disallow negative weight with non-additive types

1 files changed, 6 insertions, 3 deletions

diff --git a/wrapper/wrapper.cpp b/wrapper/wrapper.cpp
index 72ebdc7..3d77fc1 100644
--- a/wrapper/wrapper.cpp
+++ b/wrapper/wrapper.cpp
@@ -137,9 +137,12 @@ error_list_t^ get_accel_errors(AccelMode mode, AccelArgs^ args)
     
     if (args->acceleration > 1 && is_mode(am::natural, am::naturalgain))
         error_list->Add("acceleration can not be greater than 1");
-    else if (args->acceleration < 0)
-        error_list->Add("acceleration can not be negative, use a negative weight to compensate");
-    
+    else if (args->acceleration < 0) {
+        bool additive = m < am::power;
+        if (additive) error_list->Add("acceleration can not be negative, use a negative weight to compensate");
+        else error_list->Add("acceleration can not be negative");
+    }
+        
     if (args->scale <= 0)
         error_list->Add("scale must be positive");