545 lines
17 KiB
WebGPU Shading Language
545 lines
17 KiB
WebGPU Shading Language
struct PushConstants
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{
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view_projection: mat4x4<f32>,
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transform: mat4x4<f32>,
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eye_position: vec3<f32>,
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root_color: vec4<f32>,
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root_subdivided: u32,
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}
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var<push_constant> constants: PushConstants;
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struct VertexOutput
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{
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@builtin(position) pos: vec4<f32>,
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@location(0) eye_pos: vec3<f32>,
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@location(1) world_pos: vec3<f32>,
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@location(2) cube_pos: vec3<f32>,
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@location(3) root_color: vec4<f32>,
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@location(4) root_subdivided: u32
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}
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@vertex
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fn vertex_main(@builtin(vertex_index) index: u32, @builtin(instance_index) instance_index: u32) -> VertexOutput
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{
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let side_length = u32(100);
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let offset = vec3<f32>(vec3<u32>(
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instance_index % side_length,
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(instance_index / side_length) % side_length,
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instance_index / (side_length * side_length)
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));
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let cube_vertices = array<vec3<f32>, 8>(
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vec3<f32>(0., 0., 0.),
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vec3<f32>(0., 0., 1.),
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vec3<f32>(1., 0., 1.),
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vec3<f32>(1., 0., 0.),
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vec3<f32>(0., 1., 0.),
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vec3<f32>(0., 1., 1.),
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vec3<f32>(1., 1., 1.),
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vec3<f32>(1., 1., 0.),
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);
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let cube_faces = array<u32, 24>(
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// Bottom face
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1, 0, 2, 3,
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// Top face
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4, 5, 7, 6,
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// Side faces
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0, 1, 4, 5,
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1, 2, 5, 6,
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2, 3, 6, 7,
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3, 0, 7, 4,
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);
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let quad_index = index / (3 * 2);
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let triangle_index = index % (3 * 2);
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let triangle_map = array<u32, 6>(
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0, 1, 2, 1, 3, 2
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);
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let vertex = cube_vertices[cube_faces[quad_index * 4 + triangle_map[triangle_index]]];
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var output: VertexOutput;
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output.pos = constants.view_projection * constants.transform * vec4<f32>(vertex + offset, 1.);
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output.eye_pos = constants.eye_position;
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output.world_pos = (constants.transform * vec4<f32>(vertex + offset, 1.)).xyz;
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output.cube_pos = offset;
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output.root_color = constants.root_color;
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output.root_subdivided = constants.root_subdivided;
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return output;
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}
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fn is_voxel(p: vec3<i32>) -> bool
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{
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//return true;
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return length(vec3<f32>(p) - vec3<f32>(16.)) < 16.;
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}
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const N: u32 = 4;
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const N3: u32 = N * N * N;
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const MAX_DEPTH: u32 = 4;
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struct StructureTile
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{
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children: array<u32, 64>,
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}
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struct ColorTile
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{
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colors: array<vec4<f32>, 64>
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}
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// BG
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@group(0) @binding(0) var<storage> structure_tiles : array<StructureTile>;
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@group(0) @binding(1) var<storage> color_tiles : array<ColorTile>;
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fn traverse2(max_depth: u32, root_color: vec4<f32>, root_subdivided: bool, eye_pos: vec3<f32>, ray_dir: vec3<f32>) -> vec4<f32>
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{
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if max_depth == 0 || !root_subdivided
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{
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return inferno_quintic(0.);
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return root_color;
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}
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var node_structs = structure_tiles[0];
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var node_colors = color_tiles[0];
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var node_tile_idx = u32(0);
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//var stack = array<u32, 4>(0, 0, 0, 0);
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var stack_struct = array<StructureTile, 4>(node_structs, node_structs, node_structs, node_structs);
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var stack_colors = array<ColorTile, 4>(node_colors, node_colors, node_colors, node_colors);
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var voxel_scale = N * N * N;
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var scale_exp = 3;
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let voxel_scale_lut = array<u32, 4>(
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1,
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N,
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N * N,
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N * N * N
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);
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let dist = 1. / ray_dir;
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let origin = eye_pos * 256.;
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var pos = origin; // In voxel space
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let offset = - origin * dist;
