mach/src/module.zig
Stephen Gutekanst 2115f5832a module: write components using a struct pattern
Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
2024-04-06 15:18:38 -07:00

1363 lines
55 KiB
Zig

const builtin = @import("builtin");
const std = @import("std");
const testing = @import("testing.zig");
const Entities = @import("ecs/entities.zig").Entities;
const EntityID = @import("ecs/entities.zig").EntityID;
/// Verifies that M matches the basic layout of a Mach module
fn ModuleInterface(comptime M: type) type {
if (@typeInfo(M) != .Struct) @compileError("mach: expected module struct, found: " ++ @typeName(M));
if (!@hasDecl(M, "name")) @compileError("mach: module must have `pub const name = .foobar;`");
if (@typeInfo(@TypeOf(M.name)) != .EnumLiteral) @compileError("mach: module must have `pub const name = .foobar;`, found type:" ++ @typeName(M.name));
// TODO: enable once parameter dependency loop has been resolved
// if (@hasDecl(M, "global_events")) validateEvents("mach: module ." ++ @tagName(M.name) ++ " global_events ", M.global_events);
// if (@hasDecl(M, "local_events")) validateEvents("mach: module ." ++ @tagName(M.name) ++ " local_events ", M.global_events);
_ = ComponentTypesM(M);
return M;
}
// TODO: implement serialization constraints
// For now this exists just to indicate things that we expect will be required to be serializable in
// the future.
fn Serializable(comptime T: type) type {
return T;
}
/// Manages comptime .{A, B, C} modules and runtime modules.
pub fn Modules(comptime modules2: anytype) type {
// Verify that each module is valid.
inline for (modules2) |M| _ = ModuleInterface(M);
return struct {
// TODO: avoid exposing this?
/// Comptime modules
pub const modules = modules2;
// TODO: add runtime module support
pub const ModuleID = u32;
pub const EventID = u32;
pub const GlobalEvent = GlobalEventEnum(modules);
pub const LocalEvent = LocalEventEnum(modules);
/// Enables looking up a component type by module name and component name.
/// e.g. @field(@field(ComponentTypesByName, "module_name"), "component_name")
pub const component_types_by_name = ComponentTypesByName(modules){};
const ModulesT = @This();
const Event = struct {
module_name: ?ModuleID,
event_name: EventID,
args_slice: []u8,
};
const EventQueue = std.fifo.LinearFifo(Event, .Dynamic);
events_mu: std.Thread.RwLock = .{},
args_queue: std.ArrayListUnmanaged(u8) = .{},
events: EventQueue,
mod: ModsByName(modules, ModulesT),
// TODO: pass mods directly instead of ComponentTypesByName?
entities: Entities(component_types_by_name),
pub fn Mod(comptime M: type) type {
const NSComponents = ComponentTypesByName(ModulesT.modules);
return Module(M, ModulesT, NSComponents);
}
pub fn init(m: *@This(), allocator: std.mem.Allocator) !void {
// TODO: switch Entities to stack allocation like Modules is
var entities = try Entities(component_types_by_name).init(allocator);
errdefer entities.deinit();
// TODO: custom event queue allocation sizes
m.* = .{
.entities = entities,
.args_queue = try std.ArrayListUnmanaged(u8).initCapacity(allocator, 8 * 1024 * 1024),
.events = EventQueue.init(allocator),
.mod = undefined,
};
errdefer m.args_queue.deinit(allocator);
errdefer m.events.deinit();
try m.events.ensureTotalCapacity(1024);
}
pub fn deinit(m: *@This(), allocator: std.mem.Allocator) void {
m.args_queue.deinit(allocator);
m.events.deinit();
m.entities.deinit();
}
/// Returns an args tuple representing the standard, uninjected, arguments which the given
/// local event handler requires.
fn LocalArgs(module_name: ModuleName(modules), event_name: LocalEvent) type {
inline for (modules) |M| {
_ = ModuleInterface(M); // Validate the module
if (M.name != module_name) continue;
return LocalArgsM(M, event_name);
}
}
/// Returns an args tuple representing the standard, uninjected, arguments which the given
/// global event handler requires.
fn GlobalArgs(module_name: ModuleName(modules), event_name: GlobalEvent) type {
inline for (modules) |M| {
_ = ModuleInterface(M); // Validate the module
if (M.name != module_name) continue;
return GlobalArgsM(M, event_name);
}
}
/// Send a global event which the specified module defines
pub fn sendGlobal(
m: *@This(),
// TODO: is a variant of this function where event_name is not comptime known, but asserted to be a valid enum, useful?
comptime module_name: ModuleName(modules),
comptime event_name: GlobalEvent,
args: GlobalArgs(module_name, event_name),
) void {
// TODO: comptime safety/debugging
m.sendInternal(null, @intFromEnum(event_name), args);
}
/// Send an event to a specific module
pub fn sendToModule(
m: *@This(),
// TODO: is a variant of this function where module_name/event_name is not comptime known, but asserted to be a valid enum, useful?
comptime module_name: ModuleName(modules),
comptime event_name: LocalEvent,
args: LocalArgs(module_name, event_name),
) void {
// TODO: comptime safety/debugging
m.sendInternal(@intFromEnum(module_name), @intFromEnum(event_name), args);
}
/// Send a global event, using a dynamic (not known to the compiled program) event name.
pub fn sendDynamic(m: *@This(), event_name: EventID, args: anytype) void {
// TODO: runtime safety/debugging
// TODO: check args do not have obviously wrong things, like comptime values
// TODO: if module_name and event_name are valid enums, can we type-check args at comptime?
m.sendInternal(null, event_name, args);
}
/// Send an event to a specific module, using a dynamic (not known to the compiled program) module and event name.
pub fn sendToModuleDynamic(m: *@This(), module_name: ModuleID, event_name: EventID, args: anytype) void {
// TODO: runtime safety/debugging
// TODO: check args do not have obviously wrong things, like comptime values
// TODO: if module_name and event_name are valid enums, can we type-check args at comptime?
m.sendInternal(module_name, event_name, args);
}
fn sendInternal(m: *@This(), module_name: ?ModuleID, event_name: EventID, args: anytype) void {
// TODO: verify arguments are valid, e.g. not comptime types
_ = Serializable(@TypeOf(args));
// TODO: debugging
m.events_mu.lock();
defer m.events_mu.unlock();
const args_bytes = std.mem.asBytes(&args);
m.args_queue.appendSliceAssumeCapacity(args_bytes);
m.events.writeItemAssumeCapacity(.{
.module_name = module_name,
.event_name = event_name,
.args_slice = m.args_queue.items[m.args_queue.items.len - args_bytes.len .. m.args_queue.items.len],
});
}
/// Dispatches pending events, invoking their event handlers.
