chirp-imgui: Refactor menu definitions

src/bin/chirp-imgui/emu.rs

@@ -0,0 +1,192 @@
+//! The emulator's state, including the screen data
+
+use super::{error, BACKGROUND, FOREGROUND};
+use chirp::{bus, Bus, Screen, CPU};
+use pixels::Pixels;
+use std::path::{Path, PathBuf};
+use winit::event::VirtualKeyCode;
+use winit_input_helper::WinitInputHelper;
+
+/// The state of the application
+#[derive(Debug)]
+pub struct Emulator {
+    screen: Bus,
+    cpu: CPU,
+    pub ipf: usize,
+    pub rom: PathBuf,
+    pub colors: [[u8; 4]; 2],
+}
+
+impl Emulator {
+    /// Constructs a new CPU, with the provided ROM loaded at 0x0200
+    ///
+    /// # Panics
+    /// Panics if the provided ROM does not exist
+    pub fn new(ipf: usize, rom: impl AsRef<Path>) -> Self {
+        let screen = bus! {
+            Screen  [0x000..0x100],
+        };
+        let mut cpu = CPU::default();
+        cpu.load_program(&rom).expect("Loaded file MUST exist.");
+        Self {
+            cpu,
+            ipf,
+            rom: rom.as_ref().into(),
+            screen,
+            colors: [*FOREGROUND, *BACKGROUND],
+        }
+    }
+    /// Runs a single epoch
+    pub fn update(&mut self) -> Result<(), error::Error> {
+        self.cpu.multistep(&mut self.screen, self.ipf)?;
+        Ok(())
+    }
+    /// Rasterizes the screen into a [Pixels] buffer
+    pub fn draw(&mut self, pixels: &mut Pixels) -> Result<(), error::Error> {
+        if let Some(screen) = self.screen.get_region(Screen) {
+            let len_log2 = screen.len().ilog2() / 2;
+            #[allow(unused_variables)]
+            let (width, height) = (2u32.pow(len_log2 + 2), 2u32.pow(len_log2 + 1));
+            pixels.resize_buffer(width, height)?;
+            for (idx, pixel) in pixels.frame_mut().iter_mut().enumerate() {
+                let (byte, bit, component) = (idx >> 5, (idx >> 2) % 8, idx & 0b11);
+                *pixel = if screen[byte] & (0x80 >> bit) > 0 {
+                    self.colors[0][component]
+                } else {
+                    self.colors[1][component]
+                }
+            }
+        }
+        Ok(())
+    }
+    /// Processes keyboard input for the Emulator
+    pub fn input(&mut self, input: &WinitInputHelper) -> Result<(), error::Error> {
+        const KEYMAP: [VirtualKeyCode; 16] = [
+            VirtualKeyCode::X,
+            VirtualKeyCode::Key1,
+            VirtualKeyCode::Key2,
+            VirtualKeyCode::Key3,
+            VirtualKeyCode::Q,
+            VirtualKeyCode::W,
+            VirtualKeyCode::E,
+            VirtualKeyCode::A,
+            VirtualKeyCode::S,
+            VirtualKeyCode::D,
+            VirtualKeyCode::Z,
+            VirtualKeyCode::C,
+            VirtualKeyCode::Key4,
+            VirtualKeyCode::R,
+            VirtualKeyCode::F,
+            VirtualKeyCode::V,
+        ];
+        for (id, &key) in KEYMAP.iter().enumerate() {
+            if input.key_released(key) {
+                self.cpu.release(id)?;
+            }
+            if input.key_pressed(key) {
+                self.cpu.press(id)?;
+            }
+        }
+        Ok(())
+    }
+
+    pub fn quirks(&mut self) -> chirp::Quirks {
+        self.cpu.flags.quirks
+    }
+    pub fn set_quirks(&mut self, quirks: chirp::Quirks) {
