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Remove padding early to reduce memory #6

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Remove padding early to reduce memory #6

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e822809
Remove padding early to reduce memory
duckdoom5 May 14, 2024
8d6ed1a
Remove face mask padded values
duckdoom5 May 14, 2024
808a94a
Also don't need the extra data in axisCols
duckdoom5 May 14, 2024
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117 changes: 79 additions & 38 deletions src/greedy_mesher_optimized.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -22,26 +22,50 @@ pub fn build_chunk_mesh(chunks_refs: &ChunksRefs, lod: Lod) -> Option<ChunkMesh>
let mut mesh = ChunkMesh::default();

// solid binary for each x,y,z axis (3)
let mut axis_cols = [[[0u64; CHUNK_SIZE_P]; CHUNK_SIZE_P]; 3];
let mut axis_cols = [[[0u64; CHUNK_SIZE]; CHUNK_SIZE]; 3];

// the cull mask to perform greedy slicing, based on solids on previous axis_cols
let mut col_face_masks = [[[0u64; CHUNK_SIZE_P]; CHUNK_SIZE_P]; 6];
let mut col_face_masks = [[[0u32; CHUNK_SIZE]; CHUNK_SIZE]; 6];

#[inline]
fn add_voxel_to_axis_cols(
b: &crate::voxel::BlockData,
x: usize,
y: usize,
z: usize,
axis_cols: &mut [[[u64; 34]; 34]; 3],
axis_cols: &mut [[[u64; CHUNK_SIZE]; CHUNK_SIZE]; 3],
) {
if b.block_type.is_solid() {
// x,z - y axis
axis_cols[0][z][x] |= 1u64 << y as u64;
axis_cols[0][z][x] |= 1u64 << (y + 1) as u64;
// z,y - x axis
axis_cols[1][y][z] |= 1u64 << x as u64;
axis_cols[1][y][z] |= 1u64 << (x + 1) as u64;
// x,y - z axis
axis_cols[2][y][x] |= 1u64 << z as u64;
axis_cols[2][y][x] |= 1u64 << (z + 1) as u64;
}
}

#[inline]
fn add_neighbour_voxel_to_axis_cols(
b: &crate::voxel::BlockData,
x: usize,
y: usize,
z: usize,
axis_cols: &mut [[[u64; CHUNK_SIZE]; CHUNK_SIZE]; 3],
) {
if b.block_type.is_solid() {
// x,z - y axis
if z >= 0 && z < CHUNK_SIZE && x >= 0 && x < CHUNK_SIZE {
axis_cols[0][z][x] |= 1u64 << (y + 1) as u64;
}
// z,y - x axis
if y >= 0 && y < CHUNK_SIZE && z >= 0 && z < CHUNK_SIZE {
axis_cols[1][y][z] |= 1u64 << (x + 1) as u64;
}
// x,y - z axis
if y >= 0 && y < CHUNK_SIZE && x >= 0 && x < CHUNK_SIZE {
axis_cols[2][y][x] |= 1u64 << (z + 1) as u64;
}
}
}

Expand All @@ -55,51 +79,74 @@ pub fn build_chunk_mesh(chunks_refs: &ChunksRefs, lod: Lod) -> Option<ChunkMesh>
1 => 0,
_ => (z * CHUNK_SIZE + y) * CHUNK_SIZE + x,
};
add_voxel_to_axis_cols(&chunk.voxels[i], x + 1, y + 1, z + 1, &mut axis_cols)
add_voxel_to_axis_cols(&chunk.voxels[i], x, y, z, &mut axis_cols)
}
}
}

