887 lines
39 KiB
Rust
887 lines
39 KiB
Rust
//! glTF 2.0 import (`.glb`, `.gltf` with its `.bin` files next to it or embedded as `data:`
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//! URIs): triangle meshes become mesh bodies, the node tree a component plan (#1505).
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//!
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//! The `gltf` crate reads the JSON document and checks its references; the GLB container and
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//! every buffer, view and accessor are read here, with each length checked against the bytes
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//! that are really there. The file is untrusted: sizes, counts, nesting and the nodes visited
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//! are capped, and anything wrong is an error or a warning, never a panic.
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//!
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//! Geometry: glTF is in metres with Y up. Coordinates are scaled to millimetres here; turning
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//! Y up into Z up is the caller's (the import component's placement, as for STEP). A node's
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//! placement becomes an occurrence when it can be one (the rigid part of its transform); what
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//! is left (scale, shear, a mirror) is baked into the node's meshes, so the hierarchy is kept
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//! even under a scaled parent. A node that places the same mesh (and the same subtree) the
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//! same way as an earlier one is another occurrence of that node's component.
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//!
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//! Materials: one body per mesh and material; the material's base colour (linear in glTF,
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//! sRGB here), alpha (blended materials only) and metallic/roughness factors give the body's
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//! look. Textures are not read.
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use std::collections::HashMap;
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use std::hash::{Hash, Hasher};
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use gltf::accessor::{DataType, Dimensions};
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use gltf::mesh::Mode;
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use solidcraft_doc::appearance::Look;
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use solidcraft_doc::{Mat, MeshData, mat_mul};
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use solidcraft_geom::Vec3;
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use crate::{IoError, MAX_3MF_BYTES, MeshFeature, Result};
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/// Largest `.glb` / `.gltf` file read.
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pub const MAX_GLTF_BYTES: usize = MAX_3MF_BYTES;
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/// Most bytes of external and embedded buffers read for one file.
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const MAX_BUFFER_BYTES: usize = 1 << 30;
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/// Most vertices and triangles, over all bodies.
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const MAX_VERTICES: usize = 20_000_000;
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const MAX_TRIANGLES: usize = 20_000_000;
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/// Most node placements followed (a node tree that shares or loops is cut off here).
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const MAX_PLACEMENTS: usize = 100_000;
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/// Deepest nesting kept as components; deeper nodes are baked into their parent's.
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const MAX_COMPONENT_DEPTH: usize = 32;
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/// Deepest nesting followed at all.
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const MAX_DEPTH: usize = 64;
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/// Most components one file makes.
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const MAX_COMPONENTS: usize = 5_000;
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/// Millimetres in a metre.
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const MM: f64 = 1000.0;
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/// Is this a glTF file (`.glb`, `.gltf`, any case)?
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pub fn is_gltf_path(path: &str) -> bool {
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std::path::Path::new(path).extension().and_then(|e| e.to_str()).is_some_and(|e| e.eq_ignore_ascii_case("glb") || e.eq_ignore_ascii_case("gltf"))
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}
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/// A placement of a component of the plan in another (`parent`, or the import's own component
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/// when `None`), by a rigid transform in millimetres.
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#[derive(Clone, Debug, PartialEq)]
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pub struct PlanPlace {
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pub slot: usize,
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pub parent: Option<usize>,
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pub transform: Mat,
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}
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/// How a glTF file's nodes become components below the import's own: `slots` are the
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/// components (by name), `places` their placements (the first one makes the component, later
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/// ones are more occurrences of it), and `bodies` the component each mesh body goes into
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/// (`None`: the import's own). Each body's coordinates are already in its component's frame.
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#[derive(Clone, Debug, Default, PartialEq)]
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pub struct MeshPlan {
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pub slots: Vec<String>,
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pub places: Vec<PlanPlace>,
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pub bodies: Vec<Option<usize>>,
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}
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/// A glTF file read for import.
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pub struct GltfImport {
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/// The MeshImport feature: one mesh body per glTF mesh and material.
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pub feature: MeshFeature,
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/// Where the bodies go.
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pub plan: MeshPlan,
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/// Each body's look from its material (`None`: no material).
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pub looks: Vec<Option<Look>>,
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}
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impl GltfImport {
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/// Build every body where its component's first placement puts it, in the import's own
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/// frame, and drop the components.
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pub fn flatten(&mut self) {
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if self.plan.places.is_empty() {
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return;
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}
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let mut world: Vec<Option<Mat>> = vec![None; self.plan.slots.len()];
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for p in &self.plan.places {
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let parent = match p.parent {
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None => Some(solidcraft_doc::IDENTITY),
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Some(q) => world.get(q).copied().flatten(),
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};
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if let (Some(parent), Some(slot @ None)) = (parent, world.get_mut(p.slot)) {
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*slot = Some(mat_mul(&parent, &p.transform));
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}
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}
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if let solidcraft_doc::FeatureKind::MeshImport { meshes, .. } = &mut self.feature.kind {
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for (m, slot) in meshes.iter_mut().zip(&self.plan.bodies) {
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let Some(frame) = slot.and_then(|s| world.get(s).copied().flatten()) else { continue };
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for p in m.positions.as_chunks_mut::<3>().0 {
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let q = solidcraft_doc::apply_point(&frame, Vec3::new(p[0], p[1], p[2]));
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*p = [q.x, q.y, q.z];
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}
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}
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}
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self.plan = MeshPlan::default();
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}
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}
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/// Reads an external file the glTF names (`uri`, relative to the glTF file's folder, already
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/// percent-decoded and checked to stay in that folder).
