preliminary work on ecs

1 files changed, 7 insertions, 100 deletions

diff --git a/src/ecs/components.zig b/src/ecs/components.zig
index bb333c9..5c35cbf 100644
--- a/src/ecs/components.zig
+++ b/src/ecs/components.zig
@@ -1,111 +1,18 @@
 const std = @import("std");
 const Allocator = std.mem.Allocator;
 
-pub const Position = struct {
+const COMPONENT_NUMBER = 2;
+
+pub const Position = packed struct {
     x: f32,
     y: f32,
     z: f32,
-};
 
-pub const Speed = struct {
-    speed: f32,
+    pub const id: usize = 0;
 };
 
-pub const Pool = struct {
-    comptime sets_map: std.StringHashMap([]const u8) = std.StringHashMap([]const u8).init(allocator),
-    speed_set: SparseSet(Speed),
-    allocator: Allocator,
-    free_ids: std.ArrayList(usize),
-    entities: usize,
-
-    pub fn init(allocator: Allocator) !Pool {
-        try sets_map.put(@typeName(Speed), "speed_set");
-
-        return Pool{
-            .speed_set = try SparseSet(Speed).init(allocator),
-            .allocator = allocator,
-            .free_ids = try std.ArrayList(usize).initCapacity(allocator, 100),
-            .entities = 0,
-        };
-    }
-
-    pub fn deinit(self: *Pool) void {
-        self.sets_map.deinit();
-        self.speed_set.deinit();
-    }
-
-    pub fn addComponent(self: *Pool, comptime T: type, id: usize, component: T) void {
-        var set = @field(self, try self.sets_map.get(@typeName(T)));
-
-        set.insert(id, component);
-    }
-
-    pub fn insert(self: *Pool) !usize {
-        const id = self.free_ids.pop() orelse self.entities;
-
-        self.entities += 1;
-        return id;
-    }
-
-    pub fn remove(self: *Pool, id: usize) !usize {
-        if (self.speed_set.hasComponent(id)) {
-            self.speed_set.remove(id);
-        }
+pub const Speed = packed struct {
+    speed: f32,
 
-        self.entities -= 1;
-        self.free_ids.append(id);
-    }
+    pub const id: usize = 1;
 };
-
-pub fn SparseSet(comptime T: type) type {
-    return struct {
-        sparse: std.ArrayList(usize),
-        dense: std.ArrayList(usize),
-        components: std.ArrayList(T),
-
-        pub fn init(allocator: Allocator) !@This() {
-            return @This(){
-                .sparse = try std.ArrayList(usize).initCapacity(allocator, 10),
-                .dense = try std.ArrayList(usize).initCapacity(allocator, 10),
-                .components = try std.ArrayList(T).initCapacity(allocator, 10),
-            };
-        }
-
-        pub fn deinit(self: *@This()) void {
-            self.sparse.deinit();
-            self.dense.deinit();
-            self.components.deinit();
-        }
-
-        pub fn hasComponent(self: *@This(), id: usize) bool {
-            return self.dense.items[self.sparse.items[id]] == id;
-        }
-
-        pub fn insert(self: *@This(), id: usize, component: T) !void {
-            const dense_index = self.dense.items.len;
-            try self.dense.append(id);
-            try self.components.append(component);
-            try self.sparse.append(dense_index);
-        }
-
-        pub fn remove(self: *@This(), id: usize) !void {
-            const index = self.sparse.items[id];
-            const last = self.dense.getLast();
-            self.sparse.items[last] = index;
-            _ = self.dense.swapRemove(index);
-            _ = self.components.swapRemove(index);
-        }
-    };
-}
-
-pub fn test_sparse() !void {
-    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
-    const allocator = gpa.allocator();
-
-    var pool = try Pool.init(allocator);
-    defer pool.deinit();
-
-    const entity = try pool.insert();
-    std.debug.print("new entity: {d}\n", .{entity});
-    pool.addComponent(Speed, entity, .{ .speed = 5.0 });
-}