Implement first pass of Oar archive reading mechanism

src/main.zig

@@ -21,29 +21,29 @@ test {
     _ = sys;
 }
 
-fn run(ev: *sys.EventLoop, fs: *const sys.FileSystem, gr: *sys.GraphicsContext) anyerror!void {
+fn run(app: *sys.App, graphics: *sys.GraphicsContext) anyerror!void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 
     defer _ = gpa.deinit();
 
     {
-        const file_access = try ev.open(.readonly, try fs.data.joinedPath(&.{"ona.lua"}));
+        const file_access = try (try app.data().joinedPath(&.{"ona.lua"})).open(app, .readonly);
 
-        defer ev.close(file_access);
+        defer file_access.close(app);
 
-        const file_size = try file_access.size(ev);
+        const file_size = try file_access.queryLength(app);
         const allocator = gpa.allocator();
         const buffer = try allocator.alloc(u8, file_size);
 
         defer allocator.free(buffer);
 
-        if ((try ev.readFile(file_access, buffer)) != file_size)
+        if ((try file_access.read(app, buffer)) != file_size)
             return error.ScriptLoadFailure;
 
-        ev.log(.debug, buffer);
+        sys.Log.debug.write(app, buffer);
     }
 
-    while (gr.poll()) |_| {
+    while (graphics.poll()) |_| {
-        gr.present();
+        graphics.present();
     }
 }

src/math.zig

@@ -0,0 +1,6 @@
+///
+/// Rounds the `Number` `value` up to the nearest `multiple`.
+///
+pub fn roundUp(comptime Number: type, value: Number, multiple: Number) Number {
+    return value + @mod(@mod(multiple - value, multiple), multiple);
+}

src/oar.zig

@@ -0,0 +1,14 @@
+const std = @import("std");
+const sys = @import("./sys.zig");
+
+///
+/// An entry block of an Oar archive file.
+///
+/// Typically, following this block in memory is the file data it holds the meta-information for.
+///
+pub const Entry = extern struct {
+    name_length: u8,
+    name_buffer: [255]u8 = std.mem.zeroes([255]u8),
+    file_size: u64,
+    padding: [248]u8,
+};

src/tar.zig

@@ -1,29 +0,0 @@
-const std = @import("std");
-
-///
-///
-///
-pub const Archive = struct {
-    allocator: std.mem.Allocator,
-
-    pub const LoadError = error {
-        FileNotFound,
-    };
-
-    ///
-    ///
-    ///
-    pub fn init(allocator: std.mem.Allocator) Archive {
-        return Archive{
-            .allocator = allocator,
-        };
-    }
-
-    ///
-    ///
-    ///
-    pub fn load(archive: *Archive, file_path: []const u8) LoadError!void {
-        _ = file_path;
-        _ = archive;
-    }
-};