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pub type Loader<'a> = &'a mut dyn FnMut(&str) -> std::result::Result<Vec<u8>, String>;
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/// Read a `.glb` or `.gltf` file (`file` names it; its stem names the meshes when nothing in the
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/// file does). External buffers are read through `load`.
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pub fn read_gltf(bytes: &[u8], file: &str, load: Loader<'_>) -> Result<GltfImport> {
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if bytes.len() > MAX_GLTF_BYTES {
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return Err(IoError::Invalid(format!("glTF file too large ({} MB)", bytes.len() >> 20)));
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}
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let (json, blob) = if bytes.starts_with(b"glTF") { split_glb(bytes)? } else { (bytes, None) };
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let doc = parse_document(json)?;
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let stem = std::path::Path::new(file)
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.file_stem()
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.map(|s| s.to_string_lossy().trim().to_string())
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.filter(|s| !s.is_empty())
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.unwrap_or_else(|| "Mesh".into());
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let mut reader = Reader {
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doc: &doc,
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buffers: Buffers { blob, data: HashMap::new(), total: 0, load },
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meshes: Vec::new(),
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looks: Vec::new(),
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plan: MeshPlan::default(),
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keys: HashMap::new(),
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has_mesh: HashMap::new(),
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open: Vec::new(),
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slot_meshes: Vec::new(),
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placements: 0,
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vertices: 0,
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triangles: 0,
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skipped: Vec::new(),
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cut_off: false,
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stem: stem.clone(),
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};
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let roots = scene_roots(&doc);
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if roots.is_empty() {
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return Err(IoError::Invalid("glTF has no nodes to import".into()));
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}
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// One root node is the import's own component (its placement baked in); several are
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// components in it.
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let units = scale(MM);
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if let [root] = roots.as_slice() {
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let m = reader.node(*root).map(|n| mat_mul(&units, &node_matrix(&n))).unwrap_or(units);
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reader.walk_flat(*root, None, &m, 0)?;
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} else {
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for r in &roots {
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reader.walk(*r, None, &units, 0)?;
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}
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}
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if reader.meshes.is_empty() {
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let why = reader.skipped.first().map(|s| format!(": {s}")).unwrap_or_default();
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return Err(IoError::Invalid(format!("glTF has no triangle meshes{why}")));
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}
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let mut warnings = Vec::new();
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if !reader.skipped.is_empty() {
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let n = reader.skipped.len();
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let first = reader.skipped.first().cloned().unwrap_or_default();
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warnings.push(if n == 1 { format!("left out: {first}") } else { format!("{n} parts left out (first: {first})") });
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}
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if reader.cut_off {
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warnings.push(format!("the node tree is too large or too deep: only the first {MAX_PLACEMENTS} placements were read"));
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}
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if doc.textures().len() > 0 {
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warnings.push("textures are not imported: bodies take their materials' base colours".into());
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}
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if doc.skins().len() > 0 || doc.animations().len() > 0 {
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warnings.push("skins and animations are not imported: meshes are placed in their rest pose".into());
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}
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let name = match reader.meshes.as_slice() {
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[only] if !only.name.trim().is_empty() => only.name.clone(),
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_ => stem,
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};
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let file_name = std::path::Path::new(file).file_name().map(|s| s.to_string_lossy().to_string()).unwrap_or_else(|| file.to_string());
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let body_names = reader.meshes.iter().map(|m| m.name.clone()).collect();
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Ok(GltfImport {
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feature: MeshFeature { name, body_names, kind: solidcraft_doc::FeatureKind::MeshImport { file: file_name, meshes: reader.meshes }, warnings },
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plan: reader.plan,
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looks: reader.looks,
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})
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}
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/// The JSON and binary chunks of a GLB container.
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fn split_glb(bytes: &[u8]) -> Result<(&[u8], Option<&[u8]>)> {
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let bad = |m: &str| IoError::Invalid(format!("GLB: {m}"));
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let u32_at = |at: usize| bytes.get(at..at + 4).and_then(|b| b.try_into().ok()).map(u32::from_le_bytes);
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let version = u32_at(4).ok_or_else(|| bad("truncated header"))?;
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if version != 2 {
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return Err(bad(&format!("version {version} is not glTF 2.0")));
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}
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let length = u32_at(8).ok_or_else(|| bad("truncated header"))? as usize;
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if length > bytes.len() {
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return Err(bad(&format!("truncated: the header says {length} bytes, the file has {}", bytes.len())));
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}
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let mut at = 12usize;
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let (mut json, mut bin) = (None, None);
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while at + 8 <= length {
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let (Some(len), Some(kind)) = (u32_at(at), u32_at(at + 4)) else { break };
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let start = at + 8;
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let end = start.checked_add(len as usize).filter(|e| *e <= length).ok_or_else(|| bad("a chunk runs past the end of the file"))?;
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let data = bytes.get(start..end).ok_or_else(|| bad("a chunk runs past the end of the file"))?;
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match kind {
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0x4E4F_534A if json.is_none() => json = Some(data),
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0x004E_4942 if json.is_some() && bin.is_none() => bin = Some(data),
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0x4E4F_534A | 0x004E_4942 => return Err(bad("chunks out of order")),
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// Chunks of unknown types are skipped, as the specification asks.
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_ => {}
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}
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at = end;
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}
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Ok((json.ok_or_else(|| bad("no JSON chunk"))?, bin))
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}
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/// Required extensions that only change how a file looks (textures, material models): the
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/// geometry reads without them.
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const LOOK_EXTENSIONS: [&str; 5] = ["KHR_texture_transform", "KHR_texture_basisu", "EXT_texture_webp", "MSFT_texture_dds", "KHR_materials_unlit"];
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/// The checked glTF document.
