libmach: update API again, factors out init/update/deinit from native.zig main function

build.zig

@@ -123,7 +123,8 @@ pub fn build(b: *std.build.Builder) void {
     compile_all.dependOn(b.getInstallStep());
 
     // compiles the `libmach` shared library
-    const lib = b.addSharedLibrary("mach", "src/bindings.zig", .unversioned);
+    const lib = b.addSharedLibrary("mach", "src/platform/libmach.zig", .unversioned);
+    lib.main_pkg_path = "src/";
     const app_pkg = std.build.Pkg{
         .name = "app",
         .source = .{ .path = "src/platform/libmach.zig" },

libmach/test.c

@@ -4,13 +4,18 @@
 
 typedef void resize_callback(void*, uint32_t, uint32_t);
 
+typedef enum {
+  MachFailure,
+  MachSuccess
+} MachReturn;
+
 // `libmach` exported API bindings
-void* mach_init_core(void);
+void* mach_core_init(void);
-void mach_deinit(void*);
+void mach_core_deinit(void*);
-void mach_set_should_close(void*);
+void mach_core_set_should_close(void*);
-bool mach_window_should_close(void*);
+bool mach_core_window_should_close(void*);
-int mach_update(void*, resize_callback);
+MachReturn mach_core_update(void*, resize_callback);
-float mach_delta_time(void*);
+float mach_core_delta_time(void*);
 
 void resize_fn(void* core, uint32_t width, uint32_t height) {
   printf("Resize callback: %u %u\n", width, height);
@@ -19,28 +24,28 @@ void resize_fn(void* core, uint32_t width, uint32_t height) {
 static float elapsed = 0;
 
 int main() {
-  void* core = mach_init_core();
+  void* core = mach_core_init();
 
   if (core == 0) {
     printf("Error instantiating mach core\n");
     return 0;
   }
 
-  while (!mach_window_should_close(core)) {
+  while (!mach_core_window_should_close(core)) {
-    if (mach_update(core, resize_fn) == 0) {
+    if (mach_core_update(core, resize_fn) == MachFailure) {
       printf("Error updating Mach\n");
       break;
     };
 
-    elapsed += mach_delta_time(core);
+    elapsed += mach_core_delta_time(core);
     if (elapsed > 5.0) {
-      mach_set_should_close(core);
+      mach_core_set_should_close(core);
     }
 
     // printf("Elapsed: %f\n", elapsed);
   }
 
-  mach_deinit(core);
+  mach_core_deinit(core);
 
   return 0;
 }

libmach/test.lisp

@@ -15,29 +15,24 @@
 
 ;; Note: CFFI automatically translates C_style names into lispier kebab-case ones
 
-;; void* mach_init(void);
+(defcfun "mach_core_init" :pointer)
-(defcfun "mach_init_core" :pointer)
-;; for some reason, calling "mach_init" always returns a null pointer, and I have no clue why...
-;; So I renamed the API function name to "mach_init_core" instead
 
-;; int mach_update(void*, resize_callback);
+(defcfun "mach_core_update" :int
-(defcfun "mach_update" :int
   (core :pointer) (resize-fn :pointer))
 
-;; void mach_deinit(void*);
+(defcfun "mach_core_deinit" :void
-(defcfun "mach_deinit" :void
   (core :pointer))
 
 ;; void mach_set_should_close(void*);
-(defcfun "mach_set_should_close" :void
+(defcfun "mach_core_set_should_close" :void
   (core :pointer))
 
 ;; float mach_delta_time(void*);
-(defcfun "mach_delta_time" :float
+(defcfun "mach_core_delta_time" :float
   (core :pointer))
 
 ;; bool mach_window_should_close(void*);
-(defcfun "mach_window_should_close" :bool
+(defcfun "mach_core_window_should_close" :bool
   (core :pointer))
 
