From b2abc7e7f83cb1b08097579c3cdfa892351f1c77 Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Tue, 27 Oct 2020 15:31:09 +1000
Subject: [PATCH] g/s/surface: test first poisson candidate against AcceptT

---
 geom/sample/surface.hpp | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/geom/sample/surface.hpp b/geom/sample/surface.hpp
index 36931be4..f3e86229 100644
--- a/geom/sample/surface.hpp
+++ b/geom/sample/surface.hpp
@@ -55,7 +55,7 @@ namespace cruft::geom::sample {
         GeneratorT &&gen,
         AcceptT &&accept,
         DistanceT &&minimum_distance,
-        std::size_t candidates_count
+        std::size_t const candidates_count
     ) {
         using point_type = decltype (sampler.eval (gen));
         using value_type = typename point_type::value_type;
@@ -63,9 +63,20 @@ namespace cruft::geom::sample {
         std::vector<point_type> selected;
         std::vector<point_type> candidates;
 
-        // prime the found elements list with an initial point we can
-        // perform distance calculations on
-        selected.push_back (sampler.eval (gen));
+        // Prime the found elements list with an initial point we can
+        // perform distance calculations on.
+        for (std::size_t i = 0; i < candidates_count; ++i) {
+            auto const p = sampler.eval (gen);
+            if (!accept (p))
+                continue;
+
+            selected.push_back (sampler.eval (gen));
+            break;
+        }
+
+        // We couldn't find an initial candidate so abort.
+        if (selected.empty ())
+            return selected;
 
         // keep trying to add one more new point
         while (1) {