pub fn dispatch(m: *@This()) !void {
const Injectable = comptime blk: {
var types: []const type = &[0]type{};
for (@typeInfo(ModsByName(modules, ModulesT)).Struct.fields) |field| {
const ModPtr = @TypeOf(@as(*field.type, undefined));
types = types ++ [_]type{ModPtr};
}
break :blk std.meta.Tuple(types);
};
var injectable: Injectable = undefined;
outer: inline for (@typeInfo(Injectable).Struct.fields) |field| {
inline for (@typeInfo(ModsByName(modules, ModulesT)).Struct.fields) |injectable_field| {
if (*injectable_field.type == field.type) {
@field(injectable, field.name) = &@field(m.mod, injectable_field.name);
// TODO: better module initialization location
@field(injectable, field.name).entities = &m.entities;
@field(injectable, field.name).allocator = m.entities.allocator;
continue :outer;
}
}
@compileError("failed to initialize Injectable field (this is a bug): " ++ field.name ++ " " ++ @typeName(field.type));
}
return m.dispatchInternal(injectable);
}
pub fn dispatchInternal(m: *@This(), injectable: anytype) !void {
// TODO: verify injectable arguments are valid, e.g. not comptime types
// TODO: optimize to reduce send contention
// TODO: parallel / multi-threaded dispatch
// TODO: PGO
// TODO: this is wrong
defer {
m.events_mu.lock();
m.args_queue.clearRetainingCapacity();
m.events_mu.unlock();
}
while (true) {
m.events_mu.lock();
const ev = m.events.readItem() orelse {
m.events_mu.unlock();
break;
};
m.events_mu.unlock();
if (ev.module_name) |module_name| {
try @This().callLocal(@enumFromInt(module_name), @enumFromInt(ev.event_name), ev.args_slice, injectable);
} else {
try @This().callGlobal(@enumFromInt(ev.event_name), ev.args_slice, injectable);
}
}
}
/// Call global event handler with the specified name in all modules
inline fn callGlobal(event_name: GlobalEvent, args: []u8, injectable: anytype) !void {
if (@typeInfo(@TypeOf(event_name)).Enum.fields.len == 0) return;
switch (event_name) {
inline else => |ev_name| {
inline for (modules) |M| {
// TODO: DRY with callLocal
_ = ModuleInterface(M); // Validate the module
if (@hasDecl(M, "global_events")) inline for (@typeInfo(@TypeOf(M.global_events)).Struct.fields) |field| {
comptime if (!std.mem.eql(u8, @tagName(ev_name), field.name)) continue;
const handler = @field(M.global_events, @tagName(ev_name)).handler;
if (@typeInfo(@TypeOf(handler)) == .Type) continue; // Pre-declaration of what args an event has, nothing to do.
if (@typeInfo(@TypeOf(handler)) != .Fn) @compileError(std.fmt.comptimePrint("mach: module .{s} declares global event .{s} = .{{ .handler = T }}, expected fn but found: {s}", .{
@tagName(M.name),
@tagName(ev_name),
@typeName(@TypeOf(handler)),
}));
try callHandler(handler, args, injectable);
};
}
},
}
}
/// Call local event handler with the specified name in the specified module
inline fn callLocal(module_name: ModuleName(modules), event_name: LocalEvent, args: []u8, injectable: anytype) !void {
if (@typeInfo(@TypeOf(event_name)).Enum.fields.len == 0) return;
switch (event_name) {
inline else => |ev_name| {
switch (module_name) {
inline else => |mod_name| {
// TODO: DRY with callGlobal
const M = @field(NamespacedModules(@This().modules){}, @tagName(mod_name));
_ = ModuleInterface(M); // Validate the module
if (@hasDecl(M, "local_events")) inline for (@typeInfo(@TypeOf(M.local_events)).Struct.fields) |field| {
comptime if (!std.mem.eql(u8, @tagName(ev_name), field.name)) continue;
const handler = @field(M.local_events, @tagName(ev_name)).handler;
if (@typeInfo(@TypeOf(handler)) == .Type) continue; // Pre-declaration of what args an event has, nothing to do.
if (@typeInfo(@TypeOf(handler)) != .Fn) @compileError(std.fmt.comptimePrint("mach: module .{s} declares local event .{s} = .{{ .handler = T }}, expected fn but found: {s}", .{
@tagName(M.name),
@tagName(ev_name),
@typeName(@TypeOf(handler)),
}));
try callHandler(handler, args, injectable);
};
},
}
},
}
}
/// Invokes an event handler with optionally injected arguments.
inline fn callHandler(handler: anytype, args_data: []u8, injectable: anytype) !void {
const Handler = @TypeOf(handler);
const StdArgs = UninjectedArgsTuple(std.meta.Tuple, Handler);
const std_args: *StdArgs = @alignCast(@ptrCast(args_data.ptr));
const args = injectArgs(Handler, @TypeOf(injectable), injectable, std_args.*);
const Ret = @typeInfo(Handler).Fn.return_type orelse void;
switch (@typeInfo(Ret)) {
.ErrorUnion => try @call(.auto, handler, args),
else => @call(.auto, handler, args),
}
}
};
}
pub fn ModsByName(comptime modules: anytype, comptime ModulesT: type) type {
var fields: []const std.builtin.Type.StructField = &[0]std.builtin.Type.StructField{};
for (modules) |M| {
const NSComponents = ComponentTypesByName(modules);
const Mod = Module(M, ModulesT, NSComponents);
fields = fields ++ [_]std.builtin.Type.StructField{.{
.name = @tagName(M.name),
.type = Mod,
.default_value = null,
.is_comptime = false,
.alignment = @alignOf(Mod),
}};
}
return @Type(.{
.Struct = .{
.layout = .Auto,
.is_tuple = false,
.fields = fields,
.decls = &[_]std.builtin.Type.Declaration{},
},
});
}
pub fn Module(
comptime M: anytype,
comptime ModulesT: type,
comptime NSComponents: type,
) type {
const module_tag = M.name;
const components = ComponentTypesM(M){};
return struct {
state: M,
entities: *Entities(NSComponents{}),
// TODO: eliminate this global allocator and/or rethink allocation strategies for modules
allocator: std.mem.Allocator,
pub const IsInjectedArgument = void;
/// Returns a new entity.
pub fn newEntity(m: *@This()) !EntityID {
return m.entities.new();
}
/// Removes an entity.
pub fn removeEntity(m: *@This(), entity: EntityID) !void {
try m.entities.removeEntity(entity);
}
/// Sets the named component to the specified value for the given entity,
/// moving the entity from it's current archetype table to the new archetype
/// table if required.
