From 6b25722627f4ab53988de33c8945951d13e975e7 Mon Sep 17 00:00:00 2001
From: numzero <numzer0@yandex.ru>
Date: Wed, 20 Nov 2024 21:34:20 +0300
Subject: [PATCH] Pre-generate normals, for smooth look

---
 src/bin/wireframe/meshes.rs | 34 +++++++++--------------
 src/bin/wireframe/scene.rs  | 54 +++++++++++++++++++++++++------------
 2 files changed, 50 insertions(+), 38 deletions(-)

diff --git a/src/bin/wireframe/meshes.rs b/src/bin/wireframe/meshes.rs
index c439334..634bb60 100644
--- a/src/bin/wireframe/meshes.rs
+++ b/src/bin/wireframe/meshes.rs
@@ -4,6 +4,8 @@ use bytemuck::{bytes_of, cast_slice, Pod, Zeroable};
 use glam::{Vec3, Vec4};
 use wgpu::util::DeviceExt as _;
 
+use crate::scene::Face;
+
 #[repr(C)]
 #[derive(Copy, Clone, Debug, Pod, Zeroable)]
 struct Vertex {
@@ -11,6 +13,15 @@ struct Vertex {
 	pub normal: [f32; 3],
 }
 
+impl From<crate::scene::Vertex> for Vertex {
+	fn from(value: crate::scene::Vertex) -> Self {
+		Vertex {
+			position: value.position.into(),
+			normal: value.normal.into(),
+		}
+	}
+}
+
 #[repr(C)]
 #[derive(Copy, Clone, Pod, Zeroable)]
 struct PushConsts {
@@ -37,27 +48,8 @@ pub struct Mesh {
 }
 
 impl Mesh {
-	pub fn new_list(device: &wgpu::Device, attrs: Attrs, tris: Vec<[Vec3; 3]>) -> Self {
-		let data: Vec<Vertex> = tris
-			.into_iter()
-			.flat_map(|[a, b, c]| {
-				let n = (b - a).cross(c - a).normalize();
-				[
-					Vertex {
-						position: a.into(),
-						normal: n.into(),
-					},
-					Vertex {
-						position: b.into(),
-						normal: n.into(),
-					},
-					Vertex {
-						position: c.into(),
-						normal: n.into(),
-					},
-				]
-			})
-			.collect();
+	pub fn new_list(device: &wgpu::Device, attrs: Attrs, tris: Vec<Face>) -> Self {
+		let data: Vec<Vertex> = tris.into_iter().flat_map(|face| face.map(Into::into)).collect();
 		let buf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
 			label: Some("Mesh Vertex Buffer"),
 			contents: cast_slice(&data),
diff --git a/src/bin/wireframe/scene.rs b/src/bin/wireframe/scene.rs
index 009a9aa..e91bcbb 100644
--- a/src/bin/wireframe/scene.rs
+++ b/src/bin/wireframe/scene.rs
@@ -17,7 +17,12 @@ pub struct FancyLine {
 	pub pts: Vec<Ray>,
 }
 
-pub type Face = [Vec3; 3];
+pub struct Vertex {
+	pub position: Vec3,
+	pub normal: Vec3,
+}
+
+pub type Face = [Vertex; 3];
 
 pub enum Mesh {
 	List(Vec<Face>),
@@ -160,29 +165,44 @@ impl Renderable for Tube {
 			let d = Vec2::from_angle(k as f32 * step);
 			vec3(d.x, 0., d.y)
 		};
+
 		let side = vec3(0., self.external_halflength, 0.);
 		let r1 = self.inner_radius;
 		let r2 = self.outer_radius;
+
+		let vertex = |k, r, h| {
+			let n = dir(k);
+			Vertex {
+				position: r * n + h * side,
+				normal: n,
+			}
+		};
 		let inner = (0..sides).flat_map(|k| {
-			let a = r1 * dir(k);
-			let b = r1 * dir(k + 1);
-			[[a - side, b - side, a + side], [b - side, b + side, a + side]]
+			[
+				[vertex(k, -r1, -1.), vertex(k, -r1, 1.), vertex(k + 1, -r1, -1.)],
+				[vertex(k + 1, -r1, -1.), vertex(k, -r1, 1.), vertex(k + 1, -r1, 1.)],
+			]
 		});
 		let outer = (0..sides).flat_map(|k| {
-			let a = r2 * dir(k);
-			let b = r2 * dir(k + 1);
-			[[a - side, b - side, a + side], [b - side, b + side, a + side]]
-		});
-		let cap = (0..sides).flat_map(|k| {
-			let a = r1 * dir(k);
-			let b = r1 * dir(k + 1);
-			let c = r2 * dir(k + 1);
-			let d = r2 * dir(k);
 			[
-				[a - side, b - side, c - side],
-				[a - side, c - side, d - side],
-				[a + side, b + side, c + side],
-				[a + side, c + side, d + side],
+				[vertex(k, r2, -1.), vertex(k + 1, r2, -1.), vertex(k, r2, 1.)],
+				[vertex(k + 1, r2, -1.), vertex(k + 1, r2, 1.), vertex(k, r2, 1.)],
+			]
+		});
+
+		let vertex = |k, r, h| {
+			let n = dir(k);
+			Vertex {
+				position: r * n + h * side,
+				normal: h * Vec3::Y,
+			}
+		};
+		let cap = (0..sides).flat_map(|k| {
+			[
+				[vertex(k, r1, -1.), vertex(k + 1, r1, -1.), vertex(k + 1, r2, -1.)],
+				[vertex(k, r1, -1.), vertex(k + 1, r2, -1.), vertex(k, r2, -1.)],
+				[vertex(k, r1, 1.), vertex(k + 1, r1, 1.), vertex(k + 1, r2, 1.)],
+				[vertex(k, r1, 1.), vertex(k + 1, r2, 1.), vertex(k, r2, 1.)],
 			]
 		});
 		chain!(inner, outer, cap).collect()