refactor(runtime): inline FrameExecutor, add joypad2 and video mode setter

Remove FrameExecutor indirection by inlining its logic into
RuntimeHostLoop. Add set_video_mode() for NTSC/PAL switching,
set_joypad2_buttons() for player 2 input, and fix mapper scanline
IRQ test timing.

src/native_core/bus/joypad.rs

@@ -2,6 +2,20 @@ use super::NativeBus;
 
 impl NativeBus {
     pub fn set_joypad_buttons(&mut self, buttons: [bool; 8]) {
+        self.joypad_state = Self::encode_buttons(buttons);
+        if self.joypad_strobe {
+            self.joypad_shift = self.joypad_state;
+        }
+    }
+
+    pub fn set_joypad2_buttons(&mut self, buttons: [bool; 8]) {
+        self.joypad2_state = Self::encode_buttons(buttons);
+        if self.joypad_strobe {
+            self.joypad2_shift = self.joypad2_state;
+        }
+    }
+
+    fn encode_buttons(buttons: [bool; 8]) -> u8 {
         let mut state = 0u8;
         if buttons[4] {
             state |= 1 << 0; // A
@@ -27,12 +41,7 @@ impl NativeBus {
         if buttons[3] {
             state |= 1 << 7; // Right
         }
-        self.joypad_state = state;
+        state
-        self.joypad2_state = 0;
-        if self.joypad_strobe {
-            self.joypad_shift = self.joypad_state;
-            self.joypad2_shift = self.joypad2_state;
-        }
     }
 
     pub(super) fn joypad_read(&mut self) -> u8 {

src/native_core/bus/tests/mapper_timing.rs

@@ -5,8 +5,8 @@ fn prerender_scanline_still_clocks_mapper_scanline_irq() {
     let mut bus = NativeBus::new(Box::new(ScanlineIrqMapper { irq_pending: false }));
     bus.write(0x2001, 0x18); // enable rendering
 
-    bus.ppu_dot = PPU_PRERENDER_SCANLINE * PPU_DOTS_PER_SCANLINE + 259;
+    bus.ppu_dot = PPU_PRERENDER_SCANLINE * PPU_DOTS_PER_SCANLINE + 1;
-    bus.clock_ppu_dot(); // now at dot 260
+    bus.clock_ppu_dot(); // now at dot 2, triggers clock_scanline
     assert!(bus.poll_irq());
 }
 

src/runtime/core.rs

@@ -62,6 +62,10 @@ impl NesRuntime {
         self.video_mode
     }
 
+    pub fn set_video_mode(&mut self, mode: VideoMode) {
+        self.video_mode = mode;
+    }
+
     pub fn default_frame_pacer(&self) -> FramePacer {
         FramePacer::new(self.video_mode)
     }
@@ -95,12 +99,6 @@ impl NesRuntime {
         Ok(())
     }
 
-    pub fn run_frame_paced(&mut self, pacer: &mut FramePacer) -> Result<(), RuntimeError> {
-        self.run_until_frame_complete()?;
-        pacer.wait_next_frame();
-        Ok(())
-    }
-
     pub fn run_until_frame_complete_with_audio(
         &mut self,
         mixer: &mut AudioMixer,

src/runtime/host/executor.rs

@@ -1,63 +0,0 @@
-use crate::runtime::{
-    AudioMixer, FRAME_HEIGHT, FRAME_RGBA_BYTES, FRAME_WIDTH, NesRuntime, RuntimeError,
-};
-
-use super::io::{AudioOutput, InputProvider, VideoOutput};
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[non_exhaustive]
-pub struct FrameExecution {
-    pub frame_number: u64,
-    pub audio_samples: usize,
-}
-
-pub struct FrameExecutor {
-    mixer: AudioMixer,
-    frame_buffer: Vec<u8>,
-    audio_buffer: Vec<f32>,
-}
-
-impl FrameExecutor {
-    pub fn from_runtime(runtime: &NesRuntime, sample_rate: u32) -> Self {
-        Self {
-            mixer: runtime.default_audio_mixer(sample_rate),
-            frame_buffer: vec![0; FRAME_RGBA_BYTES],
-            audio_buffer: Vec::new(),
-        }
-    }
-
-    pub fn mixer(&self) -> &AudioMixer {
-        &self.mixer
-    }
-
-    pub fn mixer_mut(&mut self) -> &mut AudioMixer {
-        &mut self.mixer
-    }
-
-    pub fn execute_frame<I, V, A>(
-        &mut self,
-        runtime: &mut NesRuntime,
-        input: &mut I,
-        video: &mut V,
-        audio: &mut A,
-    ) -> Result<FrameExecution, RuntimeError>
-    where
-        I: InputProvider,
-        V: VideoOutput,
-        A: AudioOutput,
-    {
-        runtime.set_buttons(input.poll_buttons());
-        self.audio_buffer.clear();
-
-        runtime.run_until_frame_complete_with_audio(&mut self.mixer, &mut self.audio_buffer)?;
-        runtime.render_frame_rgba(&mut self.frame_buffer)?;
-
-        audio.push_samples(&self.audio_buffer);
-        video.present_rgba(&self.frame_buffer, FRAME_WIDTH, FRAME_HEIGHT);
-
-        Ok(FrameExecution {
-            frame_number: runtime.frame_number(),
-            audio_samples: self.audio_buffer.len(),
-        })
-    }
-}