pub inline fn set(
m: *@This(),
entity: EntityID,
// TODO: cleanup comptime
comptime component_name: std.meta.FieldEnum(@TypeOf(components)),
component: @field(components, @tagName(component_name)).type,
) !void {
try m.entities.setComponent(entity, module_tag, component_name, component);
}
/// gets the named component of the given type (which must be correct, otherwise undefined
/// behavior will occur). Returns null if the component does not exist on the entity.
pub inline fn get(
m: *@This(),
entity: EntityID,
// TODO: cleanup comptime
comptime component_name: std.meta.FieldEnum(@TypeOf(components)),
) ?@field(components, @tagName(component_name)).type {
return m.entities.getComponent(entity, module_tag, component_name);
}
/// Removes the named component from the entity, or noop if it doesn't have such a component.
pub inline fn remove(
m: *@This(),
entity: EntityID,
// TODO: cleanup comptime
comptime component_name: std.meta.FieldEnum(@TypeOf(components)),
) !void {
try m.entities.removeComponent(entity, module_tag, component_name);
}
pub inline fn send(m: *@This(), comptime event_name: ModulesT.LocalEvent, args: LocalArgsM(M, event_name)) void {
const MByName = ModsByName(ModulesT.modules, ModulesT);
const mod_ptr: *MByName = @alignCast(@fieldParentPtr(MByName, @tagName(module_tag), m));
const modules = @fieldParentPtr(ModulesT, "mod", mod_ptr);
modules.sendToModule(module_tag, event_name, args);
}
pub inline fn sendGlobal(m: *@This(), comptime event_name: ModulesT.GlobalEvent, args: GlobalArgsM(M, event_name)) void {
const MByName = ModsByName(ModulesT.modules, ModulesT);
const mod_ptr: *MByName = @alignCast(@fieldParentPtr(MByName, @tagName(module_tag), m));
const modules = @fieldParentPtr(ModulesT, "mod", mod_ptr);
modules.sendGlobal(module_tag, event_name, args);
}
// TODO: eliminate this
pub fn dispatchNoError(m: *@This()) void {
const MByName = ModsByName(ModulesT.modules, ModulesT);
const mod_ptr: *MByName = @alignCast(@fieldParentPtr(MByName, @tagName(module_tag), m));
const modules = @fieldParentPtr(ModulesT, "mod", mod_ptr);
modules.dispatch() catch |err| @panic(@errorName(err));
}
};
}
// TODO: see usage location
fn TupleHACK(comptime types: []const type) type {
return CreateUniqueTupleHACK(types.len, types[0..types.len].*);
}
fn CreateUniqueTupleHACK(comptime N: comptime_int, comptime types: [N]type) type {
var tuple_fields: [types.len]std.builtin.Type.StructField = undefined;
inline for (types, 0..) |T, i| {
@setEvalBranchQuota(10_000);
var num_buf: [128]u8 = undefined;
tuple_fields[i] = .{
.name = std.fmt.bufPrintZ(&num_buf, "{d}", .{i}) catch unreachable,
.type = T,
.default_value = null,
.is_comptime = false,
.alignment = if (@sizeOf(T) > 0) @alignOf(T) else 0,
};
}
return @Type(.{
.Struct = .{
// .is_tuple = true,
.is_tuple = false,
.layout = .Auto,
.decls = &.{},
.fields = &tuple_fields,
},
});
}
// Given a function, its standard arguments and injectable arguments, performs injection and
// returns the actual argument tuple which would be used to call the function.
inline fn injectArgs(
comptime Function: type,
comptime Injectable: type,
injectable_args: Injectable,
std_args: UninjectedArgsTuple(std.meta.Tuple, Function),
) std.meta.ArgsTuple(Function) {
var args: std.meta.ArgsTuple(Function) = undefined;
comptime var std_args_index = 0;
outer: inline for (@typeInfo(std.meta.ArgsTuple(Function)).Struct.fields) |arg| {
// Is this a Struct or *Struct, with a `pub const IsInjectedArgument = void;` decl? If so,
// it is considered an injected argument.
inline for (@typeInfo(Injectable).Struct.fields) |inject_field| {
if (inject_field.type == arg.type and @alignOf(inject_field.type) == @alignOf(arg.type)) {
// Inject argument
@field(args, arg.name) = @field(injectable_args, inject_field.name);
continue :outer;
}
}
// First standard argument
@field(args, arg.name) = std_args[std_args_index];
std_args_index += 1;
}
return args;
}
// Given a function type, and an args tuple of injectable parameters, returns the set of function
// parameters which would **not** be injected.
fn UninjectedArgsTuple(
comptime Tuple: fn (comptime types: []const type) type,
comptime Function: type,
) type {
var std_args: []const type = &[0]type{};
inline for (@typeInfo(std.meta.ArgsTuple(Function)).Struct.fields) |arg| {
// Is this a Struct or *Struct, with a `pub const IsInjectedArgument = void;` decl? If so,
// it is considered an injected argument.
const is_injected = blk: {
switch (@typeInfo(arg.type)) {
.Struct => break :blk @hasDecl(arg.type, "IsInjectedArgument"),
.Pointer => {
switch (@typeInfo(std.meta.Child(arg.type))) {
.Struct => break :blk @hasDecl(std.meta.Child(arg.type), "IsInjectedArgument"),
else => break :blk false,
}
},
else => break :blk false,
}
};
if (is_injected) continue; // legitimate injected argument, ignore it
std_args = std_args ++ [_]type{arg.type};
}
return Tuple(std_args);
}
// TODO: tests
fn LocalArgsM(comptime M: type, event_name: anytype) type {
return ArgsM(M, event_name, "local");
}
// TODO: tests
fn GlobalArgsM(comptime M: type, event_name: anytype) type {
return ArgsM(M, event_name, "global");
}
fn ArgsM(comptime M: type, event_name: anytype, comptime which: anytype) type {
_ = ModuleInterface(M); // Validate the module
if (!@hasDecl(M, which ++ "_events")) return @TypeOf(.{});
const m_events = @field(M, which ++ "_events"); // M.local_events or M.global_events
inline for (@typeInfo(@TypeOf(m_events)).Struct.fields) |field| {
comptime if (!std.mem.eql(u8, field.name, @tagName(event_name))) continue;
if (!@hasField(@TypeOf(m_events), @tagName(event_name))) @compileError(std.fmt.comptimePrint("mach: module .{s} declares no {s} event .{s}", .{
@tagName(M.name),
which,
@tagName(event_name),
}));
const handler = @field(m_events, @tagName(event_name)).handler;
const Handler = switch (@typeInfo(@TypeOf(handler))) {
.Type => handler, // Pre-declaration of what args an event has
.Fn => blk: {
if (@typeInfo(@TypeOf(handler)) != .Fn) @compileError(std.fmt.comptimePrint("mach: module .{s} declares {s} event .{s} = .{{ .handler = T }}, expected fn but found: {s}", .{
@tagName(M.name),
which,
@tagName(event_name),
@typeName(@TypeOf(handler)),
}));
break :blk @TypeOf(handler);
},
else => unreachable,
};
// TODO: passing std.meta.Tuple here instead of TupleHACK results in a compiler
// segfault. The only difference is that TupleHACk does not produce a real tuple,
// `@Type(.{.Struct = .{ .is_tuple = false }})` instead of `.is_tuple = true`.
