#define __DALI_MATH_UTILS_H__
/*
- * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2015 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.
*
*/
-// EXTERNAL INCLUDES
-#include <algorithm> // std::min & max
-
// INTERNAL INCLUDES
#include <dali/public-api/common/dali-common.h>
+#include <dali/public-api/common/constants.h>
-namespace Dali DALI_IMPORT_API
+namespace Dali
{
+/**
+ * @addtogroup dali_core_math
+ * @{
+ */
/**
* @brief Returns the next power of two.
*
* In case of numbers which are already a power of two this function returns the original number.
- * If i is zero returns 1
- * @param[in] i input number
- * @return next power of two or i itself in case it's a power of two
+ * If i is zero returns 1.
+ * @SINCE_1_0.0
+ * @param[in] i Input number
+ * @return The next power of two or i itself in case it's a power of two
*/
-DALI_IMPORT_API unsigned int NextPowerOfTwo( unsigned int i );
+inline unsigned int NextPowerOfTwo( unsigned int i )
+{
+ DALI_ASSERT_ALWAYS(i <= 1u << (sizeof(unsigned) * 8 - 1) && "Return type cannot represent the next power of two greater than the argument.");
+ if(i==0u)
+ {
+ return 1u;
+ }
+
+ i--;
+ i |= i >> 1;
+ i |= i >> 2;
+ i |= i >> 4;
+ i |= i >> 8;
+ i |= i >> 16;
+ i++;
+ return i;
+}
/**
* @brief Whether a number is power of two.
*
- * @param[in] i input number
- * @return true if i is power of two
+ * @SINCE_1_0.0
+ * @param[in] i Input number
+ * @return True if i is power of two.
*/
-DALI_IMPORT_API bool IsPowerOfTwo( unsigned int i );
+inline bool IsPowerOfTwo( unsigned int i )
+{
+ return (i != 0u) && ((i & (i - 1u)) == 0u);
+}
/**
* @brief Clamp a value.
*
+ * @SINCE_1_0.0
* @param[in] value The value to clamp.
* @param[in] min The minimum allowed value.
* @param[in] max The maximum allowed value.
* @return T the clamped value
*/
template< typename T >
-const T& Clamp( const T& value, const T& min, const T& max )
+inline const T& Clamp( const T& value, const T& min, const T& max )
{
- return std::max( std::min( value, max ), min );
+ const T& constrainedUpper = value < max ? value : max;
+ const T& constrainedUpperAndLower = constrainedUpper > min ? constrainedUpper : min;
+ return constrainedUpperAndLower;
}
/**
* @brief Clamp a value directly.
*
+ * @SINCE_1_0.0
* @param[in,out] value The value that will be clamped.
* @param[in] min The minimum allowed value.
* @param[in] max The maximum allowed value.
*/
template< typename T >
-void ClampInPlace( T& value, const T& min, const T& max )
+inline void ClampInPlace( T& value, const T& min, const T& max )
{
- value = std::max( std::min( value, max ), min );
+ const T& constrainedUpper = value < max ? value : max;
+ const T& constrainedUpperAndLower = constrainedUpper > min ? constrainedUpper : min;
+ value = constrainedUpperAndLower;
}
/**
* @brief Linear interpolation between two values.
*
+ * @SINCE_1_0.0
* @param[in] offset The offset through the range @p low to @p high.
- * This value is clamped between 0 and 1
+ * This value is clamped between 0 and 1.
* @param[in] low Lowest value in range
* @param[in] high Highest value in range
* @return A value between low and high.
/**
* @brief Get an epsilon that is valid for the given range.
*
+ * @SINCE_1_0.0
* @param[in] a the first value in the range
* @param[in] b the second value in the range.
* @return a suitable epsilon
*/
-DALI_IMPORT_API float GetRangedEpsilon(float a, float b);
+inline float GetRangedEpsilon( float a, float b )
+{
+ const float absA = fabsf( a );
+ const float absB = fabsf( b );
+ const float absF = absA > absB ? absA : absB;
+ const int absI = absF;
+
+ float epsilon = Math::MACHINE_EPSILON_10000;
+ if (absF < 0.1f)
+ {
+ return Math::MACHINE_EPSILON_0;
+ }
+ else if (absI < 2)
+ {
+ return Math::MACHINE_EPSILON_1;
+ }
+ else if (absI < 20)
+ {
+ return Math::MACHINE_EPSILON_10;
+ }
+ else if (absI < 200)
+ {
+ return Math::MACHINE_EPSILON_100;
+ }
+ else if (absI < 2000)
+ {
+ return Math::MACHINE_EPSILON_1000;
+ }
+ return epsilon;
+}
/**
* @brief Helper function to compare equality of a floating point value with zero.
*
+ * @SINCE_1_0.0
* @param[in] value the value to compare
* @return true if the value is equal to zero
*/
-DALI_IMPORT_API bool EqualsZero( float value );
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal"
+inline bool EqualsZero( float value )
+{
+ return value == 0.0f;
+}
+#pragma GCC diagnostic pop
/**
* @brief Helper function to compare equality of two floating point values.