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fn parse_document(json: &[u8]) -> Result<gltf::Document> {
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let parsed = solidcraft_kernel::guard("glTF", || {
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let mut root: gltf::json::Root = match gltf::json::deserialize::from_slice(json) {
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Ok(r) => r,
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Err(e) => return Ok(Err(format!("not a glTF file: {e}"))),
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};
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if let Some(asset) = root.asset.version.split('.').next().filter(|major| *major != "2") {
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return Ok(Err(format!("glTF version {asset} (only 2.x is read)")));
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}
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let geometry: Vec<String> = root
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.extensions_required
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.iter()
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.filter(|e| !LOOK_EXTENSIONS.contains(&e.as_str()) && !e.starts_with("KHR_materials_") && e.as_str() != "KHR_mesh_quantization")
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.cloned()
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.collect();
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if !geometry.is_empty() {
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let hint = if geometry.iter().any(|e| e.contains("draco") || e.contains("meshopt")) {
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" (compressed meshes: save the file uncompressed)"
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} else {
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""
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};
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return Ok(Err(format!("the file needs glTF extensions that aren't supported: {}{hint}", geometry.join(", "))));
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}
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// The ones left only change looks (or are the quantized attributes read below).
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root.extensions_required.clear();
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// gltf-json's primitive check reads the POSITION accessor without a bounds check, so one
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// naming an accessor the file lacks panics inside it. The guard catches that on the
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// desktop, but in the browser a panic aborts the app: refuse such a file before (#469).
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let accessors = root.accessors.len();
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let positions = gltf::json::validation::Checked::Valid(gltf::json::mesh::Semantic::Positions);
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for (m, mesh) in root.meshes.iter().enumerate() {
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for (p, primitive) in mesh.primitives.iter().enumerate() {
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if let Some(a) = primitive.attributes.get(&positions).filter(|a| a.value() >= accessors) {
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return Ok(Err(format!(
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"invalid glTF: mesh {m}, primitive {p}: POSITION names accessor {}, but the file has {accessors}",
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a.value()
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)));
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}
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}
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}
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Ok(gltf::Document::from_json(root).map_err(|e| format!("invalid glTF: {e}")))
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});
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match parsed {
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Ok(Ok(doc)) => Ok(doc),
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Ok(Err(e)) => Err(IoError::Invalid(e)),
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Err(e) => Err(IoError::Invalid(format!("glTF could not be read: {e}"))),
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}
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}
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/// The nodes to import: the default scene's (else the first scene's), else every node that is
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/// no other's child.
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fn scene_roots(doc: &gltf::Document) -> Vec<usize> {
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if let Some(scene) = doc.default_scene().or_else(|| doc.scenes().next()) {
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return scene.nodes().map(|n| n.index()).collect();
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}
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let mut child = vec![false; doc.nodes().len()];
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for n in doc.nodes() {
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for c in n.children() {
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if let Some(x) = child.get_mut(c.index()) {
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*x = true;
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}
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}
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}
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child.iter().enumerate().filter(|(_, c)| !**c).map(|(i, _)| i).collect()
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}
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/// The file's buffers, read when first needed.
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struct Buffers<'a, 'l> {
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blob: Option<&'a [u8]>,
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data: HashMap<usize, std::result::Result<Vec<u8>, String>>,
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total: usize,
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load: Loader<'l>,
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}
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impl Buffers<'_, '_> {
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fn get(&mut self, buffer: &gltf::Buffer<'_>) -> std::result::Result<&[u8], String> {
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let index = buffer.index();
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if let gltf::buffer::Source::Bin = buffer.source() {
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let blob = self.blob.ok_or("the file has no binary chunk for its buffer")?;
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if blob.len() < buffer.length() {
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return Err(format!("the binary chunk is shorter ({} bytes) than its buffer says ({})", blob.len(), buffer.length()));
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}
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return Ok(blob);
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}
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if !self.data.contains_key(&index) {
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let r = self.read(buffer);
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if let Ok(d) = &r {
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self.total = self.total.saturating_add(d.len());
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}
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self.data.insert(index, r);
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}
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match self.data.get(&index) {
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Some(Ok(d)) => Ok(d.as_slice()),
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Some(Err(e)) => Err(e.clone()),
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None => Err("buffer".into()),
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}
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}
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fn read(&mut self, buffer: &gltf::Buffer<'_>) -> std::result::Result<Vec<u8>, String> {
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let gltf::buffer::Source::Uri(uri) = buffer.source() else { return Err("buffer".into()) };
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if buffer.length() > MAX_BUFFER_BYTES.saturating_sub(self.total) {
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return Err(format!("buffers larger than {} MB in all", MAX_BUFFER_BYTES >> 20));
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}
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let data = if let Some(rest) = uri.strip_prefix("data:") {
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let (_, payload) = rest.split_once(";base64,").ok_or("an embedded buffer that isn't base64")?;
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base64(payload).ok_or("an embedded buffer with bad base64")?
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} else {
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let path = relative_path(uri)?;
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let data = (self.load)(&path).map_err(|e| format!("buffer file `{path}`: {e}"))?;
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if data.len() > MAX_BUFFER_BYTES.saturating_sub(self.total) {
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return Err(format!("buffers larger than {} MB in all", MAX_BUFFER_BYTES >> 20));
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}
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data
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};
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if data.len() < buffer.length() {
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return Err(format!("buffer `{}` is shorter ({} bytes) than the file says ({})", short(uri), data.len(), buffer.length()));
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}
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Ok(data)
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}
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}
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/// A URI for messages: an embedded buffer by its kind only.