return UninjectedArgsTuple(TupleHACK, Handler);
}
@compileError("mach: module ." ++ @tagName(M.name) ++ " has no " ++ which ++ " event handler for ." ++ @tagName(event_name));
}
// TODO: DRY with GlobalEventEnum
/// enum describing every possible comptime-known local event name
fn LocalEventEnum(comptime modules: anytype) type {
var enum_fields: []const std.builtin.Type.EnumField = &[0]std.builtin.Type.EnumField{};
var i: u32 = 0;
for (modules) |M| {
_ = ModuleInterface(M); // Validate the module
if (@hasDecl(M, "local_events")) inline for (@typeInfo(@TypeOf(M.local_events)).Struct.fields) |field| {
const exists_already = blk: {
for (enum_fields) |existing| if (std.mem.eql(u8, existing.name, field.name)) break :blk true;
break :blk false;
};
if (!exists_already) {
enum_fields = enum_fields ++ [_]std.builtin.Type.EnumField{.{ .name = field.name, .value = i }};
i += 1;
}
};
}
return @Type(.{
.Enum = .{
.tag_type = if (enum_fields.len > 0) std.math.IntFittingRange(0, enum_fields.len - 1) else u0,
.fields = enum_fields,
.decls = &[_]std.builtin.Type.Declaration{},
.is_exhaustive = true,
},
});
}
// TODO: DRY with GlobalEventEnumM
/// enum describing every possible comptime-known local event name
fn LocalEventEnumM(comptime M: anytype) type {
var enum_fields: []const std.builtin.Type.EnumField = &[0]std.builtin.Type.EnumField{};
var i: u32 = 0;
_ = ModuleInterface(M); // Validate the module
if (@hasDecl(M, "local_events")) inline for (@typeInfo(@TypeOf(M.local_events)).Struct.fields) |field| {
const exists_already = blk: {
for (enum_fields) |existing| if (std.mem.eql(u8, existing.name, field.name)) break :blk true;
break :blk false;
};
if (!exists_already) {
enum_fields = enum_fields ++ [_]std.builtin.Type.EnumField{.{ .name = field.name, .value = i }};
i += 1;
}
};
return @Type(.{
.Enum = .{
.tag_type = if (enum_fields.len > 0) std.math.IntFittingRange(0, enum_fields.len - 1) else u0,
.fields = enum_fields,
.decls = &[_]std.builtin.Type.Declaration{},
.is_exhaustive = true,
},
});
}
// TODO: DRY with LocalEventEnum
/// enum describing every possible comptime-known global event name
fn GlobalEventEnum(comptime modules: anytype) type {
var enum_fields: []const std.builtin.Type.EnumField = &[0]std.builtin.Type.EnumField{};
var i: u32 = 0;
for (modules) |M| {
_ = ModuleInterface(M); // Validate the module
if (@hasDecl(M, "global_events")) inline for (@typeInfo(@TypeOf(M.global_events)).Struct.fields) |field| {
const exists_already = blk: {
for (enum_fields) |existing| if (std.mem.eql(u8, existing.name, field.name)) break :blk true;
break :blk false;
};
if (!exists_already) {
enum_fields = enum_fields ++ [_]std.builtin.Type.EnumField{.{ .name = field.name, .value = i }};
i += 1;
}
};
}
return @Type(.{
.Enum = .{
.tag_type = if (enum_fields.len > 0) std.math.IntFittingRange(0, enum_fields.len - 1) else u0,
.fields = enum_fields,
.decls = &[_]std.builtin.Type.Declaration{},
.is_exhaustive = true,
},
});
}
// TODO: DRY with LocalEventEnumM
/// enum describing every possible comptime-known global event name
fn GlobalEventEnumM(comptime M: anytype) type {
var enum_fields: []const std.builtin.Type.EnumField = &[0]std.builtin.Type.EnumField{};
var i: u32 = 0;
_ = ModuleInterface(M); // Validate the module
if (@hasDecl(M, "global_events")) inline for (@typeInfo(@TypeOf(M.global_events)).Struct.fields) |field| {
const exists_already = blk: {
for (enum_fields) |existing| if (std.mem.eql(u8, existing.name, field.name)) break :blk true;
break :blk false;
};
if (!exists_already) {
enum_fields = enum_fields ++ [_]std.builtin.Type.EnumField{.{ .name = field.name, .value = i }};
i += 1;
}
};
return @Type(.{
.Enum = .{
.tag_type = if (enum_fields.len > 0) std.math.IntFittingRange(0, enum_fields.len - 1) else u0,
.fields = enum_fields,
.decls = &[_]std.builtin.Type.Declaration{},
.is_exhaustive = true,
},
});
}
/// enum describing every possible comptime-known module name
fn ModuleName(comptime modules: anytype) type {
var enum_fields: []const std.builtin.Type.EnumField = &[0]std.builtin.Type.EnumField{};
for (modules, 0..) |M, i| {
enum_fields = enum_fields ++ [_]std.builtin.Type.EnumField{.{ .name = @tagName(M.name), .value = i }};
}
return @Type(.{
.Enum = .{
.tag_type = std.math.IntFittingRange(0, enum_fields.len - 1),
.fields = enum_fields,
.decls = &[_]std.builtin.Type.Declaration{},
.is_exhaustive = true,
},
});
}
// TODO: tests
/// Struct like .{.foo = FooMod, .bar = BarMod}
fn NamespacedModules(comptime modules: anytype) type {
var fields: []const std.builtin.Type.StructField = &[0]std.builtin.Type.StructField{};
inline for (modules) |M| {
fields = fields ++ [_]std.builtin.Type.StructField{.{
.name = @tagName(M.name),
.type = type,
.default_value = &M,
.is_comptime = true,
.alignment = @alignOf(@TypeOf(M)),
}};
}
return @Type(.{
.Struct = .{
.layout = .Auto,
.is_tuple = false,
.fields = fields,
.decls = &[_]std.builtin.Type.Declaration{},
},
});
}
// TODO: tests
fn validateEvents(comptime error_prefix: anytype, comptime events: anytype) void {
if (@typeInfo(@TypeOf(events)) != .Struct or @typeInfo(@TypeOf(events)).Struct.is_tuple) {
@compileError(error_prefix ++ "expected a struct .{}, found: " ++ @typeName(@TypeOf(events)));
}
inline for (@typeInfo(@TypeOf(events)).Struct.fields) |field| {
const Event = field.type;
if (@typeInfo(Event) != .Struct) @compileError(std.fmt.comptimePrint(
error_prefix ++ "expected .{s} = .{{}}, found type: {s}",
.{ field.name, @typeName(Event) },
));
const event = @field(events, field.name);
// Verify .handler field
if (!@hasField(Event, "handler")) @compileError(std.fmt.comptimePrint(
error_prefix ++ ".{s} missing field `.handler = fn` or `.handler = @TypeOf(fn)`",
.{field.name},
));
const valid_handler_type = switch (@typeInfo(@TypeOf(event.handler))) {
.Fn => true,
.Type => switch (@typeInfo(event.handler)) {
.Fn => true,
else => false,
},
else => false,
};
if (!valid_handler_type) @compileError(std.fmt.comptimePrint(
error_prefix ++ ".{s} field .handler expected `.handler = fn` or `.handler = @TypeOf(fn)`, found found: {s}",
.{ field.name, @typeName(@TypeOf(event.handler)) },
));
}
}
// TODO: does it need to be pub?
