1 #ifndef DALI_INTERNAL_HIT_TEST_ALGORITHM_H
2 #define DALI_INTERNAL_HIT_TEST_ALGORITHM_H
5 * Copyright (c) 2022 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/devel-api/events/hit-test-algorithm.h>
23 #include <dali/integration-api/events/touch-event-integ.h>
24 #include <dali/internal/event/render-tasks/render-task-impl.h>
25 #include <dali/public-api/actors/actor.h>
35 * This namespace is provided for application developers to do hit test for the actors.
37 namespace HitTestAlgorithm
41 RenderTaskPtr renderTask; ///< The render-task displaying the actor.
42 Dali::Actor actor; ///< The hit actor.
43 Vector2 actorCoordinates; ///< The actor coordinates.
44 Vector4 rayOrigin; ///< The point of origin of the ray.
45 Vector4 rayDirection; ///< The direction vector of the ray.
46 Integration::Point point; ///< The point of event touched.
47 uint32_t eventTime; ///< The time the event occurred.
51 * Interface used by the hit-test-algorithm to determine whether the actor is hittable or whether
52 * we walk down its hierarchy.
54 struct HitTestInterface
57 * Called by the hit-test algorithm to determine whether the actor is hittable or not.
59 * @param[in] actor Raw pointer to an Actor object.
61 * @return true if actor is hittable, false otherwise.
63 virtual bool IsActorHittable(Actor* actor) = 0;
66 * Called by the hit-test algorithm to determine whether the algorithm should descend the actor's
67 * hierarchy (and hit-test its children as well).
69 * @param[in] actor Raw pointer to an Actor object.
71 * @return true if we should descend the actor's hierarchy, false otherwise.
73 virtual bool DescendActorHierarchy(Actor* actor) = 0;
76 * Called by the hit-test algorithm to determine whether the layer specified consumes the hit
77 * regardless of whether an actor in the layer requires it or not.
79 * @note If true is returned, then no layers behind this layer will be hit-test.
81 * @param[in] layer Raw pointer to a Layer object.
83 * @return true if the layer should consume the hit, false otherwise.
85 virtual bool DoesLayerConsumeHit(Layer* layer) = 0;
88 * Called by the hit-test algorithm to determine whether the actor will be hit or not.
90 * @note If true is returned, then this actor will be hit.
91 * If false is returend, then this actor passes the hit-test and the next actor performs the hit-test.
93 * @param[in] actor The hit actor.
94 * @param[in] point The point of event touched.
95 * @param[in] hitPointLocal The hit point in the Actor's local reference system.
96 * @param[in] timeStamp The time the event occurred.
98 * @return true if the actor should be the hit, false otherwise.
100 virtual bool ActorRequiresHitResultCheck(Actor* actor, Integration::Point point, Vector2 hitPointLocal, uint32_t timeStamp) = 0;
104 * Virtual destructor, no deletion through this interface
106 virtual ~HitTestInterface();
110 * Hit test specific to a given scene.
112 * @param[in] sceneSize The size of the scene.
113 * @param[in] renderTaskList The render task list of the scene.
114 * @param[in] layerList The layer list of the scene.
115 * @param[in] screenCoordinates The screen coordinates.
116 * @param[out] results The results of the hit-test.
117 * @param[in] func The function to use in the hit-test algorithm.
118 * @return true if something was hit
120 * @see HitTest(Stage&, const Vector2&, Results&, HitTestInterface&)
122 bool HitTest(const Vector2& sceneSize, RenderTaskList& renderTaskList, LayerList& layerList, const Vector2& screenCoordinates, Dali::HitTestAlgorithm::Results& results, Dali::HitTestAlgorithm::HitTestFunction func);
125 * Given screen coordinates, this method returns the hit actor & the local coordinates relative to the actor etc.
126 * @param[in] sceneSize The size of the scene.
127 * @param[in] renderTaskList The render task list of the scene.
128 * @param[in] layerList The layer list of the scene.
129 * @param[in] screenCoordinates The screen coordinates.
130 * @param[out] results The results of the hit-test.
131 * @param[in] hitTestInterface Used to determine whether the actor is hit or whether we walk down its hierarchy
132 * @return true if something was hit
134 * <h3>Hit Test Algorithm:</h3>
136 * - The regular RenderTaskList is used to hit test the on scene actors.
137 * - The bulk of the hit test algorithm is described in Dali::Actor.
138 * - In each RenderTask's its viewing parameters (the view and projection matrices, and the viewport)
139 * are used to build a picking ray into the scene which is used for our ray tests when hit testing
140 * an actor within each layer.
141 * - If an actor is deemed to be hittable, then a quicker ray sphere test on the actor is performed
142 * first to determine if the ray is in the actor's proximity.
143 * - If this is also successful, then a more accurate ray test is performed to see if we have a hit.
145 * @note Currently, we prefer a child hit over a parent (regardless of the distance from the
146 * camera) unless the parent is a RenderableActor but this is subject to change.
148 bool HitTest(const Vector2& sceneSize, RenderTaskList& renderTaskList, LayerList& layerList, const Vector2& screenCoordinates, Results& results, HitTestInterface& hitTestInterface);
151 * Default HitTest where we check if a touch is required.
153 * @param[in] sceneSize The size of the scene.
154 * @param[in] renderTaskList The render task list of the scene.
155 * @param[in] layerList The layer list of the scene.
156 * @param[in] screenCoordinates The screen coordinates.
157 * @param[out] results The results of the hit-test.
158 * @param[in] ownActor The actor from which the touch down was started.
159 * @return true if something was hit
161 * @see HitTest(Stage&, const Vector2&, Results&, HitTestInterface&)
163 bool HitTest(const Vector2& sceneSize, RenderTaskList& renderTaskList, LayerList& layerList, const Vector2& screenCoordinates, Results& results, const Actor* ownActor = nullptr);
165 } // namespace HitTestAlgorithm
167 } // namespace Internal
171 #endif // DALI_INTERNAL_HIT_TEST_ALGORITHM_H