add signals

zig-ecs/src/ecs/component_storage.zig

@@ -3,7 +3,11 @@ const warn = std.debug.warn;
 const utils = @import("utils.zig");
 
 const SparseSet = @import("sparse_set.zig").SparseSet;
+const Signal = @import("../signals/signal.zig").Signal;
+const Sink = @import("../signals/sink.zig").Sink;
 
+/// Stores an ArrayList of components along with a SparseSet of entities. The max amount that can be stored is
+/// based on the max value of DenseT
 pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime DenseT: type) type {
     std.debug.assert(!utils.isComptime(CompT));
 
@@ -25,6 +29,9 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
         instances: std.ArrayList(CompOrAlmostEmptyT),
         allocator: ?*std.mem.Allocator,
         safe_deinit: fn (*Self) void,
+        construction: Signal(EntityT),
+        update: Signal(EntityT),
+        destruction: Signal(EntityT),
 
         pub fn init(allocator: *std.mem.Allocator) Self {
             var store = Self{
@@ -37,6 +44,9 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
                     }
                 }.deinit,
                 .allocator = null,
+                .construction = Signal(EntityT).init(allocator),
+                .update = Signal(EntityT).init(allocator),
+                .destruction = Signal(EntityT).init(allocator),
             };
 
             if (!is_empty_struct)
@@ -51,6 +61,9 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
             if (!is_empty_struct)
                 store.instances = std.ArrayList(CompOrAlmostEmptyT).init(allocator);
             store.allocator = allocator;
+            store.construction = Signal(EntityT).init(allocator);
+            store.update = Signal(EntityT).init(allocator);
+            store.destruction = Signal(EntityT).init(allocator);
 
             // since we are stored as a pointer, we need to catpure this
             store.safe_deinit = struct {
@@ -69,11 +82,26 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
             // will allways be false here so we have to deinit the instances no matter what.
             self.safe_deinit(self);
             self.set.deinit();
+            self.construction.deinit();
+            self.update.deinit();
+            self.destruction.deinit();
 
             if (self.allocator) |allocator|
                 allocator.destroy(self);
         }
 
+        pub fn onConstruct(self: *Self) Sink(EntityT) {
+            return self.construction.sink();
+        }
+
+        pub fn onUpdate(self: *Self) Sink(EntityT) {
+            return self.update.sink();
+        }
+
+        pub fn onDestruct(self: *Self) Sink(EntityT) {
+            return self.destruction.sink();
+        }
+
         /// Increases the capacity of a component storage
         pub fn reserve(self: *Self, cap: usize) void {
             self.set.reserve(cap);
@@ -81,11 +109,20 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
                 self.instances.items.reserve(cap);
         }
 
-        /// Assigns an entity to a storage and constructs its object
+        /// Assigns an entity to a storage and assigns its object
         pub fn add(self: *Self, entity: EntityT, value: CompT) void {
             if (!is_empty_struct)
                 _ = self.instances.append(value) catch unreachable;
             self.set.add(entity);
+            self.construction.publish(entity);
+        }
+
+        /// Removes an entity from a storage
+        pub fn remove(self: *Self, entity: EntityT) void {
+            if (!is_empty_struct)
+                _ = self.instances.swapRemove(self.set.index(entity));
+            self.destruction.publish(entity);
+            self.set.remove(entity);
         }
 
         /// Checks if a view contains an entity
@@ -106,6 +143,12 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
                     return self.instances.items;
                 }
 
+                /// Replaces the given component for an entity
+                pub fn replace(self: *Self, entity: EntityT, value: CompT) void {
+                    self.get(entity).* = value;
+                    self.update.publish(entity);
+                }
+
                 /// Returns the object associated with an entity
                 pub fn get(self: *Self, entity: EntityT) *CompT {
                     std.debug.assert(self.contains(entity));
@@ -131,13 +174,6 @@ pub fn ComponentStorage(comptime CompT: type, comptime EntityT: type, comptime D
             return self.set.data();
         }
 
-        /// Removes an entity from a storage
-        pub fn remove(self: *Self, entity: EntityT) void {
-            if (!is_empty_struct)
-                _ = self.instances.swapRemove(self.set.index(entity));
-            self.set.remove(entity);
-        }
-
         /// Swaps entities and objects in the internal packed arrays
         pub fn swap(self: *Self, lhs: EntityT, rhs: EntityT) void {
             if (!is_empty_struct)
@@ -208,3 +244,34 @@ test "empty component" {
     store.add(3, Empty{});
     store.remove(3);
 }
+
+fn construct(e: u32) void {
+    std.debug.assert(e == 3);
+}
+fn update(e: u32) void {
+    std.debug.assert(e == 3);
+}
+fn destruct(e: u32) void {
+    std.debug.assert(e == 3);
+}
+
+test "signals" {
+    var store = ComponentStorage(f32, u32, u8).init(std.testing.allocator);
+    defer store.deinit();
+
+    store.onConstruct().connect(construct);
+    store.onUpdate().connect(update);
+    store.onDestruct().connect(destruct);
+
+    store.add(3, 66.45);
+    store.replace(3, 45.64);
+    store.remove(3);
+
+    store.onConstruct().disconnect(construct);
+    store.onUpdate().disconnect(update);
+    store.onDestruct().disconnect(destruct);
+
+    store.add(4, 66.45);
+    store.replace(4, 45.64);
+    store.remove(4);
+}

zig-ecs/src/ecs/registry.zig

@@ -70,20 +70,29 @@ pub const Registry = struct {
         return @intToPtr(*Storage(T), ptr);
     }
 
