1 #ifndef __DALI_ALPHA_FUNCTION_H__
2 #define __DALI_ALPHA_FUNCTION_H__
5 * Copyright (c) 2015 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/common/dali-common.h>
23 #include <dali/public-api/common/constants.h>
24 #include <dali/public-api/math/compile-time-math.h>
25 #include <dali/public-api/math/math-utils.h>
26 #include <dali/public-api/math/vector2.h>
27 #include <dali/public-api/math/vector4.h>
32 typedef float (*AlphaFunctionPrototype)(float progress); ///< Prototype of an alpha function
35 * @brief Alpha functions are used in animations to specify the rate of change of the animation parameter over time.
36 * Understanding an animation as a parametric function over time, the alpha function is applied to the parameter of
37 * the animation before computing the final animation value.
39 class DALI_IMPORT_API AlphaFunction
44 * Built-in alpha functions
49 LINEAR, ///< No transformation
50 REVERSE, ///< Reverse linear
52 EASE_IN_SQUARE, ///< Speeds up and comes to a sudden stop (Square)
53 EASE_OUT_SQUARE, ///< Sudden start and slows to a gradual stop (Square)
55 EASE_IN, ///< Speeds up and comes to a sudden stop (Cubic)
56 EASE_OUT, ///< Sudden start and slows to a gradual stop (Cubic)
57 EASE_IN_OUT, ///< Speeds up and slows to a gradual stop (Cubic)
59 EASE_IN_SINE, ///< Speeds up and comes to a sudden stop (sinusoidal)
60 EASE_OUT_SINE, ///< Sudden start and slows to a gradual stop (sinusoidal)
61 EASE_IN_OUT_SINE, ///< Speeds up and slows to a gradual stop (sinusoidal)
63 BOUNCE, ///< Sudden start, loses momentum and returns to start position
64 SIN, ///< Single revolution
65 EASE_OUT_BACK, ///< Sudden start, exceed end position and return to a gradual stop
71 * All possible functioning modes for the alpha function
75 BUILTIN_FUNCTION, //< The user has specified a built-in function
76 CUSTOM_FUNCTION, //< The user has provided a custom function
77 BEZIER //< The user has provided the control points of a bezier curve
81 * @brief Default constructor.
82 * Creates an alpha function object with the default built-in alpha function
83 * @return The alpha function
89 * Creates an alpha function object with the built-in alpha function passed as a parameter
91 * @param[in] function One of the built-in alpha functions
92 * @return The alpha function
94 AlphaFunction( BuiltinFunction function);
98 * Creates an alpha function object using a pointer to an alpha function passed as a paramter
100 * @param[in] function A pointer to an alpha function
101 * @return The alpha function
103 AlphaFunction( AlphaFunctionPrototype function);
106 * @brief Constructor.
107 * Creates a bezier alpha function. The bezier will have the first point at (0,0) and
108 * the end point at (1,1).
109 * @note The x components of the control points will be clamped to the range [0,1] to prevent
110 * non monotonic curves.
111 * @param[in] controlPoint0 A Vector2 which will be used as the first control point of the curve
112 * @param[in] controlPoint1 A Vector2 which will be used as the second control point of the curve
113 * @return The alpha function
115 AlphaFunction( const Dali::Vector2& controlPoint0, const Dali::Vector2& controlPoint1 );
118 * @brief Return the control points of the alpha function
119 * @return Vector4 containing the two control points of the curve.
120 * (xy for the first point and zw for the second)
122 Vector4 GetBezierControlPoints() const;
125 * @brief Returns the pointer to the custom function
126 * @return A pointer to a custom alpha function or 0 if not defined
128 AlphaFunctionPrototype GetCustomFunction() const;
131 * @brief Returns the built0in function used by the alpha function
132 * @return One of the built-in alpha functions. In case no built-in function
133 * has been specified, it will return AlphaFunction::DEfAULT
135 BuiltinFunction GetBuiltinFunction() const;
138 * @brief Returns the functioning mode of the alpha function
139 * @return The functioning mode of the alpha function
141 Mode GetMode() const;
145 Vector4 mBezierControlPoints; //< Control points for the bezier alpha function
146 AlphaFunctionPrototype mCustom; //< Pointer to an alpha function
147 BuiltinFunction mBuiltin : Log<COUNT>::value+1; //< Enum indicating the built-in alpha function
148 Mode mMode : 2; //< Enum indicating the functioning mode of the AlphaFunction
153 #endif // __DALI_ALPHA_FUNCTION_H__