Linedef Reader

Added ability to read linedef lumps. Also added all the test
functionality to make sure we are reading the linedefs correctly.

src/wad/wadfile.rs

@@ -1,8 +1,8 @@
 use std::{fs::File, io::Read, path::Path};
 
 use super::header::Header;
-use crate::lumps::{Lump, LumpType, VertexLump};
-use crate::types::Vertex;
+use crate::lumps::{LinedefLump, Lump, LumpType, VertexLump};
+use crate::types::{Linedef, Vertex};
 use crate::utils::{read_ascii, read_i16_le, read_u32_le, validate_wad};
 
 pub struct WADFile {
@@ -39,6 +39,7 @@ impl WADFile {
             let name = read_ascii(&file_buffer[startpos + 8..startpos + 16]);
             let lump_type = match name.as_str() {
                 "VERTEXES" => LumpType::Vertex,
+                "LINEDEFS" => LumpType::Linedef,
                 _ => LumpType::Unknown,
             };
             lump_dir.push(Lump {
@@ -79,4 +80,35 @@ impl WADFile {
 
         VertexLump { vertexes }
     }
+
+    pub fn get_linedef_lump(&self, lump: &Lump) -> LinedefLump {
+        let lump_offset = lump.offset as usize;
+        let lump_size = lump.size as usize;
+        let lump_data = &self.data[lump_offset..lump_offset + lump_size];
+        let lump_entries = lump_size / 14;
+        let mut linedefs: Vec<Linedef> = Vec::with_capacity(lump_entries);
+
+        for entry in 0..lump_entries {
+            let startpos = entry * 14;
+            let vertex1 = read_i16_le(&lump_data[startpos..startpos + 2]);
+            let vertex2 = read_i16_le(&lump_data[startpos + 2..startpos + 4]);
+            let flags = read_i16_le(&lump_data[startpos + 4..startpos + 6]);
+            let special = read_i16_le(&lump_data[startpos + 6..startpos + 8]);
+            let tag = read_i16_le(&lump_data[startpos + 8..startpos + 10]);
+            let front_sidedef = read_i16_le(&lump_data[startpos + 10..startpos + 12]);
+            let back_sidedef = read_i16_le(&lump_data[startpos + 12..startpos + 14]);
+
+            linedefs.push(Linedef {
+                vertex1,
+                vertex2,
+                flags,
+                special,
+                tag,
+                front_sidedef,
+                back_sidedef,
+            });
+        }
+
+        LinedefLump { linedefs }
+    }
 }