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fn short(uri: &str) -> String {
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if uri.starts_with("data:") { "(embedded)".into() } else { uri.chars().take(80).collect() }
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}
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/// A buffer's URI as a path relative to the glTF file, percent-decoded. Absolute paths, other
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/// schemes and paths leaving the file's folder are refused.
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fn relative_path(uri: &str) -> std::result::Result<String, String> {
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let mut bytes = Vec::with_capacity(uri.len());
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let raw = uri.as_bytes();
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let mut i = 0;
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while let Some(&b) = raw.get(i) {
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let hex = |k: usize| raw.get(k).and_then(|c| (*c as char).to_digit(16));
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match (b, hex(i + 1), hex(i + 2)) {
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(b'%', Some(h), Some(l)) => {
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bytes.push((h * 16 + l) as u8);
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i += 3;
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}
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_ => {
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bytes.push(b);
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i += 1;
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}
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}
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}
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let path = String::from_utf8_lossy(&bytes).replace('\\', "/");
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let outside = path.starts_with('/') || path.contains(':') || path.split('/').any(|p| p == "..");
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if path.trim().is_empty() || outside {
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return Err(format!("buffer `{}` is not a file next to the glTF file", short(uri)));
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}
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Ok(path)
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}
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/// Standard base64 (padding optional).
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fn base64(s: &str) -> Option<Vec<u8>> {
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let value = |c: u8| match c {
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b'A'..=b'Z' => Some(c - b'A'),
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b'a'..=b'z' => Some(c - b'a' + 26),
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b'0'..=b'9' => Some(c - b'0' + 52),
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b'+' | b'-' => Some(62),
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b'/' | b'_' => Some(63),
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_ => None,
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};
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let s = s.trim_end_matches('=').as_bytes();
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let mut out = Vec::with_capacity(s.len() / 4 * 3 + 3);
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for chunk in s.chunks(4) {
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let mut n = 0u32;
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for (k, c) in chunk.iter().enumerate() {
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n |= u32::from(value(*c)?) << (18 - 6 * k);
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||
}
|
||
let bytes = [(n >> 16) as u8, (n >> 8) as u8, n as u8];
|
||
match chunk.len() {
|
||
4 => out.extend_from_slice(&bytes),
|
||
3 => out.extend_from_slice(&bytes[..2]),
|
||
2 => out.push(bytes[0]),
|
||
_ => return None,
|
||
}
|
||
}
|
||
Some(out)
|
||
}
|
||
|
||
/// Uniform scale.
|
||
fn scale(s: f64) -> Mat {
|
||
[[s, 0.0, 0.0, 0.0], [0.0, s, 0.0, 0.0], [0.0, 0.0, s, 0.0], [0.0, 0.0, 0.0, 1.0]]
|
||
}
|
||
|
||
/// A node's transform (in the file's units).
|
||
fn node_matrix(node: &gltf::Node<'_>) -> Mat {
|
||
match node.transform() {
|
||
gltf::scene::Transform::Matrix { matrix } => matrix.map(|c| c.map(f64::from)),
|
||
gltf::scene::Transform::Decomposed { translation: t, rotation: r, scale: s } => {
|
||
let [mut x, mut y, mut z, mut w] = r.map(f64::from);
|
||
let n = (x * x + y * y + z * z + w * w).sqrt();
|
||
if n.is_finite() && n > 1e-12 {
|
||
(x, y, z, w) = (x / n, y / n, z / n, w / n);
|
||
} else {
|
||
(x, y, z, w) = (0.0, 0.0, 0.0, 1.0);
|
||
}
|
||
let [sx, sy, sz] = s.map(f64::from);
|
||
let rot = [
|
||
[1.0 - 2.0 * (y * y + z * z), 2.0 * (x * y + z * w), 2.0 * (x * z - y * w)],
|
||
[2.0 * (x * y - z * w), 1.0 - 2.0 * (x * x + z * z), 2.0 * (y * z + x * w)],
|
||
[2.0 * (x * z + y * w), 2.0 * (y * z - x * w), 1.0 - 2.0 * (x * x + y * y)],
|
||
];
|
||
let col = |c: usize, k: f64| {
|
||
let r = rot.get(c).copied().unwrap_or([0.0; 3]);
|
||
[r[0] * k, r[1] * k, r[2] * k, 0.0]
|
||
};
|
||
[col(0, sx), col(1, sy), col(2, sz), [f64::from(t[0]), f64::from(t[1]), f64::from(t[2]), 1.0]]
|
||
}
|
||
}
|
||
}
|
||
|
||
/// `m` as a rigid placement and what is left: `m = place · rest`, `rest` without translation.
|
||
/// `None` when `m` is not finite or its translation is out of range.
|
||
fn split_rigid(m: &Mat) -> Option<(Mat, Mat)> {
|
||
if !m.iter().flatten().all(|v| v.is_finite()) || m[3][..3].iter().any(|v| v.abs() > 1e9) {
|
||
return None;
|
||
}
|
||
let col = |i: usize| Vec3::new(m[i][0], m[i][1], m[i][2]);
|
||
let frame = (|| {
|
||
let x = col(0).normalized()?;
|
||
let y = (col(1) - x * col(1).dot(x)).normalized()?;
|
||
Some((x, y, x.cross(y)))
|
||
})();
|
||
let (x, y, z) = frame.unwrap_or((Vec3::X, Vec3::Y, Vec3::Z));
|
||
let place = [[x.x, x.y, x.z, 0.0], [y.x, y.y, y.z, 0.0], [z.x, z.y, z.z, 0.0], [m[3][0], m[3][1], m[3][2], 1.0]];
|
||
// The inverse of a rotation is its transpose; the translation goes with the placement.
