Viewport picking: a BVH per body mesh and a GPU pick buffer for visible edges (#1776)

Thanks @oursland.
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Jackson Oursland authored and GitHub committed 2026-10-16 14:26:38 -04:00
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//! A bounding volume hierarchy over boxes: the nearest hit along a ray, or every item whose box
//! passes a test, without looking at each item. Built once (median split on the widest axis of
//! the box centres, a few items per leaf) and only read afterwards. [`MeshIndex`] holds one over
//! a mesh's triangles and one over its edge segments, for picking.
use crate::{Aabb3, Mesh, Vec3};
/// Most items in a leaf.
const LEAF: usize = 4;
#[derive(Clone, Copy, Debug)]
struct Node {
bounds: Aabb3,
/// A leaf: the first of its `count` items in [`Bvh::order`]. Otherwise its children are
/// `first` and `first + 1`.
first: u32,
count: u32,
}
/// A hierarchy over boxes; items are the boxes' indices.
#[derive(Clone, Debug, Default)]
pub struct Bvh {
nodes: Vec<Node>,
order: Vec<u32>,
}
impl Bvh {
/// The hierarchy over `boxes` (empty boxes are left out).
pub fn new(boxes: &[Aabb3]) -> Bvh {
let mut order: Vec<u32> =
(0..boxes.len().min(u32::MAX as usize)).filter(|&i| boxes.get(i).is_some_and(|b| !b.is_empty() && finite(b))).map(|i| i as u32).collect();
if order.is_empty() {
return Bvh::default();
}
let item = |i: u32| boxes.get(i as usize).copied().unwrap_or(Aabb3::EMPTY);
let centre = |i: u32| item(i).center();
let mut nodes = vec![Node { bounds: Aabb3::EMPTY, first: 0, count: 0 }];
// (node, start, end) in `order` still to be filled in.
let mut todo = vec![(0usize, 0usize, order.len())];
while let Some((n, start, end)) = todo.pop() {
let Some(span) = order.get_mut(start..end) else { continue };
let mut bounds = Aabb3::EMPTY;
let mut centres = Aabb3::EMPTY;
for &i in span.iter() {
bounds = bounds.union(&item(i));
centres.add(centre(i));
}
let size = centres.size();
let axis = if size.x >= size.y && size.x >= size.z {
0
} else if size.y >= size.z {
1
} else {
2
};
let extent = [size.x, size.y, size.z][axis];
if span.len() <= LEAF || !(extent > 0.0) {
if let Some(node) = nodes.get_mut(n) {
*node = Node { bounds, first: start as u32, count: span.len() as u32 };
}
continue;
}
let key = |i: &u32| {
let c = centre(*i);
[c.x, c.y, c.z][axis]
};
let mid = span.len() / 2;
span.select_nth_unstable_by(mid, |a, b| key(a).total_cmp(&key(b)));
let left = nodes.len();
nodes.push(Node { bounds: Aabb3::EMPTY, first: 0, count: 0 });
nodes.push(Node { bounds: Aabb3::EMPTY, first: 0, count: 0 });
if let Some(node) = nodes.get_mut(n) {
*node = Node { bounds, first: left as u32, count: 0 };
}
todo.push((left, start, start + mid));
todo.push((left + 1, start + mid, end));
}
Bvh { nodes, order }
}
/// The box around everything (empty for no items).
pub fn bounds(&self) -> Aabb3 {
self.nodes.first().map_or(Aabb3::EMPTY, |n| n.bounds)
}
/// Calls `item` with every item in a leaf whose box, and every box above it, `enter` accepts.
pub fn visit(&self, mut enter: impl FnMut(&Aabb3) -> bool, mut item: impl FnMut(u32)) {
let mut stack = vec![0usize];
while let Some(n) = stack.pop() {
let Some(node) = self.nodes.get(n) else { continue };
if !enter(&node.bounds) {
continue;
}
if node.count > 0 {
let (a, b) = (node.first as usize, node.first as usize + node.count as usize);
for &i in self.order.get(a..b).unwrap_or(&[]) {
item(i);
}
} else {
stack.push(node.first as usize + 1);
stack.push(node.first as usize);
}
}
}
/// The nearest item along the ray from `o` along `d`: `hit` gives an item's distance along
/// `d` (`None`: missed). Equal distances go to the lowest item, as a scan in item order
/// keeping strictly nearer hits would answer. Boxes are entered nearest first, and one that
/// starts past the best hit so far is skipped.
pub fn nearest(&self, o: Vec3, d: Vec3, mut hit: impl FnMut(u32) -> Option<f64>) -> Option<(f64, u32)> {
if ![o.x, o.y, o.z, d.x, d.y, d.z].iter().all(|v| v.is_finite()) {
return None;
}
let inv = Vec3::new(1.0 / d.x, 1.0 / d.y, 1.0 / d.z);
let mut best: Option<(f64, u32)> = None;
let root = self.nodes.first().and_then(|n| ray_box(o, d, inv, &n.bounds, 0.0))?;
let mut stack = vec![(0usize, root)];
while let Some((n, t0)) = stack.pop() {
if best.is_some_and(|(bt, _)| t0 > bt) {
continue;
}
let Some(node) = self.nodes.get(n) else { continue };
if node.count > 0 {
let (a, b) = (node.first as usize, node.first as usize + node.count as usize);
for &i in self.order.get(a..b).unwrap_or(&[]) {
if let Some(t) = hit(i)
&& best.is_none_or(|(bt, bi)| t < bt || (t == bt && i < bi))
{
best = Some((t, i));
}
}
continue;
}
let (l, r) = (node.first as usize, node.first as usize + 1);
let tl = self.nodes.get(l).and_then(|c| ray_box(o, d, inv, &c.bounds, 0.0));
let tr = self.nodes.get(r).and_then(|c| ray_box(o, d, inv, &c.bounds, 0.0));
// The nearer child is popped first.
match (tl, tr) {
(Some(a), Some(b)) if a <= b => stack.extend([(r, b), (l, a)]),
(Some(a), Some(b)) => stack.extend([(l, a), (r, b)]),
(Some(a), None) => stack.push((l, a)),
(None, Some(b)) => stack.push((r, b)),
(None, None) => {}
}
}
best
}
}
fn finite(b: &Aabb3) -> bool {
[b.min.x, b.min.y, b.min.z, b.max.x, b.max.y, b.max.z].iter().all(|v| v.is_finite())
}
/// Where the ray from `o` along `d` (`inv` = 1 / `d` per axis) enters box `b` grown by `pad`,
/// from 0 on; `None` when it misses or the box lies behind.
fn ray_box(o: Vec3, d: Vec3, inv: Vec3, b: &Aabb3, pad: f64) -> Option<f64> {
let (mut t0, mut t1) = (0.0f64, f64::INFINITY);
for (o, d, inv, lo, hi) in [(o.x, d.x, inv.x, b.min.x, b.max.x), (o.y, d.y, inv.y, b.min.y, b.max.y), (o.z, d.z, inv.z, b.min.z, b.max.z)] {
let (lo, hi) = (lo - pad, hi + pad);
if d == 0.0 || !inv.is_finite() {
if o < lo || o > hi {
return None;
}
continue;
}
let (a, b) = ((lo - o) * inv, (hi - o) * inv);
let (a, b) = if a <= b { (a, b) } else { (b, a) };
t0 = t0.max(a);
t1 = t1.min(b);
if t0 > t1 {
return None;
}
}
(t0 <= t1).then_some(t0)
}
/// The farthest any corner of `b` lies along `d` from `o` (0 when the box is behind).
fn farthest_along(o: Vec3, d: Vec3, b: &Aabb3) -> f64 {
let along = |lo: f64, hi: f64, o: f64, d: f64| if d >= 0.0 { (hi - o) * d } else { (lo - o) * d };
(along(b.min.x, b.max.x, o.x, d.x) + along(b.min.y, b.max.y, o.y, d.y) + along(b.min.z, b.max.z, o.z, d.z)).max(0.0)
}
/// A mesh's triangles and edge segments in hierarchies, for picking: the nearest triangle along
/// a ray, and the edge segments near one. Built from one mesh and answers only for it.
#[derive(Clone, Debug, Default)]
pub struct MeshIndex {
triangles: Bvh,
triangle_count: usize,
segments: Bvh,
/// Per segment item: its edge, and its first point in that edge's polyline.
segment_of: Vec<(u32, u32)>,
}
impl MeshIndex {
/// The index of `mesh`.
pub fn new(mesh: &Mesh) -> MeshIndex {
let pad = |mut b: Aabb3| {
// Flat boxes (a triangle square to an axis) are grown a little, so a ray through
// them is never lost to rounding in the box test.
let scale = [b.min.x, b.min.y, b.min.z, b.max.x, b.max.y, b.max.z].iter().fold(1.0f64, |m, v| m.max(v.abs()));
let e = scale * 1e-9;
b.min -= Vec3::new(e, e, e);
b.max += Vec3::new(e, e, e);
b
};
let boxes: Vec<Aabb3> = mesh
.triangles
.iter()
.map(|t| {
let mut b = Aabb3::EMPTY;
for p in mesh.tri(t).into_iter().flatten() {
b.add(p);
}
if b.is_empty() { b } else { pad(b) }
})
.collect();
let mut segment_of = Vec::new();
let mut seg_boxes = Vec::new();
for (ei, e) in mesh.edges.iter().enumerate() {
// A one-point edge still has its vertex: it stands as a segment from it to itself.
let n = if e.len() == 1 { 1 } else { e.len().saturating_sub(1) };
for si in 0..n {
let (Some(a), Some(b)) = (e.get(si), e.get(si + 1).or(e.get(si))) else { continue };
let mut bx = Aabb3::EMPTY;
bx.add(*a);
bx.add(*b);
seg_boxes.push(pad(bx));
segment_of.push((ei as u32, si as u32));
}
}
MeshIndex { triangles: Bvh::new(&boxes), triangle_count: mesh.triangles.len(), segments: Bvh::new(&seg_boxes), segment_of }
}
/// [`Mesh::raycast`] through the index: the same answer, including which triangle wins a tie.
