From a27869d1c81f256136c58441134f36395e2d399d Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Wed, 19 Jul 2017 17:19:20 +1000
Subject: [PATCH] region: commenting and style for test cases

---
 test/region.cpp | 53 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 17 deletions(-)

diff --git a/test/region.cpp b/test/region.cpp
index 9f4a26d0..eb24e262 100644
--- a/test/region.cpp
+++ b/test/region.cpp
@@ -10,35 +10,54 @@ main (int, char **)
 {
     util::TAP::logger tap;
 
+    // check that two overlapping regions successfully test for intersection
     {
-        util::point2d  ap { 32.7, -6.09703 };
-        util::extent2d ae { 0.8, 2. };
+        const util::point2d  ap { 32.7, -6.09703 };
+        const util::extent2d ae { 0.8, 2. };
+        const util::region2d a (ap, ae);
 
-        util::point2d bp {33.5, -4.5};
-        util::extent2d be { 0.5, 0.5 };
-
-        util::region2d a (ap, ae);
-        util::region2d b (bp, be);
+        const util::point2d  bp {33.5, -4.5};
+        const util::extent2d be { 0.5, 0.5 };
+        const util::region2d b (bp, be);
 
         tap.expect (!a.intersects (b), "simple 2d intersection");
     }
 
-    tap.expect (util::region2d::max ().intersects (util::region2d::unit ()), "maximal region2d intersection");
-    tap.expect (util::region2f::max ().intersects (util::region2f::unit ()), "maximal region2f intersection");
+    // check various floating point maximums successfully test for
+    // intersection. the concern is that infinities are incorrectly handled
+    // in some comparisons.
+    tap.expect (
+        util::region2d::max ().intersects (
+            util::region2d::unit ()
+        ),
+        "maximal region2d intersection"
+    );
 
+    tap.expect (
+        util::region2f::max ().intersects (
+            util::region2f::unit ()
+        ),
+        "maximal region2f intersection"
+    );
+
+    // ensure unit regions are... unit sized...
     tap.expect_eq (util::region2d::unit ().area (), 1.0,  "unit region2d area");
     tap.expect_eq (util::region2f::unit ().area (), 1.0f, "unit region2f area");
 
-    util::point2u  p0 { 0 };
-    util::extent2u e0 { 2 };
+    // test boundary cases of includes and contains
+    {
+        const util::point2u  p0 { 0 };
+        const util::extent2u e0 { 2 };
+        const util::region2u r  {p0, e0};
 
-    tap.expect (util::region2u (p0, e0).includes (util::point2u {1, 1}), "unsigned region centre inclusion");
-    tap.expect (util::region2u (p0, e0).includes (util::point2u {0, 0}), "unsigned region base inclusion");
-    tap.expect (util::region2u (p0, e0).includes (util::point2u {2, 2}), "unsigned region corner inclusion");
+        tap.expect (r.includes (util::point2u {1, 1}), "unsigned region centre inclusion");
+        tap.expect (r.includes (util::point2u {0, 0}), "unsigned region base inclusion");
+        tap.expect (r.includes (util::point2u {2, 2}), "unsigned region corner inclusion");
 
-    tap.expect ( util::region2u (p0, e0).contains (util::point2u {1, 1}), "unsigned region center contains");
-    tap.expect (!util::region2u (p0, e0).contains (util::point2u {0, 0}), "unsigned region base contains");
-    tap.expect (!util::region2u (p0, e0).contains (util::point2u {2, 2}), "unsigned region corner contains");
+        tap.expect ( r.contains (util::point2u {1, 1}), "unsigned region center contains");
+        tap.expect (!r.contains (util::point2u {0, 0}), "unsigned region base contains");
+        tap.expect (!r.contains (util::point2u {2, 2}), "unsigned region corner contains");
+    }
 
     //CHECK (region<2,intmax_t> (0, 0, 10, 10).includes (point2d (0.4, 0.01)));
     //CHECK (region<2,intmax_t> (0, 0, 10, 10).contains (point2d (0.4, 0.01)));