// TODO: tests
/// Returns a struct type defining all module's components by module name, e.g.:
///
/// ```
/// struct {
/// builtin: struct {
/// id: @TypeOf() = .{ .type = EntityID, .description = "Entity ID" },
/// },
/// physics: struct {
/// location: @TypeOf() = .{ .type = Vec3, .description = null },
/// rotation: @TypeOf() = .{ .type = Vec2, .description = "rotation component" },
/// },
/// renderer: struct {
/// location: @TypeOf() = .{ .type = Vec2, .description = null },
/// },
/// }
/// ```
pub fn ComponentTypesByName(comptime modules: anytype) type {
var fields: []const std.builtin.Type.StructField = &[0]std.builtin.Type.StructField{};
inline for (modules) |M| {
const MC = ComponentTypesM(M);
fields = fields ++ [_]std.builtin.Type.StructField{.{
.name = @tagName(M.name),
.type = MC,
.default_value = &MC{},
.is_comptime = true,
.alignment = @alignOf(MC),
}};
}
// Builtin components
// TODO: better method of injecting builtin module?
const BuiltinMC = ComponentTypesM(struct {
pub const name = .builtin;
pub const components = .{
.id = .{ .type = EntityID, .description = "Entity ID" },
};
});
fields = fields ++ [_]std.builtin.Type.StructField{.{
.name = "entity",
.type = BuiltinMC,
.default_value = &BuiltinMC{},
.is_comptime = true,
.alignment = @alignOf(BuiltinMC),
}};
return @Type(.{
.Struct = .{
.layout = .Auto,
.is_tuple = false,
.fields = fields,
.decls = &[_]std.builtin.Type.Declaration{},
},
});
}
// TODO: tests
/// Returns a struct type defining the module's components, e.g.:
///
/// ```
/// struct {
/// location: @TypeOf() = .{ .type = Vec3, .description = null },
/// rotation: @TypeOf() = .{ .type = Vec2, .description = "rotation component" },
/// }
/// ```
fn ComponentTypesM(comptime M: anytype) type {
const error_prefix = "mach: module ." ++ @tagName(M.name) ++ " .components ";
if (!@hasDecl(M, "components")) {
return struct {};
}
if (@typeInfo(@TypeOf(M.components)) != .Struct or @typeInfo(@TypeOf(M.components)).Struct.is_tuple) {
@compileError(error_prefix ++ "expected a struct .{}, found: " ++ @typeName(@TypeOf(M.components)));
}
var fields: []const std.builtin.Type.StructField = &[0]std.builtin.Type.StructField{};
inline for (@typeInfo(@TypeOf(M.components)).Struct.fields) |field| {
const Component = field.type;
if (@typeInfo(Component) != .Struct) @compileError(std.fmt.comptimePrint(
error_prefix ++ "expected .{s} = .{{}}, found type: {s}",
.{ field.name, @typeName(Component) },
));
const component = @field(M.components, field.name);
// Verify .type = Foo, field
if (!@hasField(Component, "type")) @compileError(std.fmt.comptimePrint(
error_prefix ++ ".{s} missing field `.type = T`",
.{field.name},
));
if (@typeInfo(@TypeOf(component.type)) != .Type) @compileError(std.fmt.comptimePrint(
error_prefix ++ ".{s} expected field `.type = T`, found: {s}",
.{ field.name, @typeName(@TypeOf(component.type)) },
));
const description = blk: {
if (@hasField(Component, "description")) {
if (!isString(@TypeOf(component.description))) @compileError(std.fmt.comptimePrint(
error_prefix ++ ".{s} expected (optional) field `.description = \"foo\"`, found: {s}",
.{ field.name, @typeName(@TypeOf(component.description)) },
));
break :blk component.description;
} else break :blk null;
};
const NSComponent = struct {
type: type,
description: ?[]const u8,
};
const ns_component = NSComponent{ .type = component.type, .description = description };
fields = fields ++ [_]std.builtin.Type.StructField{.{
.name = field.name,
.type = NSComponent,
.default_value = &ns_component,
.is_comptime = true,
.alignment = @alignOf(NSComponent),
}};
}
return @Type(.{
.Struct = .{
.layout = .Auto,
.is_tuple = false,
.fields = fields,
.decls = &[_]std.builtin.Type.Declaration{},
},
});
}
fn isString(comptime S: type) bool {
return switch (@typeInfo(S)) {
.Pointer => |p| switch (p.size) {
.Many, .Slice => p.child == u8,
.One => switch (@typeInfo(p.child)) {
.Array => |a| a.child == u8,
else => false,
},
else => false,
},
else => false,
};
}
test isString {
const x: [*:0]const u8 = "foobar";
const y: []const u8 = "foobar";
const z: *const [6:0]u8 = "foobar";
try testing.expect(bool, true).eql(isString(@TypeOf(x)));
try testing.expect(bool, true).eql(isString(@TypeOf(y)));
try testing.expect(bool, true).eql(isString(@TypeOf(z)));
try testing.expect(bool, true).eql(isString(@TypeOf("baz")));
const v0: []const u32 = undefined;
const v1: u32 = undefined;
const v2: *u8 = undefined;
try testing.expect(bool, false).eql(isString(@TypeOf(v0)));
try testing.expect(bool, false).eql(isString(@TypeOf(v1)));
try testing.expect(bool, false).eql(isString(@TypeOf(v2)));
}
test {
testing.refAllDeclsRecursive(@This());
}
test ModuleInterface {
_ = ModuleInterface(struct {
// Physics module state
pointer: usize,
// Globally unique module name
pub const name = .engine_physics;