/// For a mesh other than the one indexed, the plain scan answers.
pub fn raycast(&self, mesh: &Mesh, o: Vec3, dir: Vec3) -> Option<(f64, usize)> {
if mesh.triangles.len() != self.triangle_count {
return mesh.raycast(o, dir);
}
let frame = crate::mesh::RayFrame::new(o, dir)?;
self.triangles
.nearest(o, dir, |i| mesh.triangles.get(i as usize).and_then(|t| mesh.tri(t)).and_then(|p| frame.hit(p)))
.map(|(t, i)| (t, i as usize))
}
/// Calls `f(edge, first point)` for every edge segment that may come within `a + b·t` of the
/// ray from `o` along unit `d`, `t` being the distance along it (each at most once). A
/// constant `a` suits an orthographic view; a perspective view widens with `b`.
pub fn segments_near(&self, o: Vec3, d: Vec3, a: f64, b: f64, mut f: impl FnMut(usize, usize)) {
if ![a, b, o.x, o.y, o.z, d.x, d.y, d.z].iter().all(|v| v.is_finite()) {
return;
}
let inv = Vec3::new(1.0 / d.x, 1.0 / d.y, 1.0 / d.z);
self.segments.visit(
|bx| {
let reach = a.max(0.0) + b.max(0.0) * farthest_along(o, d, bx);
ray_box(o, d, inv, bx, reach).is_some()
},
|i| {
if let Some((e, s)) = self.segment_of.get(i as usize) {
f(*e as usize, *s as usize);
}
},
);
}
}
#[cfg(test)]
#[path = "bvh_tests.rs"]
mod tests;
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use super::*;
/// A small deterministic generator (the tests need no crate for randomness).
struct Lcg(u64);
impl Lcg {
fn next(&mut self) -> f64 {
self.0 = self.0.wrapping_mul(6364136223846793005).wrapping_add(1442695040888963407);
(self.0 >> 11) as f64 / (1u64 << 53) as f64
}
fn range(&mut self, lo: f64, hi: f64) -> f64 {
lo + (hi - lo) * self.next()
}
fn vec(&mut self, r: f64) -> Vec3 {
Vec3::new(self.range(-r, r), self.range(-r, r), self.range(-r, r))
}
}
/// A grid of `n` × `n` squares of two triangles on z = 0, and `extra` random triangles above.
fn mesh(n: u32, extra: usize, rng: &mut Lcg) -> Mesh {
let mut positions: Vec<Vec3> = (0..=n).flat_map(|j| (0..=n).map(move |i| Vec3::new(f64::from(i), f64::from(j), 0.0))).collect();
let id = |i: u32, j: u32| j * (n + 1) + i;
let mut triangles = Vec::new();
for j in 0..n {
for i in 0..n {
triangles.push([id(i, j), id(i + 1, j), id(i + 1, j + 1)]);
triangles.push([id(i, j), id(i + 1, j + 1), id(i, j + 1)]);
}
}
for _ in 0..extra {
let c = rng.vec(f64::from(n)) + Vec3::new(0.0, 0.0, f64::from(n));
let k = positions.len() as u32;
positions.extend([c + rng.vec(1.5), c + rng.vec(1.5), c + rng.vec(1.5)]);
triangles.push([k, k + 1, k + 2]);
}
let edges =
(0..n).map(|i| (0..=n).map(|j| Vec3::new(f64::from(i), f64::from(j), 0.0)).collect()).chain([vec![Vec3::new(0.5, 0.5, 2.0)]]).collect();
Mesh { tri_face: vec![0; triangles.len()], positions, triangles, edges, ..Default::default() }
}
#[test]
fn indexed_raycast_answers_as_the_scan_does() {
let mut rng = Lcg(7);
let m = mesh(12, 400, &mut rng);
let index = MeshIndex::new(&m);
let mut hits = 0;
for k in 0..4000 {
// Every few rays go straight down through grid vertices and edges, where two or more
// triangles tie.
let (o, d) = if k % 4 == 0 {
let p = Vec3::new(f64::from(k % 13), f64::from((k / 13) % 13) * 0.5, 50.0);
(p, Vec3::new(0.0, 0.0, -1.0))
} else {
let o = rng.vec(40.0) + Vec3::new(6.0, 6.0, 0.0);
let target = Vec3::new(rng.range(-1.0, 13.0), rng.range(-1.0, 13.0), rng.range(-2.0, 14.0));
let Some(d) = (target - o).normalized() else { continue };
(o, d)
};
let want = m.raycast(o, d);
assert_eq!(index.raycast(&m, o, d), want, "ray {k} from {o:?} along {d:?}");
hits += usize::from(want.is_some());
}
assert!(hits > 1000, "the rays should mostly hit ({hits})");
}
#[test]
fn indexed_raycast_of_another_mesh_falls_back_to_the_scan() {
let mut rng = Lcg(3);
let (a, b) = (mesh(2, 0, &mut rng), mesh(5, 0, &mut rng));
let index = MeshIndex::new(&a);
let (o, d) = (Vec3::new(4.5, 4.2, 9.0), Vec3::new(0.0, 0.0, -1.0));
assert!(b.raycast(o, d).is_some());
assert_eq!(index.raycast(&b, o, d), b.raycast(o, d));
}
/// Distance from point `p` to the ray from `o` along unit `d` (from its start on), and how far along.
fn ray_point(o: Vec3, d: Vec3, p: Vec3) -> (f64, f64) {
let t = (p - o).dot(d).max(0.0);
((o + d * t).dist(p), t)
}
#[test]
fn segments_near_the_ray_are_all_reported() {
let mut rng = Lcg(11);
let m = mesh(16, 0, &mut rng);
let index = MeshIndex::new(&m);
for k in 0..500 {
let o = rng.vec(30.0) + Vec3::new(8.0, 8.0, 30.0);
let target = Vec3::new(rng.range(0.0, 16.0), rng.range(0.0, 16.0), 0.0);
let Some(d) = (target - o).normalized() else { continue };
let (a, b) = if k % 2 == 0 { (0.3, 0.0) } else { (0.0, 0.01) };
let mut got = std::collections::HashSet::new();
index.segments_near(o, d, a, b, |e, s| {
assert!(got.insert((e, s)), "segment {e}/{s} reported twice");
});
for (ei, e) in m.edges.iter().enumerate() {
for (si, w) in e.windows(2).enumerate() {
// Sampled along the segment: any point within reach must have its segment reported.
for f in 0..=8 {
let p = w[0] + (w[1] - w[0]) * (f64::from(f) / 8.0);
let (dist, t) = ray_point(o, d, p);
if dist <= a + b * t {
assert!(got.contains(&(ei, si)), "ray {k}: segment {ei}/{si} is within reach but was not reported");
}
}
}
}
// The one-point edge stands as its own segment.
let last = m.edges.len() - 1;
let (dist, t) = ray_point(o, d, Vec3::new(0.5, 0.5, 2.0));
if dist <= a + b * t {
assert!(got.contains(&(last, 0)));
}
}
}
#[test]
fn hostile_boxes_never_panic() {
let nan = Vec3::new(f64::NAN, 0.0, 0.0);
let boxes = [Aabb3::EMPTY, Aabb3 { min: nan, max: nan }, Aabb3 { min: Vec3::ZERO, max: Vec3::new(1.0, 1.0, 1.0) }];
let bvh = Bvh::new(&boxes);
assert_eq!(bvh.nearest(Vec3::new(0.5, 0.5, 5.0), Vec3::new(0.0, 0.0, -1.0), |i| Some(f64::from(i))), Some((2.0, 2)));
assert_eq!(bvh.nearest(Vec3::ZERO, Vec3::new(f64::NAN, 0.0, 0.0), |_| Some(1.0)), None);
let empty = Bvh::new(&[]);
assert!(empty.nearest(Vec3::ZERO, Vec3::new(0.0, 0.0, 1.0), |_| Some(1.0)).is_none());
empty.visit(|_| true, |_| panic!("an empty hierarchy has no items"));
let m = Mesh { positions: vec![Vec3::ZERO], triangles: vec![[0, 5, 9]], ..Default::default() };
assert!(MeshIndex::new(&m).raycast(&m, Vec3::new(0.0, 0.0, 1.0), Vec3::new(0.0, 0.0, -1.0)).is_none());
MeshIndex::new(&m).segments_near(Vec3::ZERO, Vec3::new(0.0, 0.0, 1.0), f64::NAN, 0.0, |_, _| panic!("no segments"));
}
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@@ -12,6 +12,7 @@ mod arcfit;
pub mod blend;
pub mod brep;
pub mod bspline;
mod bvh;
pub mod compare;
pub mod env;
pub mod fill;
@@ -25,6 +26,7 @@ mod vec;
pub use arcfit::MAX_FIT_PIECES;
pub use blend::hermite_bezier;
pub use bvh::{Bvh, MeshIndex};
pub use mesh::{Aabb3, BoxedTriangle, InsideIndex, MassProperties, Mesh, MeshMeasure, find_close_pair};
pub use plane::Plane;
pub use profile::{Loop2, MAX_BEZIER_CTRL, MAX_BEZIER_DEGREE, MAX_DERIVATIVE_ORDER, Region2, Seg2, bezier, regions_apart};
+57 -33
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@@ -559,13 +559,39 @@ impl Mesh {
/// two triangles that share an edge get exactly opposite values there. A ray through a
/// shared edge or vertex hits at least one of them; it never slips between them.
pub fn raycast(&self, o: Vec3, dir: Vec3) -> Option<(f64, usize)> {
let comp = |v: Vec3, k: usize| match k {
0 => v.x,
1 => v.y,
_ => v.z,
};
// The ray's dominant axis becomes z; x and y follow it cyclically, swapped to keep
// the frame right-handed when the ray runs towards −z.
let frame = RayFrame::new(o, dir)?;
let mut best: Option<(f64, usize)> = None;
for (i, t) in self.triangles.iter().enumerate() {
let Some(p) = self.tri(t) else { continue };
if let Some(t) = frame.hit(p)
&& best.is_none_or(|(bt, _)| t < bt)
{
best = Some((t, i));
}
}
best
}
}
/// A ray in the frame of [`Mesh::raycast`]'s watertight test: its dominant axis becomes z; x and
/// y follow it cyclically, swapped to keep the frame right-handed when the ray runs towards −z.
pub(crate) struct RayFrame {
o: Vec3,
k: [usize; 3],
s: [f64; 3],
}
fn comp(v: Vec3, k: usize) -> f64 {
match k {
0 => v.x,
1 => v.y,
_ => v.z,
}
}
impl RayFrame {
/// `None` for a direction that is zero or not finite.
pub(crate) fn new(o: Vec3, dir: Vec3) -> Option<RayFrame> {
let a = [dir.x.abs(), dir.y.abs(), dir.z.abs()];
let kz = if a[0] >= a[1] && a[0] >= a[2] {
0
@@ -582,33 +608,31 @@ impl Mesh {
if dz < 0.0 {
std::mem::swap(&mut kx, &mut ky);
}
let (sx, sy, sz) = (comp(dir, kx) / dz, comp(dir, ky) / dz, 1.0 / dz);
// A vertex in the ray's frame: (x, y) across the ray, z scaled along it.
