From 20e2a6ee2e14c3252ec4904d190661749ddac3f7 Mon Sep 17 00:00:00 2001
From: biochem_fan <nakane.t@gmail.com>
Date: Tue, 15 Oct 2024 16:45:15 +0900
Subject: [PATCH] Allow triangles in polygon masking (fixes #757) (#761)

---
 newsfragments/761.bugfix    | 1 +
 src/dxtbx/masking/masking.h | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)
 create mode 100644 newsfragments/761.bugfix

diff --git a/newsfragments/761.bugfix b/newsfragments/761.bugfix
new file mode 100644
index 000000000..6fc582975
--- /dev/null
+++ b/newsfragments/761.bugfix
@@ -0,0 +1 @@
++ allow triangles in polygon masking
diff --git a/src/dxtbx/masking/masking.h b/src/dxtbx/masking/masking.h
index e020fa6cc..2a849c631 100644
--- a/src/dxtbx/masking/masking.h
+++ b/src/dxtbx/masking/masking.h
@@ -119,7 +119,7 @@ namespace dxtbx { namespace masking {
    */
   void mask_untrusted_polygon(scitbx::af::ref<bool, scitbx::af::c_grid<2> > mask,
                               const scitbx::af::const_ref<vec2<double> > &polygon) {
-    DXTBX_ASSERT(polygon.size() > 3);
+    DXTBX_ASSERT(polygon.size() >= 3);
     std::size_t height = mask.accessor()[0];
     std::size_t width = mask.accessor()[1];
     int x0 = (int)std::floor(polygon[0][0]);