increase legalize stack

Author: delfrrr

bench/run.cpp

@@ -7,6 +7,7 @@
 
 std::vector<double> generate_uniform(std::size_t n) {
     std::vector<double> coords;
+    coords.reserve(2 * n);
     std::srand(350);
     double norm = static_cast<double>(RAND_MAX) / 1e3;
     for (size_t i = 0; i < n; i++) {
@@ -35,5 +36,6 @@ void BM_uniform(benchmark::State& state) {
 
 BENCHMARK(BM_45K_geojson_nodes)->Unit(benchmark::kMillisecond);
 BENCHMARK(BM_uniform)->Arg(2000)->Arg(100000)->Arg(200000)->Arg(500000)->Arg(1000000)->Unit(benchmark::kMillisecond);
+// BENCHMARK(BM_uniform)->Arg(1000000 * 100)->Unit(benchmark::kMillisecond);
 
 BENCHMARK_MAIN()

include/delaunator.hpp

@@ -148,7 +148,9 @@ inline bool in_circle(
 
 constexpr double EPSILON = std::numeric_limits<double>::epsilon();
 constexpr std::size_t INVALID_INDEX = std::numeric_limits<std::size_t>::max();
-constexpr std::size_t LEGALIZE_STACK_SIZE = 128;
+
+//@see https://stackoverflow.com/questions/30208196/maximum-recursive-function-calls-in-c-c-before-stack-is-full-and-gives-a-segme
+constexpr std::size_t LEGALIZE_STACK_SIZE = 1024;
 
 inline bool check_pts_equal(double x1, double y1, double x2, double y2) {
     return std::fabs(x1 - x2) <= EPSILON &&
@@ -451,10 +453,6 @@ std::size_t Delaunator::legalize(std::size_t ia) {
     size_t size = 1;
     while (i < size) {
 
-        if (i >= LEGALIZE_STACK_SIZE) {
-            throw std::runtime_error("Legalize stack overflow");
-        }
-
         auto const a = m_legalize_stack[i];
         i++;
 
@@ -526,6 +524,10 @@ std::size_t Delaunator::legalize(std::size_t ia) {
 
             std::size_t br = b0 + (b + 1) % 3;
 
+            if (size + 2 >= (LEGALIZE_STACK_SIZE)) {
+                throw std::runtime_error("Legalize stack overflow");
+            }
+
             if (i < size) {
                 //move elements down the stack
                 for (auto mi = size - 1; mi >= i; mi--) {