1 /*
2 * Copyright (C) 2023 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #ifndef API_CORE_ECS_ICOMPONENT_MANAGER_H
17 #define API_CORE_ECS_ICOMPONENT_MANAGER_H
18
19 #include <base/containers/array_view.h>
20 #include <base/containers/string_view.h>
21 #include <base/containers/vector.h>
22 #include <base/util/uid.h>
23 #include <core/ecs/entity.h>
24 #include <core/namespace.h>
25
26 CORE_BEGIN_NAMESPACE()
27 class IPropertyApi;
28 class IPropertyHandle;
29 class IEcs;
30
31 /** \addtogroup group_ecs_icomponentmanager
32 * @{
33 */
34 /** Component manager modified flag bits */
35 enum ComponentManagerModifiedFlagBits {
36 /** Component added bit */
37 CORE_COMPONENT_MANAGER_COMPONENT_ADDED_BIT = 0x00000001,
38 /** Component removed bit */
39 CORE_COMPONENT_MANAGER_COMPONENT_REMOVED_BIT = 0x00000002,
40 /** Component updated bit */
41 CORE_COMPONENT_MANAGER_COMPONENT_UPDATED_BIT = 0x00000004,
42 /** Modified flag bits max enumeration */
43 CORE_COMPONENT_MANAGER_MODIFIED_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
44 };
45 /** Container for component manager modified flag bits */
46 using ComponentManagerModifiedFlags = uint32_t;
47
48 /**
49 Component Manager.
50
51 */
52 class IComponentManager {
53 public:
54 using ComponentId = uint32_t;
55 static constexpr ComponentId INVALID_COMPONENT_ID = 0xFFFFFFFF;
56
57 /** Returns the name of the component type.
58 */
59 virtual BASE_NS::string_view GetName() const = 0;
60
61 /** Returns the UID of the component type.
62 */
63 virtual BASE_NS::Uid GetUid() const = 0;
64
65 /** Returns the total number of components. Includes components that are being destroyed but are not yet garbage
66 * collected.
67 */
68 virtual size_t GetComponentCount() const = 0;
69
70 /** Access to metadata defining the contents of the component.
71 */
72 virtual const IPropertyApi& GetPropertyApi() const = 0;
73
74 /** Returns entity for component index. May return invalid entity if the entity is being destroyed.
75 */
76 virtual Entity GetEntity(IComponentManager::ComponentId index) const = 0;
77
78 /** Get component generation id, which is incremented every time the component data is changed.
79 */
80 virtual uint32_t GetComponentGeneration(IComponentManager::ComponentId index) const = 0;
81
82 // Entity api.
83 /** Checks if Entity has component.
84 * @param entity Entity to be checked.
85 */
86 virtual bool HasComponent(Entity entity) const = 0;
87
88 /** Retrieves component id for a given entity.
89 * @param entity Entity to be used as a search key.
90 */
91 virtual IComponentManager::ComponentId GetComponentId(Entity entity) const = 0;
92
93 /** Creates a default component for entity.
94 * @param entity Entity which for component is created.
95 */
96 virtual void Create(Entity entity) = 0;
97
98 /** Removes component from entity.
99 * @param entity Entity where component is removed.
100 */
101 virtual bool Destroy(Entity entity) = 0;
102
103 /** Garbage collect components.
104 * This is called automatically by the ECS, but can be called by the user too to force cleanup.
105 */
106 virtual void Gc() = 0;
107
108 /** Remove components from entities.
109 * @param gcList List of entities to have their components removed
110 */
111 virtual void Destroy(BASE_NS::array_view<const Entity> gcList) = 0;
112
113 /** Get list of entities that have new components of this type (since last call).
114 */
115 virtual BASE_NS::vector<Entity> GetAddedComponents() = 0;
116
117 /** Get list of entities that no longer have components of this type (since last call).
118 */
119 virtual BASE_NS::vector<Entity> GetRemovedComponents() = 0;
120
121 /** Get list of entities that have been modified (since last call).
122 */
123 virtual BASE_NS::vector<Entity> GetUpdatedComponents() = 0;
124
125 /** Returns flags if component is added, removed or updated.
126 */
127 virtual ComponentManagerModifiedFlags GetModifiedFlags() const = 0;
128
129 /** Clears all flags of component (Application developer should not call this since its been automatically called
130 * after every frame).
131 */
132 virtual void ClearModifiedFlags() = 0;
133
134 /** Number of changes occured in this component manager since start of its life.
135 */
136 virtual uint32_t GetGenerationCounter() const = 0;
137
138 /** Set data for entity. Copies the data from "data" handle to the component for entity.
139 * @param entity Entity which is set-up.
140 * @param data property handle for entity.
141 */
142 virtual void SetData(Entity entity, const IPropertyHandle& data) = 0;
143
144 /** Get data for entity. This handle can be used to directly read the component for entity.
145 * @param entity Entity where we get our property handle.
146 */
147 virtual const IPropertyHandle* GetData(Entity entity) const = 0;
148
149 /** Get data for entity. This handle can be used to directly modify the component for entity.
150 * @param entity Entity where we get our property handle.
151 */
152 virtual IPropertyHandle* GetData(Entity entity) = 0;
153
154 /** Set data for entity. Copies the data from "data" handle to the component.
155 * @param index Index what is used to add or update the component if index is same as before.
156 * @param data Data which is set to component.
157 */
158 virtual void SetData(ComponentId index, const IPropertyHandle& data) = 0;
159
160 /** Get data for entity. This handle can be used to directly read the component for entity.
161 * @param index Index to get data from
162 */
163 virtual const IPropertyHandle* GetData(ComponentId index) const = 0;
164
165 /** Get data for entity. This handle can be used to directly modify the component for entity.
166 * @param index Index to get data from
167 */
168 virtual IPropertyHandle* GetData(ComponentId index) = 0;
169
170 /** Get the ECS instance using this manager.
171 * @return Reference to owning ECS instance.
172 */
173 virtual IEcs& GetEcs() const = 0;
174
175 protected:
176 IComponentManager() = default;
177 IComponentManager(const IComponentManager&) = delete;
178 IComponentManager(IComponentManager&&) = delete;
179 IComponentManager& operator=(const IComponentManager&) = delete;
180 virtual ~IComponentManager() = default;
181 };
182
183 /** Get name */
184 template<class T>
GetName()185 inline constexpr BASE_NS::string_view GetName()
186 {
187 return GetName((const T*)nullptr);
188 }
189
190 /** Get UID */
191 template<class T>
GetUid()192 inline constexpr BASE_NS::Uid GetUid()
193 {
194 return GetUid((const T*)nullptr);
195 }
196
197 /** Create component */
198 template<class T>
CreateComponent(T & componentManager,const Entity & entity)199 inline auto CreateComponent(T& componentManager, const Entity& entity)
200 {
201 componentManager.Create(entity);
202 return componentManager.Get(entity);
203 }
204
205 /** @} */
206 CORE_END_NAMESPACE()
207
208 #endif // API_CORE_ECS_ICOMPONENT_MANAGER_H
209