|
||
let inverse_rotation = [[x.x, y.x, z.x, 0.0], [x.y, y.y, z.y, 0.0], [x.z, y.z, z.z, 0.0], [0.0, 0.0, 0.0, 1.0]];
|
||
let mut linear = *m;
|
||
linear[3] = [0.0, 0.0, 0.0, 1.0];
|
||
Some((place, mat_mul(&inverse_rotation, &linear)))
|
||
}
|
||
|
||
fn hash_mat(m: &Mat, h: &mut impl Hasher) {
|
||
for v in m.iter().flatten() {
|
||
// Equal to within rounding is equal.
|
||
((v * 1e6).round() as i64).hash(h);
|
||
}
|
||
}
|
||
|
||
fn det3(m: &Mat) -> f64 {
|
||
let a = |r: usize, c: usize| m[c][r];
|
||
a(0, 0) * (a(1, 1) * a(2, 2) - a(1, 2) * a(2, 1)) - a(0, 1) * (a(1, 0) * a(2, 2) - a(1, 2) * a(2, 0))
|
||
+ a(0, 2) * (a(1, 0) * a(2, 1) - a(1, 1) * a(2, 0))
|
||
}
|
||
|
||
fn clean_name(s: &str) -> String {
|
||
s.trim().chars().filter(|c| !c.is_control()).take(128).collect()
|
||
}
|
||
|
||
struct Reader<'d, 'a, 'l> {
|
||
doc: &'d gltf::Document,
|
||
buffers: Buffers<'a, 'l>,
|
||
meshes: Vec<MeshData>,
|
||
looks: Vec<Option<Look>>,
|
||
plan: MeshPlan,
|
||
/// Instance keys of the components made, to their slots.
|
||
keys: HashMap<u64, usize>,
|
||
has_mesh: HashMap<usize, bool>,
|
||
/// Each component's mesh's name.
|
||
slot_meshes: Vec<Option<String>>,
|
||
/// The components being filled (the current node's ancestors).
|
||
open: Vec<usize>,
|
||
placements: usize,
|
||
vertices: usize,
|
||
triangles: usize,
|
||
/// What was left out, and why.
|
||
skipped: Vec<String>,
|
||
cut_off: bool,
|
||
stem: String,
|
||
}
|
||
|
||
impl<'d> Reader<'d, '_, '_> {
|
||
fn node(&self, index: usize) -> Option<gltf::Node<'d>> {
|
||
self.doc.nodes().nth(index)
|
||
}
|
||
|
||
/// Does the subtree of node `index` hold a mesh? (Loops count as no.)
|
||
fn subtree_has_mesh(&mut self, index: usize, depth: usize) -> bool {
|
||
if let Some(&known) = self.has_mesh.get(&index) {
|
||
return known;
|
||
}
|
||
if depth > MAX_DEPTH {
|
||
return false;
|
||
}
|
||
// In progress: a loop back here adds nothing.
|
||
self.has_mesh.insert(index, false);
|
||
let Some(node) = self.node(index) else { return false };
|
||
let children: Vec<usize> = node.children().map(|c| c.index()).collect();
|
||
let mut any = node.mesh().is_some();
|
||
for c in children {
|
||
any |= self.subtree_has_mesh(c, depth + 1);
|
||
}
|
||
self.has_mesh.insert(index, any);
|
||
any
|
||
}
|
||
|
||
fn budget(&mut self, depth: usize) -> bool {
|
||
self.placements += 1;
|
||
if self.placements > MAX_PLACEMENTS || depth > MAX_DEPTH {
|
||
self.cut_off = true;
|
||
return false;
|
||
}
|
||
true
|
||
}
|
||
|
||
/// Node `index` under component `parent` (`None`: the import's own), whose frame sees the
|
||
/// node's parent through `outer` (the parent's leftover scale, with the units).
|
||
fn walk(&mut self, index: usize, parent: Option<usize>, outer: &Mat, depth: usize) -> Result<()> {
|
||
if !self.subtree_has_mesh(index, 0) || !self.budget(depth) {
|
||
return Ok(());
|
||
}
|
||
let Some(node) = self.node(index) else { return Ok(()) };
|
||
let local = mat_mul(outer, &node_matrix(&node));
|
||
let split = split_rigid(&local);
|
||
let Some((place, rest)) = split.filter(|_| depth < MAX_COMPONENT_DEPTH && self.plan.slots.len() < MAX_COMPONENTS) else {
|
||
// No component of its own: built where its parent is.
|
||
return self.walk_flat(index, parent, &local, depth);
|
||
};
|
||
let key = self.key(index, &rest, 0);
|
||
if let Some(&slot) = self.keys.get(&key) {
|
||
if self.open.contains(&slot) {
|
||
// A node inside itself (the file's tree loops): not followed.
|
||
self.cut_off = true;
|
||
return Ok(());
|
||
}
|
||
// The same mesh and subtree placed again: another occurrence. Placed by nodes of
|
||
// other names, it goes by its mesh's.
