performance-aware-programming/haversine_02/generator.cpp

116 lines
2.8 KiB
C++

#include "generator.h"
#include "aliases.h"
#include "point_types.h"
#include <math.h>
#include <stdlib.h>
#define X_MIN -180.0
#define X_MAX 180.0
#define Y_MIN -90.0
#define Y_MAX 90.0
f64 generate_random_double(f64 min, f64 max);
Point generate_random_point(f64 x_min, f64 x_max, f64 y_min, f64 y_max);
PointPair generate_random_pair(f64 x_min, f64 x_max, f64 y_min, f64 y_max);
void fill_pairs_array(PairArray *pairs, bool clustered) {
if (clustered) {
u64 digit_count = (u64)log10(pairs->count) + 1;
u64 cluster_count = 0;
if (digit_count > 2) {
cluster_count = digit_count * 8;
} else {
cluster_count = digit_count;
}
Point clusters[cluster_count];
f64 radii[cluster_count];
u64 pairs_per_cluster = pairs->count / cluster_count;
u64 generated_pairs = 0;
u64 pairs_to_generate = 0;
for (u64 i = 0; i < cluster_count; ++i) {
clusters[i] = {
generate_random_double(X_MIN, X_MAX),
generate_random_double(Y_MIN, Y_MAX),
};
radii[i] = generate_random_double(0.0, (digit_count - 1) * 40.0);
f64 cluster_x_min = clusters[i].x - radii[i];
if (cluster_x_min < X_MIN) {
cluster_x_min = X_MIN;
}
f64 cluster_x_max = clusters[i].x + radii[i];
if (cluster_x_max > X_MAX) {
cluster_x_max = X_MAX;
}
f64 cluster_y_min = clusters[i].y - radii[i];
if (cluster_y_min < Y_MIN) {
cluster_y_min = Y_MIN;
}
f64 cluster_y_max = clusters[i].y + radii[i];
if (cluster_y_max > Y_MAX) {
cluster_y_max = Y_MAX;
}
pairs_to_generate = 0;
if (generated_pairs + pairs_per_cluster < pairs->count) {
pairs_to_generate = pairs_per_cluster;
} else {
pairs_to_generate = pairs->count - generated_pairs;
}
for (u64 i = 0; i < pairs_to_generate; ++i) {
// clang-format off
pairs->pairs[generated_pairs + i] = generate_random_pair(
cluster_x_min,
cluster_x_max,
cluster_y_min,
cluster_y_max
);
// clang-format on
}
generated_pairs += pairs_to_generate;
}
} else {
for (u64 i = 0; i < pairs->count; ++i) {
pairs->pairs[i] = generate_random_pair(X_MIN, X_MAX, Y_MIN, Y_MAX);
}
}
}
f64 generate_random_double(f64 min, f64 max) {
u32 num = rand();
f64 result = min + (((f64)num / (f64)RAND_MAX) * (max - min));
return result;
}
Point generate_random_point(f64 x_min, f64 x_max, f64 y_min, f64 y_max) {
Point p = {
generate_random_double(x_min, x_max),
generate_random_double(y_min, y_max),
};
return p;
}
PointPair generate_random_pair(f64 x_min, f64 x_max, f64 y_min, f64 y_max) {
PointPair pair = {
generate_random_point(x_min, x_max, y_min, y_max),
generate_random_point(x_min, x_max, y_min, y_max),
};
return pair;
}