let frame = |p: Vec3| {
let q = p - o;
let z = comp(q, kz);
(comp(q, kx) - sx * z, comp(q, ky) - sy * z, sz * z)
};
let mut best: Option<(f64, usize)> = None;
for (i, t) in self.triangles.iter().enumerate() {
let Some([pa, pb, pc]) = self.tri(t) else { continue };
let ((ax, ay, az), (bx, by, bz), (cx, cy, cz)) = (frame(pa), frame(pb), frame(pc));
let u = cx * by - cy * bx;
let v = ax * cy - ay * cx;
let w = bx * ay - by * ax;
if (u < 0.0 || v < 0.0 || w < 0.0) && (u > 0.0 || v > 0.0 || w > 0.0) {
continue;
}
let det = u + v + w;
if det == 0.0 {
continue;
}
let t = (u * az + v * bz + w * cz) / det;
if t.is_finite() && t > 1e-9 && best.is_none_or(|(bt, _)| t < bt) {
best = Some((t, i));
}
Some(RayFrame { o, k: [kx, ky, kz], s: [comp(dir, kx) / dz, comp(dir, ky) / dz, 1.0 / dz] })
}
/// A vertex in the ray's frame: (x, y) across the ray, z scaled along it.
fn frame(&self, p: Vec3) -> (f64, f64, f64) {
let q = p - self.o;
let z = comp(q, self.k[2]);
(comp(q, self.k[0]) - self.s[0] * z, comp(q, self.k[1]) - self.s[1] * z, self.s[2] * z)
}
/// The distance along the ray to triangle `[pa, pb, pc]` (`None`: missed, or not in front).
pub(crate) fn hit(&self, [pa, pb, pc]: [Vec3; 3]) -> Option<f64> {
let ((ax, ay, az), (bx, by, bz), (cx, cy, cz)) = (self.frame(pa), self.frame(pb), self.frame(pc));
let u = cx * by - cy * bx;
let v = ax * cy - ay * cx;
let w = bx * ay - by * ax;
if (u < 0.0 || v < 0.0 || w < 0.0) && (u > 0.0 || v > 0.0 || w > 0.0) {
return None;
}
best
let det = u + v + w;
if det == 0.0 {
return None;
}
let t = (u * az + v * bz + w * cz) / det;
(t.is_finite() && t > 1e-9).then_some(t)
}
}
+1
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@@ -21,6 +21,7 @@ use wgpu::util::DeviceExt;
pub mod capture;
mod pbr;
pub mod pick;
#[cfg(not(target_arch = "wasm32"))]
pub mod select;
pub mod view;
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@@ -0,0 +1,503 @@
//! The pick buffer: which model edges are visible at each pixel of the viewport, for picking on a
//! large model without testing every edge. Surfaces are drawn into the depth buffer only; then
//! every edge segment is drawn as a line carrying its id, depth tested against them (lifted
//! toward the eye by the picker's slack, the depth by which an edge may lie behind a face and
//! still count as visible) and written into an `R32Uint` id texture (0: no edge).
//!
//! The pass is drawn once per view (camera, viewport size, model), and only small tiles around
//! the cursor are read back, so a pointer moving over a still view reads a few kilobytes and
//! draws nothing. Read-backs arrive a frame or two later ([`PickResults`]); until a tile is in,
//! the picker answers on the CPU. The ids are hints: the picker still runs its exact tests on
//! the edges a tile names.
use std::sync::atomic::{AtomicU8, Ordering};
use std::sync::{Arc, Mutex};
use wgpu::util::DeviceExt;
/// The side of a read-back tile, in pixels (a multiple of 64, so rows need no padding).
pub const TILE: u32 = 128;
/// Most tiles kept from one view.
const KEEP: usize = 6;
/// Most read-backs in flight.
const IN_FLIGHT: usize = 3;
/// Bytes per surface vertex (position) and per edge vertex (position, id).
const FACE_VERTEX: u64 = 12;
const EDGE_VERTEX: u64 = 16;
const UNIFORM_SIZE: u64 = 96;
const SHADER: &str = r#"
struct U {
vp: mat4x4<f32>,
eye: vec4<f32>, // eye position, w = 1 for perspective
back: vec4<f32>, // toward the eye (orthographic), w = how far edges are lifted toward it
};
@group(0) @binding(0) var<uniform> u: U;
@vertex
fn vs_face(@location(0) p: vec3<f32>) -> @builtin(position) vec4<f32> {
return u.vp * vec4<f32>(p, 1.0);
}
@fragment
fn fs_face() -> @location(0) u32 {
return 0u;
}
struct EOut {
@builtin(position) pos: vec4<f32>,
@location(0) @interpolate(flat) id: u32,
};
@vertex
fn vs_edge(@location(0) p: vec3<f32>, @location(1) id: u32) -> EOut {
var toward = u.back.xyz;
if (u.eye.w > 0.5) {
let v = u.eye.xyz - p;
let l = length(v);
if (l > 0.0) {
toward = v / l;
}
}
var o: EOut;
o.pos = u.vp * vec4<f32>(p + toward * u.back.w, 1.0);
o.id = id;
return o;
}
@fragment
fn fs_edge(i: EOut) -> @location(0) u32 {
return i.id;
}
"#;
/// What the pass draws: surfaces (for depth) and edge segments with their ids (from 1).
#[derive(Default, Clone)]
pub struct PickScene {
faces: Vec<u8>,
edges: Vec<u8>,
}
impl PickScene {
pub fn triangle(&mut self, t: [[f32; 3]; 3]) {
for p in t {
for c in p {
self.faces.extend_from_slice(&c.to_le_bytes());
}
}
}
/// Segment `a`–`b` of the edge `id` (0 is no edge: not drawn).
pub fn segment(&mut self, a: [f32; 3], b: [f32; 3], id: u32) {
if id == 0 {
return;
}
for p in [a, b] {
for c in p {
self.edges.extend_from_slice(&c.to_le_bytes());
}
self.edges.extend_from_slice(&id.to_le_bytes());
}
}
pub fn is_empty(&self) -> bool {
self.edges.is_empty()
}
}
/// The view the pass is drawn for.
#[derive(Clone, Copy, Debug)]
pub struct PickView {
/// Changes whenever anything below or the scene changes.
pub key: u64,
/// Column-major view-projection (as [`crate::view::Frame::view_proj`]).
pub view_proj: [[f32; 4]; 4],
/// Eye position, and 1 for a perspective camera (0: orthographic).
pub eye: [f32; 4],
/// Direction toward the eye (orthographic).
pub back: [f32; 3],
/// How far edges are lifted toward the eye (model units).
pub lift: f32,
/// The viewport in physical pixels.
pub size: [u32; 2],
}
/// Edge ids of a block of pixels of one view.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct PickTile {
pub key: u64,
pub origin: [u32; 2],
pub size: [u32; 2],
/// Row-major, `size[0] * size[1]`.
pub ids: Vec<u32>,
}
impl PickTile {
/// Whether the tile is of view `key` and holds every pixel of `[x0, y0, x1, y1]` (inclusive)
/// that lies inside a viewport of `view` pixels.
pub fn covers(&self, key: u64, view: [u32; 2], [x0, y0, x1, y1]: [i64; 4]) -> bool {
let clamp = |v: i64, n: u32| v.clamp(0, i64::from(n.max(1)) - 1);
let (x0, x1, y0, y1) = (clamp(x0, view[0]), clamp(x1, view[0]), clamp(y0, view[1]), clamp(y1, view[1]));
let [ox, oy] = self.origin.map(i64::from);
let [w, h] = self.size.map(i64::from);
self.key == key && x0 >= ox && y0 >= oy && x1 < ox + w && y1 < oy + h
}
/// The ids within `[x0, y0, x1, y1]` (inclusive; outside the tile: none), each once.
pub fn ids_in(&self, [x0, y0, x1, y1]: [i64; 4]) -> Vec<u32> {
let [ox, oy] = self.origin.map(i64::from);
let [w, h] = self.size.map(i64::from);
let mut out = Vec::new();
for y in y0.max(oy)..=y1.min(oy + h - 1) {
for x in x0.max(ox)..=x1.min(ox + w - 1) {
if let Some(&id) = self.ids.get(((y - oy) * w + (x - ox)) as usize)
&& id != 0
{
out.push(id);
}
}
}
out.sort_unstable();
out.dedup();
out
}
}
/// The tiles read back so far (of the latest view only), newest last.
#[derive(Default, Debug)]
pub struct PickResults {
pub tiles: Vec<PickTile>,
}
impl PickResults {
/// The newest tile of view `key` covering `window`.
pub fn tile(&self, key: u64, view: [u32; 2], window: [i64; 4]) -> Option<&PickTile> {
self.tiles.iter().rev().find(|t| t.covers(key, view, window))
}
}
pub type PickOut = Arc<Mutex<PickResults>>;
/// The tile (origin and size) around pixel `centre` of a viewport of `view` pixels.
pub fn tile_around(centre: [u32; 2], view: [u32; 2]) -> ([u32; 2], [u32; 2]) {
let size = [TILE.min(view[0]), TILE.min(view[1])];
let origin = [0, 1].map(|k| centre[k].saturating_sub(size[k] / 2).min(view[k].saturating_sub(size[k])));
(origin, size)
}
const NEW: u8 = 0;
const MAPPING: u8 = 1;
const READY: u8 = 2;
const FAILED: u8 = 3;
/// A tile being copied out of the id texture.
struct Pending {
key: u64,
origin: [u32; 2],
size: [u32; 2],
bytes_per_row: u32,
buffer: wgpu::Buffer,
/// The frame whose commands copy it (it is mapped once they are submitted).
frame: u64,
state: Arc<AtomicU8>,
}
struct Target {
size: [u32; 2],
ids: wgpu::Texture,
ids_view: wgpu::TextureView,
depth_view: wgpu::TextureView,
}
struct Uploaded {
key: u64,
faces: Option<(wgpu::Buffer, u32)>,
edges: Option<(wgpu::Buffer, u32)>,
}
/// The pass's pipelines, its textures and the read-backs in flight, on one device.
pub struct PickBuffer {
face: wgpu::RenderPipeline,
edge: wgpu::RenderPipeline,
uniform: wgpu::Buffer,
bind: wgpu::BindGroup,
scene: Option<Uploaded>,
target: Option<Target>,
/// The view drawn into the textures.