+        self.cpu.flags.quirks = quirks
+    }
+    /// Prints the CPU registers and cycle count to stderr
+    pub fn print_registers(&self) {
+        self.cpu.dump()
+    }
+    /// Prints the screen (using the highest resolution available printer) to stdout
+    pub fn print_screen(&self) -> Result<(), error::Error> {
+        self.screen.print_screen()?;
+        Ok(())
+    }
+    /// Dumps the raw screen bytes to a file named `{rom}_{cycle}.bin`,
+    /// or, failing that, `screen_dump.bin`
+    pub fn dump_screen(&self) -> Result<(), error::Error> {
+        let mut path = PathBuf::new().join(format!(
+            "{}_{}.bin",
+            self.rom.file_stem().unwrap_or_default().to_string_lossy(),
+            self.cpu.cycle()
+        ));
+        path.set_extension("bin");
+        if std::fs::write(
+            &path,
+            self.screen
+                .get_region(Screen)
+                .expect("Region::Screen should exist"),
+        )
+        .is_ok()
+        {
+            eprintln!("Saved to {}", &path.display());
+        } else if std::fs::write(
+            "screen_dump.bin",
+            self.screen
+                .get_region(Screen)
+                .expect("Region::Screen should exist"),
+        )
+        .is_ok()
+        {
+            eprintln!("Saved to screen_dump.bin");
+        } else {
+            eprintln!("Failed to dump screen to file.")
+        }
+        Ok(())
+    }
+    /// Sets live disassembly
+    pub fn set_disasm(&mut self, enabled: bool) {
+        self.cpu.flags.debug = enabled;
+    }
+    /// Checks live disassembly
+    pub fn is_disasm(&mut self) {
+        eprintln!(
+            "Live Disassembly {}abled",
+            if self.cpu.flags.debug { "En" } else { "Dis" }
+        );
+    }
+    /// Toggles emulator pause
+    pub fn pause(&mut self) {
+        self.cpu.flags.pause();
+        eprintln!("{}aused", if self.cpu.flags.pause { "P" } else { "Unp" });
+    }
+    /// Single-steps the emulator, pausing afterward
+    pub fn singlestep(&mut self) -> Result<(), error::Error> {
+        self.cpu.singlestep(&mut self.screen)?;
+        Ok(())
+    }
+    /// Sets a breakpoint at the current address
+    pub fn set_break(&mut self) {
+        self.cpu.set_break(self.cpu.pc());
+        eprintln!("Set breakpoint at {}", self.cpu.pc());
+    }
+    /// Unsets a breakpoint at the current address
+    pub fn unset_break(&mut self) {
+        self.cpu.unset_break(self.cpu.pc());
+        eprintln!("Unset breakpoint at {}", self.cpu.pc());
+    }
+    /// Soft-resets the CPU, keeping the program in memory
+    pub fn soft_reset(&mut self) {
+        self.cpu.reset();
+        self.screen.clear_region(Screen);
+        eprintln!("Soft Reset");
+    }
+
+    /// Creates a new CPU with the current CPU's flags
+    pub fn hard_reset(&mut self) {
+        self.cpu.reset();
+        self.screen.clear_region(Screen);
+        // keep the flags
+        let flags = self.cpu.flags.clone();
+        // instantiate a completely new CPU, and reload the ROM from disk
+        self.cpu = CPU::default();
+        self.cpu.flags = flags;
+        self.cpu
+            .load_program(&self.rom)
+            .expect("Previously loaded ROM no longer exists (was it moved?)");
+        eprintln!("Hard Reset");
+    }
+}

