From f177cc716c5f2aa5b50b14ccbb421de89e3a7854 Mon Sep 17 00:00:00 2001 From: Kai Stevenson Date: Sun, 16 Aug 2026 17:29:42 -0700 Subject: wip --- src/sim/sim.rs | 231 --------------------------------------------------------- 1 file changed, 231 deletions(-) delete mode 100644 src/sim/sim.rs (limited to 'src/sim/sim.rs') diff --git a/src/sim/sim.rs b/src/sim/sim.rs deleted file mode 100644 index b9f4b76..0000000 --- a/src/sim/sim.rs +++ /dev/null @@ -1,231 +0,0 @@ -use std::marker::PhantomData; - -use fxhash::FxHashMap; -use rand::{Rng, SeedableRng, rngs::SmallRng}; -use rayon::iter::{IntoParallelRefIterator, ParallelIterator}; - -use crate::{ - config::CHUNK_SIZE, - sim::{cell::Cell, chunk::Chunk, materials::MaterialDef, world::World}, -}; - -struct ChunkAccess<'a> { - ptr: *mut Chunk, - len: usize, - _marker: PhantomData<&'a mut [Chunk]>, -} - -impl<'a> ChunkAccess<'a> { - pub fn new(chunks: &'a mut [Chunk]) -> Self { - Self { - ptr: chunks.as_mut_ptr(), - len: chunks.len(), - _marker: PhantomData, - } - } - unsafe fn get(&self, i: usize) -> &'a mut Chunk { - debug_assert!(i < self.len); - unsafe { &mut *self.ptr.add(i) } - } -} - -unsafe impl Sync for ChunkAccess<'_> {} - -fn get_cell(chunks: &[Option<&mut Chunk>; 9], x: i32, y: i32) -> Option { - let dcx = x.div_euclid(CHUNK_SIZE); - let dcy = y.div_euclid(CHUNK_SIZE); - if dcx != 0 || dcy != 0 { - // in a different chunk - let nc_x = x.rem_euclid(CHUNK_SIZE) as u8; - let nc_y = y.rem_euclid(CHUNK_SIZE) as u8; - - chunks[(dcx + 1 + (dcy + 1) * 3) as usize] - .as_ref() - .map(|chunk| chunk.get_cell_at_local_position(nc_x, nc_y)) - } else { - chunks[4] - .as_ref() - .map(|target| target.get_cell_at_local_position(x as u8, y as u8)) - } -} - -pub fn set_cell(chunks: &mut [Option<&mut Chunk>; 9], x: i32, y: i32, cell: Cell) { - let dcx = x.div_euclid(CHUNK_SIZE); - let dcy = y.div_euclid(CHUNK_SIZE); - if dcx != 0 || dcy != 0 { - // in a different chunk - let nc_x = x.rem_euclid(CHUNK_SIZE) as u8; - let nc_y = y.rem_euclid(CHUNK_SIZE) as u8; - - if let Some(chunk) = &mut chunks[(dcx + 1 + (dcy + 1) * 3) as usize] { - chunk.set_cell_at_local_position(nc_x, nc_y, cell); - chunk.needs_texture_update = true; - } - } else { - if let Some(target) = &mut chunks[4] { - target.set_cell_at_local_position(x as u8, y as u8, cell); - target.needs_texture_update = true; - } - } -} - -pub struct UpdateCtx<'a, 'b, 'c> { - pub chunks: &'a mut [Option<&'b mut Chunk>; 9], - pub seqno: u64, - pub seqno_parity: u8, - - pub x: i32, - pub y: i32, - pub cell: &'c mut Cell, - pub material: &'c MaterialDef, - - pub rng: &'c mut dyn Rng, -} - -impl UpdateCtx<'_, '_, '_> { - pub fn get_cell(&self, dx: i32, dy: i32) -> Option { - let x = self.x + dx; - let y = self.y + dy; - get_cell(self.chunks, x, y) - } - - pub fn set_cell(&mut self, dx: i32, dy: i32, cell: Cell) { - // cannot move out of the neighbourhood, but also cannot move to the edge of the neighbourhood - // as this would wake a chunk outside of the neighbourhood - debug_assert!(dx > -15 && dx < 15); - debug_assert!