drawn: Option<u64>,
pending: Vec<Pending>,
frame: u64,
}
const DEPTH: wgpu::TextureFormat = wgpu::TextureFormat::Depth32Float;
const IDS: wgpu::TextureFormat = wgpu::TextureFormat::R32Uint;
impl PickBuffer {
pub fn new(device: &wgpu::Device) -> PickBuffer {
let module =
device.create_shader_module(wgpu::ShaderModuleDescriptor { label: Some("sc_pick"), source: wgpu::ShaderSource::Wgsl(SHADER.into()) });
let bgl = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
label: Some("sc_pick"),
entries: &[wgpu::BindGroupLayoutEntry {
binding: 0,
visibility: wgpu::ShaderStages::VERTEX,
ty: wgpu::BindingType::Buffer { ty: wgpu::BufferBindingType::Uniform, has_dynamic_offset: false, min_binding_size: None },
count: None,
}],
});
let layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
label: Some("sc_pick"),
bind_group_layouts: &[Some(&bgl)],
immediate_size: 0,
});
let uniform = device.create_buffer(&wgpu::BufferDescriptor {
label: Some("sc_pick_u"),
size: UNIFORM_SIZE,
usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
mapped_at_creation: false,
});
let bind = device.create_bind_group(&wgpu::BindGroupDescriptor {
label: Some("sc_pick"),
layout: &bgl,
entries: &[wgpu::BindGroupEntry { binding: 0, resource: uniform.as_entire_binding() }],
});
const FA: [wgpu::VertexAttribute; 1] = wgpu::vertex_attr_array![0 => Float32x3];
const EA: [wgpu::VertexAttribute; 2] = wgpu::vertex_attr_array![0 => Float32x3, 1 => Uint32];
let pipeline = |label: &str,
vs: &str,
fs: &str,
stride: u64,
attributes: &'static [wgpu::VertexAttribute],
topology: wgpu::PrimitiveTopology,
write: bool,
mask: wgpu::ColorWrites| {
device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
label: Some(label),
layout: Some(&layout),
vertex: wgpu::VertexState {
module: &module,
entry_point: Some(vs),
buffers: &[Some(wgpu::VertexBufferLayout { array_stride: stride, step_mode: wgpu::VertexStepMode::Vertex, attributes })],
compilation_options: Default::default(),
},
primitive: wgpu::PrimitiveState { topology, ..Default::default() },
depth_stencil: Some(wgpu::DepthStencilState {
format: DEPTH,
depth_write_enabled: Some(write),
depth_compare: Some(wgpu::CompareFunction::LessEqual),
stencil: Default::default(),
bias: Default::default(),
}),
multisample: wgpu::MultisampleState::default(),
fragment: Some(wgpu::FragmentState {
module: &module,
entry_point: Some(fs),
targets: &[Some(wgpu::ColorTargetState { format: IDS, blend: None, write_mask: mask })],
compilation_options: Default::default(),
}),
multiview_mask: None,
cache: None,
})
};
let face =
pipeline("sc_pick_face", "vs_face", "fs_face", FACE_VERTEX, &FA, wgpu::PrimitiveTopology::TriangleList, true, wgpu::ColorWrites::empty());
let edge = pipeline("sc_pick_edge", "vs_edge", "fs_edge", EDGE_VERTEX, &EA, wgpu::PrimitiveTopology::LineList, false, wgpu::ColorWrites::ALL);
PickBuffer { face, edge, uniform, bind, scene: None, target: None, drawn: None, pending: Vec::new(), frame: 0 }
}
/// Before the frame is submitted: collect the tiles read back, then draw `view` of `scene`
/// (`scene_key` names it; it is uploaded when that changes) unless it is drawn already, and
/// start reading back the tile around pixel `centre` unless it is in or on its way. The tiles
/// land in `out` a frame or two later; keep frames coming until then.
#[allow(clippy::too_many_arguments)]
pub fn prepare(
&mut self,
device: &wgpu::Device,
queue: &wgpu::Queue,
encoder: &mut wgpu::CommandEncoder,
scene_key: u64,
scene: &PickScene,
view: &PickView,
centre: Option<[u32; 2]>,
out: &PickOut,
) {
self.frame += 1;
self.collect(device, out);
let [w, h] = view.size;
let max = device.limits().max_texture_dimension_2d;
if w == 0 || h == 0 || w > max || h > max {
return;
}
if self.scene.as_ref().is_none_or(|s| s.key != scene_key) {
let limit = device.limits().max_buffer_size;
let upload = |label: &str, bytes: &[u8], stride: u64| {
let n = bytes.len() as u64 / stride;
(n > 0 && (bytes.len() as u64) <= limit && n <= u64::from(u32::MAX)).then(|| {
(
device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
label: Some(label),
contents: bytes,
usage: wgpu::BufferUsages::VERTEX,
}),
n as u32,
)
})
};
self.scene = Some(Uploaded {
key: scene_key,
faces: upload("sc_pick_faces", &scene.faces, FACE_VERTEX),
edges: upload("sc_pick_edges", &scene.edges, EDGE_VERTEX),
});
self.drawn = None;
}
if self.target.as_ref().is_none_or(|t| t.size != view.size) {
let texture = |label: &str, format, usage| {
device.create_texture(&wgpu::TextureDescriptor {
label: Some(label),
size: wgpu::Extent3d { width: w, height: h, depth_or_array_layers: 1 },
mip_level_count: 1,
sample_count: 1,
dimension: wgpu::TextureDimension::D2,
format,
usage,
view_formats: &[],
})
};
let ids = texture("sc_pick_ids", IDS, wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::COPY_SRC);
let depth = texture("sc_pick_depth", DEPTH, wgpu::TextureUsages::RENDER_ATTACHMENT);
let (ids_view, depth_view) = (ids.create_view(&Default::default()), depth.create_view(&Default::default()));
self.target = Some(Target { size: view.size, ids, ids_view, depth_view });
self.drawn = None;
}
let (Some(target), Some(scene)) = (&self.target, &self.scene) else { return };
if self.drawn != Some(view.key) {
queue.write_buffer(&self.uniform, 0, &uniform_bytes(view));
let mut pass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
label: Some("sc_pick"),
color_attachments: &[Some(wgpu::RenderPassColorAttachment {
view: &target.ids_view,
depth_slice: None,
resolve_target: None,
ops: wgpu::Operations { load: wgpu::LoadOp::Clear(wgpu::Color::TRANSPARENT), store: wgpu::StoreOp::Store },
})],
depth_stencil_attachment: Some(wgpu::RenderPassDepthStencilAttachment {
view: &target.depth_view,
depth_ops: Some(wgpu::Operations { load: wgpu::LoadOp::Clear(1.0), store: wgpu::StoreOp::Discard }),
stencil_ops: None,
}),
timestamp_writes: None,
occlusion_query_set: None,
multiview_mask: None,
});
pass.set_bind_group(0, &self.bind, &[]);
for (pipeline, part) in [(&self.face, &scene.faces), (&self.edge, &scene.edges)] {
if let Some((buffer, n)) = part {
pass.set_pipeline(pipeline);
pass.set_vertex_buffer(0, buffer.slice(..));
pass.draw(0..*n, 0..1);
}
}
drop(pass);
self.drawn = Some(view.key);
// Tiles of other views no longer answer.
self.pending.retain(|p| p.key == view.key);
if let Ok(mut o) = out.lock() {
o.tiles.retain(|t| t.key == view.key);
}
}
let Some(centre) = centre else { return };
let (origin, size) = tile_around(centre, view.size);
let known = out.lock().is_ok_and(|o| o.tiles.iter().any(|t| t.key == view.key && t.origin == origin && t.size == size))
|| self.pending.iter().any(|p| p.key == view.key && p.origin == origin && p.size == size);
if known || self.pending.len() >= IN_FLIGHT {
return;
}
let bytes_per_row = (size[0] * 4).div_ceil(wgpu::COPY_BYTES_PER_ROW_ALIGNMENT) * wgpu::COPY_BYTES_PER_ROW_ALIGNMENT;
let buffer = device.create_buffer(&wgpu::BufferDescriptor {
label: Some("sc_pick_tile"),
size: u64::from(bytes_per_row) * u64::from(size[1]),
usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
mapped_at_creation: false,
});
encoder.copy_texture_to_buffer(
wgpu::TexelCopyTextureInfo {
texture: &target.ids,
mip_level: 0,
origin: wgpu::Origin3d { x: origin[0], y: origin[1], z: 0 },
aspect: wgpu::TextureAspect::All,
},
wgpu::TexelCopyBufferInfo {
buffer: &buffer,
layout: wgpu::TexelCopyBufferLayout { offset: 0, bytes_per_row: Some(bytes_per_row), rows_per_image: Some(size[1]) },
},
wgpu::Extent3d { width: size[0], height: size[1], depth_or_array_layers: 1 },
);
self.pending.push(Pending { key: view.key, origin, size, bytes_per_row, buffer, frame: self.frame, state: Arc::new(AtomicU8::new(NEW)) });
}
/// Whether read-backs are still on their way (keep frames coming).
pub fn waiting(&self) -> bool {
!self.pending.is_empty()
}
/// Maps the copies earlier frames submitted and moves the mapped ones into `out`.
fn collect(&mut self, device: &wgpu::Device, out: &PickOut) {
let frame = self.frame;
for p in &self.pending {
if p.frame < frame && p.state.load(Ordering::Acquire) == NEW {
p.state.store(MAPPING, Ordering::Release);
let state = p.state.clone();
p.buffer.slice(..).map_async(wgpu::MapMode::Read, move |r| state.store(if r.is_ok() { READY } else { FAILED }, Ordering::Release));
}
}
if self.pending.iter().any(|p| p.state.load(Ordering::Acquire) == MAPPING) {
let _ = device.poll(wgpu::PollType::Poll);
}
let mut done = Vec::new();
self.pending.retain(|p| match p.state.load(Ordering::Acquire) {
READY => {
if let Ok(bytes) = p.buffer.slice(..).get_mapped_range() {
let [w, h] = p.size;
let mut ids = Vec::with_capacity(w as usize * h as usize);
for row in bytes.chunks(p.bytes_per_row as usize).take(h as usize) {
ids.extend(row.as_chunks::<4>().0.iter().take(w as usize).map(|c| u32::from_le_bytes(*c)));
}
done.push(PickTile { key: p.key, origin: p.origin, size: p.size, ids });
}
p.buffer.unmap();
false
}
FAILED => false,
_ => true,
});
if !done.is_empty()
&& let Ok(mut o) = out.lock()
{
for t in done {
if self.drawn == Some(t.key) && t.ids.len() == t.size[0] as usize * t.size[1] as usize {
o.tiles.retain(|x| x.key == t.key);
o.tiles.push(t);
}
}
let excess = o.tiles.len().saturating_sub(KEEP);
o.tiles.drain(..excess);
}
}
}
fn uniform_bytes(v: &PickView) -> Vec<u8> {
let mut b = Vec::with_capacity(UNIFORM_SIZE as usize);
for col in v.view_proj {
for x in col {
b.extend_from_slice(&x.to_le_bytes());
}
}
for x in v.eye.into_iter().chain(v.back).chain([v.lift]) {
b.extend_from_slice(&x.to_le_bytes());
}
b
}
#[cfg(test)]
#[path = "pick_tests.rs"]
mod tests;
+79
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@@ -0,0 +1,79 @@
use super::*;
/// Looking down −z at x, y in −10..10 (orthographic): depth 0 at z = 50, 1 at z = −50.