src/bin/chirp-imgui/error.rs

@@ -3,7 +3,7 @@
 use thiserror::Error;
 
 #[derive(Debug, Error)]
-pub(crate) enum Error {
+pub enum Error {
     /// Error originated in [`chirp`]
     #[error(transparent)]
     Chirp(#[from] chirp::error::Error),

src/bin/chirp-imgui/gui.rs

@@ -7,9 +7,16 @@
 use pixels::{wgpu, PixelsContext};
 use std::time::Instant;
 
+mod about;
 mod menubar;
 use menubar::Menubar;
 
+/// Lays out the imgui widgets for a thing
+pub trait Drawable {
+    // Lay out the ImGui widgets for this thing
+    fn draw(&mut self, ui: &imgui::Ui);
+}
+
 /// Holds state of GUI
 pub(crate) struct Gui {
     imgui: imgui::Context,
@@ -20,6 +27,17 @@ pub(crate) struct Gui {
     pub menubar: Menubar,
 }
 
+/// Queries the state of the [Gui]
+#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+#[non_exhaustive]
+pub enum Wants {
+    Quit,
+    Disasm,
+    SoftReset,
+    HardReset,
+    Reset,
+}
+
 impl std::fmt::Debug for Gui {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("Gui")
@@ -43,18 +61,18 @@ impl Gui {
         platform.attach_window(
             imgui.io_mut(),
             window,
-            imgui_winit_support::HiDpiMode::Default,
+            imgui_winit_support::HiDpiMode::Locked(2.2),
         );
 
         // Configure fonts
-        // let dpi_scale = window.scale_factor();
-        // let font_size = (13.0 * dpi_scale) as f32;
-        // imgui.io_mut().font_global_scale = (1.0 / dpi_scale) as f32;
+        let dpi_scale = window.scale_factor();
+        let font_size = (13.0 * dpi_scale) as f32;
+        imgui.io_mut().font_global_scale = (1.0 / dpi_scale) as f32;
         imgui
             .fonts()
             .add_font(&[imgui::FontSource::DefaultFontData {
                 config: Some(imgui::FontConfig {
-                    size_pixels: 13.0,
+                    size_pixels: font_size,
                     oversample_h: 2,
                     oversample_v: 2,
                     pixel_snap_h: true,
@@ -112,53 +130,12 @@ impl Gui {
             self.platform.prepare_render(ui, window);
         }
 
-        let menu = &mut self.menubar;
-        let settings_menu = || {
-            use chirp::Mode::*;
-            let settings = &mut menu.settings;
-            const MODES: [chirp::Mode; 3] = [Chip8, SChip, XOChip];
-            if ui.combo_simple_string("Mode", &mut settings.mode_index, &MODES) {
-                settings.quirks = MODES[settings.mode_index].into();
-                settings.applied = true;
-            }
-            settings.applied = {
-                ui.input_scalar("IPF", &mut settings.target_ipf)
-                    .chars_decimal(true)
-                    .build()
-                    | ui.checkbox("Bin-ops don't clear vF", &mut settings.quirks.bin_ops)
-                    | ui.checkbox("DMA doesn't modify I", &mut settings.quirks.dma_inc)
-                    | ui.checkbox("Draw calls are instant", &mut settings.quirks.draw_wait)
-                    | ui.checkbox("Screen wraps at edge", &mut settings.quirks.screen_wrap)
-                    | ui.checkbox("Shift ops ignore vY", &mut settings.quirks.shift)
-                    | ui.checkbox("Jumps behave eratically", &mut settings.quirks.stupid_jumps)
-            }
-        };
-        // let file_menu = || {
-        //     let file = &mut menu.file;
-        //     file.quit = ui.menu_item("Quit");
-        // };
-        let debug_menu = || {
-            menu.debug.reset = ui.menu_item("Reset");
-            ui.checkbox("Live Disassembly", &mut menu.debug.dis);
-        };
-        let help_menu = || {
-            let about = &mut menu.about;
-            about.open = ui.menu_item("About...");
-        };
-
+        self.menubar.draw(ui);
         // Draw windows and GUI elements here
-        if menu.active {
-            ui.main_menu_bar(|| {
-                //ui.menu("File", file_menu);
-                ui.menu("Settings", settings_menu);
-                ui.menu("Debug", debug_menu);
-                ui.menu("Help", help_menu);
-            });
-        }
 
-        if menu.file.settings {}
-        if self.menubar.about.open {
-            ui.show_about_window(&mut self.menubar.about.open);
+        if self.menubar.about.about_open {
+            ui.open_popup("About");
+            self.menubar.about.about_open = false;
         }
 
