feat: sorted lazy systems (#95)

Author: zaucy

ecsact/entt/detail/internal_markers.hh

@@ -2,7 +2,8 @@
 
 #include <cstdint>
 #include <type_traits>
-#include <concepts>
+#include "entt/entt.hpp"
+#include "ecsact/entt/entity.hh"
 #include "ecsact/runtime/common.h"
 
 namespace ecsact::entt::detail {
@@ -63,9 +64,43 @@ struct created_entity {
 struct destroyed_entity {};
 
 template<typename S>
-struct system_sorted;
+struct system_sorted {
+	std::uint64_t hash = 0;
+	friend auto operator<=>(const system_sorted&, const system_sorted&) = default;
+};
 
 template<typename S>
 struct pending_lazy_execution {};
 
+template<typename>
+constexpr bool system_markers_unimplemented_by_codegen = false;
+
+template<typename C>
+auto add_system_markers_if_needed( //
+	::entt::registry&,
+	ecsact::entt::entity_id
+) -> void {
+	static_assert(system_markers_unimplemented_by_codegen<C>, R"(
+ -----------------------------------------------------------------------------
+| (!) CODEGEN ERROR                                                           |
+| `add_system_markers_if_needed<>` template specialization cannot be found.   |
+| This is typically generated by ecsact_rt_entt_codegen.                      |
+ -----------------------------------------------------------------------------
+)");
+}
+
+template<typename C>
+auto remove_system_markers_if_needed( //
+	::entt::registry&,
+	ecsact::entt::entity_id
+) -> void {
+	static_assert(system_markers_unimplemented_by_codegen<C>, R"(
+ -----------------------------------------------------------------------------
+| (!) CODEGEN ERROR                                                           |
+| `remove_system_markers_if_needed<>` template specialization cannot be found |
+| This is typically generated by ecsact_rt_entt_codegen.                      |
+ -----------------------------------------------------------------------------
+)");
+}
+
 } // namespace ecsact::entt::detail

ecsact/entt/execution.hh

@@ -4,8 +4,8 @@
 #include <unordered_map>
 #include <cassert>
 #include <span>
-#include <type_traits>
 #include "ecsact/runtime/common.h"
+#include "ecsact/entt/entity.hh"
 #include "entt/entity/registry.hpp"
 #include "ecsact/entt/detail/globals.hh"
 
@@ -142,4 +142,19 @@ auto prepare_system_like(::entt::registry&) -> void {
 )");
 }
 
+/**
+ * Checks entity 'matches' a system i.e. the system will execute on the provided
+ * entity.
+ */
+template<typename SystemLike>
+auto entity_matches_system(::entt::registry&, ecsact::entt::entity_id) -> bool {
+	static_assert(detail::unimplemented_by_codegen<SystemLike>, R"(
+ -----------------------------------------------------------------------------
+| (!) CODEGEN ERROR                                                           |
+| `entity_matches_system<>` template specialization cannot be found. This is  |
+| typically generated by ecsact_rt_entt_codegen.                              |
+ -----------------------------------------------------------------------------
+)");
+}
+
 } // namespace ecsact::entt

ecsact/entt/wrapper/core.hh

@@ -65,6 +65,8 @@ inline auto add_component( //
 			);
 			reg.emplace<C>(entity, *static_cast<const C*>(component_data));
 		}
+
+		ecsact::entt::detail::add_system_markers_if_needed<C>(reg, entity);
 	}
 
 	return err;
@@ -100,6 +102,7 @@ inline auto add_component_exec_options( //
 			reg.emplace<C>(entity, *static_cast<const C*>(component_data));
 		}
 		reg.template emplace_or_replace<component_added<C>>(entity);
+		ecsact::entt::detail::add_system_markers_if_needed<C>(reg, entity);
 	}
 
 	return err;
@@ -173,6 +176,7 @@ auto remove_component(
 	reg.template remove<component_added<C>>(entity);
 	reg.template remove<component_changed<C>>(entity);
 	reg.template emplace_or_replace<component_removed<C>>(entity);
+	ecsact::entt::detail::remove_system_markers_if_needed<C>(reg, entity);
 }
 
 template<typename C>
@@ -202,6 +206,8 @@ auto remove_component_exec_options(
 	if constexpr(!std::is_empty_v<C>) {
 		reg.template remove<detail::beforechange_storage<C>>(entity);
 	}
+
+	ecsact::entt::detail::remove_system_markers_if_needed<C>(reg, entity);
 }
 
 inline auto _trigger_create_entity_events(

rt_entt_codegen/core/BUILD.bazel

@@ -13,16 +13,25 @@ cc_library(
 _CORE_CODEGEN_METHODS = {
     "execute_systems": [],
     "create_registry": [],
+    "entity_matches": [
+        "//rt_entt_codegen/shared:sorting",
+    ],
     "init_registry_storage": [],
     "events": [],
     "print_sys_exec": [
         "//rt_entt_codegen/shared:comps_with_caps",
+        "//rt_entt_codegen/shared:sorting",
         "@entt//:entt",
         "@ecsact_rt_entt//:lib",
     ],
-    "check_error_template_specializations": [],
+    "check_error": [],
     "execution_options": [],
-    "sorting_components": [],
+    "sorting_components": [
+        "//rt_entt_codegen/shared:sorting",
+    ],
+    "system_markers": [
+        "//rt_entt_codegen/shared:sorting",
+    ],
 }
 
