Update Object structure to enforce edge endpoints corresponding to vertices

src/points.rs

@@ -1,3 +1,5 @@
+use std::collections::HashMap;
+
 use crate::consts::*;
 
 #[derive(Debug, Clone, Copy)]
@@ -6,26 +8,60 @@ pub struct Point2D {
     pub y: f64
 }
 
-impl Point2D {
-    pub fn to_canvas_coordinates(&self) -> Point3D {
-        todo!();
-    }
-
-    pub fn distance(self, p2: &Point2D) -> f64 {
-        let p1 = self;
-        // Pythagorean formula
-        // TODO: use hypot function
-        f64::sqrt(
-            (f64::powf(p2.x.max(p1.x) - p1.x.min(p2.x), 2.0)
-                + f64::powf(p2.y.max(p1.y) - p1.y.min(p2.y), 2.0)) as f64,
-        )
-    }
-}
-
 #[derive(Debug, Clone, Copy)]
 pub struct Point3D {
     pub x: f64, pub y: f64, pub z: f64
 }
+
+#[derive(Debug)]
+pub struct Object {
+    // Invariants:
+    // Every vertex in edges must have a corresponding vertex in vertices
+    pub vertices: Vec<Point3D>,
+    pub edges: Vec<(Point3D, Point3D)>,
+    pub edge_indices: Vec<(usize, usize)>,
+    pub faces: Vec<(Point3D, Point3D, Point3D)>,
+    pub face_indices: Vec<(usize, usize, usize)>,
+    // the update() function
+}
+
+impl Object {
+    /// Takes a vector of vertices and a vector of indices for each of the `edge_indices` and
+    /// `face_indices` parameters. These indices index the `vertices` array and represent the
+    /// endpoints of the line segment (in the case of an edge) or the vertices of the triangle
+    /// (in the case of a face)
+    pub fn new(vertices: Vec<Point3D>,
+            edge_indices: Vec<(usize, usize)>,
+            face_indices: Vec<(usize, usize, usize)>) -> Self {
+
+        let mut ret = Self {vertices, edges: vec![], edge_indices, faces: vec![], face_indices};
+        for (i_start, i_end) in ret.edge_indices.iter() {
+            ret.edges.push((ret.vertices[*i_start].clone(), ret.vertices[*i_end].clone()));
+        }
+
+        for (i_one, i_two, i_three /* The three vertices of the triangle */) in ret.face_indices.iter() {
+            ret.faces.push((ret.vertices[*i_one].clone(), ret.vertices[*i_two].clone(), ret.vertices[*i_three].clone()));
+        }
+
+        ret
+    }
+
+    // Updates the `edges` and `faces` to correspond to updated vertices.
+    pub fn update(&mut self) {
+        self.edges = vec![];
+        for (i_start, i_end) in self.edge_indices.iter() {
+            self.edges.push((self.vertices[*i_start].clone(), self.vertices[*i_end].clone()));
+        }
+
+        self.faces = vec![];
+        for (i_one, i_two, i_three /* The three vertices of the triangle */) in self.face_indices.iter() {
+            self.faces.push((self.vertices[*i_one].clone(), self.vertices[*i_two].clone(), self.vertices[*i_three].clone()));
+        }
+    }
+}
+
+pub type Scene = Vec<Object>;
+
 impl Point3D {
     pub fn to_screen_coordinates(&self) -> Point2D {
         let Point3D {x, y, z} = *self;
@@ -68,3 +104,19 @@ impl Point3D {
         )
     }
 }
+
+impl Point2D {
+    pub fn to_canvas_coordinates(&self) -> Point3D {
+        todo!();
+    }
+
+    pub fn distance(self, p2: &Point2D) -> f64 {
+        let p1 = self;
+        // Pythagorean formula
+        // TODO: use hypot function
+        f64::sqrt(
+            (f64::powf(p2.x.max(p1.x) - p1.x.min(p2.x), 2.0)
+                + f64::powf(p2.y.max(p1.y) - p1.y.min(p2.y), 2.0)) as f64,
+        )
+    }
+}