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let wall_offset = select(vec3(0.), vec3(1.), ray_dir > vec3(0.));
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var voxel_pos = clamp(vec3<u32>(floor(pos)), vec3(0), vec3(N * N * N * N - 1));
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let max = 20.;
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for(var iter = 0; iter < 60; iter++)
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{
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var voxel_pos = vec3<u32>(floor(pos));
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var child_pos = voxel_pos >> vec3<u32>(scale_exp * 2);
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var local_child_pos = child_pos & vec3<u32>(3);
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var child_idx = local_child_pos.x + local_child_pos.y * N + local_child_pos.z * N * N;
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while (node_structs.children[child_idx] >> 31) != 0 && (u32(4 - scale_exp) < max_depth)
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{
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//stack[scale_exp] = u32(node_tile_idx);
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stack_struct[scale_exp] = node_structs;
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stack_colors[scale_exp] = node_colors;
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scale_exp -= 1;
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voxel_scale = voxel_scale_lut[scale_exp];
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node_tile_idx = node_structs.children[child_idx] & 0x3fffffff;
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node_structs = structure_tiles[node_tile_idx];
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node_colors = color_tiles[node_tile_idx];
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child_pos = voxel_pos >> vec3<u32>(scale_exp * 2);
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local_child_pos = child_pos & vec3<u32>(3);
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child_idx = local_child_pos.x + local_child_pos.y * N + local_child_pos.z * N * N;
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}
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if node_colors.colors[child_idx].w != 0
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{
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return inferno_quintic(f32(iter) / max);
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return node_colors.colors[child_idx];
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}
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// Compute intersection
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let global_voxel = vec3<f32>(child_pos * voxel_scale);
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let cell_max = global_voxel + vec3<f32>(voxel_scale) * wall_offset;
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let t1 = fma(dist, cell_max, offset);
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let t_far = min(t1.x, min(t1.y, t1.z)) + 0.001;
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pos = origin + t_far * ray_dir;
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let diff = vec3<u32>(pos + 256) ^ vec3<u32>(global_voxel + 256);
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let diff_exp = (firstLeadingBit((diff.x | diff.y | diff.z)) >> 1);
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if diff_exp > 3
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{
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return inferno_quintic(f32(iter) / max);
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discard;
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}
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if diff_exp > u32(scale_exp)
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{
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scale_exp = i32(diff_exp);
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voxel_scale = voxel_scale_lut[scale_exp];
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//node_tile_idx = stack[scale_exp];
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node_structs = stack_struct[scale_exp];
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node_colors = stack_colors[scale_exp];
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}
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}
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return vec4(1., 0., 1., 1.);
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}
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//@fragment
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fn traverse(max_depth: u32, root_color: vec4<f32>, root_subdivided: bool, eye_pos: vec3<f32>, ray_dir: vec3<f32>) -> vec4<f32>
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{
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if max_depth == 0 || !root_subdivided
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{
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return root_color;
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}
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let chunk_size = N * N * N * N;
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let depth_child_size_lut = array<u32, 4>(N*N*N, N*N, N, 1);
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var stack_nodes = array<i32, 4>(0, 0, 0, 0);
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var stack_child_pos = array<vec3<i32>, 4>(vec3(0), vec3(0), vec3(0), vec3(0));
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var stack_node_offset = array<vec3<i32>, 4>(vec3(0), vec3(0), vec3(0), vec3(0));
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var stack_ptr = 0;
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var current_child_size = chunk_size / N;
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var current_child_pos = vec3(0);
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var current_node_offset = vec3(0);
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var current_depth = 1;
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var current_tile_index = 0;
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var current_children_data = structure_tiles[current_tile_index];
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var current_children_colors = color_tiles[current_tile_index];
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// Intersection parameters
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let dist = 1. / ray_dir;
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var offset = - (eye_pos * f32(chunk_size)) * dist;
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// Interesect with root
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let t0 = fma(dist, vec3<f32>(0.), offset);
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let t1 = fma(dist, vec3<f32>(chunk_size), offset);
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let tmin = min(t0, t1);
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let tmax = max(t0, t1);
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let t_near = max(max(tmin.x, max(tmin.y, tmin.z)), 0.);
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let t_far = min(tmax.x, min(tmax.y, tmax.z));
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let step = select(vec3(-1), vec3(1), ray_dir > vec3(0.));
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var start_pos = (eye_pos * f32(chunk_size)) + t_near * ray_dir;
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var hit_pos = start_pos;
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offset = - start_pos * dist;
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var t = 0.;
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current_child_pos = vec3(
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clamp(i32(floor(start_pos.x)), 0, i32(chunk_size) - 1),
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clamp(i32(floor(start_pos.y)), 0, i32(chunk_size) - 1),
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clamp(i32(floor(start_pos.z)), 0, i32(chunk_size) - 1),
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) / i32(current_child_size);
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//return vec4<f32>(vec3<f32>(current_child_pos) / 4., 1.);
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for(var iter = 0; iter < 300; iter++)
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{
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// Retrieve current child information
