From b147a0daa1be2c5e7faea33f500e7f22541c12a0 Mon Sep 17 00:00:00 2001
From: Stanislaw Halik <sthalik@misaki.pl>
Date: Fri, 25 Aug 2023 19:28:32 +0200
Subject: entities: add intents for metadata

It's going to be used for serialization which has different fields.
---
 editor/inspect-types.cpp | 34 +++++++++++++++++-----------------
 entity/metadata.hpp      | 14 +++++++++-----
 test/entity.cpp          |  8 ++++----
 3 files changed, 30 insertions(+), 26 deletions(-)

diff --git a/editor/inspect-types.cpp b/editor/inspect-types.cpp
index fc60992e..e29d5df9 100644
--- a/editor/inspect-types.cpp
+++ b/editor/inspect-types.cpp
@@ -16,7 +16,7 @@ namespace floormat::entities {
 using st = field_status;
 
 template<>
-struct entity_accessors<entity> {
+struct entity_accessors<entity, inspect_intent_t> {
     static constexpr auto accessors()
     {
         using E = Entity<entity>;
@@ -67,11 +67,11 @@ struct entity_accessors<entity> {
 };
 
 template<>
-struct entity_accessors<scenery> {
+struct entity_accessors<scenery, inspect_intent_t> {
     static constexpr auto accessors()
     {
         using E = Entity<scenery>;
-        auto tuple0 = entity_accessors<entity>::accessors();
+        auto tuple0 = entity_accessors<entity, inspect_intent_t>::accessors();
         auto tuple = std::tuple{
             E::type<bool>::field{"interactive"_s,
                 [](const scenery& x) { return x.interactive; },
@@ -153,15 +153,15 @@ struct enum_values<rotation, U>
     }
 };
 
-template<typename T>
-static bool inspect_type(T& x)
+template<typename T, typename Intent>
+static bool inspect_type(T& x, Intent)
 {
     size_t width = 0;
     visit_tuple([&](const auto& field) {
         const auto& name = field.name;
         auto width_ = (size_t)ImGui::CalcTextSize(name.cbegin(), name.cend()).x;
         width = std::max(width, width_);
-    }, entity_metadata<T>::accessors);
+    }, entity_metadata<T, Intent>::accessors);
 
     bool ret = false;
     visit_tuple([&](const auto& field) {
@@ -169,16 +169,16 @@ static bool inspect_type(T& x)
         using enum_type = enum_values<type, T>;
         const auto& list = enum_type::get(x);
         ret |= inspect_field<type>(&x, field.erased(), list, width);
-    }, entity_metadata<T>::accessors);
+    }, entity_metadata<T, Intent>::accessors);
     return ret;
 }
 
 template<>
-struct entity_accessors<character> {
+struct entity_accessors<character, inspect_intent_t> {
     static constexpr auto accessors()
     {
         using E = Entity<character>;
-        auto tuple0 = entity_accessors<entity>::accessors();
+        auto tuple0 = entity_accessors<entity, inspect_intent_t>::accessors();
         auto tuple = std::tuple{
             E::type<String>::field{"name"_s,
                                  [](const character& x) { return x.name; },
@@ -204,12 +204,12 @@ template<typename U> struct enum_values<light_falloff, U>
 };
 
 template<>
-struct entity_accessors<light>
+struct entity_accessors<light, inspect_intent_t>
 {
     static constexpr auto accessors()
     {
         using E = Entity<light>;
-        auto tuple0 = entity_accessors<entity>::accessors();
+        auto tuple0 = entity_accessors<entity, inspect_intent_t>::accessors();
         auto tuple = std::tuple{
             E::type<Color4ub>::field{"color"_s,
                 [](const light& x) { return x.color; },
@@ -234,9 +234,9 @@ struct entity_accessors<light>
 };
 
