From 901fb79ae6a34f223453fa2e088da1a39a4f6e42 Mon Sep 17 00:00:00 2001
From: Jarrod Doyle <thejarroddoyle@gmail.com>
Date: Fri, 22 Sep 2023 10:17:49 +0100
Subject: [PATCH] Add vertex merging

---
 csg/src/brush.rs   | 55 ++++++++++++++++++++++++++++++++++++----------
 editor/src/main.rs | 19 ++++++----------
 2 files changed, 51 insertions(+), 23 deletions(-)

diff --git a/csg/src/brush.rs b/csg/src/brush.rs
index 8b10781..ee96325 100644
--- a/csg/src/brush.rs
+++ b/csg/src/brush.rs
@@ -1,10 +1,14 @@
 use glam::Vec3;
 
-use crate::plane::{Plane, PlaneIntersection};
+use crate::{
+    math,
+    plane::{Plane, PlaneIntersection},
+};
 
-#[derive(Default)]
+#[derive(Default, Debug, Clone)]
 pub struct MaterialId(pub String);
 
+#[derive(Debug, Clone, Copy)]
 pub struct TextureProjection {
     pub u: Plane,
     pub v: Plane,
@@ -25,7 +29,7 @@ impl Default for TextureProjection {
     }
 }
 
-#[derive(Default)]
+#[derive(Default, Debug, Clone)]
 pub struct BrushPlane {
     pub plane: Plane,
     pub material: MaterialId,
@@ -34,18 +38,27 @@ pub struct BrushPlane {
 
 pub struct Brush {
     pub planes: Vec<BrushPlane>,
+    raw_vertices: Vec<PlaneIntersection>,
+    vertices: Vec<Vec3>,
 }
 
 impl Brush {
-    pub fn get_vertices(&self) -> Vec<Vec3> {
-        if self.planes.len() < 3 {
-            println!("fug");
-            return vec![];
+    pub fn new(planes: &[BrushPlane]) -> Self {
+        Self {
+            planes: planes.to_vec(),
+            raw_vertices: vec![],
+            vertices: vec![],
+        }
+    }
+
+    pub fn rebuild(&mut self) {
+        if self.planes.len() < 4 {
+            panic!("Invalid number of planes. Minimum 4 planes required.");
         }
 
         // Test all permutations of brush planes for intersections
         let mut intersections = vec![];
-        let mut vs = vec![];
+        let mut vs: Vec<Vec3> = vec![];
         let len = self.planes.len();
         for i in 0..(len - 2) {
             for j in (i + 1)..(len - 1) {
@@ -63,7 +76,7 @@ impl Brush {
 
         // Validate intersections against other brush planes
         // TODO: No need to check against planes that are part of the intersection
-        for intersection in intersections {
+        for intersection in &intersections {
             let mut valid = true;
             for bplane in &self.planes {
                 if !intersection.in_halfspace_mat(&bplane.plane) {
@@ -72,11 +85,31 @@ impl Brush {
                 }
             }
 
+            // Merge vertices
             if valid {
-                vs.push(intersection.get_intersection_point());
+                let point = intersection.get_intersection_point();
+                let mut duplicate = false;
+                for v in &vs {
+                    if v.abs_diff_eq(point, math::EPSILON) {
+                        duplicate = true;
+                        break;
+                    }
+                }
+                if !duplicate {
+                    vs.push(point);
+                }
             }
         }
 
-        vs
+        self.vertices = vs;
+        self.raw_vertices = intersections;
+    }
+
+    pub fn get_vertices(&self) -> Vec<Vec3> {
+        self.vertices.clone()
+    }
+
+    pub fn get_intersections(&self) -> Vec<PlaneIntersection> {
+        self.raw_vertices.clone()
     }
 }
diff --git a/editor/src/main.rs b/editor/src/main.rs
index 3f83e63..6363b1a 100644
--- a/editor/src/main.rs
+++ b/editor/src/main.rs
@@ -22,13 +22,9 @@ fn generate_box_brush(position: Vec3, extent: Vec3) -> Brush {
             plane: Plane::from_point_normal(point, *normal),
             ..Default::default()
         });
-
-        println!("Plane: {:?}", brush_planes.last().unwrap().plane);
     }
 
-    Brush {
-        planes: brush_planes,
-    }
+    Brush::new(&brush_planes)
 }
 
 /// Position is center of base plane
@@ -43,14 +39,12 @@ fn generate_pyramid_brush(position: Vec3, height: f32, side_count: u32) -> Brush
 
     for i in 0..side_count {
         let angle = (i as f32 / side_count as f32) * 360.0_f32.to_radians();
-        dbg!(angle);
         let rot_mat = Mat3::from_cols(
             Vec3::new(angle.cos(), 0.0, -angle.sin()),
             Vec3::Y,
             Vec3::new(angle.sin(), 0.0, angle.cos()),
         );
         let normal = rot_mat * Vec3::new(1.0, 1.0, 0.0);
-        dbg!(normal);
 
         brush_planes.push(BrushPlane {
             plane: Plane::from_point_normal(tip, normal),
@@ -58,18 +52,19 @@ fn generate_pyramid_brush(position: Vec3, height: f32, side_count: u32) -> Brush
         });
     }
 
-    Brush {
-        planes: brush_planes,
-    }
+    Brush::new(&brush_planes)
 }
 
 fn main() {
-    let brush = generate_box_brush(Vec3::new(1.0, 0.0, 0.0), Vec3::new(1.0, 2.0, 1.0));
+    let mut brush = generate_box_brush(Vec3::new(1.0, 0.0, 0.0), Vec3::new(1.0, 2.0, 1.0));
+    brush.rebuild();
     let vs = brush.get_vertices();
 
     println!("Vertices: {vs:?}");
 
-    let vs = generate_pyramid_brush(Vec3::ZERO, 1.0, 4).get_vertices();
+    let mut brush = generate_pyramid_brush(Vec3::ZERO, 1.0, 4);
+    brush.rebuild();
+    let vs = brush.get_vertices();
 
     println!("Vertices: {vs:?}");
 }