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Diffstat (limited to '')
-rw-r--r-- | third_party/jpeg-xl/lib/jxl/base/random.cc | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/third_party/jpeg-xl/lib/jxl/base/random.cc b/third_party/jpeg-xl/lib/jxl/base/random.cc new file mode 100644 index 0000000000..c99f88921c --- /dev/null +++ b/third_party/jpeg-xl/lib/jxl/base/random.cc @@ -0,0 +1,21 @@ +// Copyright (c) the JPEG XL Project Authors. All rights reserved. +// +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +#include "lib/jxl/base/random.h" + +#include <cmath> + +namespace jxl { + +Rng::GeometricDistribution::GeometricDistribution(float p) + : inv_log_1mp(1.0 / std::log(1 - p)) {} + +uint32_t Rng::Geometric(const GeometricDistribution& dist) { + float f = UniformF(0, 1); + float log = std::log(1 - f) * dist.inv_log_1mp; + return static_cast<uint32_t>(log); +} + +} // namespace jxl |