         // Render Dear ImGui with WGPU
@@ -201,17 +178,17 @@ impl Gui {
         }
     }
 
-    pub fn wants_reset(&mut self) -> bool {
-        let reset = self.menubar.debug.reset;
-        self.menubar.debug.reset = false;
-        reset
-    }
-
-    pub fn wants_disassembly(&self) -> bool {
-        self.menubar.debug.dis
-    }
-
-    pub fn wants_quit(&self) -> bool {
-        self.menubar.file.quit
+    /// Query the state of the Gui through a unified interface
+    pub fn wants(&mut self, wants: Wants) -> bool {
+        match wants {
+            Wants::Quit => self.menubar.file.quit,
+            Wants::Disasm => self.menubar.debug.dis,
+            Wants::Reset => {
+                let reset = self.menubar.debug.reset;
+                self.menubar.debug.reset = false;
+                reset
+            }
+            _ => unreachable!(),
+        }
     }
 }

src/bin/chirp-imgui/gui/about.rs

@@ -0,0 +1,28 @@
+//! Information about the crate at compile time
+
+use imgui::Ui;
+
+/// Project authors
+const AUTHORS: Option<&str> = option_env!("CARGO_PKG_AUTHORS");
+/// Compiled binary name
+const BIN: Option<&str> = option_env!("CARGO_BIN_NAME");
+/// Crate description
+const DESCRIPTION: Option<&str> = option_env!("CARGO_PKG_DESCRIPTION");
+/// Crate name
+const NAME: Option<&str> = option_env!("CARGO_PKG_NAME");
+/// Crate repository
+const REPO: Option<&str> = option_env!("CARGO_PKG_REPOSITORY");
+/// Crate version
+const VERSION: Option<&str> = option_env!("CARGO_PKG_VERSION");
+
+pub(crate) fn about(ui: &Ui) {
+    ui.popup("About", || {
+        ui.text(format!(
+            "{} v{}",
+            NAME.unwrap_or("Chirp"),
+            VERSION.unwrap_or("None"),
+        ));
+        ui.text(format!("Crafted by: {}", AUTHORS.unwrap_or("some people")));
+        ui.text(REPO.unwrap_or("Repo unavailable"));
+    });
+}

src/bin/chirp-imgui/gui/menubar.rs

@@ -1,12 +1,27 @@
 //! The menubar that shows at the top of the screen
 
+use super::Drawable;
+
 #[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Menubar {
     pub(super) active: bool,
     pub file: File,
     pub settings: Settings,
     pub debug: Debug,
-    pub about: About,
+    pub about: Help,
+}
+
+impl Drawable for Menubar {
+    fn draw(&mut self, ui: &imgui::Ui) {
+        if self.active {
+            ui.main_menu_bar(|| {
+                self.file.draw(ui);
+                self.settings.draw(ui);
+                self.debug.draw(ui);
+                self.about.draw(ui);
+            })
+        }
+    }
 }
 
 impl Default for Menubar {
@@ -23,20 +38,52 @@ impl Default for Menubar {
 
 #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct File {
-    pub(super) settings: bool,
     pub(super) reset: bool,
     pub(super) quit: bool,
 }
 
+impl Drawable for File {
+    fn draw(&mut self, ui: &imgui::Ui) {
+        ui.menu("File", || {
+            self.reset = ui.menu_item("Reset");
+            self.quit = ui.menu_item("Quit");
+        })
+    }
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct Debug {
     pub(super) reset: bool,
     pub(super) dis: bool,
 }
 
