core: move input state tracking from Platform to Core

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

src/Core.zig

@@ -156,6 +156,8 @@ descriptor: gpu.SwapChain.Descriptor,
 
 // Internal state
 events: EventQueue,
+input_state: InputState,
+oom: std.Thread.ResetEvent = .{},
 
 // TODO: this needs to be removed.
 pub const InitOptions = struct {
@@ -208,6 +210,7 @@ fn init(core: *Mod, entities: *mach.Entities.Mod) !void {
         .allocator = allocator,
         .main_window = main_window,
         .events = events,
+        .input_state = .{},
 
         // TODO: remove undefined initialization (disgusting!)
         .platform = undefined,
@@ -617,6 +620,41 @@ pub inline fn nextEvent(core: *@This()) ?Event {
     return core.events.readItem();
 }
 
+/// Push an event onto the event queue, or set OOM if no space is available.
+///
+/// Updates the input_state tracker.
+pub inline fn pushEvent(core: *@This(), event: Event) void {
+    // Write event
+    core.events.writeItem(event) catch {
+        core.oom.set();
+        return;
+    };
+
+    // Update input state
+    switch (event) {
+        .key_press => |ev| core.input_state.keys.setValue(@intFromEnum(ev.key), true),
+        .key_release => |ev| core.input_state.keys.setValue(@intFromEnum(ev.key), false),
+        .mouse_press => |ev| core.input_state.mouse_buttons.setValue(@intFromEnum(ev.button), true),
+        .mouse_release => |ev| core.input_state.mouse_buttons.setValue(@intFromEnum(ev.button), false),
+        .mouse_motion => |ev| core.input_state.mouse_position = ev.pos,
+        .focus_lost => {
+            // Clear input state that may be 'stuck' when focus is regained.
+            core.input_state.keys = InputState.KeyBitSet.initEmpty();
+            core.input_state.mouse_buttons = InputState.MouseButtonSet.initEmpty();
+        },
+        else => {},
+    }
+}
+
+/// Reports whether mach.Core ran out of memory, indicating events may have been dropped.
+///
+/// Once called, the OOM flag is reset and mach.Core will continue operating normally.
+pub fn outOfMemory(core: *@This()) bool {
+    if (!core.oom.isSet()) return false;
+    core.oom.reset();
+    return true;
+}
+
 /// Sets the window title. The string must be owned by Core, and will not be copied or freed. It is
 /// advised to use the `core.title` buffer for this purpose, e.g.:
 ///
@@ -672,6 +710,26 @@ pub inline fn headless(core: *@This()) bool {
     return core.platform.headless;
 }
 
+pub fn keyPressed(core: *@This(), key: Key) bool {
+    return core.input_state.isKeyPressed(key);
+}
+
+pub fn keyReleased(core: *@This(), key: Key) bool {
+    return core.input_state.isKeyReleased(key);
+}
+
+pub fn mousePressed(core: *@This(), button: MouseButton) bool {
+    return core.input_state.isMouseButtonPressed(button);
+}
+
+pub fn mouseReleased(core: *@This(), button: MouseButton) bool {
+    return core.input_state.isMouseButtonReleased(button);
+}
+
+pub fn mousePosition(core: *@This()) Position {
+    return core.input_state.mouse_position;
+}
+
 pub const VSyncMode = enum {
     /// Potential screen tearing.
     /// No synchronization with monitor, render frames as fast as possible.
@@ -784,31 +842,11 @@ pub inline fn cursorShape(core: *@This()) CursorShape {
     return core.platform.cursorShape();
 }
 
-pub inline fn keyPressed(core: *@This(), key: Key) bool {
-    return core.platform.keyPressed(key);
-}
-
-pub inline fn keyReleased(core: *@This(), key: Key) bool {
-    return core.platform.keyReleased(key);
-}
-
-pub inline fn mousePressed(core: *@This(), button: MouseButton) bool {
-    return core.platform.mousePressed(button);
-}
-
-pub inline fn mouseReleased(core: *@This(), button: MouseButton) bool {
-    return core.platform.mouseReleased(button);
-}
-
 pub const Position = struct {
     x: f64,
     y: f64,
 };
 
-pub inline fn mousePosition(core: *@This()) Position {
-    return core.platform.mousePosition();
-}
-
 /// Sets the minimum target frequency of the input handling thread.
 ///
 /// Input handling (the main thread) runs at a variable frequency. The thread blocks until there are
@@ -1100,12 +1138,6 @@ comptime {
 
     assertHasDecl(Platform, "setCursorShape");
     assertHasField(Platform, "cursor_shape");
-
-    assertHasDecl(Platform, "keyPressed");
-    assertHasDecl(Platform, "keyReleased");
-    assertHasDecl(Platform, "mousePressed");
-    assertHasDecl(Platform, "mouseReleased");
-    assertHasDecl(Platform, "mousePosition");
 }
 
 fn assertHasDecl(comptime T: anytype, comptime decl_name: []const u8) void {

src/core/Darwin.zig

@@ -23,7 +23,6 @@ pub const Darwin = @This();
 
