Fix GlasbeyLUT::at() for negative numbers

source/RobotAPI/libraries/core/visualization/GlasbeyLUT.h

 #pragma once
 
 #include <cmath>
+#include <type_traits>
 #include <vector>
 
 #include <RobotAPI/interface/visualization/DebugDrawerInterface.h>
@@ -30,15 +31,21 @@ namespace armarx
          * The ID is automaticall wrapped if greater than `size()`.
          * If `id` is negative, its absolute value is used.
          */
-        template <typename IntT>
+        template <typename UIntT, std::enable_if_t<std::is_unsigned<UIntT>::value, int> = 0>
+        static DrawColor at(UIntT id, float alpha = 1.f);
+        // If `id` is negative, its absolute value is used.
+        template <typename IntT, std::enable_if_t<std::is_signed<IntT>::value, int> = 0>
         static DrawColor at(IntT id, float alpha = 1.f);
         static DrawColor at(std::size_t id, float alpha = 1.f);
 
         /**
          * @brief Get a color from the lookup table with given ID (with integer values).
          * The ID is automaticall wrapped if greater than `size()`.
+         * If `id` is negative, its absolute value is used.
          */
-        template <typename IntT>
+        template <typename UIntT, std::enable_if_t<std::is_unsigned<UIntT>::value, int> = 0>
+        static DrawColor24Bit atByte(UIntT id);
+        template <typename IntT, std::enable_if_t<std::is_signed<IntT>::value, int> = 0>
         static DrawColor24Bit atByte(IntT id);
         static DrawColor24Bit atByte(std::size_t id);
 
@@ -57,13 +64,25 @@ namespace armarx
     };
 
 
-    template <typename IntT>
+    template <typename UIntT, std::enable_if_t<std::is_unsigned<UIntT>::value, int>>
+    DrawColor GlasbeyLUT::at(UIntT id, float alpha)
+    {
+        return at(static_cast<std::size_t>(id), alpha);
+    }
+
+    template <typename IntT, std::enable_if_t<std::is_signed<IntT>::value, int>>
     DrawColor GlasbeyLUT::at(IntT id, float alpha)
     {
         return at(static_cast<std::size_t>(id >= 0 ? id : std::abs(id)), alpha);
     }
 
-    template <typename IntT>
+    template <typename UIntT, std::enable_if_t<std::is_unsigned<UIntT>::value, int>>
+    DrawColor24Bit GlasbeyLUT::atByte(UIntT id)
+    {
+        return atByte(static_cast<std::size_t>(id));
+    }
+
+    template <typename IntT, std::enable_if_t<std::is_signed<IntT>::value, int>>
     DrawColor24Bit GlasbeyLUT::atByte(IntT id)
     {
         return atByte(static_cast<std::size_t>(id >= 0 ? id : std::abs(id)));