handle ticks

src/ecs/entity.zig

@@ -1,3 +1,45 @@
 const std = @import("std");
 
-pub const Entity = struct {};
+pub const Entity = struct {
+    id: usize,
+};
+
+pub const EntityCollection = struct {
+    allocator: std.mem.Allocator,
+    next_id: usize,
+    entities: std.AutoHashMap(usize, Entity),
+
+    pub fn addEntity(self: *EntityCollection) !usize {
+        try self.entities.put(self.next_id, .{
+            .id = self.next_id,
+        });
+
+        self.next_id += 1;
+
+        return self.next_id - 1;
+    }
+
+    pub fn init(allocator: std.mem.Allocator) EntityCollection {
+        return .{
+            .allocator = allocator,
+            .next_id = 0,
+            .entities = std.AutoHashMap(usize, Entity).init(allocator),
+        };
+    }
+
+    pub fn deinit(self: *EntityCollection) void {
+        self.entities.deinit();
+    }
+};
+
+test "create entities" {
+    try std.testing.expect(true);
+
+    var ec = EntityCollection.init(std.testing.allocator);
+    defer ec.deinit();
+
+    for (0..128) |i| {
+        const id = ec.addEntity();
+        try std.testing.expectEqual(i, id);
+    }
+}

src/frontend/ncurses.zig

@@ -33,7 +33,6 @@ pub const Display = struct {
     inst: ?*ncurses.WINDOW,
     msgs: ?*ncurses.WINDOW,
     stat: ?*ncurses.WINDOW,
-    allocator: std.mem.Allocator,
 
     fn validTermSize() bool {
         return ncurses.LINES >= MIN_HEIGHT and
@@ -104,6 +103,8 @@ pub const Display = struct {
     }
 
     pub fn displayMessage(self: *Display, comptime fmt: []const u8, args: anytype) void {
+        if (self.msgs == null) return;
+
         for (1..MESSAGE_PANEL_WIDTH - 1) |i| {
             const i_32 = @as(i32, @intCast(i));
             _ = ncurses.mvwaddch(self.msgs, 1, i_32, ' ');
@@ -193,11 +194,6 @@ pub const Display = struct {
             return error.CursesInitFail;
         }
 
-        if (!validTermSize()) {
-            _ = ncurses.endwin();
-            return error.InvalidTermSize;
-        }
-
         if (!colorSupport()) {
             _ = ncurses.endwin();
             return error.NoColorSupport;
@@ -208,30 +204,45 @@ pub const Display = struct {
         _ = ncurses.noecho();
         _ = ncurses.curs_set(0);
         _ = ncurses.start_color();
+        _ = ncurses.timeout(0);
 
         _ = ncurses.init_pair(1, ncurses.COLOR_WHITE, ncurses.COLOR_BLACK);
         _ = ncurses.init_pair(2, ncurses.COLOR_BLACK, ncurses.COLOR_RED);
         _ = ncurses.wattron(ncurses.stdscr, ncurses.COLOR_PAIR(1));
         _ = ncurses.refresh();
 
-        var d = Display{
+        var d: Display = undefined;
+
+        if (!validTermSize()) {
+            _ = ncurses.mvprintw(0, 0, "Terminal must be at least %dx%d", @as(i32, @intCast(MIN_WIDTH)), @as(i32, @intCast(MIN_HEIGHT)));
+            d = Display{
+                .inst = null,
+                .msgs = null,
+                .stat = null,
+                .main = null,
+            };
+        } else {
+            d = Display{
                 .inst = createInstructionPanel(),
                 .msgs = createMessagePanel(),
                 .stat = createStatisticsPanel(),
                 .main = createMainPanel(),
-            .allocator = undefined,
             };
-
             d.displayInstructions();
+        }
 
         return d;
     }
 
     fn deleteWindows(self: *Display) void {
         _ = ncurses.delwin(self.main);
+        self.main = null;
         _ = ncurses.delwin(self.inst);
+        self.inst = null;
         _ = ncurses.delwin(self.msgs);
+        self.msgs = null;
         _ = ncurses.delwin(self.stat);
+        self.stat = null;
     }
 
     pub fn deinit(self: *Display) void {

src/main.zig

@@ -3,16 +3,18 @@ const Entity = @import("ecs/entity.zig").Entity;
 const Display = @import("frontend/ncurses.zig").Display;
 const Action = @import("actions.zig").Action;
 
+const state_machine = @import("state_machine/state_machine.zig");
+
 pub fn main() u8 {
     var d = Display.init() catch |err| {
         std.log.err("{}", .{err});
         return 1;
     };
     d.displayMessage("Initialized", .{});
-    d.displayStatus(&Entity{});
     var action = Action.illegal;
     while (action != Action.exit) {
         action = d.processInput();
+        state_machine.nextTick(&d);
     }
     d.deinit();
 

src/root.zig

@@ -1,10 +1,8 @@
 const std = @import("std");
 const testing = std.testing;
 
-export fn add(a: i32, b: i32) i32 {
-    return a + b;
-}
+const entity = @import("ecs/entity.zig");
 
-test "basic add functionality" {
-    try testing.expect(add(3, 7) == 10);
+test {
+    _ = entity;
 }

src/state_machine/state_machine.zig

@@ -0,0 +1,17 @@
+const std = @import("std");
+const Display = @import("../frontend/ncurses.zig").Display;
+
+const TICK = 33;
+
+var x: u64 = 0;
+var prev: i64 = 0;
+
+pub fn nextTick(display: *Display) void {
+    const new = std.time.milliTimestamp();
+
+    if (new - prev > TICK) {
+        display.displayMessage("{}", .{x});
+        x += 1;
+        prev = new;
+    }
+}