fix(imgui): handle valid ROM titles which happen to be empty

also list dependencies (TODO: add hyperlinks)

src/core/bus/backup.zig

@@ -205,10 +205,6 @@ pub const Backup = struct {
         const file_path = try self.savePath(allocator, path);
         defer allocator.free(file_path);
 
-        // FIXME: communicate edge case to the user?
-        if (std.mem.eql(u8, &self.title, "ACE LIGHTNIN"))
-            return;
-
         switch (self.kind) {
             .Sram, .Flash, .Flash1M, .Eeprom => {
                 const file = try std.fs.createFileAbsolute(file_path, .{});

src/imgui.zig

@@ -31,13 +31,25 @@ pub const State = struct {
     fps_hist: RingBuffer(u32),
     should_quit: bool = false,
 
+    win_stat: WindowStatus = .{},
+
+    const WindowStatus = struct {
+        show_deps: bool = false,
+        show_regs: bool = false,
+        show_schedule: bool = false,
+        show_perf: bool = false,
+        show_palette: bool = false,
+    };
+
     /// if zba is initialized with a ROM already provided, this initializer should be called
     /// with `title_opt` being non-null
     pub fn init(allocator: Allocator, title_opt: ?*const [12]u8) !@This() {
         const history = try allocator.alloc(u32, histogram_len);
 
-        const title: [12:0]u8 = if (title_opt) |t| t.* ++ [_:0]u8{} else "[No Title]\x00\x00".*;
-        return .{ .title = title, .fps_hist = RingBuffer(u32).init(history) };
+        return .{
+            .title = handleTitle(title_opt),
+            .fps_hist = RingBuffer(u32).init(history),
+        };
     }
 
     pub fn deinit(self: *@This(), allocator: Allocator) void {
@@ -56,7 +68,8 @@ pub fn draw(state: *State, tex_id: GLuint, cpu: *Arm7tdmi) void {
         if (zgui.beginMenu("File", true)) {
             defer zgui.endMenu();
 
-            if (zgui.menuItem("Quit", .{})) state.should_quit = true;
+            if (zgui.menuItem("Quit", .{}))
+                state.should_quit = true;
 
             if (zgui.menuItem("Insert ROM", .{})) blk: {
                 const maybe_path = nfd.openFileDialog("gba", null) catch |e| {
@@ -76,16 +89,38 @@ pub fn draw(state: *State, tex_id: GLuint, cpu: *Arm7tdmi) void {
                     break :blk;
                 };
 
-                state.title = cpu.bus.pak.title ++ [_:0]u8{};
+                state.title = handleTitle(&cpu.bus.pak.title);
             }
         }
 
         if (zgui.beginMenu("Emulation", true)) {
             defer zgui.endMenu();
 
-            if (zgui.menuItem("Restart", .{})) {
+            if (zgui.menuItem("Registers", .{ .selected = state.win_stat.show_regs }))
+                state.win_stat.show_regs = true;
+
+            if (zgui.menuItem("Palette", .{ .selected = state.win_stat.show_palette }))
+                state.win_stat.show_palette = true;
+
+            if (zgui.menuItem("Schedule", .{ .selected = state.win_stat.show_schedule }))
+                state.win_stat.show_schedule = true;
+
+            if (zgui.menuItem("Restart", .{}))
                 emu.reset(cpu);
-            }
+        }
+
+        if (zgui.beginMenu("Stats", true)) {
+            defer zgui.endMenu();
+
+            if (zgui.menuItem("Performance", .{ .selected = state.win_stat.show_perf }))
+                state.win_stat.show_perf = true;
+        }
+
+        if (zgui.beginMenu("Help", true)) {
+            defer zgui.endMenu();
+
+            if (zgui.menuItem("Dependencies", .{ .selected = state.win_stat.show_deps }))
+                state.win_stat.show_deps = true;
         }
     }
 
@@ -100,8 +135,51 @@ pub fn draw(state: *State, tex_id: GLuint, cpu: *Arm7tdmi) void {
         zgui.image(@intToPtr(*anyopaque, tex_id), .{ .w = w, .h = h, .uv0 = .{ 0, 1 }, .uv1 = .{ 1, 0 } });
     }
 
-    {
-        _ = zgui.begin("Information", .{});
+    // TODO: Any other steps to respect the copyright of the libraries I use?
+    if (state.win_stat.show_deps) {
+        _ = zgui.begin("Dependencies", .{ .popen = &state.win_stat.show_deps });
+        defer zgui.end();
+
+        zgui.bulletText("SDL.zig by Felix Queißner", .{});
+        {
+            zgui.indent(.{});
+            defer zgui.unindent(.{});
+
+            zgui.bulletText("SDL by Sam Lantinga", .{});
+        }
+
+        zgui.bulletText("known-folders by ziglibs", .{});
+        zgui.bulletText("nfd-zig by Fabio Arnold", .{});
+        {
+            zgui.indent(.{});
+            defer zgui.unindent(.{});
+
+            zgui.bulletText("nativefiledialog by Michael Labbe", .{});
+        }
+        zgui.bulletText("zba-gdbstub by Rekai Musuka", .{});
+        zgui.bulletText("zba-util by Rekai Musuka", .{});
+        zgui.bulletText("zgui by Michal Ziulek", .{});
+        {
+            zgui.indent(.{});
+            defer zgui.unindent(.{});
+
+            zgui.bulletText("DearImGui by Omar Cornut", .{});
+        }
+        zgui.bulletText("zig-clap by Jimmi Holst Christensen", .{});
+        zgui.bulletText("zig-datetime by Jairus Martin", .{});
+        zgui.bulletText("zig-opengl by Felix Queißner", .{});
+        {
+            zgui.indent(.{});
+            defer zgui.unindent(.{});
+
+            zgui.bulletText("OpenGL-Registry by The Khronos Group", .{});
+        }
+        zgui.bulletText("zig-toml by Aeron Avery", .{});
+        zgui.bulletText("bitfield.zig by Hannes Bredberg and FlorenceOS contributors", .{});
+    }
+
+    if (state.win_stat.show_regs) {
+        _ = zgui.begin("Guest Registers", .{ .popen = &state.win_stat.show_regs });
         defer zgui.end();
 
