diff options
author | Bruno de Oliveira Abinader <bruno@mapbox.com> | 2016-10-29 18:13:12 +0300 |
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committer | Bruno de Oliveira Abinader <bruno@mapbox.com> | 2016-10-31 16:53:07 +0200 |
commit | 38f536049a8ed8f4bdf7706f4afcbbaf06c974c9 (patch) | |
tree | f65bb6ad0ebde1840e523b18d539f122548194ab /include/mbgl/math | |
parent | a70bfd89108cf1aef75181819ae43e550a69255e (diff) | |
download | qtlocation-mapboxgl-38f536049a8ed8f4bdf7706f4afcbbaf06c974c9.tar.gz |
[core] Moved util::log2 to its own header
- Added util::{MIN,MAX}_ZOOM_F to avoid consecutive conversions from
double to float
- Move util::log2 to its own header (part of mbgl/math)
Diffstat (limited to 'include/mbgl/math')
-rw-r--r-- | include/mbgl/math/log2.hpp | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/include/mbgl/math/log2.hpp b/include/mbgl/math/log2.hpp new file mode 100644 index 0000000000..8a3bc7f1c0 --- /dev/null +++ b/include/mbgl/math/log2.hpp @@ -0,0 +1,27 @@ +#pragma once + +#include <cmath> +#include <cstdint> +#include <type_traits> + +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); + +template <typename T> +typename std::enable_if_t<std::is_floating_point<T>::value, T> log2(T x) +{ +// log2() is producing wrong results on ARMv5 binaries +// running on ARMv7+ CPUs. +#if defined(__ANDROID__) + return std::log(x) / M_LN2; +#else + return std::log2(x); +#endif +} + +} // namespace util +} // namespace mbgl |