Flesh out bgmap viewer

src/memory.rs

@@ -70,9 +70,12 @@ pub struct MemoryRef<'a> {
 }
 
 impl MemoryRef<'_> {
-    pub fn read(&self, index: usize) -> u8 {
-        self.inner[index]
+    pub fn read<T: bytemuck::AnyBitPattern>(&self, index: usize) -> T {
+        let from = index * size_of::<T>();
+        let to = from + size_of::<T>();
+        *bytemuck::from_bytes(&self.inner[from..to])
     }
+
     pub fn range<T: bytemuck::AnyBitPattern>(&self, start: usize, count: usize) -> &[T] {
         let from = start * size_of::<T>();
         let to = from + (count * size_of::<T>());