replaced with table offset

Author: orange-cpp

include/omath/rev_eng/internal_rev_object.hpp

@@ -116,11 +116,11 @@ namespace omath::rev_eng
             return call_method<ReturnType>(vtable[Id], arg_list...);
         }
 
-        template<std::size_t TableIndex, std::size_t Id, class ReturnType>
+        template<std::ptrdiff_t TableOffset, std::size_t Id, class ReturnType>
         ReturnType call_virtual_method(auto... arg_list)
         {
             auto sub_this = reinterpret_cast<void*>(
-                reinterpret_cast<std::uintptr_t>(this) + TableIndex * sizeof(std::uintptr_t));
+                reinterpret_cast<std::uintptr_t>(this) + TableOffset);
             const auto vtable = *reinterpret_cast<void***>(sub_this);
 #ifdef _MSC_VER
             using Fn = ReturnType(__thiscall*)(void*, decltype(arg_list)...);
@@ -129,11 +129,11 @@ namespace omath::rev_eng
 #endif
             return reinterpret_cast<Fn>(vtable[Id])(sub_this, arg_list...);
         }
-        template<std::size_t TableIndex, std::size_t Id, class ReturnType>
+        template<std::ptrdiff_t TableOffset, std::size_t Id, class ReturnType>
         ReturnType call_virtual_method(auto... arg_list) const
         {
             auto sub_this = reinterpret_cast<const void*>(
-                reinterpret_cast<std::uintptr_t>(this) + TableIndex * sizeof(std::uintptr_t));
+                reinterpret_cast<std::uintptr_t>(this) + TableOffset);
             const auto vtable = *reinterpret_cast<void* const* const*>(sub_this);
 #ifdef _MSC_VER
             using Fn = ReturnType(__thiscall*)(const void*, decltype(arg_list)...);

tests/general/unit_test_reverse_enineering.cpp

@@ -52,18 +52,20 @@ class MultiPlayer final : public BaseA, public BaseB
 
 class RevMultiPlayer final : omath::rev_eng::InternalReverseEngineeredObject
 {
+    static constexpr std::ptrdiff_t TABLE_A_OFFSET = 0;
+    static constexpr std::ptrdiff_t TABLE_B_OFFSET = sizeof(void*);
 public:
-    // Table 0 (BaseA vtable): index 0 = get_a, 1 = get_a2
-    [[nodiscard]] int rev_get_a() const { return call_virtual_method<0, 0, int>(); }
-    [[nodiscard]] int rev_get_a2() const { return call_virtual_method<0, 1, int>(); }
+    // Table at offset 0 (BaseA vtable): index 0 = get_a, 1 = get_a2
+    [[nodiscard]] int rev_get_a() const { return call_virtual_method<TABLE_A_OFFSET, 0, int>(); }
+    [[nodiscard]] int rev_get_a2() const { return call_virtual_method<TABLE_A_OFFSET, 1, int>(); }
 
-    // Table 1 (BaseB vtable): index 0 = get_b, 1 = get_b2
-    [[nodiscard]] int rev_get_b() const { return call_virtual_method<1, 0, int>(); }
-    [[nodiscard]] int rev_get_b2() const { return call_virtual_method<1, 1, int>(); }
+    // Table at offset sizeof(void*) (BaseB vtable): index 0 = get_b, 1 = get_b2
+    [[nodiscard]] int rev_get_b() const { return call_virtual_method<TABLE_B_OFFSET, 0, int>(); }
+    [[nodiscard]] int rev_get_b2() const { return call_virtual_method<TABLE_B_OFFSET, 1, int>(); }
 
     // Non-const versions
-    int rev_get_a_mut() { return call_virtual_method<0, 0, int>(); }
-    int rev_get_b_mut() { return call_virtual_method<1, 0, int>(); }
+    int rev_get_a_mut() { return call_virtual_method<TABLE_A_OFFSET, 0, int>(); }
+    int rev_get_b_mut() { return call_virtual_method<TABLE_B_OFFSET, 0, int>(); }
 };
 
 class RevPlayer final : omath::rev_eng::InternalReverseEngineeredObject