broken GUI impl + Broken PPU scrolling

src/main.rs

@@ -12,6 +12,8 @@ use crate::bus::{Bus, NesBus};
 use crate::cartridge::Cartridge;
 use crate::cpu::Cpu;
 use crate::render::{PpmRenderer, Renderer};
+use eframe::egui;
+use crate::render::WindowRenderer;
 
 
 fn main() {
@@ -20,8 +22,9 @@ fn main() {
         1 => run_nestest(),
         3 if args[1] == "blargg" => run_blargg(&args[2]),
         3 if args[1] == "dbg" => run_dbg(&args[2]),
+        3 if args[1] == "gui" => run_gui(&args[2]),
         2 => run_cart(&args[1]),
-        _ => eprintln!("usage: rnes [<rom> | blargg <rom>]"),
+        _ => eprintln!("usage: rnes [<rom> | blargg <rom> | dbg <rom> | gui <rom>]"),
     }
 }
 
@@ -34,13 +37,8 @@ fn run_cart(path: &str) {
     let frames: u32 = 180;
 
     for _ in 0..frames {
-        while !bus.frame_done() {
-            let cycles = cpu.step(&mut bus);
-            bus.tick_ppu(cycles as u64);
-            if bus.take_nmi() { cpu.set_nmi(); }   // NMI fires when vblank hits, mid-frame
-        }
+        run_one_frame(&mut bus, &mut cpu);
         renderer.present(bus.framebuffer(), 256, 240);
-        bus.begin_frame();
     }
 }
 
@@ -94,4 +92,59 @@ fn run_dbg(path: &str) {
         bus.begin_frame();
     }
     println!("wrote debug_out/ + renders/, {frames} frames");
+}
+
+fn run_one_frame(bus: &mut NesBus, cpu: &mut Cpu) {
+    while !bus.frame_done() {
+        let cycles = cpu.step(bus);
+        bus.tick_ppu(cycles as u64);
+        if bus.take_nmi() { cpu.set_nmi(); }
+    }
+    bus.begin_frame();
+}
+
+struct GuiApp {
+    bus: NesBus,
+    cpu: Cpu,
+    renderer: WindowRenderer,
+}
+
+impl GuiApp {
+    fn new(cc: &eframe::CreationContext<'_>, cart: Cartridge) -> Self {
+        let mut bus = NesBus::new(cart);
+        let mut cpu = Cpu::new();
+        cpu.reset(&mut bus);
+        let renderer = WindowRenderer::new(cc, 256, 240);
+        Self { bus, cpu, renderer }
+    }
+}
+
+impl eframe::App for GuiApp {
+    // Non-UI work: emulation runs here, before painting.
+    fn logic(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
+        self.renderer.poll_input(self.bus.controller_mut());  // keyboard -> $4016/$4017
+        run_one_frame(&mut self.bus, &mut self.cpu);          // one emulated frame
+        self.renderer.present(self.bus.framebuffer(), 256, 240);
+        ctx.request_repaint();                                // keep it running at 60fps
+    }
+
+    // Painting: draw the framebuffer texture.
+    fn ui(&mut self, ui: &mut egui::Ui, _frame: &mut eframe::Frame) {
+        self.renderer.draw(ui);
+    }
+}
+
+fn run_gui(path: &str) {
+    let cart = Cartridge::from_file(path).unwrap();
+    let options = eframe::NativeOptions {
+        viewport: egui::ViewportBuilder::default()
+            .with_inner_size([1024.0, 960.0])
+            .with_title("rnes"),
+        ..Default::default()
+    };
+    eframe::run_native(
+        "rnes",
+        options,
+        Box::new(move |cc| Ok(Box::new(GuiApp::new(cc, cart)))),
+    ).expect("failed to run GUI");
 }