[dali_1.9.30] Merge branch 'devel/master'

[platform/core/uifw/dali-core.git] / dali / public-api / math / random.h

diff --git a/dali/public-api/math/random.h b/dali/public-api/math/random.h
index 47a6271..b422cc1 100644 (file)
--- a/dali/public-api/math/random.h
+++ b/dali/public-api/math/random.h
@@ -1,8 +1,8 @@
-#ifndef __DALI_RANDOM_H__
-#define __DALI_RANDOM_H__
+#ifndef DALI_RANDOM_H
+#define DALI_RANDOM_H
 
 /*
- * Copyright (c) 2015 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,35 +24,49 @@
 namespace Dali
 {
 /**
- * @addtogroup dali-core-math
+ * @addtogroup dali_core_math
  * @{
  */
 
 /**
  * @brief Provides methods to generate and use random values.
+ * @SINCE_1_0.0
  */
 namespace Random
 {
-
 /**
  * @brief Returns a random number between f0 and f1.
  *
  * Note, uses a limited number of values.
- * @param[in] f0 the lower bound
- * @param[in] f1 the upper bound
- * @return a random value between the lower and upper bound
+ * @SINCE_1_0.0
+ * @param[in] f0 The lower bound
+ * @param[in] f1 The upper bound
+ * @return A random value between the lower and upper bound
  */
 inline float Range(float f0, float f1)
 {
   float min = std::min(f0, f1);
   float max = std::max(f0, f1);
-  return min + (rand() & 0xfff) * (max-min) * (1.0f/4095.0f);
+
+  // Ensure we initialize only once. As it's inlined, this static variable will exist in the code-block using it, thus,
+  // will be created and then initialized again when another code-block uses this.
+  static bool initialized(false);
+  if(!initialized)
+  {
+    uint32_t seed = static_cast<uint32_t>(time(nullptr));
+    srand(seed);
+    initialized = true;
+  }
+
+  int32_t randValue = rand();
+  return static_cast<float>(randValue & 0xfff) * (1.0f / 4095.0f) * (max - min) + min;
 }
 
 /**
  * @brief Function to return a normalized axis in a random direction.
  *
- * @return the axis
+ * @SINCE_1_0.0
+ * @return The axis
  */
 inline Vector4 Axis()
 {
@@ -62,10 +76,10 @@ inline Vector4 Axis()
   do
   {
     axis.x = Range(-1.0f, 1.0f);
-    axis.y = Range( 0.0f, 1.0f);
-    axis.z = Range( 0.0f, 1.0f);
+    axis.y = Range(0.0f, 1.0f);
+    axis.z = Range(0.0f, 1.0f);
     axis.w = 0.0f;
-  } while (axis == Vector4::ZERO);
+  } while(axis == Vector4::ZERO);
   axis.Normalize();
   return axis;
 }
@@ -77,4 +91,4 @@ inline Vector4 Axis()
  */
 } // namespace Dali
 
-#endif // __DALI_RANDOM_H__
+#endif // DALI_RANDOM_H