/* Copyright 2013 Google Inc. All Rights Reserved. Distributed under MIT license. See file LICENSE for detail or copy at https://opensource.org/licenses/MIT */ /* Functions for clustering similar histograms together. */ #include "./cluster.h" #include "../common/platform.h" #include <brotli/types.h> #include "./bit_cost.h" /* BrotliPopulationCost */ #include "./fast_log.h" #include "./histogram.h" #include "./memory.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif static BROTLI_INLINE BROTLI_BOOL HistogramPairIsLess( const HistogramPair* p1, const HistogramPair* p2) { if (p1->cost_diff != p2->cost_diff) { return TO_BROTLI_BOOL(p1->cost_diff > p2->cost_diff); } return TO_BROTLI_BOOL((p1->idx2 - p1->idx1) > (p2->idx2 - p2->idx1)); } /* Returns entropy reduction of the context map when we combine two clusters. */ static BROTLI_INLINE double ClusterCostDiff(size_t size_a, size_t size_b) { size_t size_c = size_a + size_b; return (double)size_a * FastLog2(size_a) + (double)size_b * FastLog2(size_b) - (double)size_c * FastLog2(size_c); } #define CODE(X) X #define FN(X) X ## Literal #include "./cluster_inc.h" /* NOLINT(build/include) */ #undef FN #define FN(X) X ## Command #include "./cluster_inc.h" /* NOLINT(build/include) */ #undef FN #define FN(X) X ## Distance #include "./cluster_inc.h" /* NOLINT(build/include) */ #undef FN #undef CODE #if defined(__cplusplus) || defined(c_plusplus) } /* extern "C" */ #endif