         for (0..8) |i| {
@@ -124,8 +202,8 @@ pub fn draw(state: *State, tex_id: GLuint, cpu: *Arm7tdmi) void {
         widgets.interrupts("IRQ", cpu.bus.io.irq);
     }
 
-    {
-        _ = zgui.begin("Performance", .{});
+    if (state.win_stat.show_perf) {
+        _ = zgui.begin("Performance", .{ .popen = &state.win_stat.show_perf });
         defer zgui.end();
 
         const tmp = blk: {
@@ -187,8 +265,8 @@ pub fn draw(state: *State, tex_id: GLuint, cpu: *Arm7tdmi) void {
         zgui.text(" 1% Low: {:0>3} fps", .{stats[2]});
     }
 
-    {
-        _ = zgui.begin("Scheduler", .{});
+    if (state.win_stat.show_schedule) {
+        _ = zgui.begin("Schedule", .{ .popen = &state.win_stat.show_schedule });
         defer zgui.end();
 
         const scheduler = cpu.sched;
@@ -209,12 +287,59 @@ pub fn draw(state: *State, tex_id: GLuint, cpu: *Arm7tdmi) void {
         }
     }
 
-    // {
-    //     zgui.showDemoWindow(null);
-    // }
+    if (state.win_stat.show_palette) {
+        _ = zgui.begin("Palette", .{ .popen = &state.win_stat.show_palette });
+        defer zgui.end();
+
+        widgets.paletteGrid(.Background, cpu);
+
+        zgui.sameLine(.{ .spacing = 20.0 });
+
+        widgets.paletteGrid(.Object, cpu);
+    }
+
+    {
+        zgui.showDemoWindow(null);
+    }
 }
 
 const widgets = struct {
+    const PaletteKind = enum { Background, Object };
+
+    fn paletteGrid(comptime kind: PaletteKind, cpu: *const Arm7tdmi) void {
+        _ = zgui.beginGroup();
+        defer zgui.endGroup();
+
+        const address: u32 = switch (kind) {
+            .Background => 0x0500_0000,
+            .Object => 0x0500_0200,
+        };
+
+        for (0..0x100) |i| {
+            const offset = @truncate(u32, i);
+            const bgr555 = cpu.bus.dbgRead(u16, address + offset * @sizeOf(u16));
+            widgets.colourSquare(bgr555);
+
+            if ((i + 1) % 0x10 != 0) zgui.sameLine(.{});
+        }
+        zgui.text(@tagName(kind), .{});
+    }
+
+    fn colourSquare(bgr555: u16) void {
+        // FIXME: working with the packed struct enum is currently broken :pensive:
+        const ImguiColorEditFlags_NoInputs: u32 = 1 << 5;
+        const ImguiColorEditFlags_NoPicker: u32 = 1 << 2;
+        const flags = @bitCast(zgui.ColorEditFlags, ImguiColorEditFlags_NoInputs | ImguiColorEditFlags_NoPicker);
+
+        const b = @intToFloat(f32, bgr555 >> 10 & 0x1f);
+        const g = @intToFloat(f32, bgr555 >> 5 & 0x1F);
+        const r = @intToFloat(f32, bgr555 & 0x1F);
+
+        var col = [_]f32{ r / 31.0, g / 31.0, b / 31.0 };
+
+        _ = zgui.colorEdit3("", .{ .col = &col, .flags = flags });
+    }
+
     fn interrupts(comptime label: []const u8, int: anytype) void {
         const h = 15.0;
         const w = 9.0 * 2 + 3.5;
@@ -305,3 +430,13 @@ const widgets = struct {
         }.inner;
     }
 };
+
+fn handleTitle(title_opt: ?*const [12]u8) [12:0]u8 {
+    if (title_opt == null) return "[N/A Title]\x00".*; // No ROM present
+    const title = title_opt.?;
+
+    // ROM Title is an empty string (ImGui hates these)
+    if (title[0] == '\x00') return "[No Title]\x00\x00".*;
+
+    return title.* ++ [_:0]u8{};
+}

src/main.zig

@@ -86,7 +86,7 @@ pub fn main() void {
     bus.init(allocator, &scheduler, &cpu, paths) catch |e| exitln("failed to init zba bus: {}", .{e});
     defer bus.deinit();
 
-    if (config.config().guest.skip_bios or result.args.skip or paths.bios == null) {
+    if (config.config().guest.skip_bios or result.args.skip != 0 or paths.bios == null) {
         cpu.fastBoot();
     }
 
@@ -101,7 +101,7 @@ pub fn main() void {
     var items: [0x100]u8 = undefined;
     var channel = TwoWayChannel.init(&items);
 
-    if (result.args.gdb) {
+    if (result.args.gdb != 0) {
         const Server = @import("gdbstub").Server;
         const EmuThing = @import("core/emu.zig").EmuThing;