From b14dd1c1f3e198137fa8b9e0c4f5e56949b11cd0 Mon Sep 17 00:00:00 2001
From: Jon Santmyer <jon@jonsantmyer.com>
Date: Fri, 1 May 2026 16:02:59 -0400
Subject: i don't know how to get the line segments to render right

---
 src/tacmap/render.rs | 81 +++++++++++++++++++++++++++++++---------------------
 1 file changed, 48 insertions(+), 33 deletions(-)

(limited to 'src/tacmap/render.rs')

diff --git a/src/tacmap/render.rs b/src/tacmap/render.rs
index c2bd354..48823e2 100644
--- a/src/tacmap/render.rs
+++ b/src/tacmap/render.rs
@@ -1,28 +1,16 @@
 use std::{fmt::Display, num::NonZero};
 use std::error::Error;
 
+use cgmath::InnerSpace;
 use wgpu::RenderPass;
 
 use crate::canvas::Canvas;
 use crate::solar_system::Kilometers;
 use crate::tacmap::camera::Camera;
+use crate::timeman::DAY;
 use crate::wgpuctx::{RenderPassBuilder, SceneCtx};
 use crate::{solar_system::{SolarSystem, SystemId}, timeman::Second, vertex::{self, Vertex}, wgpuctx::{WgpuCtx, pipeline::RenderPipelineBuilder}};
 
-struct BodyInstance
-{
-    position: cgmath::Vector3<Kilometers>,
-    radius: f32
-}
-
-#[repr(C)]
-#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
-struct BodyInstanceRaw
-{
-    position: [f32;3],
-    radius: f32
-}
-
 #[derive(Debug, Clone)]
 pub struct NeedsRebuildError;
 
@@ -129,9 +117,17 @@ impl BodyRenderer
 
         let bodies = solar_system.bodies();
         let body_instances = bodies.iter().map(|body| {
-            let position = solar_system.body_position(body);
+            let position = body.position();
+            let origin = match body.get_orbits() {
+                Some(origin_id) => {
+                    let origin_body = &bodies[origin_id];
+                    origin_body.position()
+                },
+                None => cgmath::Vector3::new(0.0, 0.0, 0.0)
+            };
             BodyInstance {
                 position: position,
+                origin: origin,
                 radius: body.radius()
             }.raw()
         }).collect::<Vec<_>>();
@@ -160,6 +156,22 @@ impl BodyRenderer
     }
 } // impl RenderState
 
+struct BodyInstance
+{
+    position: cgmath::Vector3<Kilometers>,
+    origin: cgmath::Vector3<Kilometers>,
+    radius: f32
+}
+
+#[repr(C)]
+#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+struct BodyInstanceRaw
+{
+    position: [f32;3],
+    origin: [f32;3],
+    radius: f32
+}
+
 impl BodyInstance 
 {
     fn raw(&self) -> BodyInstanceRaw
@@ -169,6 +181,10 @@ impl BodyInstance
                 self.position.x as f32, 
                 self.position.y as f32, 
                 self.position.z as f32 ],
+            origin: [
+                self.origin.x as f32,
+                self.origin.y as f32,
+                self.origin.z as f32 ],
             radius: self.radius
         }
     }
@@ -176,23 +192,17 @@ impl BodyInstance
 
 impl BodyInstanceRaw 
 {
-    fn descr() -> wgpu::VertexBufferLayout<'static> {
+    const ATTRIBS: [wgpu::VertexAttribute;3] =
+        wgpu::vertex_attr_array![0 => Float32x3, 1 => Float32x3, 2 => Float32];
+
+    pub fn descr()
+    -> wgpu::VertexBufferLayout<'static> {
         use std::mem;
+
         wgpu::VertexBufferLayout {
-            array_stride: mem::size_of::<BodyInstanceRaw>() as wgpu::BufferAddress,
+            array_stride: mem::size_of::<Self>() as wgpu::BufferAddress,
             step_mode: wgpu::VertexStepMode::Instance,
-            attributes: &[
-                wgpu::VertexAttribute {
-                    offset: 0,
-                    shader_location: 0,
-                    format: wgpu::VertexFormat::Float32x3
-                },
-                wgpu::VertexAttribute {
-                    offset: mem::size_of::<[f32;3]>() as wgpu::BufferAddress,
-                    shader_location: 1,
-                    format: wgpu::VertexFormat::Float32
-                }
-            ]
+            attributes: &Self::ATTRIBS
         }
     }
 }
@@ -360,11 +370,12 @@ impl OrbitRenderer
             if !body.does_orbit() { return (0, None); }
 
             let period = body.orbital_period();
-            let period_interval = period as f64 / 360.0;
+            let num_points = ((period / (5 * DAY)) as usize).max(360);
+            let period_interval = period as f64 / num_points as f64;
 
             let mut points = vec![
-                OrbitVertex::default();361*2];
-            for i in 0..361 {
+                OrbitVertex::default();(num_points+1)*2];
+            for i in 0..num_points {
                 let position = body.calculate_orbit_at(
                     (i as f64 * period_interval) as u64);
 
@@ -374,8 +385,12 @@ impl OrbitRenderer
                     position.y as f32,
                     position.z as f32
                 ];
+                
                 points[(i*2)+1] = points[i*2].clone();
             }
+            points[num_points*2] = points[0].clone();
+            points[num_points*2+1] = points[1].clone();
+
             let buffer = wgpuctx.create_buffer_init(
                 &wgpu::util::BufferInitDescriptor {
                     label: None,
@@ -383,7 +398,7 @@ impl OrbitRenderer
                     contents: bytemuck::cast_slice(&points)
                 }
             );
-            (361*2, Some(buffer))
+            ((num_points+1)*2, Some(buffer))
         }).collect::<Vec<_>>());
     }
 
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