Add brush AABB generation

csg/src/aabb.rs

@@ -0,0 +1,44 @@
+use glam::Vec3;
+
+#[derive(Default, Debug)]
+pub struct Aabb {
+    pub min: Vec3,
+    pub max: Vec3,
+}
+
+impl Aabb {
+    pub fn new() -> Self {
+        Self {
+            min: Vec3::ZERO,
+            max: Vec3::ZERO,
+        }
+    }
+
+    pub fn from_min_max(min: Vec3, max: Vec3) -> Self {
+        Self { min, max }
+    }
+
+    pub fn from_positions(positions: &[Vec3]) -> Self {
+        let mut min = positions[0];
+        let mut max = min;
+
+        for pos in positions {
+            min = min.min(*pos);
+            max = max.max(*pos);
+        }
+
+        Self { min, max }
+    }
+
+    pub fn intersects(&self, other: &Aabb) -> bool {
+        (self.min.x <= other.max.x && self.max.x >= other.min.x)
+            && (self.min.y <= other.max.y && self.max.y >= other.min.y)
+            && (self.min.z <= other.max.z && self.max.z >= other.min.z)
+    }
+
+    pub fn contains(&self, other: &Aabb) -> bool {
+        (self.min.x <= other.min.x && self.max.x >= other.max.x)
+            && (self.min.y <= other.min.y && self.max.y >= other.max.y)
+            && (self.min.z <= other.min.z && self.max.z >= other.max.z)
+    }
+}

csg/src/brush.rs

@@ -1,6 +1,7 @@
 use glam::Vec3;
 
 use crate::{
+    aabb::Aabb,
     math,
     plane::{Plane, PlaneIntersection},
 };
@@ -40,6 +41,7 @@ pub struct Brush {
     pub planes: Vec<BrushPlane>,
     raw_vertices: Vec<PlaneIntersection>,
     vertices: Vec<Vec3>,
+    aabb: Aabb,
 }
 
 impl Brush {
@@ -48,6 +50,7 @@ impl Brush {
             planes: planes.to_vec(),
             raw_vertices: vec![],
             vertices: vec![],
+            aabb: Aabb::new(),
         }
     }
 
@@ -58,6 +61,7 @@ impl Brush {
 
         self.calculate_raw_vertices();
         self.merge_vertices();
+        self.aabb = Aabb::from_positions(&self.vertices);
     }
 
     pub fn get_vertices(&self) -> Vec<Vec3> {
@@ -68,6 +72,10 @@ impl Brush {
         self.raw_vertices.clone()
     }
 
+    pub fn get_aabb(&self) -> &Aabb {
+        &self.aabb
+    }
+
     fn calculate_raw_vertices(&mut self) {
         // Test all permutations of brush planes for intersections
         let mut intersections = vec![];

csg/src/lib.rs

@@ -1,3 +1,4 @@
+mod aabb;
 pub mod brush;
 pub mod math;
 pub mod plane;