 allocator: std.mem.Allocator,
 core: *Core,
-input_state: Core.InputState,
 title: [:0]const u8,
 display_mode: DisplayMode,
 vsync_mode: VSyncMode,
@@ -109,7 +108,6 @@ pub fn init(
     darwin.* = .{
         .allocator = options.allocator,
         .core = @fieldParentPtr("platform", darwin),
-        .input_state = .{},
         .title = options.title,
         .display_mode = options.display_mode,
         .vsync_mode = .none,
@@ -168,23 +166,3 @@ pub fn setCursorMode(_: *Darwin, _: CursorMode) void {
 pub fn setCursorShape(_: *Darwin, _: CursorShape) void {
     return;
 }
-
-pub fn keyPressed(_: *Darwin, _: Key) bool {
-    return false;
-}
-
-pub fn keyReleased(_: *Darwin, _: Key) bool {
-    return true;
-}
-
-pub fn mousePressed(_: *Darwin, _: MouseButton) bool {
-    return false;
-}
-
-pub fn mouseReleased(_: *Darwin, _: MouseButton) bool {
-    return true;
-}
-
-pub fn mousePosition(_: *Darwin) Position {
-    return Position{ .x = 0, .y = 0 };
-}

src/core/Null.zig

@@ -25,7 +25,6 @@ pub const Null = @This();
 
 allocator: std.mem.Allocator,
 core: *Core,
-input_state: Core.InputState,
 modifiers: KeyMods,
 title: [:0]u8,
 display_mode: DisplayMode,
@@ -92,23 +91,3 @@ pub fn setCursorMode(_: *Null, _: CursorMode) void {
 pub fn setCursorShape(_: *Null, _: CursorShape) void {
     return;
 }
-
-pub fn keyPressed(_: *Null, _: Key) bool {
-    return false;
-}
-
-pub fn keyReleased(_: *Null, _: Key) bool {
-    return true;
-}
-
-pub fn mousePressed(_: *Null, _: MouseButton) bool {
-    return false;
-}
-
-pub fn mouseReleased(_: *Null, _: MouseButton) bool {
-    return true;
-}
-
-pub fn mousePosition(_: *Null) Position {
-    return Position{ .x = 0, .y = 0 };
-}

src/core/Windows.zig

@@ -45,8 +45,6 @@ dinput: *w.IDirectInput8W,
 saved_window_rect: w.RECT,
 surface_descriptor_from_hwnd: gpu.Surface.DescriptorFromWindowsHWND,
 state: *Core,
-input_state: Core.InputState,
-oom: std.Thread.ResetEvent = .{},
 
 // ------------------------------
 // Platform interface
@@ -60,7 +58,6 @@ pub fn init(
     self.allocator = options.allocator;
     self.core = @fieldParentPtr("platform", self);
     self.size = options.size;
-    self.input_state = .{};
     self.saved_window_rect = .{ .top = 0, .left = 0, .right = 0, .bottom = 0 };
 
     const hInstance = w.GetModuleHandleW(null);
@@ -153,7 +150,7 @@ pub fn update(self: *Win32) !void {
 
 pub fn setTitle(self: *Win32, title: [:0]const u8) void {
     const wtitle = std.unicode.utf8ToUtf16LeAllocZ(self.allocator, title) catch {
-        self.oom.set();
+        self.state.oom.set();
         return;
     };
     defer self.allocator.free(wtitle);
@@ -258,26 +255,6 @@ pub fn setCursorShape(self: *Win32, shape: CursorShape) void {
     self.cursor_shape = shape;
 }
 
-pub fn keyPressed(self: *Win32, key: Key) bool {
-    return self.input_state.isKeyPressed(key);
-}
-
-pub fn keyReleased(self: *Win32, key: Key) bool {
-    return self.input_state.isKeyReleased(key);
-}
-
-pub fn mousePressed(self: *Win32, button: MouseButton) bool {
-    return self.input_state.isMouseButtonPressed(button);
-}
-
-pub fn mouseReleased(self: *Win32, button: MouseButton) bool {
-    return self.input_state.isMouseButtonReleased(button);
-}
-
-pub fn mousePosition(self: *Win32) Position {
-    return self.input_state.mouse_position;
-}
-
 pub fn nativeWindowWin32(self: *Win32) w.HWND {
     return self.window;
 }
@@ -303,18 +280,6 @@ fn restoreWindowPosition(self: *Win32) void {
     }
 }
 
-pub fn outOfMemory(self: *Win32) bool {
-    if (self.oom.isSet()) {
-        self.oom.reset();
-        return true;
-    }
-    return false;
-}
-
-fn pushEvent(self: *Win32, event: Event) void {
-    self.state.events.writeItem(event) catch self.oom.set();
-}
-
 fn getKeyboardModifiers() mach.Core.KeyMods {
     return .{
         .shift = w.GetKeyState(@as(i32, @intFromEnum(w.VK_SHIFT))) < 0, //& 0x8000 == 0x8000,
@@ -336,7 +301,7 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
 
     switch (msg) {
         w.WM_CLOSE => {
-            self.pushEvent(.close);
+            self.state.pushEvent(.close);
             return 0;
         },
         w.WM_SIZE => {
@@ -358,7 +323,7 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
             if (vkey == w.VK_PROCESSKEY) return 0;
 
             if (msg == w.WM_SYSKEYDOWN and vkey == w.VK_F4) {
-                self.pushEvent(.close);
+                self.state.pushEvent(.close);
                 return 0;
             }
 
