Added ability to read WAD directory

src/wad/directory.rs

@@ -0,0 +1,5 @@
+pub struct Directory {
+    pub filepos: u32,
+    pub size: u32,
+    pub name: String,
+}

src/wad/header.rs

@@ -0,0 +1,21 @@
+pub struct Header {
+    pub wad_id: String,
+    pub num_lumps: u32,
+    pub dir_offset: u32,
+}
+
+use crate::utils::{read_ascii, read_u32_le};
+
+impl Header {
+    pub fn read_data(data: &[u8]) -> Self {
+        let id = read_ascii(&data[..4]);
+        let lumps = read_u32_le(&data[4..8]);
+        let offset = read_u32_le(&data[8..12]);
+
+        Self {
+            wad_id: id,
+            num_lumps: lumps,
+            dir_offset: offset,
+        }
+    }
+}

src/wad/mod.rs

@@ -0,0 +1,5 @@
+mod directory;
+mod header;
+mod wadfile;
+
+pub use wadfile::WADFile;

src/wad/wadfile.rs

@@ -0,0 +1,54 @@
+use std::{fs::File, io::Read, path::Path};
+
+use super::{directory::Directory, header::Header};
+use crate::utils::{read_ascii, read_u32_le, validate_wad};
+
+pub struct WADFile {
+    pub path: String,
+    pub wad_id: String,
+    pub num_lumps: u32,
+    pub dir_offset: u32,
+    pub directory: Vec<Directory>,
+    pub wad_data: Vec<u8>,
+}
+
+impl WADFile {
+    pub fn new(path: String) -> Self {
+        if !(validate_wad(path.as_str()).unwrap()) {
+            panic!();
+        }
+
+        let file_path = Path::new(path.as_str());
+        let mut wad_file = File::open(file_path).unwrap();
+        let file_size = wad_file.metadata().unwrap().len() as usize;
+        let mut file_buffer: Vec<u8> = Vec::with_capacity(file_size);
+
+        wad_file.read_to_end(&mut file_buffer).unwrap();
+
+        let wad_header = Header::read_data(&file_buffer[0..12]);
+
+        let mut wad_dir: Vec<Directory> = Vec::with_capacity(wad_header.num_lumps as usize);
+        let offset = wad_header.dir_offset;
+
+        for entry in 0..wad_header.num_lumps {
+            let startpos = (offset + 16 * entry) as usize;
+            let filepos = read_u32_le(&file_buffer[startpos..startpos + 4]);
+            let size = read_u32_le(&file_buffer[startpos + 4..startpos + 8]);
+            let name = read_ascii(&file_buffer[startpos + 8..startpos + 16]);
+            wad_dir.push(Directory {
+                filepos,
+                name,
+                size,
+            });
+        }
+
+        Self {
+            path,
+            wad_id: wad_header.wad_id,
+            num_lumps: wad_header.num_lumps,
+            dir_offset: wad_header.dir_offset,
+            directory: wad_dir,
+            wad_data: file_buffer,
+        }
+    }
+}