) = (x as u32, y as u32, z as u32);
        (x < self.size(Axis::X) && y < self.size(Axis::Y) && z < self.size(Axis::Z))
            && (self.is_full(x, y, z))
    }

    pub fn is_full_wide_axis_cycle(&self, axis_cycle: AxisCycle, x: i32, y: i32, z: i32) -> bool {
        self.is_full_wide(
            axis_cycle.cycle_xyz(x, y, z, Axis::X),
            axis_cycle.cycle_xyz(x, y, z, Axis::Y),
            axis_cycle.cycle_xyz(x, y, z, Axis::Z),
        )
    }

    pub fn is_full(&self, x: u32, y: u32, z: u32) -> bool {
        match self {
            DiscreteVoxelShape::BitSet(shape) => shape.is_full(x, y, z),
        }
    }

    pub fn for_all_boxes(&self, consumer: impl IntLineConsumer, swap: bool) {
        BitSetDiscreteVoxelShape::for_all_boxes(self, consumer, swap)
    }
}

#[derive(Default, Clone, PartialEq, Eq, Debug)]
pub struct BitSetDiscreteVoxelShape {
    x_size: u32,
    y_size: u32,
    z_size: u32,

    storage: BitSet,
    x_min: i32,
    y_min: i32,
    z_min: i32,
    x_max: i32,
    y_max: i32,
    z_max: i32,
}

impl BitSetDiscreteVoxelShape {
    pub fn new(x_min: u32, y_min: u32, z_min: u32) -> Self {
        BitSetDiscreteVoxelShape {
            x_size: x_min,
            y_size: y_min,
            z_size: z_min,

            storage: BitSet::new((x_min * y_min * z_min).try_into().unwrap()),
            x_min: z_min.try_into().unwrap(),
            y_min: z_min.try_into().unwrap(),
            z_min: z_min.try_into().unwrap(),
            x_max: 0,
            y_max: 0,
            z_max: 0,
        }
    }

    // yeah don't really feel like fixing this one
    #[allow(clippy::too_many_arguments)]
    pub fn with_filled_bounds(
        x_size: u32,
        y_size: u32,
        z_size: u32,
        x_min: i32,
        y_min: i32,
        z_min: i32,
        x_max: i32,
        y_max: i32,
        z_max: i32,
    ) -> Self {
        let mut shape = BitSetDiscreteVoxelShape::new(x_size, y_size, z_size);
        shape.x_min = x_min;
        shape.y_min = y_min;
        shape.z_min = z_min;
        shape.x_max = x_max;
        shape.y_max = y_max;
        shape.z_max = z_max;

        for x in x_min..x_max {
            for y in y_min..y_max {
                for z in z_min..z_max {
                    shape.fill_update_bounds(
                        x.try_into().unwrap(),
                        y.try_into().unwrap(),
                        z.try_into().unwrap(),
                        false,
                    );
                }
            }
        }

        shape
    }

    fn fill_update_bounds(&mut self, x: u32, y: u32, z: u32, update: bool) {
        self.storage.set(self.get_index(x, y, z));
        if update {
            self.x_min = std::cmp::min(self.x_min, x as i32);
            self.y_min = std::cmp::min(self.y_min, y as i32);
            self.z_min = std::cmp::min(self.z_min, z as i32);
            self.x_max = std::cmp::max(self.x_max, (x + 1) as i32);
            self.y_max = std::cmp::max(self.y_max, (y + 1) as i32);
            self.z_max = std::cmp::max(self.z_max, (z + 1) as i32);
        }
    }

    pub fn fill(&mut self, x: u32, y: u32, z: u32) {
        self.fill_update_bounds(x, y, z, true);
    }

    fn get_index_from_size(x: u32, y: u32, z: u32, y_size: u32, z_size: u32) -> usize {
        ((x * y_size + y) * z_size + z) as usize
    }
    fn get_index(&self, x: u32, y: u32, z: u32) -> usize {
        Self::get_index_from_size(x, y, z, self.y_size, self.z_size)
    }

    pub fn join(
        var0: &DiscreteVoxelShape,
        var1: &DiscreteVoxelShape,
        var2: &IndexMerger,
        var3: &IndexMerger,
        var4: &IndexMerger,
        var5: impl Fn(bool, bool) -> bool,
    ) -> Self {
        let mut var6 = BitSetDiscreteVoxelShape::new(
            (var2.size() - 1) as u32,
            (var3.size() - 1) as u32,
            (var4.size() - 1) as u32,
        );
        let mut var7: [i32; 6] = [
            2147483647,
            2147483647,
            2147483647,
            -2147483648,
            -2147483648,
            -2147483648,
        ];
        var2.for_merged_indexes(|var7x: i32, var8: i32, var9: i32| {
            let mut var10 = [false];
            var3.for_merged_indexes(|var10x: i32, var11: i32, var12: i32| {
                let mut var13 = [false];
                var4.for_merged_indexes(|var12x: i32, var13x: i32, var14: i32| {
                    if var5(
                        var0.is_full_wide(var7x, var10x, var12x),
                        var1.is_full_wide(var8, var11, var13x),
                    ) {
                        var6.storage.set(var6.get_index(
                            var9.try_into().unwrap(),
                            var12.try_into().unwrap(),
                            var14.try_into().unwrap(),
                        ));
                        var7[2] = std::cmp::min(var7[2], var14);
                        var7[5] = std::cmp::max(var7[5], var14);
                        var13[0] = true;
                    }

