VMCAPIError now takes fn and res as args

lib/voicemeeter/cbindings.rb

@@ -56,11 +56,11 @@ module Voicemeeter
       res = send(fn, *args)
       if exp.nil?
         unless ok.include?(res)
-          raise Errors::VMCAPIError.new("#{fn} returned #{res}")
+          raise Errors::VMCAPIError.new(fn, res)
         end
       else
-        unless exp.call(res) && ok.include?(res)
+        unless exp.call(res) || ok.include?(res)
-          raise Errors::VMCAPIError.new("#{fn} returned #{res}")
+          raise Errors::VMCAPIError.new(fn, res)
         end
       end
       res

lib/voicemeeter/errors.rb

@@ -1,9 +1,26 @@
+require_relative "core_extensions/string/camelcase"
+
 module Voicemeeter
   module Errors
     class VMError < StandardError
     end
 
     class VMCAPIError < VMError
+      attr_reader :code
+
+      def initialize(ruby_name, code)
+        @ruby_name = ruby_name
+        @code = code
+        super(message)
+      end
+
+      def message
+        "#{fn_name} returned #{code}"
+      end
+
+      def fn_name
+        "VBVMR_#{@ruby_name.to_s.delete_prefix("bind_").camelcase.sub("macro_button", "macrobutton")}"
+      end
     end
   end
 end