/// Physics module components
pub const components = .{
.location = .{ .type = @Vector(3, f32), .description = "A location component" },
};
pub const global_events = .{
.tick = .{ .handler = tick },
};
fn tick() !void {}
});
}
test Modules {
const Physics = ModuleInterface(struct {
// Physics module state
pointer: usize,
// Globally unique module name
pub const name = .engine_physics;
/// Physics module components
pub const components = .{
.location = .{ .type = @Vector(3, f32), .description = "A location component" },
};
pub const global_events = .{
.tick = .{ .handler = tick },
};
fn tick() !void {}
});
const Renderer = ModuleInterface(struct {
pub const name = .engine_renderer;
pub const global_events = .{
.tick = .{ .handler = tick },
};
fn tick() !void {}
});
const Sprite2D = ModuleInterface(struct {
pub const name = .engine_sprite2d;
});
var modules: Modules(.{
Physics,
Renderer,
Sprite2D,
}) = undefined;
try modules.init(testing.allocator);
defer modules.deinit(testing.allocator);
testing.refAllDeclsRecursive(Physics);
testing.refAllDeclsRecursive(Renderer);
testing.refAllDeclsRecursive(Sprite2D);
}
test "event name" {
const Physics = ModuleInterface(struct {
pub const name = .engine_physics;
pub const global_events = .{
.foo = .{ .handler = foo },
.bar = .{ .handler = bar },
};
pub const local_events = .{
.baz = .{ .handler = baz },
.bam = .{ .handler = bam },
};
fn foo() !void {}
fn bar() !void {}
fn baz() !void {}
fn bam() !void {}
});
const Renderer = ModuleInterface(struct {
pub const name = .engine_renderer;
pub const global_events = .{
.foo_unused = .{ .handler = fn (f32, i32) void },
.bar_unused = .{ .handler = fn (i32, f32) void },
.tick = .{ .handler = tick },
.foo = .{ .handler = foo },
.bar = .{ .handler = bar },
};
fn tick() !void {}
fn foo() !void {} // same .foo name as .engine_physics.foo
fn bar() !void {} // same .bar name as .engine_physics.bar
});
const Sprite2D = ModuleInterface(struct {
pub const name = .engine_sprite2d;
pub const global_events = .{
.tick = .{ .handler = tick },
.foobar = .{ .handler = fooBar },
};
fn tick() void {} // same .tick as .engine_renderer.tick
fn fooBar() void {}
});
const Ms = Modules(.{
Physics,
Renderer,
Sprite2D,
});
const locals = @typeInfo(Ms.LocalEvent).Enum;
try testing.expect(type, u1).eql(locals.tag_type);
try testing.expect(usize, 2).eql(locals.fields.len);
try testing.expect([]const u8, "baz").eql(locals.fields[0].name);
try testing.expect([]const u8, "bam").eql(locals.fields[1].name);
const globals = @typeInfo(Ms.GlobalEvent).Enum;
try testing.expect(type, u3).eql(globals.tag_type);
try testing.expect(usize, 6).eql(globals.fields.len);
try testing.expect([]const u8, "foo").eql(globals.fields[0].name);
try testing.expect([]const u8, "bar").eql(globals.fields[1].name);
try testing.expect([]const u8, "foo_unused").eql(globals.fields[2].name);
try testing.expect([]const u8, "bar_unused").eql(globals.fields[3].name);
try testing.expect([]const u8, "tick").eql(globals.fields[4].name);
try testing.expect([]const u8, "foobar").eql(globals.fields[5].name);
}
test ModuleName {
const Physics = ModuleInterface(struct {
pub const name = .engine_physics;
});
const Renderer = ModuleInterface(struct {
pub const name = .engine_renderer;
});
const Sprite2D = ModuleInterface(struct {
pub const name = .engine_sprite2d;
});
const Ms = Modules(.{
Physics,
Renderer,
Sprite2D,
});
const info = @typeInfo(ModuleName(Ms.modules)).Enum;
try testing.expect(type, u2).eql(info.tag_type);
try testing.expect(usize, 3).eql(info.fields.len);
try testing.expect([]const u8, "engine_physics").eql(info.fields[0].name);
try testing.expect([]const u8, "engine_renderer").eql(info.fields[1].name);
try testing.expect([]const u8, "engine_sprite2d").eql(info.fields[2].name);
}
// TODO: remove this in favor of testing.expect
const TupleTester = struct {
fn assertTypeEqual(comptime Expected: type, comptime Actual: type) void {
if (Expected != Actual) @compileError("Expected type " ++ @typeName(Expected) ++ ", but got type " ++ @typeName(Actual));
}
fn assertTuple(comptime expected: anytype, comptime Actual: type) void {
const info = @typeInfo(Actual);
if (info != .Struct) @compileError("Expected struct type");
if (!info.Struct.is_tuple) @compileError("Struct type must be a tuple type");
const fields_list = std.meta.fields(Actual);
if (expected.len != fields_list.len) @compileError("Argument count mismatch");
inline for (fields_list, 0..) |fld, i| {
if (expected[i] != fld.type) {
@compileError("Field " ++ fld.name ++ " expected to be type " ++ @typeName(expected[i]) ++ ", but was type " ++ @typeName(fld.type));
}
}
}
};
test injectArgs {
// Injected arguments should generally be *struct types to avoid conflicts with any user-passed
// parameters, though we do not require it - so we test with other types here.
