1 #ifndef __DALI_PATH_H__
2 #define __DALI_PATH_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/public-api/object/handle.h>
27 namespace Internal DALI_INTERNAL
32 * @brief A 3D parametric curve
34 * Paths can be used to animate position and orientation of actors using Dali::Animate( Actor, Path, ... )
37 class DALI_IMPORT_API Path : public Handle
41 static const Property::Index POINTS; ///< name "points", type ARRAY of Vector3
42 static const Property::Index CONTROL_POINTS; ///< name "control-points", type ARRAY of Vector3
44 * @brief Create an initialized Path handle.
46 * @return a handle to a newly allocated Dali resource.
51 * @brief Downcast an Object handle to Path handle.
53 * If handle points to a KeyFrames object the downcast produces
54 * valid handle. If not the returned handle is left uninitialized.
55 * @param[in] handle to An object
56 * @return handle to a Path object or an uninitialized handle
58 static Path DownCast( BaseHandle handle );
61 * @brief Create an uninitialized Path handle.
63 * This can be initialized with Path::New(). Calling member
64 * functions with an uninitialized Dali::Object is not allowed.
71 * This is non-virtual since derived Handle types must not contain data or virtual methods.
76 * @brief This copy constructor is required for (smart) pointer semantics.
78 * @param [in] handle A reference to the copied handle
80 Path(const Path& handle);
83 * @brief This assignment operator is required for (smart) pointer semantics.
85 * @param [in] rhs A reference to the copied handle
86 * @return A reference to this
88 Path& operator=(const Path& rhs);
91 * @brief Add an interpolation point.
93 * @param[in] point The new interpolation point to be added
95 void AddPoint(const Vector3& point );
98 * @brief Add a control point.
100 * @param[in] point The new control point to be added
102 void AddControlPoint(const Vector3& point );
105 * @brief Automatic generation of control points. Generated control points which result in a smooth join between the splines of each segment.
107 * The generating algorithm is as follows:
108 * For a given knot point K[N], find the vector that bisects K[N-1],[N] and [N],[N+1].
109 * Calculate the tangent vector by taking the normal of this bisector.
110 * The in control point is the length of the preceding segment back along this bisector multiplied by the curvature
111 * The out control point is the length of the succeeding segment forward along this bisector multiplied by the curvature
113 * @pre There are at least two points in the path ( one segment ).
115 * @param[in] curvature The curvature of the spline. 0 gives straight lines between the knots,
116 * negative values means the spline contains loops, positive values up to
117 * 0.5 result in a smooth curve, positive values between 0.5 and 1 result
118 * in looped curves where the loops are not distinct (i.e. the curve appears
119 * to be non-continuous), positive values higher than 1 result in looped curves.
121 void GenerateControlPoints( float curvature );
124 * @brief Sample path at a given progress. Calculates position and tangent at that point of the curve
126 * @param[in] progress A floating point value between 0.0 and 1.0.
127 * @param[out] position The interpolated position at that progress.
128 * @param[out] tangent The interpolated tangent at that progress.
130 void Sample( float progress, Vector3& position, Vector3& tangent ) const;
133 * @brief Accessor for the interpolation points.
135 * @param[in] index The index of the interpolation point.
136 * @return A reference to the interpolation point.
138 Vector3& GetPoint( size_t index );
141 * @brief Accessor for the control points.
143 * @param[in] index The index of the control point.
144 * @return A reference to the control point.
146 Vector3& GetControlPoint( size_t index );
149 * @brief Get the number of interpolation points in the path
151 * @return The number of interpolation points in the path
153 size_t GetPointCount() const;
155 public: // Not intended for application developers
157 * @brief This constructor is used by Dali::New() methods.
159 * @param[in] path A pointer to an internal path resource
161 explicit DALI_INTERNAL Path(Internal::Path* path);
166 #endif // __DALI_KEY_FRAMES_H__