+impl Drawable for Debug {
+    fn draw(&mut self, ui: &imgui::Ui) {
+        ui.menu("Debug", || {
+            self.reset = ui.menu_item("Reset");
+            ui.checkbox("Live Disassembly", &mut self.dis);
+        })
+    }
+}
+
+impl Debug {
+    pub fn reset(&self) -> bool {
+        self.reset
+    }
+    pub fn dis(&self) -> bool {
+        self.dis
+    }
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct About {
-    pub(super) open: bool,
+pub struct Help {
+    pub(super) about_open: bool,
+}
+
+impl Drawable for Help {
+    fn draw(&mut self, ui: &imgui::Ui) {
+        ui.menu("Help", || self.about_open = ui.menu_item("About..."))
+    }
 }
 
 #[derive(Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -48,6 +95,31 @@ pub struct Settings {
     pub(super) applied: bool,
 }
 
+impl Drawable for Settings {
+    fn draw(&mut self, ui: &imgui::Ui) {
+        self.applied = false;
+        ui.menu("Settings", || {
+            use chirp::Mode::*;
+            const MODES: [chirp::Mode; 3] = [Chip8, SChip, XOChip];
+            if ui.combo_simple_string("Mode", &mut self.mode_index, &MODES) {
+                self.quirks = MODES[self.mode_index].into();
+                self.applied |= true;
+            }
+            self.applied |= {
+                ui.input_scalar("IPF", &mut self.target_ipf)
+                    .chars_decimal(true)
+                    .build()
+                    | ui.checkbox("Bin-ops don't clear vF", &mut self.quirks.bin_ops)
+                    | ui.checkbox("DMA doesn't modify I", &mut self.quirks.dma_inc)
+                    | ui.checkbox("Draw calls are instant", &mut self.quirks.draw_wait)
+                    | ui.checkbox("Screen wraps at edge", &mut self.quirks.screen_wrap)
+                    | ui.checkbox("Shift ops ignore vY", &mut self.quirks.shift)
+                    | ui.checkbox("Jumps behave eratically", &mut self.quirks.stupid_jumps)
+            }
+        })
+    }
+}
+
 impl Settings {
     pub fn target_ipf(&mut self) -> &mut usize {
         &mut self.target_ipf
@@ -55,7 +127,6 @@ impl Settings {
     pub fn quirks(&mut self) -> &mut chirp::Quirks {
         &mut self.quirks
     }
-
     pub fn applied(&mut self) -> Option<(usize, chirp::Quirks)> {
         self.applied.then_some((self.target_ipf, self.quirks))
     }

src/bin/chirp-imgui/main.rs

@@ -1,8 +1,13 @@
 #![forbid(unsafe_code)]
 #![deny(clippy::all)]
 #![allow(dead_code)] // TODO: finish writing the code
+
+mod emu;
+mod error;
+mod gui;
+
+use crate::emu::*;
 use crate::gui::*;
-use chirp::*;
 use core::panic;
 use pixels::{Pixels, SurfaceTexture};
 use std::result::Result;
@@ -12,23 +17,25 @@ use winit::event_loop::{ControlFlow, EventLoop};
 use winit::window::WindowBuilder;
 use winit_input_helper::WinitInputHelper;
 
-mod error;
-mod gui;
+// TODO: Make these configurable in the frontend
 
 const FOREGROUND: &[u8; 4] = &0xFFFF00FF_u32.to_be_bytes();
 const BACKGROUND: &[u8; 4] = &0x623701FF_u32.to_be_bytes();
+const INIT_SPEED: usize = 10;
 
-/// The state of the application
-#[derive(Debug)]
-struct Emulator {
+struct Application {
     gui: Gui,
-    screen: Bus,
-    cpu: CPU,
-    ipf: usize,
-    colors: [[u8; 4]; 2],
+    emu: Emulator,
 }
 
 fn main() -> Result<(), error::Error> {
+    let rom_path;
+    if let Some(path) = std::env::args().nth(1) {
+        rom_path = path;
+    } else {
+        panic!("Supply a rom!");
+    }
+
     let event_loop = EventLoop::new();
     let mut input = WinitInputHelper::new();
 
@@ -46,33 +53,32 @@ fn main() -> Result<(), error::Error> {
         Pixels::new(128, 64, surface_texture)?
     };
 
