WIP flecs-zig-ble new system init

.gitignore

@@ -3,5 +3,6 @@
 /zig-out/
 
 # Dependencies (cloned manually)
-/libs/flecs-zig-ble/
-/libs/zig-gamedev/
+# Could be symlinks, so not including trailing slash.
+/libs/flecs-zig-ble
+/libs/zig-gamedev

build.zig

@@ -18,7 +18,7 @@ pub fn build(b: *std.Build) !void {
 
     const app = try mach.CoreApp.init(b, mach_dep.builder, .{
         .name = "zig-bloxel-game",
-        .src = "src/main.zig",
+        .src = "src/App.zig",
         .target = target,
         .optimize = optimize,
         .deps = &.{
@@ -36,7 +36,7 @@ pub fn build(b: *std.Build) !void {
     run_step.dependOn(&app.run.step);
 
     const unit_tests = b.addTest(.{
-        .root_source_file = .{ .path = "src/main.zig" },
+        .root_source_file = .{ .path = "src/App.zig" },
         .target = target,
         .optimize = optimize,
     });

src/App.zig

@@ -2,18 +2,15 @@ const std = @import("std");
 const GeneralPurposeAllocator = std.heap.GeneralPurposeAllocator(.{});
 
 const core = @import("mach").core;
-const Renderer = @import("./renderer.zig");
+const Renderer = @import("./Renderer.zig");
 
 const flecszigble = @import("flecs-zig-ble");
+const flecs = flecszigble.flecs;
+
 const Context = flecszigble.Context(void);
 const World = Context.World;
 const Iter = Context.Iter;
 
-const flecs = flecszigble.flecs;
-const OnLoad = flecs.pipeline.OnLoad;
-const OnUpdate = flecs.pipeline.OnUpdate;
-const OnStore = flecs.pipeline.OnStore;
-
 pub const App = @This();
 
 gpa: GeneralPurposeAllocator,
@@ -57,14 +54,10 @@ pub fn init(app: *App) !void {
     app.world = world;
 
     // Create a singleton component for accessing the `App` from ECS.
-    _ = try world.singleton("App", *App, app);
-
-    // TODO: The way we register systems using flecs-zig-ble is still very WIP.
-    _ = try world.system("PollEvents", pollEvents, OnLoad, "App");
+    _ = try world.singleton(*App, app);
 
-    const s = try world.system("UpdateWindowTitle", updateWindowTitle, OnStore, "");
-    // Set the update interval of the `UpdateWindowTitle` system to 1 second.
-    _ = flecszigble.c.ecs_set_interval(world.raw, s.raw, 1.0);
+    _ = try world.system(PollEvents);
+    _ = try world.system(UpdateWindowTitle);
 
     app.renderer = try Renderer.init(app);
 }
@@ -84,30 +77,36 @@ pub fn update(app: *App) !bool {
     return !app.world.progress(0.0);
 }
 
-/// Read events from the OS such as input.
-pub fn pollEvents(it: Iter) void {
-    const app = it.field(*App, 1)[0];
-
+/// System that reads events from the OS such as input.
+pub const PollEvents = struct {
+    pub const phase = flecs.pipeline.OnLoad;
+    pub const expr = "App($)";
+    pub fn callback(world: *World, app: *const *App) void {
         var pollIter = core.pollEvents();
         while (pollIter.next()) |event| {
             switch (event) {
                 // Allow the renderer to act on the window being resized.
                 // This is required so we can resize necessary buffers.
-            .framebuffer_resize => |_| app.renderer.resize(),
+                .framebuffer_resize => |_| app.*.renderer.resize(),
 
                 // Close the window when requested, such as when
                 // pressing the X button in the window title bar.
-            .close => it.world.quit(),
+                .close => world.quit(),
 
                 else => {},
             }
         }
     }
+};
 
-/// Update the window title to show FPS and input frequency.
-pub fn updateWindowTitle(_: Iter) void {
+/// System that updates the window title to show FPS and input frequency.
+pub const UpdateWindowTitle = struct {
+    pub const phase = flecs.pipeline.OnStore;
+    pub const interval = 1.0; // Run only once a second.
+    pub fn callback(_: Iter) void {
         core.printTitle(
             "Triangle [ {d}fps ] [ Input {d}hz ]",
             .{ core.frameRate(), core.inputRate() },
         ) catch @panic("Title too long!");
     }
+};

src/Renderer.zig

@@ -11,20 +11,19 @@ const zm = @import("zmath");
 const vec = zm.f32x4;
 const Mat = zm.Mat;
 
-const App = @import("./main.zig");
+const App = @import("./App.zig");
 
 const primitives = @import("./primitives.zig");
 const VertexData = primitives.VertexData;
 const PrimitiveData = primitives.PrimitiveData;
 
 const flecszigble = @import("flecs-zig-ble");
+const flecs = flecszigble.flecs;
+
 const Context = flecszigble.Context(void);
 const Entity = Context.Entity;
 const Iter = Context.Iter;
 
-const flecs = flecszigble.flecs;
-const OnStore = flecs.pipeline.OnStore;
-
 const Transform = struct { value: Mat };
 const CameraPerspective = struct {
     /// Vertical field of view (in degrees).
@@ -231,8 +230,8 @@ pub fn init(app: *App) !*Renderer {
     }
 
     // Register components necessary for the camera.
-    _ = try app.world.component("Transform", Transform);
-    _ = try app.world.component("CameraPerspective", CameraPerspective);
+    _ = try app.world.component(Transform);
+    _ = try app.world.component(CameraPerspective);
 
     const camera_entity = try app.world.entity(
         .{ .name = "Camera", .symbol = "Camera" },
@@ -244,8 +243,7 @@ pub fn init(app: *App) !*Renderer {
         .far_plane = 80.0,
     });
 
-    const render_expr = "App, [in] CameraPerspective(Camera), [out] Transform(Camera)";
-    _ = try app.world.system("Render", render, OnStore, render_expr);
+    _ = try app.world.system(Render);
 
     const result = try app.allocator.create(Renderer);
     result.* = .{
@@ -293,7 +291,11 @@ pub fn resize(self: *Renderer) void {
     self.recreateDepthTexture();
 }
 
-pub fn render(it: Iter) void {
+/// System which renders the game world from the camera entity's perspective.
+pub const Render = struct {
+    pub const phase = flecs.pipeline.OnStore;
+    pub const expr = "App($), [in] CameraPerspective(Camera), [out] Transform(Camera)";
+    pub fn callback(it: Iter) void {
         const app = it.field(*App, 1)[0];
         const camera_perspective = it.field(CameraPerspective, 2)[0];
         const camera_transform = &it.field(Transform, 3)[0];
@@ -392,6 +394,7 @@ pub fn render(it: Iter) void {
         // Submit the command(s) to the GPU.
         core.queue.submit(&.{command});
     }
+};
 
 /// Loads a texture from the provided buffer and uploads it to the GPU.
 pub fn loadTexture(allocator: std.mem.Allocator, buffer: []const u8) !*gpu.TextureView {

src/primitives.zig

@@ -3,7 +3,7 @@ const tau = std.math.tau;
 
 const gpu = @import("mach").core.gpu;
 
-const Renderer = @import("./renderer.zig");
+const Renderer = @import("./Renderer.zig");
 const createAndWriteBuffer = Renderer.createAndWriteBuffer;
 
 /// Describes the layout of each vertex that a primitive is made of.