5 * Copyright (c) 2019 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/math/vector4.h>
27 * @addtogroup dali_core_math
32 * @brief Provides methods to generate and use random values.
39 * @brief Returns a random number between f0 and f1.
41 * Note, uses a limited number of values.
43 * @param[in] f0 The lower bound
44 * @param[in] f1 The upper bound
45 * @return A random value between the lower and upper bound
47 inline float Range(float f0, float f1)
49 float min = std::min(f0, f1);
50 float max = std::max(f0, f1);
52 // Ensure we initialize only once. As it's inlined, this static variable will exist in the code-block using it, thus,
53 // will be created and then initialized again when another code-block uses this.
54 static bool initialized( false );
57 uint32_t seed = static_cast<uint32_t>( time( NULL ) );
62 int32_t randValue = rand();
63 return static_cast<float>(randValue & 0xfff) * (1.0f/4095.0f) * (max-min) + min;
67 * @brief Function to return a normalized axis in a random direction.
75 // This function needs to return a vector with direction, that is to say a non-zero vector
76 // There is a possibility that a random vector will be a zero vector, so a loop is needed to ensure that a non-zero vector is returned
79 axis.x = Range(-1.0f, 1.0f);
80 axis.y = Range( 0.0f, 1.0f);
81 axis.z = Range( 0.0f, 1.0f);
83 } while (axis == Vector4::ZERO);
95 #endif // DALI_RANDOM_H