const VIEW: [[f32; 4]; 4] = [[0.1, 0.0, 0.0, 0.0], [0.0, 0.1, 0.0, 0.0], [0.0, 0.0, -0.01, 0.0], [0.0, 0.0, 0.5, 1.0]];
const SIZE: u32 = 64;
/// The pixel of model point (x, y).
fn px(x: f32, y: f32) -> [i64; 2] {
[((x / 10.0 + 1.0) * 0.5 * SIZE as f32) as i64, ((1.0 - y / 10.0) * 0.5 * SIZE as f32) as i64]
}
/// A square face at z = 0 (x, y in −5..5), and three edges: 1 on it, 2 well behind it, 3 behind
/// it by less than the lift.
fn scene() -> PickScene {
let mut s = PickScene::default();
let (a, b, c, d) = ([-5.0, -5.0, 0.0], [5.0, -5.0, 0.0], [5.0, 5.0, 0.0], [-5.0, 5.0, 0.0]);
s.triangle([a, b, c]);
s.triangle([a, c, d]);
s.segment([-8.0, 0.0, 0.0], [8.0, 0.0, 0.0], 1);
s.segment([2.0, -8.0, -3.0], [2.0, 8.0, -3.0], 2);
s.segment([-2.0, -8.0, -0.2], [-2.0, 8.0, -0.2], 3);
s
}
#[test]
fn the_pick_buffer_names_the_edges_seen_at_each_pixel() {
let (_, device, queue) = match crate::open_headless() {
Ok(d) => d,
Err(e) => {
assert!(std::env::var_os("SOLIDCRAFT_REQUIRE_GPU").is_none(), "a GPU is required here: {e}");
eprintln!("skipping: {e}");
return;
}
};
let mut pb = PickBuffer::new(&device);
let out = PickOut::default();
let view = PickView { key: 7, view_proj: VIEW, eye: [0.0, 0.0, 100.0, 0.0], back: [0.0, 0.0, 1.0], lift: 0.5, size: [SIZE, SIZE] };
let scene = scene();
let all = [0, 0, SIZE as i64 - 1, SIZE as i64 - 1];
for _ in 0..8 {
let mut encoder = device.create_command_encoder(&Default::default());
pb.prepare(&device, &queue, &mut encoder, 1, &scene, &view, Some([SIZE / 2, SIZE / 2]), &out);
queue.submit([encoder.finish()]);
let _ = device.poll(wgpu::PollType::wait_indefinitely());
if out.lock().unwrap().tile(7, [SIZE, SIZE], all).is_some() {
break;
}
}
let results = out.lock().unwrap();
let tile = results.tile(7, [SIZE, SIZE], all).expect("the tile is read back within a few frames");
let at = |x: f32, y: f32| {
let [px, py] = px(x, y);
tile.ids_in([px - 1, py - 1, px + 1, py + 1])
};
assert_eq!(at(0.0, 0.0), vec![1], "the edge on the face");
assert_eq!(at(2.0, 3.0), Vec::<u32>::new(), "the edge behind the face is hidden");
assert_eq!(at(2.0, 7.5), vec![2], "and seen where the face does not cover it");
assert_eq!(at(-2.0, 3.0), vec![3], "an edge behind the face by less than the lift counts as seen");
assert_eq!(at(3.5, 3.5), Vec::<u32>::new(), "the face itself names no edge");
assert!(results.tile(8, [SIZE, SIZE], all).is_none(), "another view's tile does not answer");
drop(results);
assert!(!pb.waiting());
}
#[test]
fn tiles_cover_the_window_around_the_cursor_inside_the_view() {
assert_eq!(tile_around([10, 10], [1000, 800]), ([0, 0], [TILE, TILE]));
assert_eq!(tile_around([500, 400], [1000, 800]), ([500 - TILE / 2, 400 - TILE / 2], [TILE, TILE]));
assert_eq!(tile_around([999, 799], [1000, 800]), ([1000 - TILE, 800 - TILE], [TILE, TILE]));
assert_eq!(tile_around([30, 20], [50, 40]), ([0, 0], [50, 40]));
let t = PickTile { key: 1, origin: [100, 100], size: [TILE, TILE], ids: vec![0; (TILE * TILE) as usize] };
assert!(t.covers(1, [1000, 800], [110, 110, 120, 120]));
assert!(!t.covers(1, [1000, 800], [90, 110, 120, 120]));
assert!(!t.covers(2, [1000, 800], [110, 110, 120, 120]));
// A window past the view's border needs only the pixels inside it.
let corner = PickTile { key: 1, origin: [0, 0], size: [TILE, TILE], ids: vec![5; (TILE * TILE) as usize] };
assert!(corner.covers(1, [1000, 800], [-8, -8, 8, 8]));
assert_eq!(corner.ids_in([-8, -8, 8, 8]), vec![5]);
}
+1 -1
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@@ -136,7 +136,7 @@ pub(crate) fn offscreen_backends() -> wgpu::Backends {
/// A device of its own for an offscreen render or check (`None` without a GPU adapter), on
/// [`offscreen_backends`].
#[cfg(all(test, not(target_arch = "wasm32")))]
fn offscreen_device() -> Option<(wgpu::Adapter, wgpu::Device, wgpu::Queue)> {
pub(crate) fn offscreen_device() -> Option<(wgpu::Adapter, wgpu::Device, wgpu::Queue)> {
let mut desc = wgpu::InstanceDescriptor::new_without_display_handle_from_env();
desc.backends = offscreen_backends();
let instance = wgpu::Instance::new(desc);
+2
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@@ -112,6 +112,8 @@ mod fillet_spline_handle_tests;
pub(crate) mod navigation;
pub mod palette;
pub mod params_dialog;
pub(crate) mod pick_buffer;
pub(crate) mod pick_index;
pub mod prefs;
#[cfg(test)]
mod preselect_tests;
+259
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@@ -0,0 +1,259 @@
//! The GPU pick buffer in the viewport ([`solidcraft_gpu::pick`]): which model edges are seen at
//! each pixel, so a pick over a large model tests only the edges near the cursor that are not
//! hidden, instead of every edge the cursor's ray passes near.
//!
//! The pass is drawn for a view once it holds still (the same view two frames running), and a
//! tile around the cursor is read back; the tile arrives a frame or two later, and until it
//! does (and while the view moves) the picker answers from the CPU indexes
//! ([`crate::pick_index`]). The tile only narrows the candidates: the picker's exact tests
//! still decide. Not used for Select Other (every target along the ray), in wireframe (nothing
//! hides an edge there), without a GPU, or for a model past [`MAX_TRIANGLES`].
use std::collections::HashMap;
use std::hash::{Hash, Hasher};
use std::sync::{Arc, Mutex};
use egui::Pos2;
use solidcraft_engine::doc::ModelState;
use solidcraft_gpu::pick::{PickBuffer, PickOut, PickScene, PickView};
use crate::SolveApp;
use crate::viewport::Proj;
/// Most surface triangles the pass draws (beyond them the CPU indexes answer alone).
pub const MAX_TRIANGLES: usize = 6_000_000;
/// How near the cursor an edge's pixels are looked for (points): vertices pick within 7, edges 6.
const WINDOW: f32 = 8.0;
/// Frames kept coming after a tile is asked for, so its read-back lands.
const FRAMES: u8 = 4;
/// The pass's scene for one model state: the ids it draws stand for (body, edge).
struct Scene {
state: Arc<ModelState>,
key: u64,
scene: Arc<PickScene>,
/// Per id − 1: (body index in the state, edge index).
edges: Vec<(u32, u32)>,
/// One-point edges (no line to draw): always candidates.
points: Vec<(u32, u32)>,
}
#[derive(Default)]
pub(crate) struct State {
scene: Mutex<Option<Arc<Scene>>>,
out: PickOut,
/// A pick found no tile for its cursor: the view it was in and the pixel.
want: Mutex<Option<(u64, [u32; 2])>>,
/// The view of the last frame (the pass is drawn for a view that held still).
last_view: u64,
/// Frames still to request so read-backs land.
frames: u8,
}
/// The edges a tile names near the cursor, per body index of the world state.
pub(crate) struct NearEdges {
by_body: HashMap<usize, Vec<usize>>,
}
impl NearEdges {
/// Every segment of the named edges of body `index` of `mesh`, as (edge, first point), in
/// edge order.
pub(crate) fn segments(&self, index: usize, mesh: &solidcraft_engine::geom::Mesh) -> Vec<(usize, usize)> {
let mut v = Vec::new();
for &ei in self.by_body.get(&index).map_or(&[][..], |e| &e[..]) {
let n = mesh.edges.get(ei).map_or(0, |e| e.len().max(2) - 1);
v.extend((0..n).map(|si| (ei, si)));
}
v
}
}
/// What the pass's scene depends on: the world state, and which bodies show.
fn model_key(app: &SolveApp, st: &Arc<ModelState>) -> u64 {
let mut h = std::collections::hash_map::DefaultHasher::new();
(Arc::as_ptr(st) as usize).hash(&mut h);
app.session.revision.hash(&mut h);
app.session.visibility.hidden_bodies.hash(&mut h);
app.session.visibility.hidden_occurrences.hash(&mut h);
h.finish()
}
/// The view's pixels: the viewport's size in physical pixels.
