diff options
Diffstat (limited to 'core/math/random_pcg.cpp')
| -rw-r--r-- | core/math/random_pcg.cpp | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/core/math/random_pcg.cpp b/core/math/random_pcg.cpp index 45a9285ddd..55787a0b57 100644 --- a/core/math/random_pcg.cpp +++ b/core/math/random_pcg.cpp @@ -31,6 +31,7 @@ #include "random_pcg.h" #include "core/os/os.h" +#include "core/templates/vector.h" RandomPCG::RandomPCG(uint64_t p_seed, uint64_t p_inc) : pcg(), @@ -42,6 +43,26 @@ void RandomPCG::randomize() { seed(((uint64_t)OS::get_singleton()->get_unix_time() + OS::get_singleton()->get_ticks_usec()) * pcg.state + PCG_DEFAULT_INC_64); } +int64_t RandomPCG::rand_weighted(const Vector<float> &p_weights) { + ERR_FAIL_COND_V_MSG(p_weights.is_empty(), -1, "Weights array is empty."); + int64_t weights_size = p_weights.size(); + const float *weights = p_weights.ptr(); + float weights_sum = 0.0; + for (int64_t i = 0; i < weights_size; ++i) { + weights_sum += weights[i]; + } + + float remaining_distance = randf() * weights_sum; + for (int64_t i = 0; i < weights_size; ++i) { + remaining_distance -= weights[i]; + if (remaining_distance < 0) { + return i; + } + } + + return -1; +} + double RandomPCG::random(double p_from, double p_to) { return randd() * (p_to - p_from) + p_from; } |