1 #ifndef __DALI_INTERNAL_HIT_TEST_ALGORITHM_H__
2 #define __DALI_INTERNAL_HIT_TEST_ALGORITHM_H__
5 * Copyright (c) 2014 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/public-api/render-tasks/render-task.h>
34 * This namespace is provided for application developers to do hit test for the actors.
36 namespace HitTestAlgorithm
41 Dali::RenderTask 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.
49 * Interface used by the hit-test-algorithm to determine whether the actor is hittable or whether
50 * we walk down its hierarchy.
52 struct HitTestInterface
55 * Called by the hit-test algorithm to determine whether the actor is hittable or not.
57 * @param[in] actor Raw pointer to an Actor object.
59 * @return true if actor is hittable, false otherwise.
61 virtual bool IsActorHittable( Actor* actor ) = 0;
64 * Called by the hit-test algorithm to determine whether the algorithm should descend the actor's
65 * hierarchy (and hit-test its children as well).
67 * @param[in] actor Raw pointer to an Actor object.
69 * @return true if we should descend the actor's hierarchy, false otherwise.
71 virtual bool DescendActorHierarchy( Actor* actor ) = 0;
74 * Called by the hit-test algorithm to determine whether the layer specified consumes the hit
75 * regardless of whether an actor in the layer requires it or not.
77 * @note If true is returned, then no layers behind this layer will be hit-test.
79 * @param[in] layer Raw pointer to a Layer object.
81 * @return true if the layer should consume the hit, false otherwise.
83 virtual bool DoesLayerConsumeHit( Layer* layer ) = 0;
87 * @copydoc Dali::HitTestAlgorithm::HitTest(Stage stage, const Vector2& screenCoordinates, Results& results, HitTestFunction func )
89 bool HitTest( Stage& stage, const Vector2& screenCoordinates, Dali::HitTestAlgorithm::Results& results, Dali::HitTestAlgorithm::HitTestFunction func );
92 * Given screen coordinates, this method returns the hit actor & the local coordinates relative to the actor etc.
93 * @param[in] stage The stage.
94 * @param[in] screenCoordinates The screen coordinates.
95 * @param[out] results The results of the hit-test.
96 * @param[in] hitTestInterface Used to determine whether the actor is hit or whether we walk down its hierarchy
97 * @return true if something was hit
99 * <h3>Hit Test Algorithm:</h3>
101 * - The system overlay RenderTaskList is hit-tested first.
102 * - If no hit then the regular RenderTaskList is used to hit test the on stage actors.
103 * - The bulk of the hit test algorithm is described in Dali::Actor.
104 * - In each RenderTask's its viewing parameters (the view and projection matrices, and the viewport)
105 * are used to build a picking ray into the scene which is used for our ray tests when hit testing
106 * an actor within each layer.
107 * - If an actor is deemed to be hittable, then a quicker ray sphere test on the actor is performed
108 * first to determine if the ray is in the actor's proximity.
109 * - If this is also successful, then a more accurate ray test is performed to see if we have a hit.
111 * @note Currently, we prefer a child hit over a parent (regardless of the distance from the
112 * camera) unless the parent is a RenderableActor but this is subject to change.
114 bool HitTest( Stage& stage, const Vector2& screenCoordinates, Results& results, HitTestInterface& hitTestInterface );
117 * Default HitTest where we check if a touch is required.
119 * @param[in] stage The stage.
120 * @param[in] screenCoordinates The screen coordinates.
121 * @param[out] results The results of the hit-test.
122 * @return true if something was hit
124 * @see HitTest(Stage&, const Vector2&, Results&, HitTestInterface&)
126 bool HitTest( Stage& stage, const Vector2& screenCoordinates, Results& results );
129 * Hit test specific to a given RenderTask
131 * @param[in] stage The stage.
132 * @param[in] renderTask The render task for hit test
133 * @param[in] screenCoordinates The screen coordinates.
134 * @param[out] results The results of the hit-test.
135 * @param[in] func The function to use in the hit-test algorithm.
136 * @return true if something was hit
138 bool HitTest( Stage& stage, RenderTask& renderTask, const Vector2& screenCoordinates,
139 Dali::HitTestAlgorithm::Results& results, Dali::HitTestAlgorithm::HitTestFunction func );
141 } // namespace HitTestAlgorithm
143 } // namespace Internal
147 #endif // __DALI_INTERNAL_HIT_TEST_ALGORITHM_H__