fn view_size(app: &SolveApp, proj: &Proj) -> [u32; 2] {
let ppp = app.viewport.pixels_per_point();
[(proj.rect.width() * ppp).round().max(0.0) as u32, (proj.rect.height() * ppp).round().max(0.0) as u32]
}
/// How far edges are lifted toward the eye: the picker's slack for an edge behind a face.
fn lift(app: &SolveApp) -> f64 {
crate::viewport::scene_radius(app) * 0.02
}
/// Everything the drawn ids depend on.
fn view_key(app: &SolveApp, proj: &Proj, model: u64) -> u64 {
let mut h = std::collections::hash_map::DefaultHasher::new();
model.hash(&mut h);
for col in proj.vp.to_f32() {
for x in col {
x.to_bits().hash(&mut h);
}
}
view_size(app, proj).hash(&mut h);
lift(app).to_bits().hash(&mut h);
h.finish()
}
fn usable(app: &SolveApp) -> bool {
app.viewport.gpu.is_some() && app.ui.visual_style != 2
}
/// The edges seen within reach of `pos`, when a tile of this view is in; otherwise `None`, and
/// a tile around `pos` is asked for.
pub(crate) fn edges_near(app: &SolveApp, proj: &Proj, pos: Pos2, st: &Arc<ModelState>) -> Option<NearEdges> {
if !usable(app) {
return None;
}
let model = model_key(app, st);
let scene = app.viewport.pick_buffer.scene.lock().ok()?.clone().filter(|s| s.key == model && Arc::ptr_eq(&s.state, st));
let key = view_key(app, proj, model);
let size = view_size(app, proj);
let ppp = app.viewport.pixels_per_point();
let (x, y) = ((pos.x - proj.rect.left()) * ppp, (pos.y - proj.rect.top()) * ppp);
if !(x >= 0.0 && y >= 0.0 && x < size[0] as f32 && y < size[1] as f32) {
return None;
}
let (x, y) = (x as i64, y as i64);
let r = (WINDOW * ppp).ceil() as i64;
let window = [x - r, y - r, x + r, y + r];
let ids = scene.as_ref().and_then(|_| app.viewport.pick_buffer.out.lock().ok()?.tile(key, size, window).map(|t| t.ids_in(window)));
let (Some(scene), Some(ids)) = (scene, ids) else {
if let Ok(mut w) = app.viewport.pick_buffer.want.lock() {
*w = Some((key, [x as u32, y as u32]));
}
return None;
};
let mut by_body: HashMap<usize, Vec<usize>> = HashMap::new();
for (b, e) in ids.iter().filter_map(|id| scene.edges.get((*id as usize).checked_sub(1)?)).chain(&scene.points) {
by_body.entry(*b as usize).or_default().push(*e as usize);
}
for v in by_body.values_mut() {
v.sort_unstable();
v.dedup();
}
Some(NearEdges { by_body })
}
/// The pass's scene for the world state: visible bodies' triangles, and their pickable edges.
/// `None` past [`MAX_TRIANGLES`] or without edges.
fn scene(app: &SolveApp, st: &Arc<ModelState>, key: u64) -> Option<Arc<Scene>> {
let f = |p: solidcraft_engine::geom::Vec3| [p.x as f32, p.y as f32, p.z as f32];
let mut scene = PickScene::default();
let (mut edges, mut points, mut triangles) = (Vec::new(), Vec::new(), 0usize);
for (bi, b) in st.bodies.iter().enumerate() {
if !app.session.body_visible(&b.name) {
continue;
}
let m = b.mesh();
triangles += m.triangles.len();
if triangles > MAX_TRIANGLES {
return None;
}
for t in &m.triangles {
if let Some([a, b, c]) = m.tri(t) {
scene.triangle([f(a), f(b), f(c)]);
}
}
for (ei, e) in m.edges.iter().enumerate() {
if !m.edge_pickable(ei) || edges.len() >= u32::MAX as usize - 1 {
continue;
}
if e.len() == 1 {
points.push((bi as u32, ei as u32));
continue;
}
edges.push((bi as u32, ei as u32));
let id = edges.len() as u32;
for w in e.windows(2) {
scene.segment(f(w[0]), f(w[1]), id);
}
}
}
(!scene.is_empty()).then(|| Arc::new(Scene { state: st.clone(), key, scene: Arc::new(scene), edges, points }))
}
/// In the frame's GPU paint: draw the pass for a view that held still when a pick asked for a
/// tile, and keep frames coming until the read-back lands.
pub(crate) fn paint(app: &mut SolveApp, ctx: &egui::Context, painter: &egui::Painter, proj: &Proj) {
if !usable(app) {
return;
}
let st = app.session.world_state();
let model = model_key(app, &st);
let key = view_key(app, proj, model);
let state = &mut app.viewport.pick_buffer;
let still = std::mem::replace(&mut state.last_view, key) == key;
let want = state.want.lock().ok().and_then(|mut w| w.take()).filter(|(k, _)| *k == key && still);
if want.is_none() && state.frames == 0 {
return;
}
state.frames = if want.is_some() { FRAMES } else { state.frames.saturating_sub(1) };
let cached = state.scene.lock().ok().and_then(|s| s.clone()).filter(|s| s.key == model && Arc::ptr_eq(&s.state, &st));
let scene = match cached {
Some(s) => s,
None => {
let Some(s) = scene(app, &st, model) else { return };
if let Ok(mut slot) = app.viewport.pick_buffer.scene.lock() {
*slot = Some(s.clone());
}
s
}
};
let e = proj.cam.eye().to_f32();
let view = PickView {
key,
view_proj: proj.vp.to_f32(),
eye: [e[0], e[1], e[2], if proj.cam.fov > 0.0 { 1.0 } else { 0.0 }],
back: proj.cam.back().to_f32(),
lift: lift(app) as f32,
size: view_size(app, proj),
};
let cb =
PickCallback { scene_key: scene.key, scene: scene.scene.clone(), view, centre: want.map(|w| w.1), out: app.viewport.pick_buffer.out.clone() };
painter.add(egui_wgpu::Callback::new_paint_callback(proj.rect, cb));
ctx.request_repaint();
}
/// The pass as an egui paint callback: all its work is in `prepare` (it draws into its own
/// textures, not the frame).
struct PickCallback {
scene_key: u64,
scene: Arc<PickScene>,
view: PickView,
centre: Option<[u32; 2]>,
out: PickOut,
}
impl egui_wgpu::CallbackTrait for PickCallback {
fn prepare(
&self,
device: &egui_wgpu::wgpu::Device,
queue: &egui_wgpu::wgpu::Queue,
_screen: &egui_wgpu::ScreenDescriptor,
encoder: &mut egui_wgpu::wgpu::CommandEncoder,
resources: &mut egui_wgpu::CallbackResources,
) -> Vec<egui_wgpu::wgpu::CommandBuffer> {
if resources.get::<PickBuffer>().is_none() {
resources.insert(PickBuffer::new(device));
}
if let Some(pb) = resources.get_mut::<PickBuffer>() {
pb.prepare(device, queue, encoder, self.scene_key, &self.scene, &self.view, self.centre, &self.out);
}
Vec::new()
}
fn paint(&self, _info: egui::PaintCallbackInfo, _pass: &mut egui_wgpu::wgpu::RenderPass<'static>, _resources: &egui_wgpu::CallbackResources) {}
}
#[cfg(test)]
#[path = "pick_buffer_tests.rs"]
mod tests;
+141
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@@ -0,0 +1,141 @@
use egui::{Rect, pos2};
use serde_json::json;
use solidcraft_engine::geom::Vec3;
use solidcraft_gpu::pick::{PickTile, TILE, tile_around};
use super::*;
use crate::viewport::{Hit, pick, projection};
fn app() -> SolveApp {
let mut s = solidcraft_engine::Session::default();
s.execute("solid.box", &json!({"length": 40, "width": 30, "height": 20})).unwrap();
s.execute("solid.fillet", &json!({"edges": [[40, 15, 20]], "radius": 4})).unwrap();
s.execute("solid.cylinder", &json!({"radius": 8, "height": 35, "base": [10, 10, 0], "operation": "new_body"})).unwrap();
let mut app = SolveApp::new(s, crate::Services::default());
app.ui.show_origin = false;
app.cam.target = Vec3::new(20.0, 15.0, 12.0);
app.cam.distance = 110.0;
// A GPU viewport (no device is needed to hand the picker a tile).
app.viewport.gpu = Some(crate::gpu::GpuTarget { format: egui_wgpu::wgpu::TextureFormat::Rgba8Unorm, depth: None, samples: 1, tess: false });
app
}
const RECT: Rect = Rect { min: pos2(0.0, 0.0), max: pos2(640.0, 480.0) };
/// Installs the pass's scene, as `paint` makes it, and returns the view's key.
fn install_scene(app: &SolveApp, proj: &Proj) -> u64 {
let st = app.session.world_state();
let model = model_key(app, &st);
let s = scene(app, &st, model).unwrap();
*app.viewport.pick_buffer.scene.lock().unwrap() = Some(s);
view_key(app, proj, model)
}
/// A tile only narrows the edges: the edge it names near the cursor is picked as the CPU picks
/// it, an edge it does not name (hidden there) is not, and without a tile the CPU indexes answer
/// and a tile is asked for.