|
||
let name = node.name().map(clean_name).unwrap_or_default();
|
||
if let (Some(own), Some(Some(mesh))) = (self.plan.slots.get_mut(slot), self.slot_meshes.get(slot))
|
||
&& *own != name
|
||
{
|
||
own.clone_from(mesh);
|
||
}
|
||
self.plan.places.push(PlanPlace { slot, parent, transform: place });
|
||
return Ok(());
|
||
}
|
||
let slot = self.plan.slots.len();
|
||
let name = node.name().map(clean_name).filter(|n| !n.is_empty());
|
||
let name = name.or_else(|| node.mesh().and_then(|m| m.name().map(clean_name)).filter(|n| !n.is_empty()));
|
||
self.plan.slots.push(name.unwrap_or_else(|| format!("Node {index}")));
|
||
self.slot_meshes.push(node.mesh().and_then(|m| m.name().map(clean_name)).filter(|n| !n.is_empty()));
|
||
self.plan.places.push(PlanPlace { slot, parent, transform: place });
|
||
self.keys.insert(key, slot);
|
||
self.node_meshes(index, Some(slot), &rest)?;
|
||
let children: Vec<usize> = node.children().map(|c| c.index()).collect();
|
||
self.open.push(slot);
|
||
for c in children {
|
||
self.walk(c, Some(slot), &rest, depth + 1)?;
|
||
}
|
||
self.open.pop();
|
||
Ok(())
|
||
}
|
||
|
||
/// Node `index` built in component `parent`, `local` being its whole placement there (scale
|
||
/// and all): its meshes are baked with it.
|
||
fn walk_flat(&mut self, index: usize, parent: Option<usize>, local: &Mat, depth: usize) -> Result<()> {
|
||
if !self.subtree_has_mesh(index, 0) || !self.budget(depth) {
|
||
return Ok(());
|
||
}
|
||
let Some(node) = self.node(index) else { return Ok(()) };
|
||
self.node_meshes(index, parent, local)?;
|
||
let children: Vec<usize> = node.children().map(|c| c.index()).collect();
|
||
for c in children {
|
||
if depth + 1 < MAX_COMPONENT_DEPTH && self.plan.slots.len() < MAX_COMPONENTS {
|
||
self.walk(c, parent, local, depth + 1)?;
|
||
} else {
|
||
let Some(child) = self.node(c) else { continue };
|
||
let m = mat_mul(local, &node_matrix(&child));
|
||
self.walk_flat(c, parent, &m, depth + 1)?;
|
||
}
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
/// What makes two placements the same component: the node's mesh, how it is baked, and the
|
||
/// same children placed the same way below it.
|
||
fn key(&mut self, index: usize, rest: &Mat, depth: usize) -> u64 {
|
||
let mut h = std::collections::hash_map::DefaultHasher::new();
|
||
let Some(node) = self.node(index) else { return 0 };
|
||
node.mesh().map(|m| m.index()).hash(&mut h);
|
||
hash_mat(rest, &mut h);
|
||
if depth < 8 {
|
||
let children: Vec<usize> = node.children().map(|c| c.index()).collect();
|
||
for c in children {
|
||
if !self.subtree_has_mesh(c, 0) {
|
||
continue;
|
||
}
|
||
let Some(child) = self.node(c) else { continue };
|
||
let local = mat_mul(rest, &node_matrix(&child));
|
||
match split_rigid(&local) {
|
||
Some((place, child_rest)) => {
|
||
hash_mat(&place, &mut h);
|
||
self.key(c, &child_rest, depth + 1).hash(&mut h);
|
||
}
|
||
None => c.hash(&mut h),
|
||
}
|
||
}
|
||
} else {
|
||
// Too deep to compare: only the very same node is the same.
|
||
index.hash(&mut h);
|
||
}
|
||
h.finish()
|
||
}
|
||
|
||
/// Bodies of node `index`'s mesh, baked with `bake` (its frame in component `slot`).
|
||
fn node_meshes(&mut self, index: usize, slot: Option<usize>, bake: &Mat) -> Result<()> {
|
||
let Some(node) = self.node(index) else { return Ok(()) };
|
||
let Some(mesh) = node.mesh() else { return Ok(()) };
|
||
let base = mesh
|
||
.name()
|
||
.map(clean_name)
|
||
.filter(|n| !n.is_empty())
|
||
.or_else(|| node.name().map(clean_name).filter(|n| !n.is_empty()))
|
||
.unwrap_or_else(|| self.stem.clone());
|
||
if !bake.iter().flatten().all(|v| v.is_finite()) || det3(bake).abs() < 1e-18 {
|
||
self.skipped.push(format!("mesh `{base}` (its node scales it to nothing)"));
|
||
return Ok(());
|
||
}
|
||
let flip = det3(bake) < 0.0;
|
||
// Primitives by material, in the order they first appear.
|
||
let mut groups: Vec<(Option<usize>, Vec<Vec3>, Vec<[u32; 3]>)> = Vec::new();
|
||
for (k, prim) in mesh.primitives().enumerate() {
|
||
let tris = match self.primitive(&prim) {
|
||
Ok(Some(t)) => t,
|
||
Ok(None) => continue,
|
||
Err(e) => {
|
||
self.skipped.push(format!("mesh `{base}` part {k}: {e}"));
|
||
continue;
|
||
}
|
||
};
|
||
let material = prim.material().index();
|
||
let at = match groups.iter().position(|g| g.0 == material) {
|
||
Some(at) => at,
|
||
None => {
|
||
groups.push((material, Vec::new(), Vec::new()));
|
||
groups.len() - 1
|
||
}
|
||
};
|
||
let Some(group) = groups.get_mut(at) else { continue };
|
||
let offset = u32::try_from(group.1.len()).map_err(|_| IoError::Invalid("glTF mesh too large".into()))?;
|
||
group.1.extend(tris.0.iter().map(|p| solidcraft_doc::apply_point(bake, *p)));
|
||
group.2.extend(tris.1.iter().map(|t| {
|
||
let t = t.map(|i| i + offset);
|
||
if flip { [t[0], t[2], t[1]] } else { t }
|
||
}));
|
||
}
|
||
let several = groups.len() > 1;
|
||
for (k, (material, positions, triangles)) in groups.into_iter().enumerate() {
|
||
if triangles.is_empty() {
|
||
continue;
|
||
}
|
||
let look = material.and_then(|m| self.doc.materials().nth(m)).map(|m| look_of(&m));
|
||
let name = if several {
|
||
let suffix = look.as_ref().map(|l| l.name.clone()).filter(|n| !n.is_empty()).unwrap_or_else(|| format!("{}", k + 1));
|
||
format!("{base} ({suffix})")
|
||
} else {
|
||
base.clone()
|
||
};
|
||
if let Err(e) = solidcraft_kernel::mesh_body(&positions, &triangles) {
|
||
self.skipped.push(format!("mesh `{name}`: {e}"));
|
||
continue;
|
||
}
|
||
self.meshes.push(MeshData {
|
||
name,
|
||
positions: positions.iter().flat_map(|p| [p.x, p.y, p.z]).collect(),
|
||
triangles: triangles.iter().flatten().copied().collect(),
|
||
color: look.as_ref().map(Look::rgb),
|
||
});
|
||
self.looks.push(look);
|
||
self.plan.bodies.push(slot);
|
||
}
|
||
Ok(())
|
||
}
|
||
|
||
/// A primitive's vertices (file units) and triangles; `None` for points and lines.
