clean up "static" and "constexpr" types

- use `static constexpr inline' to avoid requiring
  explicit declarations in object code
- use `const Foo* const' to maybe put into readonly
  binary segment (at least for ELF DSOs)
- `constexpr' in function scope has storage, avoid
  `static'
- don't use `constexpr' where there's no advantage,
  like arrays

We'd like to avoid overhead of atomic initialization
for each function call. No idea how `static constexpr'
requiring storage in the standard plays with atomic
initialization requirement. Hearsay points that
`constexpr' without `static' in block scope behaves
more to our liking. It's all hazy though.

I'm not 100% sure if `static inline constexpr' has any
storage. Hopefully none, like a #define, and stuff
bigger than registers gets coalesced within the same
module, with small stuff being immediates.

2 files changed, 27 insertions, 28 deletions

diff --git a/tracker-aruco/ftnoir_tracker_aruco.cpp b/tracker-aruco/ftnoir_tracker_aruco.cpp
index c322d323..faa8bb44 100644
--- a/tracker-aruco/ftnoir_tracker_aruco.cpp
+++ b/tracker-aruco/ftnoir_tracker_aruco.cpp
@@ -33,6 +33,32 @@
 #include <algorithm>
 #include <iterator>
 
+static const int adaptive_sizes[] =
+{
+#if defined USE_EXPERIMENTAL_CANNY
+    10,
+    30,
+    80,
+#else
+    7,
+    9,
+    13,
+#endif
+};
+
+struct resolution_tuple
+{
+    int width;
+    int height;
+};
+
+static const resolution_tuple resolution_choices[] =
+{
+    { 640, 480 },
+    { 320, 240 },
+    { 0, 0 }
+};
+
 aruco_tracker::aruco_tracker()
 {
     cv::setBreakOnError(true);
diff --git a/tracker-aruco/ftnoir_tracker_aruco.h b/tracker-aruco/ftnoir_tracker_aruco.h
index 3a98e9d1..b753fdec 100644
--- a/tracker-aruco/ftnoir_tracker_aruco.h
+++ b/tracker-aruco/ftnoir_tracker_aruco.h
@@ -69,7 +69,7 @@ class aruco_tracker : protected virtual QThread, public ITracker
 {
     Q_OBJECT
     friend class aruco_dialog;
-    static constexpr float c_search_window = 1.3f;
+    static constexpr inline float c_search_window = 1.3f;
 public:
     aruco_tracker();
     ~aruco_tracker() override;
@@ -124,44 +124,17 @@ private:
     unsigned adaptive_size_pos = 0;
     bool use_otsu = false;
 
-    struct resolution_tuple
-    {
-        int width;
-        int height;
-    };
-
-    static constexpr inline const int adaptive_sizes[] =
-    {
-#if defined USE_EXPERIMENTAL_CANNY
-        10,
-        30,
-        80,
-#else
-        7,
-        9,
-        13,
-#endif
-    };
-
 #if !defined USE_EXPERIMENTAL_CANNY
     static constexpr inline int adaptive_thres = 6;
 #else
     static constexpr inline int adaptive_thres = 3;
 #endif
 
-    static constexpr inline const resolution_tuple resolution_choices[] =
-    {
-        { 640, 480 },
-        { 320, 240 },
-        { 0, 0 }
-    };
-
 #ifdef DEBUG_UNSHARP_MASKING
     static constexpr inline double gauss_kernel_size = 3;
 #endif
 
     static constexpr inline double timeout = 1;
-
     static constexpr inline double timeout_backoff_c = 4./11;
 
     static constexpr inline float size_min = 0.05;