#[test]
fn a_tile_names_the_edges_the_picker_tests() {
let app = app();
let proj = projection(&app, RECT);
// A point on the box's top front edge (y = 0, z = 20).
let at = proj.to_screen(Vec3::new(20.0, 0.0, 20.0)).unwrap();
let cpu = pick(&app, &proj, at);
let Some(Hit::Edge { index, body, .. }) = cpu.iter().find(|h| matches!(h, Hit::Edge { .. })).cloned() else { panic!("{cpu:?}") };
assert!(app.viewport.pick_buffer.want.lock().unwrap().is_some(), "no tile yet: one is asked for");
let key = install_scene(&app, &proj);
let st = app.session.world_state();
let bi = st.bodies.iter().position(|b| b.name == body).unwrap();
let s = app.viewport.pick_buffer.scene.lock().unwrap().clone().unwrap();
let id = s.edges.iter().position(|&(b, e)| b as usize == bi && e as usize == index).unwrap() as u32 + 1;
let size = view_size(&app, &proj);
let (origin, tsize) = tile_around([at.x as u32, at.y as u32], size);
let tile = |ids: Vec<u32>| PickTile { key, origin, size: tsize, ids };
let n = (tsize[0] * tsize[1]) as usize;
// The edge's id at the cursor's pixel.
let mut ids = vec![0; n];
ids[((at.y as u32 - origin[1]) * tsize[0] + (at.x as u32 - origin[0])) as usize] = id;
app.viewport.pick_buffer.out.lock().unwrap().tiles = vec![tile(ids)];
assert_eq!(pick(&app, &proj, at), cpu, "the named edge is picked as the CPU picks it");
// A tile naming no edge there: no edge or vertex is picked.
app.viewport.pick_buffer.out.lock().unwrap().tiles = vec![tile(vec![0; n])];
let none = pick(&app, &proj, at);
assert!(!none.iter().any(|h| matches!(h, Hit::Edge { .. } | Hit::Vertex { .. })), "{none:?}");
assert!(none.iter().any(|h| matches!(h, Hit::Face { .. })), "faces are still picked: {none:?}");
// A tile of another view does not answer.
app.viewport.pick_buffer.out.lock().unwrap().tiles = vec![PickTile { key: key ^ 1, ..tile(vec![0; n]) }];
assert_eq!(pick(&app, &proj, at), cpu);
// Wireframe: nothing hides an edge, and the buffer is not used.
let mut wire = app;
wire.ui.visual_style = 2;
wire.viewport.pick_buffer.out.lock().unwrap().tiles = vec![tile(vec![0; n])];
assert!(edges_near(&wire, &proj, at, &wire.session.world_state()).is_none());
}
/// On a real device: the pass drawn for the view, and picks over a grid of the view helped by its
/// tiles answer as the CPU picks (an edge's pixels and the CPU's visibility test can disagree by
/// a pixel at a silhouette, so a few may differ). Skipped without a GPU adapter.
#[cfg(not(target_arch = "wasm32"))]
#[test]
fn picks_through_the_pass_match_the_cpu() {
let Some((_, device, queue)) = crate::gpu::offscreen_device() else {
assert!(std::env::var_os("SOLIDCRAFT_REQUIRE_GPU").is_none(), "a GPU is required here");
eprintln!("skipping: no GPU adapter");
return;
};
let mut app = app();
for (perspective, yaw, pitch) in [(false, 0.6, 0.5), (true, 2.4, 0.3)] {
app.ui.perspective = perspective;
app.cam.yaw = yaw;
app.cam.pitch = pitch;
let proj = projection(&app, RECT);
let key = install_scene(&app, &proj);
let s = app.viewport.pick_buffer.scene.lock().unwrap().clone().unwrap();
let e = proj.cam.eye().to_f32();
let view = PickView {
key,
view_proj: proj.vp.to_f32(),
eye: [e[0], e[1], e[2], if proj.cam.fov > 0.0 { 1.0 } else { 0.0 }],
back: proj.cam.back().to_f32(),
lift: lift(&app) as f32,
size: view_size(&app, &proj),
};
let mut pb = PickBuffer::new(&device);
let out = app.viewport.pick_buffer.out.clone();
// Tiles over the whole view.
let mut wanted = Vec::new();
for ty in (0..view.size[1]).step_by(TILE as usize - 32) {
for tx in (0..view.size[0]).step_by(TILE as usize - 32) {
wanted.push([tx + TILE / 2, ty + TILE / 2]);
}
}
let mut tiles = Vec::new();
for c in wanted {
for _ in 0..6 {
let mut encoder = device.create_command_encoder(&Default::default());
pb.prepare(&device, &queue, &mut encoder, s.key, &s.scene, &view, Some(c), &out);
queue.submit([encoder.finish()]);
let _ = device.poll(egui_wgpu::wgpu::PollType::wait_indefinitely());
}
tiles.append(&mut out.lock().unwrap().tiles);
}
let (mut same, mut differ, mut edges) = (0, 0, 0);
for j in 0..46 {
for i in 0..62 {
let p = pos2(10.0 + i as f32 * 10.0 + (j % 3) as f32, 10.0 + j as f32 * 10.0);
let r = 8i64;
let w = [p.x as i64 - r, p.y as i64 - r, p.x as i64 + r, p.y as i64 + r];
let Some(t) = tiles.iter().find(|t| t.covers(key, view.size, w)).cloned() else { continue };
out.lock().unwrap().tiles = vec![t];
let through = pick(&app, &proj, p);
out.lock().unwrap().tiles.clear();
let cpu = pick(&app, &proj, p);
edges += usize::from(cpu.iter().any(|h| matches!(h, Hit::Edge { .. })));
if through == cpu { same += 1 } else { differ += 1 }
}
}
eprintln!("perspective {perspective}: {same} same, {differ} differ, {edges} with an edge");
assert!(edges > 100, "the grid reaches edges ({edges})");
assert!(differ * 100 <= same + differ, "{differ} of {} picks differ", same + differ);
}
}
+102
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@@ -0,0 +1,102 @@
//! Picking without scanning every triangle and edge: each body mesh's [`MeshIndex`] (its
//! triangles and edge segments in hierarchies), made the first time a pick reaches the body and
//! kept while the mesh is. The viewport's picker asks it for the nearest triangle along the
//! cursor's ray and for the edge segments near that ray, then runs its exact screen tests on
//! those alone.
use std::collections::HashMap;
use std::sync::{Arc, Mutex};
use egui::{Pos2, vec2};
use solidcraft_engine::geom::{Mesh, MeshIndex, Vec3};
use crate::viewport::Proj;
/// Indexes by mesh address, each with its mesh held (so the address stays its own).
#[derive(Default)]
pub(crate) struct PickIndexes(Mutex<HashMap<usize, (Arc<Mesh>, Arc<MeshIndex>)>>);
impl PickIndexes {
/// The index of `mesh`, made now when there is none yet.
pub(crate) fn of(&self, mesh: &Arc<Mesh>) -> Arc<MeshIndex> {
let key = Arc::as_ptr(mesh) as usize;
let Ok(mut map) = self.0.lock() else { return Arc::new(MeshIndex::new(mesh)) };
if let Some((_, index)) = map.get(&key) {
return index.clone();
}
let index = Arc::new(MeshIndex::new(mesh));
map.insert(key, (mesh.clone(), index.clone()));
index
}
/// Drops the indexes of meshes `keep` no longer names (a new model state).
pub(crate) fn retain(&self, keep: impl Fn(usize) -> bool) {
if let Ok(mut map) = self.0.lock() {
map.retain(|k, _| keep(*k));
}
}
#[cfg(test)]
pub(crate) fn len(&self) -> usize {
self.0.lock().map_or(0, |m| m.len())
}
}
/// How far from the ray through `pos` a point may lie and still come within `px` points of it on
/// screen: `a + b·t` at distance `t` along the ray (constant for an orthographic view, widening
/// with depth in perspective), with room to spare.
pub(crate) fn reach(proj: &Proj, pos: Pos2, px: f32) -> (f64, f64) {
let (o, d) = proj.ray(pos);
let (mut a, mut b) = (0.0f64, 0.0f64);
for step in [vec2(px, 0.0), vec2(0.0, px), vec2(-px, 0.0), vec2(0.0, -px)] {
let (o2, d2) = proj.ray(pos + step);
a = a.max(o2.dist(o));
b = b.max(d2.dist(d));
}
// A screen offset of `px` along a diagonal, and rounding: half again.
(a * 1.5, b * 1.5)
}
/// The edge segments of `index` that may come within reach of the ray, as (edge, first point),
/// in edge order and then along each edge: the order a scan of every edge would meet them in.
pub(crate) fn segments_near(index: &MeshIndex, mesh: &Mesh, o: Vec3, d: Vec3, (a, b): (f64, f64)) -> Vec<(usize, usize)> {
let mut v = Vec::new();
if scanning() {
for (ei, e) in mesh.edges.iter().enumerate() {
v.extend((0..e.len().max(2) - 1).map(|si| (ei, si)));
}
return v;
}
index.segments_near(o, d, a, b, |e, s| v.push((e, s)));
v.sort_unstable();
v
}
/// The nearest triangle of `mesh` along the ray, through its index.
pub(crate) fn raycast(index: &MeshIndex, mesh: &Mesh, o: Vec3, d: Vec3) -> Option<(f64, usize)> {
if scanning() {
return mesh.raycast(o, d);
}
index.raycast(mesh, o, d)
}
#[cfg(test)]
thread_local! {
/// Tests: pick by scanning every triangle and edge, as before the indexes, to compare.
pub(crate) static SCAN: std::cell::Cell<bool> = const { std::cell::Cell::new(false) };
}
fn scanning() -> bool {
#[cfg(test)]
{
SCAN.with(|s| s.get())
}
#[cfg(not(test))]
{
false
}
}
#[cfg(test)]
#[path = "pick_index_tests.rs"]
mod tests;
+122
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@@ -0,0 +1,122 @@
use egui::{Rect, pos2, vec2};
use serde_json::json;
use crate::SolveApp;
use crate::viewport::{Hit, pick, pick_all, projection};
/// Overlapping bodies with flat and curved faces, filleted edges and seams.
fn assembly() -> SolveApp {
let mut s = solidcraft_engine::Session::default();
s.execute("solid.box", &json!({"length": 40, "width": 30, "height": 20})).unwrap();
s.execute("solid.fillet", &json!({"edges": [[40, 15, 20]], "radius": 4})).unwrap();
s.execute("solid.cylinder", &json!({"radius": 8, "height": 35, "base": [10, 10, 0], "operation": "new_body"})).unwrap();
s.execute("solid.sphere", &json!({"radius": 9, "center": [30, 25, 22]})).unwrap();
let mut app = SolveApp::new(s, crate::Services::default());
app.ui.show_origin = false;
app
}
/// Every cursor position on a grid over the view, for each camera: the indexed pick answers what
/// scanning every triangle and edge answers (the nearest of each kind, and Select Other's list).
#[test]
fn indexed_picks_match_the_full_scan() {
let mut app = assembly();
let rect = Rect::from_min_size(pos2(0.0, 0.0), vec2(640.0, 480.0));
let mut compared = (0, 0, 0);
for (perspective, yaw, pitch) in [(false, 0.6, 0.5), (true, 0.6, 0.5), (true, 2.4, -0.3), (false, 0.0, 1.5)] {
app.ui.perspective = perspective;
app.cam.yaw = yaw;
app.cam.pitch = pitch;
app.cam.target = solidcraft_engine::geom::Vec3::new(20.0, 15.0, 12.0);
app.cam.distance = 110.0;
let proj = projection(&app, rect);
for j in 0..48 {
for i in 0..64 {
let p = pos2(5.0 + i as f32 * 10.0 + (j % 3) as f32, 5.0 + j as f32 * 10.0);
let fast = (pick(&app, &proj, p), pick_all(&app, &proj, p));
super::SCAN.with(|s| s.set(true));
let scan = (pick(&app, &proj, p), pick_all(&app, &proj, p));
super::SCAN.with(|s| s.set(false));
assert_eq!(fast, scan, "at {p:?} (perspective {perspective}, yaw {yaw}, pitch {pitch})");
compared.0 += usize::from(fast.0.iter().any(|h| matches!(h, Hit::Face { .. })));
compared.1 += usize::from(fast.0.iter().any(|h| matches!(h, Hit::Edge { .. })));
compared.2 += usize::from(fast.0.iter().any(|h| matches!(h, Hit::Vertex { .. })));
}
}
}
// The grid reaches every kind many times over.
assert!(compared.0 > 2000 && compared.1 > 100 && compared.2 > 10, "{compared:?}");
assert_eq!(app.viewport.pick_index.len(), 3, "one index per body mesh");
}
/// A new model state lets go of the indexes of meshes it no longer has.