*
+ * @SINCE_1_0.0
* @param[in] a the first value to compare
* @param[in] b the second value to compare
* @return true if the values are equal within a minimal epsilon for their values
*/
-DALI_IMPORT_API bool Equals( float a, float b );
+inline bool Equals( float a, float b )
+{
+ return ( fabsf( a - b ) <= GetRangedEpsilon( a, b ) );
+}
/**
* @brief Helper function to compare equality of two floating point values.
*
+ * @SINCE_1_0.0
* @param[in] a the first value to compare
* @param[in] b the second value to compare
* @param[in] epsilon the minimum epsilon value that will be used to consider the values different
* @return true if the difference between the values is less than the epsilon
*/
-DALI_IMPORT_API bool Equals( float a, float b, float epsilon );
+inline bool Equals( float a, float b, float epsilon )
+{
+ return ( fabsf( a - b ) <= epsilon );
+}
/**
* @brief Get an float that is rounded at specified place of decimals.
*
+ * @SINCE_1_0.0
* @param[in] value float value
* @param[in] pos decimal place
* @return a rounded float
*/
-DALI_IMPORT_API float Round( float value, int pos );
+inline float Round(float value, int pos)
+{
+ float temp;
+ temp = value * powf( 10, pos );
+ temp = floorf( temp + 0.5 );
+ temp *= powf( 10, -pos );
+ return temp;
+}
/**
* @brief Wrap x in domain (start) to (end).
* start: 2
* end: 8
*
+ * @code
* 2 8
* (\ / start) (\ / end)
* |----x |
+ * @endcode
*
* The value x will be confined to this domain.
* If x is below 2 e.g. 0, then it is wraped to 6.
* If x is above or equal to 8 e.g. 8.1 then it is
- * wrapped to 2.1
+ * wrapped to 2.1.
*
* Domain wrapping is useful for various problems from
* calculating positions in a space that repeats, to
* computing angles that range from 0 to 360.
*
+ * @SINCE_1_0.0
* @param[in] x the point to be wrapped within the domain
* @param[in] start The start of the domain
* @param[in] end The end of the domain
*
- * @note if start = end (i.e. size of domain 0), then wrapping will not occur
+ * @return the wrapped value over the domain (start) (end)
+ * @note If start = end (i.e. size of domain 0), then wrapping will not occur
* and result will always be equal to start.
*
- * @return the wrapped value over the domain (start) (end)
*/
-DALI_IMPORT_API float WrapInDomain(float x, float start, float end);
+inline float WrapInDomain(float x, float start, float end)
+{
+ float domain = end - start;
+ x -= start;
+
+ if(fabsf(domain) > Math::MACHINE_EPSILON_1)
+ {
+ return start + (x - floorf(x / domain) * domain);
+ }
+
+ return start;
+}
+
/**
* @brief Find the shortest distance (magnitude) and direction (sign)
* from (a) to (b) in domain (start) to (end).
*
- * (\ / start) (\ / end)
- * |-a b<----|
+ * @code
+ * (\ / start) (\ / end)
+ * |-a b<----|
+ * @endcode
*
* Knowing the shortest distance is useful with wrapped domains
* to solve problems such as determing the closest object to
* return -20. i.e. subtract 20 from current value (10) to reach
* target wrapped value (350).
*
- * @note assumes both (a) and (b) are already within the domain
- * (start) to (end)
- *
+ * @SINCE_1_0.0
* @param a the current value
* @param b the target value
* @param start the start of the domain
* @param end the end of the domain
* @return the shortest direction (the sign) and distance (the magnitude)
+ * @note Assumes both (a) and (b) are already within the domain
+ * (start) to (end).
+ *
+ */
+inline float ShortestDistanceInDomain( float a, float b, float start, float end )
+{
+ // (a-start + end-b)
+ float size = end-start;
+ float vect = b-a;
+
+ if(vect > 0)
+ {
+ // +ve vector, let's try perspective 1 domain to the right,
+ // and see if closer.
+ float aRight = a+size;
+ if( aRight-b < vect )
+ {
+ return b-aRight;
+ }
+ }
+ else
+ {
+ // -ve vector, let's try perspective 1 domain to the left,
+ // and see if closer.
+ float aLeft = a-size;
+ if( aLeft-b > vect )
+ {
+ return b-aLeft;
+ }
+ }
+
+ return vect;
+}
+
+/**
+ * @brief Extracts the sign of a number
+ *
+ * @SINCE_1_0.0
+ * @param[in] value The value we want to extract the sign
+ * @return -1 for negative values, +1 for positive values and 0 if value is 0
*/
-DALI_IMPORT_API float ShortestDistanceInDomain(float a, float b, float start, float end);
+template <typename T>
+int Sign( T value )
+{
+ return ( T(0) < value ) - ( value < T(0) );
+}
+/**
+ * @}
+ */
} // namespace Dali
#endif // __DALI_MATH_UTILS_H__
projects / platform / core / uifw / dali-core.git / blobdiff