const Foo = struct {
foo: f32,
pub const IsInjectedArgument = void;
};
const Bar = struct {
bar: i32,
pub const IsInjectedArgument = void;
};
const Baz = struct {
baz: bool,
pub const IsInjectedArgument = void;
};
var foo = Foo{ .foo = 0.1234 };
var bar = Bar{ .bar = 1234 };
var baz = Baz{ .baz = true };
const foo_ptr = &foo;
const bar_ptr = &bar;
const baz_ptr = &baz;
// No standard, no injected
try testing.expect(struct {}, .{}).eql(injectArgs(fn () void, @TypeOf(.{}), .{}, .{}));
const injectable = .{ foo_ptr, bar_ptr, baz_ptr };
try testing.expect(struct {}, .{}).eql(injectArgs(fn () void, @TypeOf(injectable), injectable, .{}));
// Standard parameters only, no injected
try testing.expect(std.meta.Tuple(&.{i32}), .{0}).eql(injectArgs(fn (a: i32) void, @TypeOf(injectable), injectable, .{0}));
try testing.expect(std.meta.Tuple(&.{ i32, f32 }), .{ 1, 0.5 }).eql(injectArgs(fn (a: i32, b: f32) void, @TypeOf(injectable), injectable, .{ 1, 0.5 }));
// Injected parameters only, no standard
try testing.expect(std.meta.Tuple(&.{*Foo}), .{foo_ptr}).eql(injectArgs(fn (a: *Foo) void, @TypeOf(injectable), injectable, .{}));
try testing.expect(std.meta.Tuple(&.{ *Foo, *Bar }), .{ foo_ptr, bar_ptr }).eql(injectArgs(fn (a: *Foo, b: *Bar) void, @TypeOf(injectable), injectable, .{}));
try testing.expect(std.meta.Tuple(&.{ *Foo, *Bar, *Baz }), .{ foo_ptr, bar_ptr, baz_ptr }).eql(injectArgs(fn (a: *Foo, b: *Bar, c: *Baz) void, @TypeOf(injectable), injectable, .{}));
try testing.expect(std.meta.Tuple(&.{ *Bar, *Baz, *Foo }), .{ bar_ptr, baz_ptr, foo_ptr }).eql(injectArgs(fn (a: *Bar, b: *Baz, c: *Foo) void, @TypeOf(injectable), injectable, .{}));
try testing.expect(std.meta.Tuple(&.{ *Foo, *Foo, *Baz }), .{ foo_ptr, foo_ptr, baz_ptr }).eql(injectArgs(fn (a: *Foo, b: *Foo, c: *Baz) void, @TypeOf(injectable), injectable, .{}));
// As long as the argument is a Struct or *Struct with an IsInjectedArgument decl, it is
// considered an injected argument.
// try testing.expect(std.meta.Tuple(&.{*const Foo}), .{foo_ptr}).eql(injectArgs(fn (a: *const Foo) void, @TypeOf(injectable), injectable, .{}));
const injectable2 = .{ foo, foo_ptr, bar_ptr, baz_ptr };
try testing.expect(std.meta.Tuple(&.{Foo}), .{foo_ptr.*}).eql(injectArgs(fn (a: Foo) void, @TypeOf(injectable2), injectable2, .{}));
// Order doesn't matter, injected arguments can be placed inbetween any standard arguments, etc.
try testing.expect(std.meta.Tuple(&.{ i32, *Foo, *Foo, *Baz }), .{ 1337, foo_ptr, foo_ptr, baz_ptr }).eql(injectArgs(fn (z: i32, a: *Foo, b: *Foo, c: *Baz) void, @TypeOf(injectable), injectable, .{1337}));
try testing.expect(std.meta.Tuple(&.{ i32, *Foo, f32, *Foo, *Baz }), .{ 1337, foo_ptr, 1.337, foo_ptr, baz_ptr }).eql(injectArgs(fn (z: i32, a: *Foo, w: f32, b: *Foo, c: *Baz) void, @TypeOf(injectable), injectable, .{ 1337, 1.337 }));
try testing.expect(std.meta.Tuple(&.{ i32, f32, *Foo, *Foo, *Baz }), .{ 1337, 1.337, foo_ptr, foo_ptr, baz_ptr }).eql(injectArgs(fn (z: i32, w: f32, a: *Foo, b: *Foo, c: *Baz) void, @TypeOf(injectable), injectable, .{ 1337, 1.337 }));
try testing.expect(std.meta.Tuple(&.{ *Foo, *Foo, *Baz, i32, f32 }), .{ foo_ptr, foo_ptr, baz_ptr, 1337, 1.337 }).eql(injectArgs(fn (az: *Foo, b: *Foo, c: *Baz, z: i32, w: f32) void, @TypeOf(injectable), injectable, .{ 1337, 1.337 }));
}
test UninjectedArgsTuple {
const Foo = struct {
foo: f32,
pub const IsInjectedArgument = void;
};
const Bar = struct {
bar: bool,
pub const IsInjectedArgument = void;
};
// No standard, no injected
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn () void));
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn () void));
// Standard parameters only, no injected
TupleTester.assertTuple(.{i32}, UninjectedArgsTuple(std.meta.Tuple, fn (a: i32) void));
TupleTester.assertTuple(.{ i32, f32 }, UninjectedArgsTuple(std.meta.Tuple, fn (a: i32, b: f32) void));
// Injected parameters only, no standard
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Foo) void));
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Bar) void));
// As long as the argument is a Struct or *Struct with an IsInjectedArgument decl, it is
// considered an injected argument.
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Foo, b: *Bar, c: Foo, d: Bar) void));
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: Foo) void));
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: Bar) void));
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *const Foo) void));
TupleTester.assertTuple(.{}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *const Bar) void));
// Order doesn't matter, injected arguments can be placed inbetween any standard arguments, etc.
TupleTester.assertTuple(.{ f32, bool }, UninjectedArgsTuple(std.meta.Tuple, fn (i: f32, a: *Foo, k: bool, b: *Bar, c: Foo, d: Bar) void));
TupleTester.assertTuple(.{f32}, UninjectedArgsTuple(std.meta.Tuple, fn (i: f32, a: *Foo, b: *Bar, c: Foo, d: Bar) void));
TupleTester.assertTuple(.{f32}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Foo, i: f32, b: *Bar, c: Foo, d: Bar) void));
TupleTester.assertTuple(.{f32}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Foo, b: *Bar, i: f32, c: Foo, d: Bar) void));
TupleTester.assertTuple(.{f32}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Foo, b: *Bar, c: Foo, i: f32, d: Bar) void));
TupleTester.assertTuple(.{f32}, UninjectedArgsTuple(std.meta.Tuple, fn (a: *Foo, b: *Bar, c: Foo, d: Bar, i: f32) void));
}
test "event name calling" {
// TODO: verify that event handlers error return signatures are correct
const global = struct {
var ticks: usize = 0;
var physics_updates: usize = 0;
var physics_calc: usize = 0;
var renderer_updates: usize = 0;
};
const Physics = ModuleInterface(struct {
pub const name = .engine_physics;
pub const global_events = .{
.tick = .{ .handler = tick },
};
pub const local_events = .{
.update = .{ .handler = update },
.calc = .{ .handler = calc },
};
fn tick() void {
global.ticks += 1;
}
fn update() void {
global.physics_updates += 1;
}
fn calc() void {
global.physics_calc += 1;
}
});
const Renderer = ModuleInterface(struct {
pub const name = .engine_renderer;
pub const global_events = .{
.tick = .{ .handler = tick },
};
pub const local_events = .{
.update = .{ .handler = update },
};
fn tick() void {
global.ticks += 1;
}
fn update() void {
global.renderer_updates += 1;
}
});
var modules: Modules(.{
Physics,
Renderer,
}) = undefined;
try modules.init(testing.allocator);
defer modules.deinit(testing.allocator);
try @TypeOf(modules).callGlobal(.tick, &.{}, .{});
try testing.expect(usize, 2).eql(global.ticks);
// Check we can use .callGlobal() with a runtime-known event name.
