| #pragma once |
| |
| #include <cmath> |
| #include <cstdint> |
| #include <type_traits> |
| |
| #if defined(__ANDROID__) |
| #include <android/api-level.h> |
| #endif |
| |
| namespace mbgl { |
| namespace util { |
| |
| // Computes the log2(x) rounded up to the next integer. |
| // (== number of bits required to store x) |
| uint32_t ceil_log2(uint64_t x); |
| |
| } // namespace util |
| } // namespace mbgl |
| |
| // log2 is not available on Android before API 18. |
| #if defined(__ANDROID__) && defined(__GNUC__) && \ |
| defined(__ANDROID_API__) && __ANDROID_API__ < 18 |
| |
| template <typename T> |
| typename std::enable_if_t<std::is_floating_point<T>::value, T> log2(T x) { |
| return ::log(x) / M_LN2; |
| } |
| |
| #endif |