(dy > -15 && dy < 15); - let x = self.x + dx; - let y = self.y + dy; - set_cell(self.chunks, x, y, cell); - self.chunks.iter_mut().for_each(|c| { - if let Some(chunk) = c { - chunk.sleeping = false; - } - }) - } - - pub fn candidates_swap(&mut self, candidates: &[(i32, i32)]) -> bool { - for &(dx, dy) in candidates { - let candidate_cell = self.get_cell(dx, dy); - if candidate_cell.is_some_and(|c| c.material.def().density < self.material.density) { - self.set_cell(0, 0, candidate_cell.unwrap()); - self.set_cell(dx, dy, *self.cell); - return true; - } - } - false - } -} - -pub fn sim_tick_chunk(chunks: &mut [Option<&mut Chunk>; 9], seqno: u64) { - puffin::profile_function!(); - let seqno_parity = (seqno as u8) & 0b1; - let mut rng = SmallRng::seed_from_u64(seqno); - - if chunks[4].is_some() { - for y in (0..CHUNK_SIZE).rev() { - for i in 0..CHUNK_SIZE { - let x = if seqno_parity == 0 { - i - } else { - (CHUNK_SIZE) - i - 1 - }; - - let mut cell = get_cell(chunks, x, y).unwrap(); - let material = cell.material.def(); - - if let Some(update) = material.sim_update - && cell.parity() == seqno_parity - { - cell.flip_parity(); - // apply the flipped parity in case the sim target doesn't - set_cell(chunks, x, y, cell); - - let mut update_ctx = UpdateCtx { - chunks, - seqno, - seqno_parity, - - x, - y, - cell: &mut cell, - material, - - // TODO this is platform-dependent, will break for multiplayer - rng: &mut rng, - }; - - update(&mut update_ctx); - } - } - } - } -} - -const NEIGHBORHOOD_OFFSETS: [(i32, i32); 9] = [ - (-1, -1), - (0, -1), - (1, -1), - (-1, 0), - (0, 0), - (1, 0), - (-1, 1), - (0, 1), - (1, 1), -]; - -pub fn sim_tick(world: &mut World, seqno: u64, use_threading: bool) { - puffin::profile_function!(); - - let mut columns: FxHashMap> = FxHashMap::default(); - for &(cx, cy) in world.chunk_position_to_chunk_idx.keys() { - columns.entry(cx).or_default().push(cy); - } - - // color columns s.t. columns of same color are separated by two columns - // and sort the column bottom-to-top - // -------------------- - // | 0, 1, 2, 0, 1, 2 | - // | 0, 1, 2, 0, 1, 2 | - // | 0, 1, 2, 0, 1, 2 | - // -------------------- - let mut columns_by_color: [Vec<(i32, Vec)>; 3] = Default::default(); - for (cx, mut cys) in columns { - cys.sort_unstable_by(|a, b| b.cmp(a)); - columns_by_color[cx.rem_euclid(3) as usize].push((cx, cys)); - } - - let access = ChunkAccess::new(&mut world.chunks); - - for color in &columns_by_color { - puffin::profile_scope!("chunk_color"); - - let chunk_closure = |(cx, cys): &(i32, Vec)| { - let cx = *cx; - for &cy in cys { - let mut chunks: [Option<&mut Chunk>; 9] = NEIGHBORHOOD_OFFSETS.map(|(dx, dy)| { - world - .chunk_position_to_chunk_idx - .get(&(cx + dx, cy + dy)) - .map(|&idx| unsafe { access.get(idx) }) - }); - - if let Some(target) = &mut chunks[4] { - if target.sleeping { - continue; - } - target.sleeping = true; - } - - sim_tick_chunk(&mut chunks, seqno); - } - }; - - if use_threading { - // TODO use forte - color.par_iter().for_each(chunk_closure); - } else { - color.iter().for_each(chunk_closure); - }; - } -} -- cgit v1.3.1