Scoping all variable uses, and less copying.

This commit resolves AtomicGameEngine/AtomicGameEngine#454

Source/AtomicJS/Javascript/JSAPI.cpp

@@ -452,18 +452,7 @@ void js_push_variantmap(duk_context* ctx, const VariantMap &vmap)
 
 void js_push_variant(duk_context *ctx, const Variant& v)
 {
-    VariantType type = v.GetType();
-    RefCounted* ref;
-    Vector2 vector2 = Vector2::ZERO;
-    IntVector2 intVector2 = IntVector2::ZERO;
-    Vector3 vector3 = Vector3::ZERO;
-    Vector4 vector4 = Vector4::ZERO;
-    Color color = Color::BLACK;
-    Resource* resource = NULL;
-    ResourceCache* cache = NULL;
-    ResourceRef resourceRef;
-
-    switch (type)
+    switch (v.GetType())
     {
     case VAR_NONE:
         duk_push_undefined(ctx);
@@ -472,9 +461,10 @@ void js_push_variant(duk_context *ctx, const Variant& v)
     case VAR_VOIDPTR:
         duk_push_null(ctx);
         break;
-    case VAR_PTR:
 
-        ref = v.GetPtr();
+    case VAR_PTR:
+    {
+        RefCounted* ref = v.GetPtr();
 
         // if we're null or don't have any refs, return null
         if (!ref || !ref->Refs())
@@ -485,7 +475,7 @@ void js_push_variant(duk_context *ctx, const Variant& v)
 
         // check that class is supported
         duk_push_heap_stash(ctx);
-        duk_push_pointer(ctx, (void*) ref->GetClassID());
+        duk_push_pointer(ctx, (void*)ref->GetClassID());
         duk_get_prop(ctx, -2);
 
         if (!duk_is_object(ctx, -1))
@@ -499,54 +489,67 @@ void js_push_variant(duk_context *ctx, const Variant& v)
             js_push_class_object_instance(ctx, ref);
         }
 
-        break;
+    }   break;
 
     case VAR_RESOURCEREF:
-        resourceRef = v.GetResourceRef();
-        cache = JSVM::GetJSVM(ctx)->GetContext()->GetSubsystem<ResourceCache>();
-        resource = cache->GetResource(resourceRef.type_, resourceRef.name_);
+    {
+        const ResourceRef& resourceRef(v.GetResourceRef());
+        ResourceCache* cache = JSVM::GetJSVM(ctx)->GetContext()->GetSubsystem<ResourceCache>();
+        Resource* resource = cache->GetResource(resourceRef.type_, resourceRef.name_);
         js_push_class_object_instance(ctx, resource);
-        break;
+    }   break;
 
     case VAR_BOOL:
         duk_push_boolean(ctx, v.GetBool() ? 1 : 0);
         break;
+
     case VAR_INT:
         duk_push_number(ctx, v.GetInt());
         break;
+
     case VAR_FLOAT:
         duk_push_number(ctx, v.GetFloat());
         break;
+
     case VAR_STRING:
-        duk_push_string(ctx, v.GetString().CString());
-        break;
+    {
+        const String& string(v.GetString());
+        duk_push_lstring(ctx, string.CString(), string.Length());
+    }   break;
+
     case VAR_BUFFER:
     {
         const PODVector<unsigned char>& buffer(v.GetBuffer()); // The braces are to scope this reference.
         duk_push_fixed_buffer(ctx, buffer.Size());
         duk_push_buffer_object(ctx, -1, 0, buffer.Size(), DUK_BUFOBJ_UINT8ARRAY);
         duk_replace(ctx, -2);
-        unsigned char* data((unsigned char*)duk_require_buffer_data(ctx, -1, (duk_size_t*)nullptr));
+        unsigned char* data = (unsigned char*)duk_require_buffer_data(ctx, -1, (duk_size_t*)nullptr);
         memcpy(data, buffer.Buffer(), buffer.Size());
     }   break;
+
     case VAR_VECTOR2:
-        vector2 = v.GetVector2();
+    {
+        const Vector2& vector2(v.GetVector2());
         duk_push_array(ctx);
         duk_push_number(ctx, vector2.x_);
         duk_put_prop_index(ctx, -2, 0);
         duk_push_number(ctx, vector2.y_);
         duk_put_prop_index(ctx, -2, 1);
-        break;
+    }   break;
+
     case VAR_INTVECTOR2:
-        intVector2 = v.GetIntVector2();
+    {
+        const IntVector2& intVector2(v.GetIntVector2());
         duk_push_array(ctx);
         duk_push_number(ctx, intVector2.x_);
         duk_put_prop_index(ctx, -2, 0);
         duk_push_number(ctx, intVector2.y_);
         duk_put_prop_index(ctx, -2, 1);
-        break;
+    }   break;
+
     case VAR_VECTOR3:
-        vector3 = v.GetVector3();
+    {
+        const Vector3& vector3(v.GetVector3());
         duk_push_array(ctx);
         duk_push_number(ctx, vector3.x_);
         duk_put_prop_index(ctx, -2, 0);
@@ -554,9 +557,11 @@ void js_push_variant(duk_context *ctx, const Variant& v)
         duk_put_prop_index(ctx, -2, 1);
         duk_push_number(ctx, vector3.z_);
         duk_put_prop_index(ctx, -2, 2);
-        break;
+    }   break;
+
     case VAR_QUATERNION:
-        vector3 = v.GetQuaternion().EulerAngles();
+    {
+        const Vector3& vector3(v.GetQuaternion().EulerAngles());
         duk_push_array(ctx);
         duk_push_number(ctx, vector3.x_);
         duk_put_prop_index(ctx, -2, 0);
@@ -564,9 +569,11 @@ void js_push_variant(duk_context *ctx, const Variant& v)
         duk_put_prop_index(ctx, -2, 1);
         duk_push_number(ctx, vector3.z_);
         duk_put_prop_index(ctx, -2, 2);
-        break;
+    }   break;
+
     case VAR_COLOR:
-        color = v.GetColor();
+    {
+        const Color& color(v.GetColor());
         duk_push_array(ctx);
         duk_push_number(ctx, color.r_);
         duk_put_prop_index(ctx, -2, 0);
@@ -576,9 +583,11 @@ void js_push_variant(duk_context *ctx, const Variant& v)
         duk_put_prop_index(ctx, -2, 2);
         duk_push_number(ctx, color.a_);
         duk_put_prop_index(ctx, -2, 3);
-        break;
+    }   break;
+
     case VAR_VECTOR4:
-        vector4 = v.GetVector4();
+    {
+        const Vector4& vector4(v.GetVector4());
         duk_push_array(ctx);
         duk_push_number(ctx, vector4.x_);
         duk_put_prop_index(ctx, -2, 0);
@@ -588,7 +597,7 @@ void js_push_variant(duk_context *ctx, const Variant& v)
         duk_put_prop_index(ctx, -2, 2);
         duk_push_number(ctx, vector4.w_);
         duk_put_prop_index(ctx, -2, 3);
-        break;
+    }   break;
 
     default:
         duk_push_undefined(ctx);