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 * @addtogroup dali-core-animation
36 typedef float (*AlphaFunctionPrototype)(float progress); ///< Prototype of an alpha function
39 * @brief Alpha functions are used in animations to specify the rate of change of the animation parameter over time.
40 * Understanding an animation as a parametric function over time, the alpha function is applied to the parameter of
41 * the animation before computing the final animation value.
43 class DALI_IMPORT_API AlphaFunction
48 * Built-in alpha functions
53 LINEAR, ///< No transformation
54 REVERSE, ///< Reverse linear
56 EASE_IN_SQUARE, ///< Speeds up and comes to a sudden stop (Square)
57 EASE_OUT_SQUARE, ///< Sudden start and slows to a gradual stop (Square)
59 EASE_IN, ///< Speeds up and comes to a sudden stop (Cubic)
60 EASE_OUT, ///< Sudden start and slows to a gradual stop (Cubic)
61 EASE_IN_OUT, ///< Speeds up and slows to a gradual stop (Cubic)
63 EASE_IN_SINE, ///< Speeds up and comes to a sudden stop (sinusoidal)
64 EASE_OUT_SINE, ///< Sudden start and slows to a gradual stop (sinusoidal)
65 EASE_IN_OUT_SINE, ///< Speeds up and slows to a gradual stop (sinusoidal)
67 BOUNCE, ///< Sudden start, loses momentum and returns to start position
68 SIN, ///< Single revolution
69 EASE_OUT_BACK, ///< Sudden start, exceed end position and return to a gradual stop
75 * All possible functioning modes for the alpha function
79 BUILTIN_FUNCTION, //< The user has specified a built-in function
80 CUSTOM_FUNCTION, //< The user has provided a custom function
81 BEZIER //< The user has provided the control points of a bezier curve
85 * @brief Default constructor.
86 * Creates an alpha function object with the default built-in alpha function
87 * @return The alpha function
93 * Creates an alpha function object with the built-in alpha function passed as a parameter
95 * @param[in] function One of the built-in alpha functions
96 * @return The alpha function
98 AlphaFunction( BuiltinFunction function);
101 * @brief Constructor.
102 * Creates an alpha function object using a pointer to an alpha function passed as a paramter
104 * @param[in] function A pointer to an alpha function
105 * @return The alpha function
107 AlphaFunction( AlphaFunctionPrototype function);
110 * @brief Constructor.
111 * Creates a bezier alpha function. The bezier will have the first point at (0,0) and
112 * the end point at (1,1).
113 * @note The x components of the control points will be clamped to the range [0,1] to prevent
114 * non monotonic curves.
115 * @param[in] controlPoint0 A Vector2 which will be used as the first control point of the curve
116 * @param[in] controlPoint1 A Vector2 which will be used as the second control point of the curve
117 * @return The alpha function
119 AlphaFunction( const Dali::Vector2& controlPoint0, const Dali::Vector2& controlPoint1 );
122 * @brief Return the control points of the alpha function
123 * @return Vector4 containing the two control points of the curve.
124 * (xy for the first point and zw for the second)
126 Vector4 GetBezierControlPoints() const;
129 * @brief Returns the pointer to the custom function
130 * @return A pointer to a custom alpha function or 0 if not defined
132 AlphaFunctionPrototype GetCustomFunction() const;
135 * @brief Returns the built0in function used by the alpha function
136 * @return One of the built-in alpha functions. In case no built-in function
137 * has been specified, it will return AlphaFunction::DEfAULT
139 BuiltinFunction GetBuiltinFunction() const;
142 * @brief Returns the functioning mode of the alpha function
143 * @return The functioning mode of the alpha function
145 Mode GetMode() const;
149 Vector4 mBezierControlPoints; //< Control points for the bezier alpha function
150 AlphaFunctionPrototype mCustom; //< Pointer to an alpha function
151 BuiltinFunction mBuiltin : Log<COUNT>::value+1; //< Enum indicating the built-in alpha function
152 Mode mMode : 2; //< Enum indicating the functioning mode of the AlphaFunction
160 #endif // __DALI_ALPHA_FUNCTION_H__