+    /// Prepares a pool for the given type if required
     pub fn prepare(self: *Registry, comptime T: type) void {
-        unreachable;
+        _ = self.assure(T);
     }
 
+    /// Returns the number of existing components of the given type
     pub fn len(self: *Registry, comptime T: type) usize {
         self.assure(T).len();
     }
 
+    /// Increases the capacity of the registry or of the pools for the given component
+    pub fn reserve(self: *Self, comptime T: type, cap: usize) void {
+        self.assure(T).reserve(cap);
+    }
+
+    /// Direct access to the list of components of a given pool
     pub fn raw(self: Registry, comptime T: type) []T {
         return self.assure(T).raw();
     }
 
-    pub fn reserve(self: *Self, comptime T: type, cap: usize) void {
-        self.assure(T).reserve(cap);
+    /// Direct access to the list of entities of a given pool
+    pub fn data(self: Registry, comptime T: type) []Entity {
+        return self.assure(T).data();
     }
 
     pub fn valid(self: *Registry, entity: Entity) bool {
@@ -122,10 +131,10 @@ pub const Registry = struct {
         self.add(entity, value);
     }
 
+    /// Replaces the given component for an entity
     pub fn replace(self: *Registry, entity: Entity, value: var) void {
         assert(self.valid(entity));
-        var ptr = self.assure(@TypeOf(value)).get(entity);
-        ptr.* = value;
+        self.assure(@TypeOf(value)).replace(entity, value);
     }
 
     /// shortcut for replacing raw comptime_int/float without having to @as cast
@@ -165,7 +174,13 @@ pub const Registry = struct {
     /// Removes all the components from an entity and makes it orphaned
     pub fn removeAll(self: *Registry, entity: Entity) void {
         assert(self.valid(entity));
-        // unreachable;
+
+        var it = self.components.iterator();
+        while (it.next()) |ptr| {
+            // HACK: we dont know the Type here but we need to be able to call methods on the Storage(T)
+            var store = @intToPtr(*Storage(u128), ptr.value);
+            if (store.contains(entity)) store.remove(entity);
+        }
     }
 
     pub fn has(self: *Registry, comptime T: type, entity: Entity) bool {
@@ -194,6 +209,21 @@ pub const Registry = struct {
         return self.assure(T).tryGet(entity);
     }
 
+    /// Returns a Sink object for the given component to add/remove listeners with
+    pub fn onConstruct(self: *Self, comptime T: type) Sink(Entity) {
+        return self.assure(T).onConstruct();
+    }
+
+    /// Returns a Sink object for the given component to add/remove listeners with
+    pub fn onUpdate(self: *Self, comptime T: type) Sink(Entity) {
+        return self.assure(T).onUpdate();
+    }
+
+    /// Returns a Sink object for the given component to add/remove listeners with
+    pub fn onDestruct(self: *Self, comptime T: type) Sink(Entity) {
+        return self.assure(T).onDestruct();
+    }
+
     /// Binds an object to the context of the registry
     pub fn setContext(self: *Registry, context: var) void {
         std.debug.assert(@typeInfo(@TypeOf(context)) == .Pointer);
@@ -291,3 +321,40 @@ test "component context get/set/unset" {
     ctx = reg.getContext(SomeType);
     std.testing.expectEqual(ctx, null);
 }
+
+test "destroy" {
+    var reg = Registry.init(std.testing.allocator);
+    defer reg.deinit();
+
+    var i = @as(u8, 0);
+    while (i < 255) : (i += 1) {
+        const e = reg.create();
+        reg.add(e, Position{ .x = @intToFloat(f32, i), .y = @intToFloat(f32, i) });
+    }
+
+    reg.destroy(3);
+    reg.destroy(4);
+
+    i = 0;
+    while (i < 6) : (i += 1) {
+        if (i != 3 and i != 4)
+            std.testing.expectEqual(Position{ .x = @intToFloat(f32, i), .y = @intToFloat(f32, i)}, reg.getConst(Position, i));
+    }
+}
+
+test "remove all" {
+    var reg = Registry.init(std.testing.allocator);
+    defer reg.deinit();
+
+    var e = reg.create();
+    reg.add(e, Position{.x = 1, .y = 1});
+    reg.addTyped(u32, e, 666);
+
+    std.testing.expect(reg.has(Position, e));
+    std.testing.expect(reg.has(u32, e));
+
+    reg.removeAll(e);
+
+    std.testing.expect(!reg.has(Position, e));
+    std.testing.expect(!reg.has(u32, e));
+}

zig-ecs/src/ecs/sparse_set.zig

@@ -85,7 +85,7 @@ pub fn SparseSet(comptime SparseT: type, comptime DenseT: type) type {
 
         fn assure(self: *Self, pos: usize) []DenseT {
             // TODO: support paging
-            if (self.sparse.capacity < pos or self.sparse.capacity == 0) {
+            if (self.sparse.capacity <= pos or self.sparse.capacity == 0) {
                 const amount = pos + 1 - self.sparse.capacity;
 
                 // expand and fill with maxInt as an identifier

zig-ecs/src/signals/signal.zig

@@ -10,7 +10,7 @@ pub fn Signal(comptime Event: type) type {
         allocator: ?*std.mem.Allocator = null,
 
         pub fn init(allocator: *std.mem.Allocator) Self {
-            // we purposely do not store the allocator locally in this case!
+            // we purposely do not store the allocator locally in this case so we know not to destroy ourself in deint!
             return Self{
                 .calls = std.ArrayList(Delegate(Event)).init(allocator),
             };