 //template bool inspect_type(entity&);
-template bool inspect_type(scenery&);
-template bool inspect_type(character&);
-template bool inspect_type(light&);
+template bool inspect_type(scenery&, inspect_intent_t);
+template bool inspect_type(character&, inspect_intent_t);
+template bool inspect_type(light&, inspect_intent_t);
 
 bool inspect_entity_subtype(entity& x)
 {
@@ -244,9 +244,9 @@ bool inspect_entity_subtype(entity& x)
     {
     default: fm_warn_once("unknown entity subtype '%d'", (int)type); return false;
     //case entity_type::none: return inspect_type(x);
-    case entity_type::scenery: return inspect_type(static_cast<scenery&>(x));
-    case entity_type::character: return inspect_type(static_cast<character&>(x));
-    case entity_type::light: return inspect_type(static_cast<light&>(x));
+    case entity_type::scenery: return inspect_type(static_cast<scenery&>(x), inspect_intent_t{});
+    case entity_type::character: return inspect_type(static_cast<character&>(x), inspect_intent_t{});
+    case entity_type::light: return inspect_type(static_cast<light&>(x), inspect_intent_t{});
     }
 }
 
diff --git a/entity/metadata.hpp b/entity/metadata.hpp
index 1902091f..dd82ce8a 100644
--- a/entity/metadata.hpp
+++ b/entity/metadata.hpp
@@ -17,7 +17,11 @@
 
 namespace floormat::entities {
 
-template<typename T> struct entity_accessors;
+struct inspect_intent_t   {};
+struct serialize_intent_t {};
+struct report_intent_t    {};
+
+template<typename T, typename Intent> struct entity_accessors;
 
 } // namespace floormat::entities
 
@@ -248,7 +252,7 @@ constexpr bool find_in_tuple(F&& fun, Tuple&& tuple)
 
 namespace floormat {
 
-template<typename T>
+template<typename T, typename Intent>
 class entity_metadata final {
     static_assert(std::is_same_v<T, std::decay_t<T>>);
 
@@ -257,14 +261,14 @@ class entity_metadata final {
 
 public:
     static constexpr StringView class_name = name_of<T>;
-    static constexpr auto accessors = entities::entity_accessors<T>::accessors();
+    static constexpr auto accessors = entities::entity_accessors<T, Intent>::accessors();
     static constexpr size_t size = std::tuple_size_v<std::decay_t<decltype(accessors)>>;
     static constexpr auto erased_accessors = erased_helper(accessors, std::make_index_sequence<size>{});
 };
 
-template<typename T>
+template<typename T, typename Intent>
 template<typename Tuple, std::size_t... Ns>
-consteval auto entity_metadata<T>::erased_helper(const Tuple& tuple, std::index_sequence<Ns...>)
+consteval auto entity_metadata<T, Intent>::erased_helper(const Tuple& tuple, std::index_sequence<Ns...>)
 {
     std::array<entities::erased_accessor, sizeof...(Ns)> array { std::get<Ns>(tuple).erased()..., };
     return array;
diff --git a/test/entity.cpp b/test/entity.cpp
index 1ae77129..3c099a37 100644
--- a/test/entity.cpp
+++ b/test/entity.cpp
@@ -20,7 +20,7 @@ struct TestAccessors {
 
 namespace floormat::entities {
 
-template<> struct entity_accessors<TestAccessors> {
+template<> struct entity_accessors<TestAccessors, inspect_intent_t> {
     static constexpr auto accessors()
     {
         using entity = Entity<TestAccessors>;
@@ -126,7 +126,7 @@ void test_erasure() {
 
 void test_metadata()
 {
-    constexpr auto m = entity_metadata<TestAccessors>();
+    constexpr auto m = entity_metadata<TestAccessors, inspect_intent_t>();
     static_assert(sizeof m == 1);
     fm_assert(m.class_name == name_of<TestAccessors>);
     fm_assert(m.class_name.contains("TestAccessors"_s));
@@ -160,7 +160,7 @@ void test_type_name()
     constexpr auto foo = entity::type<int>::field{"foo"_s, &TestAccessors::foo, nullptr};
     static_assert(foo.writer == nullptr);
     static_assert(!foo.can_write);
-    static_assert(std::get<0>(entity_accessors<TestAccessors>::accessors()).can_write);
+    static_assert(std::get<0>(entity_accessors<TestAccessors, inspect_intent_t>::accessors()).can_write);
 }
 
 void test_predicate()
@@ -185,7 +185,7 @@ void test_predicate()
 
 constexpr bool test_names()
 {
-    constexpr auto m = entity_metadata<TestAccessors>();
+    constexpr auto m = entity_metadata<TestAccessors, inspect_intent_t>();
     auto [foo1, bar1, baz1] = m.accessors;
     auto [foo2, bar2, baz2] = m.erased_accessors;
 
-- 
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