 [cc_library(

rt_entt_codegen/core/check_error_template_specializations.cc renamed to rt_entt_codegen/core/check_error.cc

@@ -56,4 +56,19 @@ auto print_entity_sorting_components( //
 	const ecsact_entt_details& details
 ) -> void;
 
+auto print_system_marker_add_fn(
+	codegen_plugin_context&    ctx,
+	const ecsact_entt_details& details
+) -> void;
+
+auto print_system_marker_remove_fn(
+	codegen_plugin_context&    ctx,
+	const ecsact_entt_details& details
+) -> void;
+
+auto print_entity_match_fn(
+	codegen_plugin_context&    ctx,
+	const ecsact_entt_details& details
+) -> void;
+
 } // namespace ecsact::rt_entt_codegen::core

rt_entt_codegen/core/core.hh

@@ -0,0 +1,60 @@
+#include "rt_entt_codegen/core/core.hh"
+
+#include <ranges>
+#include <format>
+#include "ecsact/runtime/meta.hh"
+#include "ecsact/lang-support/lang-cc.hh"
+#include "ecsact/cpp_codegen_plugin_util.hh"
+#include "rt_entt_codegen/shared/util.hh"
+
+using ecsact::cpp_codegen_plugin_util::block;
+using ecsact::cpp_codegen_plugin_util::method_printer;
+
+auto ecsact::rt_entt_codegen::core::print_entity_match_fn(
+	codegen_plugin_context&    ctx,
+	const ecsact_entt_details& details
+) -> void {
+	using ecsact::rt_entt_codegen::util::decl_cpp_ident;
+	using std::views::transform;
+
+	for(auto sys_id : details.all_systems) {
+		auto sys_details = ecsact_entt_system_details::from_system_like(
+			ecsact_id_cast<ecsact_system_like_id>(sys_id)
+		);
+		auto system_name = ecsact::meta::decl_full_name(sys_id);
+		auto system_cpp_ident = cc_lang_support::cpp_identifier(system_name);
+		auto method_name =
+			"ecsact::entt::entity_matches_system<" + system_cpp_ident + ">";
+
+		ctx.write("template<>\n");
+		auto printer = //
+			method_printer{ctx, method_name}
+				.parameter("::entt::registry&", "reg")
+				.parameter("ecsact::entt::entity_id", "entity")
+				.return_type("bool");
+
+		auto get_comps_str = util::comma_delim(
+			sys_details.get_comps |
+			transform(decl_cpp_ident<ecsact_component_like_id>)
+		);
+
+		block(ctx, std::format("if(!reg.all_of<{}>(entity))", get_comps_str), [&] {
+			ctx.write("return false;");
+		});
+
+		if(!sys_details.exclude_comps.empty()) {
+			auto exclude_comps_str = util::comma_delim(
+				sys_details.exclude_comps |
+				transform(decl_cpp_ident<ecsact_component_like_id>)
+			);
+
+			block(
+				ctx,
+				std::format("if(reg.any_of<{}>(entity))", exclude_comps_str),
+				[&] { ctx.write("return false;"); }
+			);
+		}
+
+		ctx.write("return true;\n");
+	}
+}

rt_entt_codegen/core/entity_matches.cc

@@ -1,9 +1,6 @@
 #include "core.hh"
 
-#include <concepts>
-#include <fenv.h>
 #include <ranges>
-#include <set>
 #include <string>
 #include <type_traits>
 #include <unordered_map>
@@ -17,6 +14,7 @@
 #include "rt_entt_codegen/shared/ecsact_entt_details.hh"
 #include "rt_entt_codegen/shared/util.hh"
 #include "rt_entt_codegen/shared/comps_with_caps.hh"
+#include "rt_entt_codegen/shared/sorting.hh"
 
 using capability_t =
 	std::unordered_map<ecsact_component_like_id, ecsact_system_capability>;
@@ -26,6 +24,7 @@ concept system_or_action =
 	std::same_as<T, ecsact_system_id> || std::same_as<T, ecsact_action_id>;
 
 using ecsact::rt_entt_codegen::system_comps_with_caps;
+using ecsact::rt_entt_codegen::system_needs_sorted_entities;
 
 template<system_or_action T>
 static auto print_sys_exec_ctx_action(
@@ -483,58 +482,6 @@ static auto print_sys_exec_ctx_other(
 	ctx.write("return nullptr;");
 }
 