-    let mut emu = Emulator::new(
+    let mut app = Application::new(
+        Emulator::new(INIT_SPEED, rom_path),
         Gui::new(&window, &pixels),
-        bus! {
-            Screen  [0x000..0x100],
-        },
-        CPU::default(),
-        10,
     );
 
     // set initial parameters
-    *emu.gui.menubar.settings.target_ipf() = emu.cpu.flags.monotonic.unwrap_or(10);
-    *emu.gui.menubar.settings.quirks() = emu.cpu.flags.quirks;
-    if let Some(path) = std::env::args().nth(1) {
-        emu.cpu.load_program(path)?;
-    } else {
-        panic!("Supply a rom!");
-    }
+    *app.gui.menubar.settings.target_ipf() = INIT_SPEED;
+    *app.gui.menubar.settings.quirks() = app.emu.quirks();
 
     // Run event loop
     event_loop.run(move |event, _, control_flow| {
+        let toggle_fullscreen = || {
+            window.set_fullscreen(if window.fullscreen().is_some() {
+                None
+            } else {
+                Some(winit::window::Fullscreen::Borderless(None))
+            })
+        };
+
         let redraw = |gui: &mut Gui, pixels: &mut Pixels| -> Result<(), error::Error> {
             // Prepare gui for redraw
             gui.prepare(&window)?;
 
             // Render everything together
             pixels.render_with(|encoder, render_target, context| {
-                // Render the world texture
+                // Render the emulator's screen
                 context.scaling_renderer.render(encoder, render_target);
                 // Render Dear ImGui
                 gui.render(&window, encoder, render_target, context)?;
@@ -81,7 +87,7 @@ fn main() -> Result<(), error::Error> {
             Ok(())
         };
 
-        let mut handle_events = |state: &mut Emulator,
+        let mut handle_events = |state: &mut Application,
                                  pixels: &mut Pixels,
                                  control_flow: &mut ControlFlow|
          -> Result<(), error::Error> {
@@ -89,29 +95,30 @@ fn main() -> Result<(), error::Error> {
             if input.update(&event) {
                 use VirtualKeyCode::*;
                 match_pressed!( match input {
-                    Escape | input.quit() | state.gui.wants_quit() => {
+                    Escape | input.quit() | state.gui.wants(Wants::Quit) => {
                         *control_flow = ControlFlow::Exit;
                         return Ok(());
                     },
-                    F1 => state.cpu.dump(),
-                    F2 => state.screen.print_screen()?,
-                    F3 => eprintln!("TODO: Dump screen"),
-                    F4 => state.cpu.flags.debug(),
-                    F5 => state.cpu.flags.pause(),
-                    F6 => state.cpu.singlestep(&mut state.screen)?,
-                    F7 => state.cpu.set_break(state.cpu.pc()),
-                    F8 => state.cpu.unset_break(state.cpu.pc()),
-                    Delete => state.cpu.reset(),
-                    F11 => window.set_maximized(!window.is_maximized()),
+                    F1 => state.emu.print_registers(),
+                    F2 => state.emu.print_screen()?,
+                    F3 => state.emu.dump_screen()?,
+                    F4 => state.emu.is_disasm(),
+                    F5 => state.emu.pause(),
+                    F6 => state.emu.singlestep()?,
+                    F7 => state.emu.set_break(),
+                    F8 => state.emu.unset_break(),
+                    Delete => state.emu.soft_reset(),
+                    Insert => state.emu.hard_reset(),
+                    F11 => toggle_fullscreen(),
                     LAlt => state.gui.show_menubar(None),
                 });
-                state.input(&input)?;
+                state.emu.input(&input)?;
 
                 // Apply settings
                 if let Some((ipf, quirks)) = state.gui.menubar.settings.applied() {
-                    state.ipf = ipf;
-                    state.cpu.flags.monotonic = Some(ipf);
-                    state.cpu.flags.quirks = quirks;
+                    state.emu.ipf = ipf;
+                    state.emu.set_quirks(quirks);
+                    println!("'A");
                 }
 
