From eef5ddef0e99d639c2239a696bf457b8a0b0e8e7 Mon Sep 17 00:00:00 2001
From: Ichthyostega <prg@ichthyostega.de>
Date: Wed, 16 Sep 2026 19:42:55 +0200
Subject: [PATCH] Parameters: integrate the cyclic-wrap function

a much more complete and robust implementation,
but requires a precision limit to be pre-computed in the floating-point case
---
 src/lib/par/scale.hpp                  | 30 ++++++++++++++++++++------
 src/lib/util-quant.hpp                 |  2 +-
 tests/lib/par/parameter-scale-test.cpp |  9 ++++++--
 3 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/src/lib/par/scale.hpp b/src/lib/par/scale.hpp
index 56e2d12a6..bde3ca386 100644
--- a/src/lib/par/scale.hpp
+++ b/src/lib/par/scale.hpp
@@ -28,14 +28,18 @@
 #define LIB_PAR_SCALE_H
 
 
+#include "lib/error.hpp"
 #include "lib/par/domain.hpp"
-#include "lib/util.hpp"
+#include "lib/util-quant.hpp"
+#include "lib/format-string.hpp"
+//#include "lib/util.hpp"
 
 #include <optional>
 
 
 namespace lib {
 namespace par {
+  namespace err = lumiera::error;
   
   using std::optional;
   
@@ -66,12 +70,13 @@ namespace par {
       optional<VAL> neutral{};
       optional<VAL> defVal{};
       /////////////////////////////OOO »Sentinels« and nominal scales?
-      bool cyclic{false};
+      VAL cyclicLim =0;
       
       /* ===== information functions ===== */
       
       bool isValid()  const;
       bool isFactor() const;
+      bool isCyclic() const;
       
       /* ===== conforming operations ===== */
       
@@ -113,7 +118,7 @@ namespace par {
               and (not minVal or *minVal <= *defVal)
               )
            )
-       and (not cyclic
+       and (not isCyclic()
            or (minVal and maxVal and *minVal < *maxVal)
            )
            ;
@@ -128,6 +133,13 @@ namespace par {
        and *neutral == VAL(1);
   }
   
+  template<typename VAL>
+  inline bool
+  Scale<VAL>::isCyclic()  const
+  {
+    return VAL(0) != cyclicLim;
+  }
+  
   
   
   /* ===== conforming operations ===== */
@@ -150,13 +162,17 @@ namespace par {
   inline VAL
   Scale<VAL>::conform (VAL const& rawVal)  const
   {
-    if (cyclic)
+    if (isCyclic())
       {
         REQUIRE (minVal and maxVal);
         REQUIRE (*minVal < *maxVal);
-        const VAL PERIOD = *maxVal - *minVal;
-        ENSURE (0 < PERIOD);
-        return (rawVal - *minVal) % PERIOD;
+        if (std::is_floating_point_v<VAL>)
+          if (not (std::abs (rawVal) < cyclicLim))
+            throw err::Invalid {util::_Fmt{"Parameter value %4.2g beyond supported numeric precision "
+                                           "for cyclic wrapping into (%4.2g ... %4.2g("}
+                                          % rawVal % minVal % maxVal
+                               };
+        return util::cyclicWrap (rawVal, *minVal, *maxVal);
       }
     if (minVal and rawVal < *minVal)
       return *minVal;
diff --git a/src/lib/util-quant.hpp b/src/lib/util-quant.hpp
index b77cc39a7..843a2ed77 100644
--- a/src/lib/util-quant.hpp
+++ b/src/lib/util-quant.hpp
@@ -244,7 +244,7 @@ namespace util {
   inline constexpr F
   limit_cyclicWrap (F period)
   {
-    REQUIRE (std::isfinite (period));
+    REQUIRE (std::isnormal (period));
     REQUIRE (F(0) < period);
     F limit = period / std::numeric_limits<F>::epsilon();
     if (not std::isfinite (limit))
diff --git a/tests/lib/par/parameter-scale-test.cpp b/tests/lib/par/parameter-scale-test.cpp
index e6dc296e0..7ee377a5e 100644
--- a/tests/lib/par/parameter-scale-test.cpp
+++ b/tests/lib/par/parameter-scale-test.cpp
@@ -58,7 +58,7 @@ namespace test{
       run (Arg)
         {
           simpleUsage();
-          verify_Bounds();
+          verify_Conforming();
         }
       
       
@@ -80,8 +80,13 @@ namespace test{
        * @todo WIP 9/26 🔁 define ⟶ implement
        */
       void
-      verify_Bounds()
+      verify_Conforming()
         {
+          Scale<float> scale;
+          CHECK (1e5f == scale.conform (1e5f));
+          
+          scale.maxVal = -5.0f;
+          CHECK (-5.0f == scale.conform (1e5f));
         }
     };