// neighbor chunk voxels.
// note(leddoo): couldn't be bothered to optimize these.
// might be worth it though. together, they take
// almost as long as the entire "inner chunk" loop.
for z in [0, CHUNK_SIZE_P - 1] {
// Process z-static faces (front and back) (<0-31>,<0-31>,0), (<0-31>,<0-31>,31)
for x in 0..CHUNK_SIZE_P {
for y in 0..CHUNK_SIZE_P {
for x in 0..CHUNK_SIZE_P {
let pos = ivec3(x as i32, y as i32, z as i32) - IVec3::ONE;
add_voxel_to_axis_cols(chunks_refs.get_block(pos), x, y, z, &mut axis_cols);
}
let pos = ivec3(x as i32, y as i32, 0) - IVec3::ONE;
add_neighbour_voxel_to_axis_cols(chunks_refs.get_block(pos), pos.x, pos.y, pos.z, &mut axis_cols);
}
}
for z in 0..CHUNK_SIZE_P {
for y in [0, CHUNK_SIZE_P - 1] {
for x in 0..CHUNK_SIZE_P {
let pos = ivec3(x as i32, y as i32, z as i32) - IVec3::ONE;
add_voxel_to_axis_cols(chunks_refs.get_block(pos), x, y, z, &mut axis_cols);
}
for x in 0..CHUNK_SIZE_P {
for y in 0..CHUNK_SIZE_P {
let pos = ivec3(x as i32, y as i32, CHUNK_SIZE_P - 1) - IVec3::ONE;
add_neighbour_voxel_to_axis_cols(chunks_refs.get_block(pos), pos.x, pos.y, pos.z, &mut axis_cols);
}
}
for z in 0..CHUNK_SIZE_P {
for x in [0, CHUNK_SIZE_P - 1] {
for y in 0..CHUNK_SIZE_P {
let pos = ivec3(x as i32, y as i32, z as i32) - IVec3::ONE;
add_voxel_to_axis_cols(chunks_refs.get_block(pos), x, y, z, &mut axis_cols);
}

// Process x-static faces (left and right) (0,<0-31>,<1-30>), (31,<0-31>,<1-30>). Skip corners (already processed)
for z in [1, CHUNK_SIZE_P - 1] {
for y in 0..CHUNK_SIZE_P {
let pos = ivec3(0, y as i32, z as i32) - IVec3::ONE;
add_neighbour_voxel_to_axis_cols(chunks_refs.get_block(pos), pos.x, pos.y, pos.z, &mut axis_cols);
}
for y in 0..CHUNK_SIZE_P {
let pos = ivec3(CHUNK_SIZE_P - 1, y as i32, z as i32) - IVec3::ONE;
add_neighbour_voxel_to_axis_cols(chunks_refs.get_block(pos), pos.x, pos.y, pos.z, &mut axis_cols);
}
}


// Process y-static faces (top and bottom) (<1-30>,0,<1-30>), (<1-30>,31,<1-30>). Skip corners (already processed)
for z in [1, CHUNK_SIZE_P - 1] {
for x in [1, CHUNK_SIZE_P - 1] {
std::forward<F>(callback)(vec3u{ x, 0, z });
std::forward<F>(callback)(vec3u{ x, ExtentMask, z });

let pos_t = ivec3(x as i32, 0, z as i32) - IVec3::ONE;
add_neighbour_voxel_to_axis_cols(chunks_refs.get_block(pos_t), pos_t.x, pos_t.y, pos_t.z, &mut axis_cols);

let pos_b = ivec3(x as i32, CHUNK_SIZE_P - 1, z as i32) - IVec3::ONE;
add_neighbour_voxel_to_axis_cols(chunks_refs.get_block(pos_b), pos_b.x, pos_b.y, pos_b.z, &mut axis_cols);
}
}

#[inline]
fn remove_padding(col: u64) {
// removes the right most padding value, because it's invalid
col >>= 1;
// removes the left most padding value, because it's invalid
col &= !(1 << CHUNK_SIZE as u64);

return col as u32;
}

// face culling
for axis in 0..3 {
for z in 0..CHUNK_SIZE_P {
for x in 0..CHUNK_SIZE_P {
for z in 0..CHUNK_SIZE {
for x in 0..CHUNK_SIZE {
// set if current is solid, and next is air
let col = axis_cols[axis][z][x];

// sample descending axis, and set true when air meets solid
col_face_masks[2 * axis + 0][z][x] = col & !(col << 1);
col_face_masks[2 * axis + 0][z][x] = remove_padding(col & !(col << 1));
// sample ascending axis, and set true when air meets solid
col_face_masks[2 * axis + 1][z][x] = col & !(col >> 1);
col_face_masks[2 * axis + 1][z][x] = remove_padding(col & !(col >> 1));
}
}
}
Expand All @@ -123,13 +170,7 @@ pub fn build_chunk_mesh(chunks_refs: &ChunksRefs, lod: Lod) -> Option<ChunkMesh>
for axis in 0..6 {
for z in 0..CHUNK_SIZE {
for x in 0..CHUNK_SIZE {
// skip padded by adding 1(for x padding) and (z+1) for (z padding)
let mut col = col_face_masks[axis][z + 1][x + 1];

// removes the right most padding value, because it's invalid
col >>= 1;
// removes the left most padding value, because it's invalid
col &= !(1 << CHUNK_SIZE as u64);
let mut col = col_face_masks[axis][z][x];

while col != 0 {
let y = col.trailing_zeros();
Expand Down