fixed component queries

src/main.zig

@@ -11,6 +11,25 @@ const wasm = @import("mods/wasm.zig");
 const components = @import("ecs/components.zig");
 const entities = @import("ecs/entities.zig");
 
+fn testSystem2(pool: *entities.Pool) void {
+    var i = @as(usize, 0);
+    //std.debug.print("test: {d}\n", .{pool.position.components.items.len});
+    for (pool.position.components.items) |position| {
+        const entity = pool.position.dense.items[i];
+        if (pool.speed.dense.items[pool.speed.sparse.items[entity]] == entity) {
+            const speed = pool.speed.components.items[pool.speed.sparse.items[entity]];
+            std.debug.print("entity{d}: {any},{any},{any} {any}\n", .{ i, position.x, position.y, position.z, speed.speed });
+        }
+
+        i += 1;
+    }
+}
+
+fn testSystem(pool: *entities.Pool) void {
+    _ = pool;
+    std.debug.print("test\n", .{});
+}
+
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     const allocator = gpa.allocator();
@@ -31,8 +50,17 @@ pub fn main() !void {
 
         var pool = try entities.Pool.init(allocator);
         defer pool.deinit(allocator);
+
+        //try pool.addSystemGroup(&[_]entities.System{
+        //    testSystem,
+        //});
+        try pool.addSystemGroup(&[_]entities.System{
+            testSystem2,
+        });
+
         const entity = try pool.createEntity();
-        try pool.addComponent(entity, components.Speed{ .speed = 0.0 });
+        try pool.addComponent(entity, components.Position{ .x = 1.0, .y = 0.5, .z = 3.0 });
+        try pool.addComponent(entity, components.Speed{ .speed = 5.0 });
 
         // TODO(luccie-cmd): Renderer.create shouldn't return an error
         var r = try Renderer.create(allocator, w);
@@ -41,6 +69,7 @@ pub fn main() !void {
         while (!w.shouldClose()) {
             c.glfwPollEvents();
             try r.tick();
+            pool.tick();
         }
     }