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let child_index = current_child_pos.x + current_child_pos.y * i32(N) + current_child_pos.z * i32(N * N);
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let child_u32 = current_children_data.children[child_index];
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let child_subdivided = (child_u32 >> 31) == 1;
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let child_color = current_children_colors.colors[child_index];
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if child_color.w != 0. // Child is solid
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&& (max_depth == u32(current_depth) || !child_subdivided)
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{
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// Sample mat
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let voxel_pos = current_node_offset + current_child_pos * i32(current_child_size);
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//return vec4(child_color.xyz, 1.);
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return child_color+ vec4<f32>(vec3<f32>(f32(iter) / 200.), 1.);
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}
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// Advance
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// Project current child
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let global_child_pos = current_child_pos * i32(current_child_size) + current_node_offset;
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let t0 = fma(dist, vec3<f32>(global_child_pos), offset);
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let t1 = fma(dist, vec3<f32>(global_child_pos) + vec3<f32>(current_child_size), offset);
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let tmin = min(t0, t1);
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let tmax = max(t0, t1);
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let t_near = max(max(tmin.x, max(tmin.y, tmin.z)), 0.);
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let t_far = min(tmax.x, min(tmax.y, tmax.z));
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if child_subdivided
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{
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// Push operation
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stack_nodes[stack_ptr] = current_tile_index;
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stack_child_pos[stack_ptr] = current_child_pos;
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stack_node_offset[stack_ptr] = current_node_offset;
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stack_ptr ++;
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// Retrieve child information
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current_tile_index = i32(child_u32 & 0x3fffffff);
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current_children_data = structure_tiles[current_tile_index];
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current_children_colors = color_tiles[current_tile_index];
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// Determine child of the child
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let hit_pos = start_pos + ray_dir * t_near;
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let next_node_offset = current_node_offset + current_child_pos * i32(current_child_size);
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let next_child_size = current_child_size / N;
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current_child_pos =
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(clamp(vec3<i32>(floor(hit_pos)), global_child_pos, global_child_pos + vec3(i32(current_child_size - 1))) - next_node_offset) / i32(next_child_size);
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current_child_size = next_child_size;
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current_node_offset = next_node_offset;
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current_depth ++;
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}
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else
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{
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// ADVANCE
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let advance_mask = min_mask3i32(tmax);
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let next_child = current_child_pos + advance_mask * step;
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if any(next_child < vec3(0)) || any(next_child >= vec3(i32(N)))
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{
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let aligned_child = select(vec3(0), vec3(i32(N)), vec3(step) > vec3(0));
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let masked_aligned = advance_mask * ((aligned_child * i32(current_child_size)) + current_node_offset);
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let exiting_axis = masked_aligned.x + masked_aligned.y + masked_aligned.z + 256;
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// HARDCODED FOR N = 4
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let ctz = countTrailingZeros(exiting_axis) / 2;
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let exiting_depth = 4 - ctz;
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if exiting_depth == 0 // Getting out of root
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{
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return vec4(f32(iter) / 200.);
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discard;
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}
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// Restore destination depth
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current_depth = exiting_depth;
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stack_ptr = current_depth - 1;
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current_tile_index = stack_nodes[stack_ptr];
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current_children_data = structure_tiles[current_tile_index];
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current_children_colors = color_tiles[current_tile_index];
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current_node_offset = stack_node_offset[stack_ptr];
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current_child_pos = stack_child_pos[stack_ptr] + step * advance_mask;
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current_child_size = depth_child_size_lut[current_depth - 1];
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}else{
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current_child_pos = next_child;
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}
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}
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}
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return vec4<f32>(100., 0., 100., 100.);
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}
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fn sample_mat(pos: vec3<i32>) -> f32
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{
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var voxel = pos;
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var div = 1;
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var overlay = 1.;
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for(var i = 1; i <= 4; i++)
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{
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let x = (voxel.x / div + voxel.y / div + voxel.z / div) % 2 == 0;
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overlay -= select(0., 1. / (f32(i) * 2.5), x);
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div *= 4;
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}
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return overlay;
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}
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@fragment
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fn fragment_tree_main(in: VertexOutput) -> @location(0) vec4<f32>
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{
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var hit_pos = vec3(0.);
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let dir = normalize(in.world_pos.xyz - in.eye_pos);
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let chunk_size = 4 * 4 * 4 * 4;
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if all(in.eye_pos > in.cube_pos) && all(in.eye_pos < (in.cube_pos + vec3(1.)))