@@ -381,16 +346,26 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
             const mods = getKeyboardModifiers();
             const key = keyFromScancode(scancode);
             if (msg == w.WM_KEYDOWN or msg == w.WM_SYSKEYDOWN) {
-                if (flags & w.KF_REPEAT == 0) {
+                if (flags & w.KF_REPEAT == 0)
-                    self.pushEvent(.{ .key_press = .{ .key = key, .mods = mods } });
+                    self.state.pushEvent(.{
-                    self.input_state.keys.setValue(@intFromEnum(key), true);
+                        .key_press = .{
-                } else {
+                            .key = key,
-                    self.pushEvent(.{ .key_repeat = .{ .key = key, .mods = mods } });
+                            .mods = mods,
-                }
+                        },
-            } else {
+                    })
-                self.pushEvent(.{ .key_release = .{ .key = key, .mods = mods } });
+                else
-                self.input_state.keys.setValue(@intFromEnum(key), false);
+                    self.state.pushEvent(.{
-            }
+                        .key_repeat = .{
+                            .key = key,
+                            .mods = mods,
+                        },
+                    });
+            } else self.state.pushEvent(.{
+                .key_release = .{
+                    .key = key,
+                    .mods = mods,
+                },
+            });
 
             return 0;
         },
@@ -408,7 +383,7 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
             }
             var iter = std.unicode.Utf16LeIterator.init(chars);
             if (iter.nextCodepoint()) |codepoint| {
-                self.pushEvent(.{ .char_input = .{ .codepoint = codepoint.? } });
+                self.state.pushEvent(.{ .char_input = .{ .codepoint = codepoint.? } });
             } else |err| {
                 err catch {};
             }
@@ -439,14 +414,20 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
                 w.WM_MBUTTONDOWN,
                 w.WM_RBUTTONDOWN,
                 w.WM_XBUTTONDOWN,
-                => {
+                => self.state.pushEvent(.{
-                    self.pushEvent(.{ .mouse_press = .{ .button = button, .mods = mods, .pos = .{ .x = x, .y = y } } });
+                    .mouse_press = .{
-                    self.input_state.mouse_buttons.setValue(@intFromEnum(button), true);
+                        .button = button,
+                        .mods = mods,
+                        .pos = .{ .x = x, .y = y },
                     },
-                else => {
+                }),
-                    self.pushEvent(.{ .mouse_release = .{ .button = button, .mods = mods, .pos = .{ .x = x, .y = y } } });
+                else => self.state.pushEvent(.{
-                    self.input_state.mouse_buttons.setValue(@intFromEnum(button), false);
+                    .mouse_release = .{
+                        .button = button,
+                        .mods = mods,
+                        .pos = .{ .x = x, .y = y },
                     },
+                }),
             }
 
             return if (msg == w.WM_XBUTTONDOWN or msg == w.WM_XBUTTONUP) w.TRUE else 0;
@@ -454,8 +435,7 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
         w.WM_MOUSEMOVE => {
             const x: f64 = @floatFromInt(@as(i16, @truncate(lParam & 0xFFFF)));
             const y: f64 = @floatFromInt(@as(i16, @truncate((lParam >> 16) & 0xFFFF)));
-
+            self.state.pushEvent(.{
-            self.pushEvent(.{
                 .mouse_motion = .{
                     .pos = .{
                         .x = x,
@@ -463,8 +443,6 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
                     },
                 },
             });
-            self.input_state.mouse_position = .{ .x = x, .y = y };
-
             return 0;
         },
         w.WM_MOUSEWHEEL => {
@@ -472,7 +450,7 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
             const wheel_high_word: u16 = @truncate((wParam >> 16) & 0xffff);
             const delta_y: f32 = @as(f32, @floatFromInt(@as(i16, @bitCast(wheel_high_word)))) / WHEEL_DELTA;
 
-            self.pushEvent(.{
+            self.state.pushEvent(.{
                 .mouse_scroll = .{
                     .xoffset = 0,
                     .yoffset = delta_y,
@@ -481,13 +459,11 @@ fn wndProc(wnd: w.HWND, msg: u32, wParam: w.WPARAM, lParam: w.LPARAM) callconv(w
             return 0;
         },
         w.WM_SETFOCUS => {
-            self.pushEvent(.{ .focus_gained = {} });
+            self.state.pushEvent(.{ .focus_gained = {} });
             return 0;
         },
         w.WM_KILLFOCUS => {
-            self.pushEvent(.{ .focus_lost = {} });
+            self.state.pushEvent(.{ .focus_lost = {} });
-            // Clear input state when focus is lost to avoid "stuck" button when focus is regained.
-            self.input_state = .{};
             return 0;
         },
         else => return w.DefWindowProcW(wnd, msg, wParam, lParam),