-static auto comma_delim(auto&& range) -> std::string {
-	auto result = std::string{};
-
-	for(auto str : range) {
-		result += str + ", ";
-	}
-
-	if(result.ends_with(", ")) {
-		result = result.substr(0, result.size() - 2);
-	}
-
-	return result;
-}
-
-static auto make_view( //
-	ecsact::codegen_plugin_context&                            ctx,
-	auto&&                                                     view_var_name,
-	auto&&                                                     registry_var_name,
-	const ecsact::rt_entt_codegen::ecsact_entt_system_details& details,
-	std::vector<std::string> additional_components = {}
-) -> void {
-	using namespace std::string_literals;
-	using ecsact::rt_entt_codegen::util::decl_cpp_ident;
-	using std::views::transform;
-
-	ctx.write("auto ", view_var_name, " = ", registry_var_name, ".view<");
-
-	ctx.write(comma_delim(
-		details.get_comps | transform(decl_cpp_ident<ecsact_component_like_id>)
-	));
-
-	if(!additional_components.empty()) {
-		ctx.write(", ");
-		ctx.write(comma_delim(additional_components));
-	}
-
-	ctx.write(">(");
-
-	if(!details.exclude_comps.empty()) {
-		ctx.write(
-			"::entt::exclude<",
-			comma_delim(
-				details.exclude_comps |
-				transform(decl_cpp_ident<ecsact_component_like_id>)
-			),
-			">"
-		);
-	}
-
-	ctx.write(");\n");
-}
-
 template<typename SystemLikeID>
 static auto print_apply_pendings(
 	ecsact::codegen_plugin_context&                            ctx,
@@ -634,6 +581,11 @@ static auto print_ecsact_entt_system_details(
 		options.system_name
 	);
 
+	auto system_sorting_struct_name = std::format(
+		"::ecsact::entt::detail::system_sorted<{}>",
+		options.system_name
+	);
+
 	auto additional_view_components = std::vector<std::string>{};
 
 	if(lazy_iteration_rate > 0) {
@@ -647,13 +599,22 @@ static auto print_ecsact_entt_system_details(
 		additional_view_components.push_back(pending_lazy_exec_struct);
 	}
 
-	make_view(
+	if(system_needs_sorted_entities(options.sys_like_id, details)) {
+		additional_view_components.push_back(system_sorting_struct_name);
+	}
+
+	ecsact::rt_entt_codegen::util::make_view(
 		ctx,
 		"view",
 		options.registry_var_name,
 		details,
 		additional_view_components
 	);
+
+	if(system_needs_sorted_entities(options.sys_like_id, details)) {
+		ctx.write("view.use<", system_sorting_struct_name, ">();\n");
+	}
+
 	block(ctx, "struct : ecsact_system_execution_context ", [&] {
 		ctx.write("decltype(view)* view;\n");
 
@@ -814,7 +775,21 @@ static auto print_ecsact_entt_system_details(
 		);
 		ctx.write("assert(iteration_count_ <= lazy_iteration_rate_);\n");
 		block(ctx, "if(iteration_count_ < lazy_iteration_rate_)", [&] {
-			make_view(
+			ctx.write(
+				"_recalc_sorting_hash<",
+				options.system_name,
+				">(",
+				options.registry_var_name,
+				");\n"
+			);
+			ctx.write(
+				options.registry_var_name,
+				".sort<",
+				system_sorting_struct_name,
+				">([](const auto& a, const auto& b) { return a.hash < b.hash; });\n"
+			);
+
+			ecsact::rt_entt_codegen::util::make_view(
 				ctx,
 				"view_no_pending_lazy_",
 				options.registry_var_name,
@@ -914,7 +889,12 @@ static auto print_other_contexts(
 		auto other_details =
 			ecsact_entt_system_details::from_capabilities(assoc_detail.capabilities);
 
-		make_view(ctx, view_name, "registry", other_details);
+		ecsact::rt_entt_codegen::util::make_view(
+			ctx,
+			view_name,
+			"registry",
+			other_details
+		);
 
 		block(ctx, "struct " + struct_header, [&] {
 			using namespace std::string_literals;
@@ -1011,7 +991,7 @@ static auto print_trivial_system_like(
 			.parameter("ecsact_system_execution_context*", "parent_context")
 			.return_type("void");
 
-	make_view(ctx, "view", "registry", details);
+	ecsact::rt_entt_codegen::util::make_view(ctx, "view", "registry", details);
 
 	block(ctx, "for(auto entity : view)", [&] {
 		for(auto&& [comp_id, capability] : sys_capabilities) {