|
||
#[allow(clippy::type_complexity)]
|
||
fn primitive(&mut self, prim: &gltf::Primitive<'_>) -> std::result::Result<Option<(Vec<Vec3>, Vec<[u32; 3]>)>, String> {
|
||
let mode = prim.mode();
|
||
if !matches!(mode, Mode::Triangles | Mode::TriangleStrip | Mode::TriangleFan) {
|
||
return Ok(None);
|
||
}
|
||
let acc = prim.get(&gltf::Semantic::Positions).ok_or("no positions")?;
|
||
let raw = self.accessor(&acc, Dimensions::Vec3)?;
|
||
let positions: Vec<Vec3> = raw.as_chunks::<3>().0.iter().map(|c| Vec3::new(c[0], c[1], c[2])).collect();
|
||
let n = positions.len();
|
||
let indices: Vec<u32> = match prim.indices() {
|
||
Some(a) => {
|
||
if !matches!(a.data_type(), DataType::U8 | DataType::U16 | DataType::U32) {
|
||
return Err("indices that aren't unsigned integers".into());
|
||
}
|
||
self.accessor(&a, Dimensions::Scalar)?.into_iter().map(|v| v as u32).collect()
|
||
}
|
||
None => (0..u32::try_from(n).map_err(|_| "too many vertices")?).collect(),
|
||
};
|
||
if let Some(bad) = indices.iter().find(|i| **i as usize >= n) {
|
||
return Err(format!("index {bad} past its {n} vertices"));
|
||
}
|
||
let at = |k: usize| indices.get(k).copied().unwrap_or(0);
|
||
let mut tris = Vec::new();
|
||
match mode {
|
||
Mode::TriangleStrip => {
|
||
for k in 0..indices.len().saturating_sub(2) {
|
||
tris.push(if k % 2 == 0 { [at(k), at(k + 1), at(k + 2)] } else { [at(k + 1), at(k), at(k + 2)] });
|
||
}
|
||
}
|
||
Mode::TriangleFan => {
|
||
for k in 1..indices.len().saturating_sub(1) {
|
||
tris.push([at(0), at(k), at(k + 1)]);
|
||
}
|
||
}
|
||
_ => tris.extend(indices.as_chunks::<3>().0.iter().copied()),
|
||
}
|
||
// Degenerate triangles (a repeated corner) close nothing.
|
||
tris.retain(|t| t[0] != t[1] && t[1] != t[2] && t[0] != t[2]);
|
||
if tris.is_empty() {
|
||
return Ok(None);
|
||
}
|
||
// Only the vertices used.
|
||
let mut map: HashMap<u32, u32> = HashMap::new();
|
||
let mut used = Vec::new();
|
||
for t in &mut tris {
|
||
for i in t.iter_mut() {
|
||
let next = used.len() as u32;
|
||
*i = *map.entry(*i).or_insert_with(|| {
|
||
used.push(positions.get(*i as usize).copied().unwrap_or(Vec3::ZERO));
|
||
next
|
||
});
|
||
}
|
||
}
|
||
self.vertices = self.vertices.saturating_add(used.len());
|
||
self.triangles = self.triangles.saturating_add(tris.len());
|
||
if self.vertices > MAX_VERTICES || self.triangles > MAX_TRIANGLES {
|
||
return Err(format!("more than {MAX_TRIANGLES} triangles or {MAX_VERTICES} vertices in all"));
|
||
}
|
||
Ok(Some((used, tris)))
|
||
}
|
||
|
||
/// An accessor's values (`dims` per element) as numbers; normalized integers as fractions.
|
||
fn accessor(&mut self, acc: &gltf::Accessor<'_>, dims: Dimensions) -> std::result::Result<Vec<f64>, String> {
|
||
if acc.sparse().is_some() {
|
||
return Err("sparse accessors aren't supported".into());
|
||
}
|
||
if acc.dimensions() != dims {
|
||
return Err(format!("accessor {} has {:?} values, not {dims:?}", acc.index(), acc.dimensions()));
|
||
}
|
||
let view = acc.view().ok_or("an accessor without data")?;
|
||
let width = dims.multiplicity();
|
||
let size = acc.data_type().size();
|
||
let elem = width * size;
|
||
let stride = view.stride().unwrap_or(elem);
|
||
let count = acc.count();
|
||
if stride < elem || count > MAX_VERTICES.max(3 * MAX_TRIANGLES) {
|
||
return Err(format!("accessor {} is malformed", acc.index()));
|
||
}
|
||
// Every element must lie in the view, and the view in its buffer.