const alloc = try testing.allocator.create(u3);
defer testing.allocator.destroy(alloc);
const GE = @TypeOf(modules).GlobalEvent;
const LE = @TypeOf(modules).LocalEvent;
alloc.* = @intFromEnum(@as(GE, .tick));
const global_event_name = @as(GE, @enumFromInt(alloc.*));
try @TypeOf(modules).callGlobal(global_event_name, &.{}, .{});
try testing.expect(usize, 4).eql(global.ticks);
// Check we can use .callLocal() with a runtime-known event and module name.
const m_alloc = try testing.allocator.create(u3);
defer testing.allocator.destroy(m_alloc);
const M = ModuleName(@TypeOf(modules).modules);
m_alloc.* = @intFromEnum(@as(M, .engine_renderer));
alloc.* = @intFromEnum(@as(LE, .update));
var module_name = @as(M, @enumFromInt(m_alloc.*));
var local_event_name = @as(LE, @enumFromInt(alloc.*));
try @TypeOf(modules).callLocal(module_name, local_event_name, &.{}, .{});
try @TypeOf(modules).callLocal(module_name, local_event_name, &.{}, .{});
try testing.expect(usize, 4).eql(global.ticks);
try testing.expect(usize, 0).eql(global.physics_updates);
try testing.expect(usize, 2).eql(global.renderer_updates);
m_alloc.* = @intFromEnum(@as(M, .engine_physics));
alloc.* = @intFromEnum(@as(LE, .update));
module_name = @as(M, @enumFromInt(m_alloc.*));
local_event_name = @as(LE, @enumFromInt(alloc.*));
try @TypeOf(modules).callLocal(module_name, local_event_name, &.{}, .{});
try testing.expect(usize, 1).eql(global.physics_updates);
m_alloc.* = @intFromEnum(@as(M, .engine_physics));
alloc.* = @intFromEnum(@as(LE, .calc));
module_name = @as(M, @enumFromInt(m_alloc.*));
local_event_name = @as(LE, @enumFromInt(alloc.*));
try @TypeOf(modules).callLocal(module_name, local_event_name, &.{}, .{});
try testing.expect(usize, 4).eql(global.ticks);
try testing.expect(usize, 1).eql(global.physics_calc);
try testing.expect(usize, 1).eql(global.physics_updates);
try testing.expect(usize, 2).eql(global.renderer_updates);
}
test "dispatch" {
const global = struct {
var ticks: usize = 0;
var physics_updates: usize = 0;
var physics_calc: usize = 0;
var renderer_updates: usize = 0;
var basic_args_sum: usize = 0;
};
var foo = struct {
injected_args_sum: usize = 0,
pub const IsInjectedArgument = void;
}{};
const Minimal = ModuleInterface(struct {
pub const name = .engine_minimal;
});
const Physics = ModuleInterface(struct {
pub const name = .engine_physics;
pub const global_events = .{
.tick = .{ .handler = tick },
};
pub const local_events = .{
.update = .{ .handler = update },
.calc = .{ .handler = calc },
};
fn tick() void {
global.ticks += 1;
}
fn update() void {
global.physics_updates += 1;
}
fn calc() void {
global.physics_calc += 1;
}
});
const Renderer = ModuleInterface(struct {
pub const name = .engine_renderer;
pub const global_events = .{
.tick = .{ .handler = tick },
.frame_done = .{ .handler = fn (i32) void },
};
pub const local_events = .{
.update = .{ .handler = update },
.basic_args = .{ .handler = basicArgs },
.injected_args = .{ .handler = injectedArgs },
};
pub const frameDone = fn (i32) void;
fn tick() void {
global.ticks += 1;
}
fn update() void {
global.renderer_updates += 1;
}
fn basicArgs(a: u32, b: u32) void {
global.basic_args_sum = a + b;
}
fn injectedArgs(foo_ptr: *@TypeOf(foo), a: u32, b: u32) void {
foo_ptr.*.injected_args_sum = a + b;
}
});
var modules: Modules(.{
Minimal,
Physics,
Renderer,
}) = undefined;
try modules.init(testing.allocator);
defer modules.deinit(testing.allocator);
const GE = @TypeOf(modules).GlobalEvent;
const LE = @TypeOf(modules).LocalEvent;
const M = ModuleName(@TypeOf(modules).modules);
// Global events
//
// The 2nd parameter (arguments to the tick event handler) is inferred based on the `pub fn tick`
// global event handler declaration within a module. It is required that all global event handlers
// of the same name have the same standard arguments, although they can start with different
// injected arguments.
modules.sendGlobal(.engine_renderer, .tick, .{});
try testing.expect(usize, 0).eql(global.ticks);
try modules.dispatchInternal(.{&foo});
try testing.expect(usize, 2).eql(global.ticks);
// TODO: make sendDynamic take an args type to avoid footguns with comptime values, etc.
modules.sendDynamic(@intFromEnum(@as(GE, .tick)), .{});
try modules.dispatchInternal(.{&foo});
try testing.expect(usize, 4).eql(global.ticks);
// Global events which are not handled by anyone yet can be written as `pub const fooBar = fn() void;`
// within a module, which allows pre-declaring that `fooBar` is a valid global event, and enables
// its arguments to be inferred still like this:
modules.sendGlobal(.engine_renderer, .frame_done, .{ .@"0" = 1337 });
// Local events
modules.sendToModule(.engine_renderer, .update, .{});
try modules.dispatchInternal(.{&foo});
try testing.expect(usize, 1).eql(global.renderer_updates);
modules.sendToModule(.engine_physics, .update, .{});
modules.sendToModuleDynamic(
@intFromEnum(@as(M, .engine_physics)),
@intFromEnum(@as(LE, .calc)),
.{},
);
try modules.dispatchInternal(.{&foo});
try testing.expect(usize, 1).eql(global.physics_updates);
try testing.expect(usize, 1).eql(global.physics_calc);
// Local events
modules.sendToModule(.engine_renderer, .basic_args, .{ .@"0" = @as(u32, 1), .@"1" = @as(u32, 2) }); // TODO: match arguments against fn ArgsTuple, for correctness and type inference
modules.sendToModule(.engine_renderer, .injected_args, .{ .@"0" = @as(u32, 1), .@"1" = @as(u32, 2) });
try modules.dispatchInternal(.{&foo});
try testing.expect(usize, 3).eql(global.basic_args_sum);
try testing.expect(usize, 3).eql(foo.injected_args_sum);
}