feat: lazy execution values in meta codegen (#133)

Author: zaucy

cpp_meta_header_codegen/cpp_meta_header_codegen.cc

@@ -436,6 +436,23 @@ static void write_fields_info_constexpr(
 	ctx.write("\n}\n");
 }
 
+static inline auto write_lazy_system_iteration_rate( //
+	ecsact::codegen_plugin_context& ctx,
+	ecsact_system_id                id
+) -> void {
+	using ecsact::cc_lang_support::cpp_identifier;
+
+	auto lazy_iteration_rate = ecsact_meta_get_lazy_iteration_rate(id);
+
+	ctx.write(
+		"template<> struct ecsact::system_lazy_execution_iteration_rate<",
+		cpp_identifier(get_sys_full_name(ctx.package_id, id)),
+		"> : std::integral_constant<int32_t, ",
+		lazy_iteration_rate,
+		"> {};"
+	);
+}
+
 void ecsact_codegen_plugin(
 	ecsact_package_id         package_id,
 	ecsact_codegen_write_fn_t write_fn
@@ -594,4 +611,8 @@ void ecsact_codegen_plugin(
 	for(auto& act_id : ecsact::meta::get_action_ids(ctx.package_id)) {
 		write_system_capabilities_info_struct(ctx, act_id);
 	}
+
+	for(auto& sys_id : ecsact::meta::get_system_ids(ctx.package_id)) {
+		write_lazy_system_iteration_rate(ctx, sys_id);
+	}
 }

ecsact/cpp/type_info.hh

@@ -31,8 +31,8 @@ template<typename SystemT>
 struct system_lazy_execution_iteration_rate;
 
 template<typename SystemT>
-using system_lazy_execution_iteration_rate_v =
-	typename system_lazy_execution_iteration_rate<SystemT>::value;
+constexpr auto system_lazy_execution_iteration_rate_v =
+	system_lazy_execution_iteration_rate<SystemT>::value;
 
 template<typename SystemLikeT>
 struct system_capabilities_info {

test/BUILD.bazel

@@ -80,6 +80,17 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "meta_check",
+    copts = copts,
+    srcs = ["meta_check.cc"],
+    deps = [
+        "//:ecsact_cc",
+        "@ecsact_lang_cpp//:type_info",
+        "@ecsact_runtime//:lib",
+    ],
+)
+
 cc_binary(
     name = "example_system_impls",
     copts = copts,

test/example.ecsact

@@ -8,3 +8,19 @@ system ExampleSystemFromImports {
 	readwrite pkg.b.ExampleB;
 }
 
+system ExampleLazy(lazy) {
+	readwrite pkg.a.ExampleA;
+}
+
+system LazyLeap(lazy: 24) {
+	readwrite pkg.b.ExampleB;
+}
+
+system ExplicitlyNoLazy(lazy: false) {
+	readwrite pkg.b.ExampleB;
+}
+
+system ExplicitlyNoLazyZero(lazy: 0) {
+	readwrite pkg.b.ExampleB;
+}
+

test/meta_check.cc

@@ -0,0 +1,23 @@
+#include "example.ecsact.meta.hh"
+
+static_assert(
+	ecsact::system_lazy_execution_iteration_rate_v<
+		example::ExampleSystemFromImports> == 0
+);
+
+static_assert(
+	ecsact::system_lazy_execution_iteration_rate_v<example::ExampleLazy> == 1
+);
+
+static_assert(
+	ecsact::system_lazy_execution_iteration_rate_v<example::LazyLeap> == 24
+);
+
+static_assert(
+	ecsact::system_lazy_execution_iteration_rate_v<example::ExplicitlyNoLazy> == 0
+);
+
+static_assert(
+	ecsact::system_lazy_execution_iteration_rate_v<
+		example::ExplicitlyNoLazyZero> == 0
+);

test/system_impls.cc

@@ -10,3 +10,15 @@ void example::ExampleSystemFromImports::impl(context& ctx) {
 	ctx.update(a);
 	ctx.update(b);
 }
+
+void example::ExampleLazy::impl(context&) {
+}
+
+void example::LazyLeap::impl(context&) {
+}
+
+void example::ExplicitlyNoLazy::impl(context&) {
+}
+
+void example::ExplicitlyNoLazyZero::impl(context&) {
+}