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refactor mesh construction

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This commit is contained in:
numzero 2026-10-17 23:04:31 +03:00
parent 4fad56a7d1
commit 80433d5ed6
1 changed files with 29 additions and 94 deletions
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113
src/crown_gear.rs
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@ -1,6 +1,6 @@
use std::f32::consts::PI;
use glam::{Vec3, vec3};
use glam::{Mat3A, Vec3, vec3};
use crate::{
profile::Profile,
@ -27,104 +27,39 @@ impl CrownGear {
mesh.faces.reserve_exact(8 * sides);
for k in 0..sides {
let t = k as f32 / sides as f32;
let phi = 2.0 * PI * t;
let (s, c) = phi.sin_cos();
let rot = Mat3A::from_rotation_z(2.0 * PI * t);
let tooth = t * teeth;
let y = self.profile.y_from_tooth(tooth);
let n_top = {
let eps = 1e-3;
let dy_dt = teeth
* (self.profile.y_from_tooth(tooth + eps) - self.profile.y_from_tooth(tooth - eps))
* (self.profile.y_from_tooth(tooth + eps)
- self.profile.y_from_tooth(tooth - eps))
/ (2.0 * eps);
vec3(-2.0 * PI * y, -dy_dt, 2.0 * PI * self.pitch_radius)
};
let v_radial = vec3(c * self.pitch_radius, s * self.pitch_radius, y);
let v_tan = vec3(-2.0 * PI * s, 2.0 * PI * c, dy_dt / self.pitch_radius);
let n_top = v_radial.cross(v_tan).normalize();
let n_top = vec3(
s * dy_dt - 2.0 * PI * c * y,
-c * dy_dt - 2.0 * PI * s * y,
2.0 * PI * self.pitch_radius,
);
let vertex = |x, z, n| Vertex {
position: rot * vec3(x, 0.0, z),
color,
normal: n,
};
mesh.vertices.extend([
// top
mesh.vertices.push(Vertex {
position: vec3(
c * self.outer_radius,
s * self.outer_radius,
outer_scale * y,
),
color,
normal: n_top,
});
mesh.vertices.push(Vertex {
position: vec3(
c * self.inner_radius,
s * self.inner_radius,
inner_scale * y,
),
color,
normal: n_top,
});
vertex(self.outer_radius, outer_scale * y, n_top),
vertex(self.inner_radius, inner_scale * y, n_top),
// bottom
mesh.vertices.push(Vertex {
position: vec3(
c * self.inner_radius,
s * self.inner_radius,
-self.base_thickness,
),
color,
normal: vec3(0.0, 0.0, -1.0),
});
mesh.vertices.push(Vertex {
position: vec3(
c * self.outer_radius,
s * self.outer_radius,
-self.base_thickness,
),
color,
normal: vec3(0.0, 0.0, -1.0),
});
vertex(self.inner_radius, -self.base_thickness, -Vec3::Z),
vertex(self.outer_radius, -self.base_thickness, -Vec3::Z),
// inner
mesh.vertices.push(Vertex {
position: vec3(
c * self.inner_radius,
s * self.inner_radius,
inner_scale * y,
),
color,
normal: vec3(-c, -s, 0.0),
});
mesh.vertices.push(Vertex {
position: vec3(
c * self.inner_radius,
s * self.inner_radius,
-self.base_thickness,
),
color,
normal: vec3(-c, -s, 0.0),
});
vertex(self.inner_radius, inner_scale * y, -Vec3::X),
vertex(self.inner_radius, -self.base_thickness, -Vec3::X),
// outer
mesh.vertices.push(Vertex {
position: vec3(
c * self.outer_radius,
s * self.outer_radius,
-self.base_thickness,
),
color,
normal: vec3(c, s, 0.0),
});
mesh.vertices.push(Vertex {
position: vec3(
c * self.outer_radius,
s * self.outer_radius,
outer_scale * y,
),
color,
normal: vec3(c, s, 0.0),
});
vertex(self.outer_radius, -self.base_thickness, Vec3::X),
vertex(self.outer_radius, outer_scale * y, Vec3::X),
]);
let base1 = 8 * k;
let base2 = 8 * ((k + 1) % sides);