 ;; main
@@ -46,20 +41,18 @@
 (defcallback resize-fn :void ((core :pointer) (width :unsigned-int) (height :unsigned-int))
   (format t "Resize Callback: ~S ~S~%" width height))
 
-(setf core (mach-init-core))
+(setf core (mach-core-init))
-
-(format t "Core: ~S~%" core)
 
 (when (pointer-eq core (null-pointer))
   (format t "Failed to initialize mach core~%")
   (sb-ext:exit))
 
-(loop while (not (mach-window-should-close core))
+(loop while (not (mach-core-window-should-close core))
       do (progn
-           (when (= 0 (mach-update core (callback resize-fn)))
+           (when (= 0 (mach-core-update core (callback resize-fn)))
              (format t "Error updating mach~%")
              (sb-ext:exit))
-           (when (> (incf *elapsed* (mach-delta-time core)) 5.0)
+           (when (> (incf *elapsed* (mach-core-delta-time core)) 5.0)
-             (mach-set-should-close core))))
+             (mach-core-set-should-close core))))
 
 (sb-ext:exit)

src/platform/libmach.zig

@@ -3,6 +3,7 @@ const Core = @import("../Core.zig");
 const gpu = @import("gpu");
 const ecs = @import("ecs");
 const glfw = @import("glfw");
+const native = @import("native.zig");
 
 pub const App = @This();
 
@@ -19,89 +20,42 @@ pub fn update(_: *App, _: *Core) !void { }
 // 2. Core might need to expose more state so more API functions can be exposed (for example, the WebGPU API)
 // 3. Be very careful about arguments, types, memory, etc - any mismatch will result in undefined behavior
 
-pub export fn mach_set_should_close(core: *Core) void {
+pub export fn mach_core_set_should_close(core: *Core) void {
     core.setShouldClose(true);
 }
 
-pub export fn mach_delta_time(core: *Core) f32 {
+pub export fn mach_core_delta_time(core: *Core) f32 {
     return core.delta_time;
 }
 
+pub export fn mach_core_window_should_close(core: *Core) bool {
+    return core.internal.window.shouldClose();
+}
+
 var gpa = std.heap.GeneralPurposeAllocator(.{}){};
 const allocator = gpa.allocator();
 
-// Initializes and returns Mach's core structure
+// Returns a pointer to a newly allocated Core
-// Uses an optional type so it is valid to return 0 (on an error)
+// Will return a null pointer if an error occurred while initializing Core
-// TODO: come up with a better error reporting system
+pub export fn mach_core_init() ?*Core {
-pub export fn mach_init_core() ?*Core {
+    const core = native.core_init(allocator) catch {
-    const core: *Core = allocator.create(Core) catch {
+        return @intToPtr(?*Core, 0);
-        return @intToPtr(?*Core, 0); // on error, return null pointer
     };
-    core.* = Core.init(allocator) catch {
-        return @intToPtr(?*Core, 0); // on error, return null pointer
-    };
-
-    // // Glfw specific: initialize the user pointer used in callbacks
-    core.*.internal.initCallback();
-
     return core;
 }
 
-// Deinitializes mach core structure
+pub export fn mach_core_deinit(core: *Core) void {
-pub export fn mach_deinit(core: *Core) void {
+    native.core_deinit(core);
-    core.internal.deinit();
-    allocator.destroy(core);
 }
 
-pub export fn mach_window_should_close(core: *Core) bool {
+pub export fn mach_core_update(core: *Core, resize: ?native.CoreResizeCallback) MachReturn {
-    return core.internal.window.shouldClose();
+    native.core_update(core, resize) catch {
+        return MachReturn.Failure;
+    };
+    return MachReturn.Success;
 }
 
