/// Global render configuration
///
/// Variables are ordered to require no padding
struct Config {
/// Screen-to-model transform matrix, converting pixels to model space
///
/// Note that each row is padded to 16 bytes
mat: mat3x3f,
/// Mapping from X, Y, Z to input indices
axes: vec3u,
/// Next empty position in `tape_data`
tape_data_offset: atomic<u32>,
/// Render size, in voxels (always a multiple of 64)
render_size: vec2u,
/// Image size, in pixels
image_size: vec2u,
/// Z position at which to render the image
z: f32,
/// Flag indicating whether to recurse down to individual pixels
pixel_perfect: u32,
/// Length of the `tape_data` array (in `u32` words)
tape_data_capacity: u32,
/// Padding
_pad: u32,
/// Tape data, tightly packed per-tile (flexible array member)
tape_data: array<TapeWord>,
}
/// Common render configuration and tape data
@group(0) @binding(0) var<storage, read_write> config: Config;
/// Map from tile to tape index
///
/// See the comment in the computation of `tile_tape_words` for details on how
/// this buffer is packed.
@group(0) @binding(1) var<storage, read_write> tile_tape: array<u32>;
/// Array of values for (non-xyz) variables
@group(0) @binding(2) var<storage, read> var_values: array<f32>;
/// For a given position and recursion level, return the offset into `tile_tape`
fn get_tape_offset_for_level(corner_pos: vec2u, level: u32) -> u32 {
var offset = 0u; // current position in the buffer
let size64 = config.render_size / 64;
if level == 64u {
// 64^2 root tile tapes are densely packed
let corner_pos64 = corner_pos / 64;
let index64 = corner_pos64.x + corner_pos64.y * size64.x;
return index64;
}
offset += size64.x * size64.y;
let size8 = config.render_size / 8;
if level == 8u {
let corner_pos8 = corner_pos / 8;
return offset + corner_pos8.x + corner_pos8.y * size8.x;
}
// invalid level, return the base tape
return 0;
}