|
||
let span = if count == 0 { 0 } else { (count - 1).checked_mul(stride).and_then(|s| s.checked_add(elem)).ok_or("accessor too large")? };
|
||
let end = acc.offset().checked_add(span).ok_or("accessor too large")?;
|
||
if end > view.length() {
|
||
return Err(format!("accessor {} runs past its buffer view", acc.index()));
|
||
}
|
||
let view_end = view.offset().checked_add(view.length()).ok_or("buffer view too large")?;
|
||
let data = self.buffers.get(&view.buffer())?;
|
||
if view_end > data.len() || view_end > view.buffer().length() {
|
||
return Err(format!("buffer view {} runs past its buffer (the file may be truncated)", view.index()));
|
||
}
|
||
let base = view.offset() + acc.offset();
|
||
let normalized = acc.normalized();
|
||
let ty = acc.data_type();
|
||
let mut out = Vec::with_capacity(count * width);
|
||
for e in 0..count {
|
||
for c in 0..width {
|
||
let at = base + e * stride + c * size;
|
||
let b = data.get(at..at + size).ok_or("accessor out of range")?;
|
||
let v = match ty {
|
||
DataType::F32 => f64::from(f32::from_le_bytes([b[0], b[1], b[2], b[3]])),
|
||
DataType::U32 => f64::from(u32::from_le_bytes([b[0], b[1], b[2], b[3]])),
|
||
DataType::U16 => {
|
||
let v = f64::from(u16::from_le_bytes([b[0], b[1]]));
|
||
if normalized { v / 65535.0 } else { v }
|
||
}
|
||
DataType::I16 => {
|
||
let v = f64::from(i16::from_le_bytes([b[0], b[1]]));
|
||
if normalized { (v / 32767.0).max(-1.0) } else { v }
|
||
}
|
||
DataType::U8 => {
|
||
let v = f64::from(b[0]);
|
||
if normalized { v / 255.0 } else { v }
|
||
}
|
||
DataType::I8 => {
|
||
let v = f64::from(b[0] as i8);
|
||
if normalized { (v / 127.0).max(-1.0) } else { v }
|
||
}
|
||
};
|
||
if !v.is_finite() {
|
||
return Err(format!("accessor {} holds a number that isn't finite", acc.index()));
|
||
}
|
||
out.push(v);
|
||
}
|
||
}
|
||
Ok(out)
|
||
}
|
||
}
|
||
|
||
/// Linear to sRGB (0–1).
|
||
fn srgb(c: f32) -> f32 {
|
||
let c = if c.is_finite() { c.clamp(0.0, 1.0) } else { 0.8 };
|
||
if c <= 0.003_130_8 { 12.92 * c } else { 1.055 * c.powf(1.0 / 2.4) - 0.055 }
|
||
}
|
||
|
||
/// A material's look: base colour, alpha when blended, metallic/roughness when opaque.
|
||
fn look_of(m: &gltf::Material<'_>) -> Look {
|
||
let pbr = m.pbr_metallic_roughness();
|
||
let [r, g, b, a] = pbr.base_color_factor();
|
||
let color = [r, g, b].map(|c| (srgb(c) * 255.0).round() as u8);
|
||
let opacity = match m.alpha_mode() {
|
||
gltf::material::AlphaMode::Blend if a.is_finite() => f64::from(a).clamp(0.0, 1.0),
|
||
_ => 1.0,
|
||
};
|
||
let name = m.name().map(clean_name).filter(|n| !n.is_empty()).unwrap_or_else(|| "glTF material".into());
|
||
let finite = |v: f32, d: f64| if v.is_finite() { f64::from(v).clamp(0.0, 1.0) } else { d };
|
||
let pbr = (opacity >= 1.0)
|
||
.then(|| {
|
||
solidcraft_doc::pbr_appearance::PbrParameters::new(finite(pbr.metallic_factor(), 1.0), finite(pbr.roughness_factor(), 1.0), 1.5).ok()
|
||
})
|
||
.flatten();
|
||
Look { name, color, opacity, pbr }
|
||
}
|
||
|
||
/// A GLB container of `json` and an optional binary chunk (each padded to four bytes).
|
||
pub fn glb_container(json: &[u8], bin: &[u8]) -> Vec<u8> {
|
||
let pad = |n: usize| (4 - n % 4) % 4;
|
||
let json_len = json.len() + pad(json.len());
|
||
let bin_len = bin.len() + pad(bin.len());
|
||
let total = 12 + 8 + json_len + if bin.is_empty() { 0 } else { 8 + bin_len };
|
||
let mut out = Vec::with_capacity(total);
|
||
out.extend_from_slice(b"glTF");
|
||
out.extend_from_slice(&2u32.to_le_bytes());
|
||
out.extend_from_slice(&(total as u32).to_le_bytes());
|
||
out.extend_from_slice(&(json_len as u32).to_le_bytes());
|
||
out.extend_from_slice(b"JSON");
|
||
out.extend_from_slice(json);
|
||
out.extend(std::iter::repeat_n(b' ', pad(json.len())));
|
||
if !bin.is_empty() {
|
||
out.extend_from_slice(&(bin_len as u32).to_le_bytes());
|
||
out.extend_from_slice(b"BIN\0");
|
||
out.extend_from_slice(bin);
|
||
out.extend(std::iter::repeat_n(0u8, pad(bin.len())));
|
||
}
|
||
out
|
||
}
|
||
|
||
#[cfg(test)]
|
||
#[path = "gltf_in_tests.rs"]
|
||
pub(crate) mod tests;
|