                 // Update the scale factor
@@ -130,14 +137,14 @@ fn main() -> Result<(), error::Error> {
                     }
                 }
 
-                state.cpu.flags.debug = state.gui.wants_disassembly();
-                if state.gui.wants_reset() {
-                    state.cpu.reset();
+                state.emu.set_disasm(state.gui.wants(Wants::Disasm));
+                if state.gui.wants(Wants::Reset) {
+                    state.emu.hard_reset();
                 }
 
                 // Run the game loop
-                state.update()?;
-                state.draw(pixels)?;
+                state.emu.update()?;
+                state.emu.draw(pixels)?;
 
                 // redraw the window
                 window.request_redraw();
@@ -146,81 +153,22 @@ fn main() -> Result<(), error::Error> {
         };
 
         if let Event::RedrawRequested(_) = event {
-            if let Err(e) = redraw(&mut emu.gui, &mut pixels) {
+            if let Err(e) = redraw(&mut app.gui, &mut pixels) {
                 eprintln!("{e}");
                 *control_flow = ControlFlow::Exit;
             }
         }
 
-        if let Err(e) = handle_events(&mut emu, &mut pixels, control_flow) {
+        if let Err(e) = handle_events(&mut app, &mut pixels, control_flow) {
             eprintln!("{e}");
             *control_flow = ControlFlow::Exit;
         }
     });
 }
 
-impl Emulator {
-    pub fn new(gui: Gui, mem: Bus, cpu: CPU, ipf: usize) -> Self {
-        Self {
-            gui,
-            screen: mem,
-            cpu,
-            ipf,
-            colors: [*FOREGROUND, *BACKGROUND],
-        }
-    }
-
-    pub fn update(&mut self) -> Result<(), error::Error> {
-        self.cpu.multistep(&mut self.screen, self.ipf)?;
-        Ok(())
-    }
-
-    pub fn draw(&mut self, pixels: &mut Pixels) -> Result<(), error::Error> {
-        if let Some(screen) = self.screen.get_region(Screen) {
-            let len_log2 = screen.len().ilog2() / 2;
-            #[allow(unused_variables)]
-            let (width, height) = (2u32.pow(len_log2 + 2), 2u32.pow(len_log2 + 1));
-            pixels.resize_buffer(width, height)?;
-            for (idx, pixel) in pixels.frame_mut().iter_mut().enumerate() {
-                let (byte, bit, component) = (idx >> 5, (idx >> 2) % 8, idx & 0b11);
-                *pixel = if screen[byte] & (0x80 >> bit) > 0 {
-                    self.colors[0][component]
-                } else {
-                    self.colors[1][component]
-                }
-            }
-        }
-        Ok(())
-    }
-
-    pub fn input(&mut self, input: &WinitInputHelper) -> Result<(), error::Error> {
-        const KEYMAP: [VirtualKeyCode; 16] = [
-            VirtualKeyCode::X,
-            VirtualKeyCode::Key1,
-            VirtualKeyCode::Key2,
-            VirtualKeyCode::Key3,
-            VirtualKeyCode::Q,
-            VirtualKeyCode::W,
-            VirtualKeyCode::E,
-            VirtualKeyCode::A,
-            VirtualKeyCode::S,
-            VirtualKeyCode::D,
-            VirtualKeyCode::Z,
-            VirtualKeyCode::C,
-            VirtualKeyCode::Key4,
-            VirtualKeyCode::R,
-            VirtualKeyCode::F,
-            VirtualKeyCode::V,
-        ];
-        for (id, &key) in KEYMAP.iter().enumerate() {
-            if input.key_released(key) {
-                self.cpu.release(id)?;
-            }
-            if input.key_pressed(key) {
-                self.cpu.press(id)?;
-            }
-        }
-        Ok(())
+impl Application {
+    fn new(emu: Emulator, gui: Gui) -> Self {
+        Self { gui, emu }
     }
 }