                    true
                });
                if var13[0] {
                    var7[1] = std::cmp::min(var7[1], var12);
                    var7[4] = std::cmp::max(var7[4], var12);
                    var10[0] = true;
                }

                true
            });
            if var10[0] {
                var7[0] = std::cmp::min(var7[0], var9);
                var7[3] = std::cmp::max(var7[3], var9);
            }

            true
        });
        var6.x_min = var7[0];
        var6.y_min = var7[1];
        var6.z_min = var7[2];
        var6.x_max = var7[3] + 1;
        var6.y_max = var7[4] + 1;
        var6.z_max = var7[5] + 1;
        var6
    }

    pub fn for_all_boxes(
        var0: &DiscreteVoxelShape,
        mut consumer: impl IntLineConsumer,
        var2: bool,
    ) {
        let mut var3 = BitSetDiscreteVoxelShape::from(var0);
        for var4 in 0..var3.y_size {
            for var5 in 0..var3.x_size {
                let mut var6 = None;
                for var7 in 0..=var3.z_size {
                    if var3.is_full_wide(var5, var4, var7) {
                        if var2 {
                            if var6.is_none() {
                                var6 = Some(var7);
                            }
                        } else {
                            consumer(var5, var4, var7, var5 + 1, var4 + 1, var7 + 1);
                        }
                    } else if var6.is_some() {
                        let mut var8 = var5;
                        let mut var9 = var4;
                        var3.clear_z_strip(var6.unwrap(), var7, var5, var4);
                        while var3.is_z_strip_full(var6.unwrap(), var7, var8 + 1, var4) {
                            var3.clear_z_strip(var6.unwrap(), var7, var8 + 1, var4);
                            var8 += 1;
                        }
                        while var3.is_xz_rectangle_full(
                            var5,
                            var8 + 1,
                            var6.unwrap(),
                            var7,
                            var9 + 1,
                        ) {
                            for var10 in var5..=var8 {
                                var3.clear_z_strip(var6.unwrap(), var7, var10, var9 + 1);
                            }
                            var9 += 1;
                        }
                        consumer(var5, var4, var6.unwrap(), var8 + 1, var9 + 1, var7);
                        var6 = None;
                    }
                }
            }
        }
    }

    fn is_z_strip_full(&self, var1: u32, var2: u32, var3: u32, var4: u32) -> bool {
        if var3 < self.x_size && var4 < self.y_size {
            self.storage
                .next_clear_bit(self.get_index(var3, var4, var1))
                >= self.get_index(var3, var4, var2)
        } else {
            false
        }
    }

    fn is_xz_rectangle_full(&self, var1: u32, var2: u32, var3: u32, var4: u32, var5: u32) -> bool {
        for var6 in var1..var2 {
            if !self.is_z_strip_full(var3, var4, var6, var5) {
                return false;
            }
        }
        true
    }

    fn clear_z_strip(&mut self, var1: u32, var2: u32, var3: u32, var4: u32) {
        self.storage.clear(
            self.get_index(var3, var4, var1),
            self.get_index(var3, var4, var2),
        );
    }
}

impl BitSetDiscreteVoxelShape {
    fn size(&self, axis: Axis) -> u32 {
        axis.choose(self.x_size, self.y_size, self.z_size)
    }

    fn first_full(&self, axis: Axis) -> i32 {
        axis.choose(self.x_min, self.y_min, self.z_min)
    }

    fn last_full(&self, axis: Axis) -> i32 {
        axis.choose(self.x_max, self.y_max, self.z_max)
    }

    fn is_full(&self, x: u32, y: u32, z: u32) -> bool {
        self.storage.index(self.get_index(x, y, z))
    }

    fn is_full_wide(&self, x: u32, y: u32, z: u32) -> bool {
        (x < self.size(Axis::X) && y < self.size(Axis::Y) && z < self.size(Axis::Z))
            && (self.is_full(x, y, z))
    }
}

impl From<&DiscreteVoxelShape> for BitSetDiscreteVoxelShape {
    fn from(shape: &DiscreteVoxelShape) -> Self {
        let x_size = shape.size(Axis::X);
        let y_size = shape.size(Axis::Y);
        let z_size = shape.size(Axis::Z);
        let mut storage;
        // more things could be added to DiscreteVoxelShape in the future
        #[allow(irrefutable_let_patterns)]
        if let DiscreteVoxelShape::BitSet(shape) = shape {
            storage = shape.storage.clone();
        } else {
            storage = BitSet::new((x_size * y_size * z_size) as usize);
            for x in 0..x_size {
                for y in 0..y_size {
                    for z in 0..z_size {
                        if shape.is_full(x, y, z) {
                            storage.set(Self::get_index_from_size(x, y, z, y_size, z_size));
                        }
                    }
                }
            }
        }

        Self {
            x_size,
            y_size,
            z_size,
            storage,
            x_min: shape.first_full(Axis::X),
            y_min: shape.first_full(Axis::Y),
            z_min: shape.first_full(Axis::Z),
            x_max: shape.last_full(Axis::X),
            y_max: shape.last_full(Axis::Y),
            z_max: shape.last_full(Axis::Z),
        }
    }
}