-pub const CoreCallback = fn (*Core, u32, u32) callconv(.C) void;
+const MachReturn = enum(c_int) { 
-
+    Failure,
-// Adapted from native.zig
+    Success,
-pub export fn mach_update(core: *Core, resize_fn: ?CoreCallback) i32 {
+};
-    if (core.internal.wait_event_timeout > 0.0) {
-        if (core.internal.wait_event_timeout == std.math.inf(f64)) {
-            // Wait for an event
-            glfw.waitEvents() catch {
-                return 0;
-            };
-        } else {
-            // Wait for an event with a timeout
-            glfw.waitEventsTimeout(core.internal.wait_event_timeout) catch {
-                return 0;
-            };
-        }
-    } else {
-        // Don't wait for events
-        glfw.pollEvents() catch {
-            return 0;
-        };
-    }
-
-    core.delta_time_ns = core.timer.lapPrecise();
-    core.delta_time = @intToFloat(f32, core.delta_time_ns) / @intToFloat(f32, std.time.ns_per_s);
-
-    var framebuffer_size = core.getFramebufferSize();
-    core.target_desc.width = framebuffer_size.width;
-    core.target_desc.height = framebuffer_size.height;
-
-    if (core.swap_chain == null or !core.current_desc.equal(&core.target_desc)) {
-        const use_legacy_api = core.surface == null;
-        if (!use_legacy_api) {
-            core.swap_chain = core.device.nativeCreateSwapChain(core.surface, &core.target_desc);
-        } else core.swap_chain.?.configure(
-            core.swap_chain_format,
-            .{ .render_attachment = true },
-            core.target_desc.width,
-            core.target_desc.height,
-        );
-
-        if (resize_fn != null) {
-            resize_fn.?(core, core.target_desc.width, core.target_desc.height);
-        }
-        core.current_desc = core.target_desc;
-    }
-    return 1;
-}

src/platform/native.zig

@@ -587,23 +587,45 @@ pub const Platform = struct {
 
 pub const BackingTimer = std.time.Timer;
 
+var app: App = undefined;
+
 pub fn main() !void {
     var gpa = std.heap.GeneralPurposeAllocator(.{}){};
     defer _ = gpa.deinit();
     const allocator = gpa.allocator();
 
-    var core = try Core.init(allocator);
+    var core = try core_init(allocator);
-    defer core.internal.deinit();
+    defer core_deinit(core);
-    var app: App = undefined;
 
-    try app.init(&core);
+    try app.init(core);
-    defer app.deinit(&core);
+    defer app.deinit(core);
 
-    // Glfw specific: initialize the user pointer used in callbacks
+    while (!core.internal.window.shouldClose()) {
-    core.internal.initCallback();
+        try core_update(core, null);
 
-    const window = core.internal.window;
+        try app.update(core);
-    while (!window.shouldClose()) {
+    }
+}
+
+pub fn core_init(allocator: std.mem.Allocator) !*Core {
+    const core: *Core = try allocator.create(Core);
+    core.* = try Core.init(allocator);
+
+    // // Glfw specific: initialize the user pointer used in callbacks
+    core.*.internal.initCallback();
+
+    return core;
+}
+
+pub export fn core_deinit(core: *Core) void {
+    core.internal.deinit();
+    // assumes that core.allocator is the same allocator used to allocate core
+    core.allocator.destroy(core); // "I used the core to destroy the core"
+}
+
+pub const CoreResizeCallback = fn (*Core, u32, u32) callconv(.C) void;
+
+pub fn core_update(core: *Core, resize: ?CoreResizeCallback) !void {
     if (core.internal.wait_event_timeout > 0.0) {
         if (core.internal.wait_event_timeout == std.math.inf(f64)) {
             // Wait for an event
@@ -636,11 +658,10 @@ pub fn main() !void {
         );
 
         if (@hasDecl(App, "resize")) {
-                try app.resize(&core, core.target_desc.width, core.target_desc.height);
+            try app.resize(core, core.target_desc.width, core.target_desc.height);
+        } else if (resize != null) {
+            resize.?(core, core.target_desc.width, core.target_desc.height);
         }
         core.current_desc = core.target_desc;
     }
-
-        try app.update(&core);
-    }
 }