#[test]
fn indexes_follow_the_model_state() {
let mut app = assembly();
let rect = Rect::from_min_size(pos2(0.0, 0.0), vec2(640.0, 480.0));
app.cam.target = solidcraft_engine::geom::Vec3::new(20.0, 15.0, 12.0);
let proj = projection(&app, rect);
let centre = proj.to_screen(solidcraft_engine::geom::Vec3::new(20.0, 15.0, 10.0)).unwrap();
pick(&app, &proj, centre);
assert!(app.viewport.pick_index.len() >= 1);
app.session.execute("solid.box", &json!({"length": 5, "width": 5, "height": 5, "corner": [-20, -20, 0], "operation": "new_body"})).unwrap();
pick(&app, &proj, centre);
assert!(app.viewport.pick_index.len() <= 4, "indexes of meshes gone with the old state are dropped");
app.session.execute("solid.box", &json!({"length": 5, "width": 5, "height": 5, "corner": [-40, -20, 0], "operation": "new_body"})).unwrap();
pick(&app, &proj, centre);
assert!(app.viewport.pick_index.len() <= 5);
}
/// Timing, not a check (`cargo test -p solidcraft-ui-egui --lib pick_timing -- --ignored
/// --nocapture`): picks over a grid of the view, scanning every triangle and edge versus through
/// the indexes, on many curved bodies and on one body with many curved faces.
#[test]
#[ignore]
fn pick_timing_on_curved_models() {
let mut many = solidcraft_engine::Session::default();
for i in 0..12 {
for j in 0..12 {
let (x, y) = (f64::from(i) * 30.0, f64::from(j) * 30.0);
many.execute("solid.cylinder", &json!({"radius": 9, "height": 30, "base": [x, y, 0], "operation": "new_body"})).unwrap();
many.execute("solid.sphere", &json!({"radius": 8, "center": [x, y, 40], "operation": "new_body"})).unwrap();
}
}
let mut one = solidcraft_engine::Session::default();
one.execute("solid.box", &json!({"length": 340, "width": 340, "height": 10, "corner": [-15, -15, -5]})).unwrap();
for i in 0..8 {
for j in 0..8 {
let (x, y) = (f64::from(i) * 42.0, f64::from(j) * 42.0);
one.execute("solid.cylinder", &json!({"radius": 14, "height": 30, "base": [x, y, 0], "operation": "join"})).unwrap();
}
}
for (name, s) in [("many bodies", many), ("one body", one)] {
let mut app = SolveApp::new(s, crate::Services::default());
app.ui.show_origin = false;
app.cam.target = solidcraft_engine::geom::Vec3::new(160.0, 160.0, 15.0);
app.cam.distance = 900.0;
let st = app.session.world_state();
let (tris, segs) = st
.bodies
.iter()
.map(|b| b.mesh())
.fold((0, 0), |(t, s), m| (t + m.triangles.len(), s + m.edges.iter().map(|e| e.len().saturating_sub(1)).sum::<usize>()));
let rect = Rect::from_min_size(pos2(0.0, 0.0), vec2(1400.0, 900.0));
let proj = projection(&app, rect);
let points: Vec<_> = (0..20).flat_map(|j| (0..30).map(move |i| pos2(30.0 + i as f32 * 45.0, 30.0 + j as f32 * 42.0))).collect();
// Indexes made once, before timing.
for p in &points {
pick(&app, &proj, *p);
}
let time = |scan: bool| {
super::SCAN.with(|s| s.set(scan));
let t = std::time::Instant::now();
for p in &points {
std::hint::black_box(pick(&app, &proj, *p));
}
super::SCAN.with(|s| s.set(false));
t.elapsed().as_secs_f64() * 1000.0 / points.len() as f64
};
let (scan, indexed) = (time(true), time(false));
eprintln!("{name}: {} bodies, {tris} triangles, {segs} edge segments: scan {scan:.3} ms per pick, indexed {indexed:.3} ms", st.bodies.len());
}
}
+38 -16
View File
@@ -55,6 +55,11 @@ pub struct ViewportState {
lod_view: u64,
/// Each body mesh's box (the mesh held, so its address stays its own), from the last state.
mesh_bounds: std::sync::Mutex<std::collections::HashMap<usize, (std::sync::Arc<solidcraft_engine::geom::Mesh>, solidcraft_engine::geom::Aabb3)>>,
/// Each body mesh's picking index (made the first time a pick reaches the body), kept while
/// the mesh is part of the world state.
pub(crate) pick_index: crate::pick_index::PickIndexes,
/// The GPU pick buffer's scene, read-backs and requests.
pub(crate) pick_buffer: crate::pick_buffer::State,
/// The last click in the view was the middle button's (for the middle double-click).
pub(crate) middle_clicked: bool,
/// The last pick (its key and hits): reused while nothing it depends on changed.
@@ -1003,6 +1008,7 @@ fn body_bounds(
})
.collect::<Vec<_>>(),
);
app.viewport.pick_index.retain(|k| now.contains_key(&k));
if let Ok(mut k) = app.viewport.mesh_bounds.lock() {
*k = now;
}
@@ -1269,7 +1275,7 @@ fn pick_hits(app: &SolveApp, proj: &Proj, pos: Pos2, other_sketch_points: bool,
}
}
let m = b.mesh();
if let Some((t, ti)) = m.raycast(o, d) {
if let Some((t, ti)) = crate::pick_index::raycast(&app.viewport.pick_index.of(&m), &m, o, d) {
let fi = m.tri_face.get(ti).copied().unwrap_or(0) as usize;
let hit = Hit::Face { body: b.name.clone(), index: fi, point: o + d * t };
if bestf.as_ref().is_none_or(|(bt, _)| t < *bt) {
@@ -1284,7 +1290,11 @@ fn pick_hits(app: &SolveApp, proj: &Proj, pos: Pos2, other_sketch_points: bool,
// Wireframe draws no faces, so nothing hides an edge or a vertex.
let wireframe = app.ui.visual_style == 2;
let visible = |p: Vec3| wireframe || bestf.as_ref().is_none_or(|(t, _)| (p - o).dot(d) <= *t + slack);
// Vertices (edge end points) and edges.
// Vertices (edge end points) and edges, within 7 and 6 points of the cursor.
let reach = crate::pick_index::reach(proj, pos, 8.0);
// The edges seen near the cursor, when the GPU pick buffer has them for this view (Select
// Other wants hidden ones too).
let seen = if all { None } else { crate::pick_buffer::edges_near(app, proj, pos, &st) };
let mut bestv = Near::new(all);
let mut beste = Near::new(all);
for (i, b) in st.bodies.iter().enumerate() {
@@ -1298,26 +1308,37 @@ fn pick_hits(app: &SolveApp, proj: &Proj, pos: Pos2, other_sketch_points: bool,
continue;
}
let m = b.mesh();
for (ei, e) in m.edges.iter().enumerate() {
// Only the segments that can come near the cursor: of the edges the pick buffer sees
// there, else from the index. Either way in the order a scan of every edge would meet
// them, so ties go the same way.
let near = match &seen {
Some(seen) => seen.segments(i, &m),
None => crate::pick_index::segments_near(&app.viewport.pick_index.of(&m), &m, o, d, reach),
};
let mut last_edge = None;
for (ei, si) in near {
let Some(e) = m.edges.get(ei) else { continue };
if !m.edge_pickable(ei) {
continue;
}
for v in [e.first(), e.last()].into_iter().flatten() {
if let Some(sp) = proj.to_screen(*v) {
let dd = sp.distance(pos);
if dd < 7.0 && visible(*v) && bestv.wants(dd) {
bestv.offer(dd, Hit::Vertex { body: b.name.clone(), point: *v });
if last_edge != Some(ei) {
last_edge = Some(ei);
for v in [e.first(), e.last()].into_iter().flatten() {
if let Some(sp) = proj.to_screen(*v) {
let dd = sp.distance(pos);
if dd < 7.0 && visible(*v) && bestv.wants(dd) {
bestv.offer(dd, Hit::Vertex { body: b.name.clone(), point: *v });
}
}
}
}
for w in e.windows(2) {
let (Some(a), Some(c)) = (proj.to_screen(w[0]), proj.to_screen(w[1])) else { continue };
let dd = seg_dist(pos, a, c);
// Visible where the cursor is: the edge's point under the cursor, not an end or
// the middle, which can lie deeper than the face the cursor is on.
if dd < 6.0 && beste.wants(dd) && visible(ray_segment_closest(o, d, w[0], w[1])) {
beste.offer(dd, Hit::Edge { body: b.name.clone(), index: ei, mid: polyline_mid(e) });
}
let (Some(p0), Some(p1)) = (e.get(si), e.get(si + 1)) else { continue };
let (Some(a), Some(c)) = (proj.to_screen(*p0), proj.to_screen(*p1)) else { continue };
let dd = seg_dist(pos, a, c);
// Visible where the cursor is: the edge's point under the cursor, not an end or
// the middle, which can lie deeper than the face the cursor is on.
if dd < 6.0 && beste.wants(dd) && visible(ray_segment_closest(o, d, *p0, *p1)) {
beste.offer(dd, Hit::Edge { body: b.name.clone(), index: ei, mid: polyline_mid(e) });
}
}
}
@@ -2377,6 +2398,7 @@ pub fn show(app: &mut SolveApp, ui: &mut egui::Ui) {
},
});
painter.add(egui_wgpu::Callback::new_paint_callback(rect, cb));
crate::pick_buffer::paint(app, ui.ctx(), &painter, &proj);
}
analysis_legend(app, &painter, rect);
crate::frame_rate::paint(app, ui.ctx(), &painter, rect);