Fix: AgentVector::internal_resize() would reduce size without updatin…

…g size()

Noticed this whilst resolving it's copy-paste comment, no evidence it was used in this manner. Full test suite still passes.

include/flamegpu/simulation/AgentVector.h

@@ -600,9 +600,10 @@ class AgentVector {
      */
     virtual void _requireLength() const { }
     /**
-     * Notify any subclasses that all variables are about to be accessed
-     * Should be called by operations which move agents (e.g. insert/erase)
-     * @note This is not called in conjunction with _insert() or _erase()
+     * Resize the capacity of the AgentVector
+     * @param count The new capacity of the agent vector
+     * @param init Whether any new agents should be default init
+     * @note If count < size() agent data will be lost
      */
     void internal_resize(size_type count, bool init);
     /**

src/flamegpu/simulation/AgentVector.cpp

@@ -543,13 +543,6 @@ void AgentVector::internal_resize(size_type count, bool init) {
             // Need to create the variable's vector
             auto t = std::unique_ptr<detail::GenericMemoryVector>(v.second.memory_vector->clone());
             t->resize(count);
-            // Default init all new elements
-            if (init) {
-                char* t_data = static_cast<char*>(t->getDataPtr());
-                for (unsigned int i = 0; i < count; ++i) {
-                    memcpy(t_data + i * variable_size, v.second.default_value, variable_size);
-                }
-            }
             _data->emplace(v.first, std::move(t));
         } else {
             // Need to resize the variables vector
@@ -561,6 +554,8 @@ void AgentVector::internal_resize(size_type count, bool init) {
     // Default init all new elements
     if (init && count > old_capacity) {
         this->init(old_capacity, _capacity);
+    } else if (count < old_capacity) {
+        _size = count;
     }
 }
 void AgentVector::swap(AgentVector& other) noexcept {