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{
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hit_pos = in.eye_pos - in.cube_pos;
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}
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else
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{
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let aabb = intersectAABB(in.eye_pos, dir, in.cube_pos, in.cube_pos + vec3(1.));
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hit_pos = in.eye_pos + aabb.x * dir - in.cube_pos;
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}
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let cube_color = vec3(1.);
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var pos = hit_pos * f32(chunk_size);
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let step = vec3<i32>(
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select(-1, 1, dir.x > 0.),
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select(-1, 1, dir.y > 0.),
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select(-1, 1, dir.z > 0.)
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);
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var voxel = vec3<i32>(
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clamp(i32(floor(pos.x)), 0, chunk_size - 1),
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clamp(i32(floor(pos.y)), 0, chunk_size - 1),
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clamp(i32(floor(pos.z)), 0, chunk_size - 1),
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);
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var div = 1;
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var overlay = 1.;
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for(var i = 1; i <= 4; i++)
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{
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let x = (voxel.x / div + voxel.y / div + voxel.z / div) % 2 == 0;
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overlay -= select(0., 1. / (f32(i) * 2.5), x);
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div *= 4;
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}
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overlay = 1.;
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return overlay * traverse2(4, in.root_color, in.root_subdivided != 0, hit_pos, dir);
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}
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@fragment
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fn fragment_main(in: VertexOutput) -> @location(0) vec4<f32>
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{
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let chunk_size = 32;
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let dir = normalize(in.world_pos.xyz - in.eye_pos);
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var hit_pos = vec3(0.);
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if all(in.eye_pos > in.cube_pos) && all(in.eye_pos < (in.cube_pos + vec3(1.)))
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{
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hit_pos = in.eye_pos - in.cube_pos;
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}
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else
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{
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let aabb = intersectAABB(in.eye_pos, dir, in.cube_pos, in.cube_pos + vec3(1.));
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hit_pos = in.eye_pos + aabb.x * dir - in.cube_pos;
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}
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let cube_color = vec3(1.);
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var pos = hit_pos * f32(chunk_size);
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let step = vec3<i32>(
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select(-1, 1, dir.x > 0.),
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select(-1, 1, dir.y > 0.),
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select(-1, 1, dir.z > 0.)
