93a131661d
# Objective - Added a bunch of backticks to things that should have them, like equations, abstract variable names, - Changed all small x, y, and z to capitals X, Y, Z. This might be more annoying than helpful; Feel free to refuse this PR.
104 lines
2.6 KiB
Rust
104 lines
2.6 KiB
Rust
use crate::mesh::{Indices, Mesh};
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use wgpu::PrimitiveTopology;
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/// A regular polygon in the `XY` plane
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#[derive(Debug, Copy, Clone)]
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pub struct RegularPolygon {
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/// Inscribed radius in the `XY` plane.
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pub radius: f32,
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/// Number of sides.
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pub sides: usize,
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}
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impl Default for RegularPolygon {
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fn default() -> Self {
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Self {
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radius: 0.5,
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sides: 6,
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}
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}
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}
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impl RegularPolygon {
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/// Creates a regular polygon in the `XY` plane
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pub fn new(radius: f32, sides: usize) -> Self {
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Self { radius, sides }
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}
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}
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impl From<RegularPolygon> for Mesh {
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fn from(polygon: RegularPolygon) -> Self {
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let RegularPolygon { radius, sides } = polygon;
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debug_assert!(sides > 2, "RegularPolygon requires at least 3 sides.");
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let mut positions = Vec::with_capacity(sides);
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let mut normals = Vec::with_capacity(sides);
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let mut uvs = Vec::with_capacity(sides);
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let step = std::f32::consts::TAU / sides as f32;
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for i in 0..sides {
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let theta = std::f32::consts::FRAC_PI_2 - i as f32 * step;
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let (sin, cos) = theta.sin_cos();
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positions.push([cos * radius, sin * radius, 0.0]);
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normals.push([0.0, 0.0, 1.0]);
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uvs.push([0.5 * (cos + 1.0), 1.0 - 0.5 * (sin + 1.0)]);
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}
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let mut indices = Vec::with_capacity((sides - 2) * 3);
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for i in 1..(sides as u32 - 1) {
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indices.extend_from_slice(&[0, i + 1, i]);
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}
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let mut mesh = Mesh::new(PrimitiveTopology::TriangleList);
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mesh.insert_attribute(Mesh::ATTRIBUTE_POSITION, positions);
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mesh.insert_attribute(Mesh::ATTRIBUTE_NORMAL, normals);
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mesh.insert_attribute(Mesh::ATTRIBUTE_UV_0, uvs);
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mesh.set_indices(Some(Indices::U32(indices)));
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mesh
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}
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}
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/// A circle in the `XY` plane
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pub struct Circle {
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/// Inscribed radius in the `XY` plane.
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pub radius: f32,
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/// The number of vertices used.
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pub vertices: usize,
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}
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impl Default for Circle {
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fn default() -> Self {
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Self {
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radius: 0.5,
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vertices: 64,
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}
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}
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}
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impl Circle {
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/// Creates a circle in the `XY` plane
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pub fn new(radius: f32) -> Self {
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Self {
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radius,
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..Default::default()
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}
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}
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}
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impl From<Circle> for RegularPolygon {
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fn from(circle: Circle) -> Self {
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Self {
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radius: circle.radius,
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sides: circle.vertices,
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}
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}
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}
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impl From<Circle> for Mesh {
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fn from(circle: Circle) -> Self {
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Mesh::from(RegularPolygon::from(circle))
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}
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}
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