fixed compile time errors; still runtime error inside mesh.render

opengl_beginnings/src/custom/sphere_generator.rs

@@ -24,7 +24,7 @@ impl OctaSphere {
     pub fn render(&mut self, gl: &Context) {
         match self.mesh.as_mut() {
             None => {self.generate_sphere(); self.render(gl)},
-            Some(mut mesh) => {mesh.render(gl)}
+            Some(mesh) => {mesh.render(gl)}
         }
     }
 
@@ -65,12 +65,12 @@ impl OctaSphereGenerator {
         vertices.extend_from_slice(&base_vertices);
 
         // Create 12 edges, with n vertices added along them (n = numDivisions)
-        let mut edges = Vec::<Edge>::with_capacity(12);
+        let mut edges: [Edge; 12] = Default::default();
         for i in (0..vertex_pairs.len()).step_by(2) {
             let start_vertex = vertices[vertex_pairs[i]];
             let end_vertex = vertices[vertex_pairs[i + 1]];
 
-            let mut edge_vertex_indices = Vec::<u32>::with_capacity((num_divisions + 2) as usize);
+            let mut edge_vertex_indices = vec![0;(num_divisions + 2) as usize];
             edge_vertex_indices[0] = vertex_pairs[i] as u32;
 
             // Add vertices along edge
@@ -156,6 +156,7 @@ impl OctaSphereGenerator {
     }
 }
 
+#[derive(Default)]
 struct Edge {
     vertex_indices: Vec<u32>,
 }

opengl_beginnings/src/engine/mesh.rs

@@ -24,7 +24,7 @@ impl Mesh {
         Self {
             vertices,
             indices,
-            normals: Vec::with_capacity(num_vertices),
+            normals: vec![Vector3::default();num_vertices],
             vao: None,
             vbo: None,
             ebo: None,