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);
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var voxel = vec3<i32>(
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clamp(i32(floor(pos.x)), 0, chunk_size - 1),
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clamp(i32(floor(pos.y)), 0, chunk_size - 1),
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clamp(i32(floor(pos.z)), 0, chunk_size - 1),
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);
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let tDelta = vec3<f32>(1.) / abs(dir);
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var dist = vec3(
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select(pos.x - f32(voxel.x), f32(voxel.x) + 1. - pos.x, step.x > 0),
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select(pos.y - f32(voxel.y), f32(voxel.y) + 1. - pos.y, step.y > 0),
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select(pos.z - f32(voxel.z), f32(voxel.z) + 1. - pos.z, step.z > 0),
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);
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var tMax = dist * tDelta;
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//var tMax = (ceil(vec3<f32>(step) * pos) - vec3<f32>(step) * pos) * tDelta;
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var t = 0.;
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// Loop
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loop
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{
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if any(voxel >= vec3<i32>(chunk_size)) || any(voxel < vec3<i32>(0))
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{
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discard;
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//break;
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}
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// Sample
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if is_voxel(voxel)
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{
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// Compute normal
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let voxel_center = vec3<f32>(voxel) + vec3(0.5);
|
|
let pos = pos + t * dir;
|
|
|
|
let norm_dir = normalize(pos - voxel_center);
|
|
let norm_dir_max = max_mask3 (abs(norm_dir));
|
|
let norm = sign(norm_dir * norm_dir_max);
|
|
|
|
let color = (1.2 + dot(norm, vec3<f32>(0., 1., 0.))) * 0.5;
|
|
return vec4(vec3<f32>(color) * cube_color, 1.);
|
|
return vec4(vec3<f32>(color), 1.);
|
|
}
|
|
|
|
// Select which to step
|
|
let mask = min_mask3(tMax);
|
|
let delta = tDelta * mask;
|
|
|
|
let next_t_vec = tMax * mask;
|
|
t = next_t_vec.x + next_t_vec.y + next_t_vec.z;
|
|
|
|
tMax += delta;
|
|
|
|
voxel += step * vec3<i32>(mask);
|
|
|
|
}
|
|
|
|
// Ray direction
|
|
return vec4<f32>(1., 0., 1., 1.);
|
|
}
|
|
|
|
fn min_mask3(v: vec3<f32>) -> vec3<f32>
|
|
{
|
|
let min = min(v.x, min(v.y, v.z));
|
|
|
|
return vec3<f32>
|
|
(
|
|
select(0., 1., v.x == min),
|
|
select(0., 1., v.y == min),
|
|
select(0., 1., v.z == min),
|
|
);
|
|
}
|
|
|
|
fn min_mask3i32(v: vec3<f32>) -> vec3<i32>
|
|
{
|
|
let min = min(v.x, min(v.y, v.z));
|
|
|
|
return vec3<i32>
|
|
(
|
|
select(0, 1, v.x == min),
|
|
select(0, 1, v.y == min),
|
|
select(0, 1, v.z == min),
|
|
);
|
|
}
|
|
|
|
fn max_mask3(v: vec3<f32>) -> vec3<f32>
|
|
{
|
|
let max = max(v.x, max(v.y, v.z));
|
|
|
|
return vec3<f32>
|
|
(
|
|
select(0., 1., v.x == max),
|
|
select(0., 1., v.y == max),
|
|
select(0., 1., v.z == max),
|
|
);
|
|
}
|
|
|
|
fn intersectAABB(rayOrigin: vec3<f32>, rayDir: vec3<f32>, boxMin: vec3<f32>, boxMax: vec3<f32>) -> vec2<f32> {
|
|
let tMin = (boxMin - rayOrigin) / rayDir;
|
|
let tMax = (boxMax - rayOrigin) / rayDir;
|
|
let t1 = min(tMin, tMax);
|
|
let t2 = max(tMin, tMax);
|
|
let tNear = max(max(t1.x, t1.y), t1.z);
|
|
let tFar = min(min(t2.x, t2.y), t2.z);
|
|
return vec2(tNear, tFar);
|
|
};
|
|
|
|
fn inferno_quintic( xx: f32 ) -> vec4<f32>
|
|
{
|
|
let x = saturate(xx);
|
|
let x1 = vec4( 1.0, x, x * x, x * x * x ); // 1 x x2 x3
|
|
let x2 = x1 * x1.w * x; // x4 x5 x6 x7
|
|
return vec4(saturate( vec3(
|
|
dot( x1.xyzw, vec4( -0.027780558, 1.228188385, 0.278906882, 3.892783760 ) ) + dot( x2.xy, vec2( -8.490712758, 4.069046086 ) ),
|
|
dot( x1.xyzw, vec4( 0.014065206, 0.015360518, 1.605395918, -4.821108251 ) ) + dot( x2.xy, vec2( 8.389314011, -4.193858954 ) ),
|
|
dot( x1.xyzw, vec4( -0.019628385, 3.122510347, -5.893222355, 2.798380308 ) ) + dot( x2.xy, vec2( -3.608884658, 4.324996022 ) ) ) ), 1.);
|
|
}
|