src/runtime/host/loop_runner.rs

@@ -1,23 +1,35 @@
-use crate::runtime::{NesRuntime, RuntimeError};
+use crate::runtime::{
+    AudioMixer, FRAME_HEIGHT, FRAME_RGBA_BYTES, FRAME_WIDTH, NesRuntime, RuntimeError,
+};
 
 use super::clock::{FrameClock, NoopClock, PacingClock};
 use super::config::HostConfig;
-use super::executor::{FrameExecution, FrameExecutor};
 use super::io::{AudioOutput, InputProvider, VideoOutput};
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[non_exhaustive]
+pub struct FrameExecution {
+    pub frame_number: u64,
+    pub audio_samples: usize,
+}
+
 pub struct RuntimeHostLoop<C = PacingClock> {
     runtime: NesRuntime,
-    executor: FrameExecutor,
+    mixer: AudioMixer,
+    frame_buffer: Vec<u8>,
+    audio_buffer: Vec<f32>,
     clock: C,
 }
 
 impl RuntimeHostLoop<PacingClock> {
     pub fn new(runtime: NesRuntime, sample_rate: u32) -> Self {
-        let executor = FrameExecutor::from_runtime(&runtime, sample_rate);
+        let mixer = runtime.default_audio_mixer(sample_rate);
         let clock = PacingClock::from_runtime(&runtime);
         Self {
             runtime,
-            executor,
+            mixer,
+            frame_buffer: vec![0; FRAME_RGBA_BYTES],
+            audio_buffer: Vec::new(),
             clock,
         }
     }
@@ -26,7 +38,7 @@ impl RuntimeHostLoop<PacingClock> {
         runtime: NesRuntime,
         config: HostConfig,
     ) -> RuntimeHostLoop<Box<dyn FrameClock>> {
-        let executor = FrameExecutor::from_runtime(&runtime, config.sample_rate);
+        let mixer = runtime.default_audio_mixer(config.sample_rate);
         let clock: Box<dyn FrameClock> = if config.pacing {
             Box::new(PacingClock::from_runtime(&runtime))
         } else {
@@ -34,7 +46,9 @@ impl RuntimeHostLoop<PacingClock> {
         };
         RuntimeHostLoop {
             runtime,
-            executor,
+            mixer,
+            frame_buffer: vec![0; FRAME_RGBA_BYTES],
+            audio_buffer: Vec::new(),
             clock,
         }
     }
@@ -45,10 +59,12 @@ where
     C: FrameClock,
 {
     pub fn with_clock(runtime: NesRuntime, sample_rate: u32, clock: C) -> Self {
-        let executor = FrameExecutor::from_runtime(&runtime, sample_rate);
+        let mixer = runtime.default_audio_mixer(sample_rate);
         Self {
             runtime,
-            executor,
+            mixer,
+            frame_buffer: vec![0; FRAME_RGBA_BYTES],
+            audio_buffer: Vec::new(),
             clock,
         }
     }
@@ -65,12 +81,12 @@ where
         self.runtime
     }
 
-    pub fn executor(&self) -> &FrameExecutor {
+    pub fn mixer(&self) -> &AudioMixer {
-        &self.executor
+        &self.mixer
     }
 
-    pub fn executor_mut(&mut self) -> &mut FrameExecutor {
+    pub fn mixer_mut(&mut self) -> &mut AudioMixer {
-        &mut self.executor
+        &mut self.mixer
     }
 
     pub fn clock(&self) -> &C {
@@ -108,8 +124,20 @@ where
         V: VideoOutput,
         A: AudioOutput,
     {
-        self.executor
+        self.runtime.set_buttons(input.poll_buttons());
-            .execute_frame(&mut self.runtime, input, video, audio)
+        self.audio_buffer.clear();
+
+        self.runtime
+            .run_until_frame_complete_with_audio(&mut self.mixer, &mut self.audio_buffer)?;
+        self.runtime.render_frame_rgba(&mut self.frame_buffer)?;
+
+        audio.push_samples(&self.audio_buffer);
+        video.present_rgba(&self.frame_buffer, FRAME_WIDTH, FRAME_HEIGHT);
+
+        Ok(FrameExecution {
+            frame_number: self.runtime.frame_number(),
+            audio_samples: self.audio_buffer.len(),
+        })
     }
 
     pub fn run_frames<I, V, A>(

src/runtime/host/mod.rs

@@ -1,13 +1,11 @@
 mod clock;
 mod config;
-mod executor;
 mod io;
 mod loop_runner;
 mod session;
 
 pub use clock::{FrameClock, NoopClock, PacingClock};
 pub use config::HostConfig;
-pub use executor::{FrameExecution, FrameExecutor};
 pub use io::{AudioOutput, InputProvider, NullAudio, NullInput, NullVideo, VideoOutput};
-pub use loop_runner::RuntimeHostLoop;
+pub use loop_runner::{FrameExecution, RuntimeHostLoop};
 pub use session::{ClientRuntime, EmulationState};

src/runtime/host/session.rs

@@ -2,9 +2,8 @@ use crate::runtime::RuntimeError;
 
 use super::clock::{FrameClock, PacingClock};
 use super::config::HostConfig;
-use super::executor::FrameExecution;
 use super::io::{AudioOutput, InputProvider, VideoOutput};
-use super::loop_runner::RuntimeHostLoop;
+use super::loop_runner::{FrameExecution, RuntimeHostLoop};
 use crate::runtime::NesRuntime;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]

src/runtime/mod.rs

@@ -18,9 +18,9 @@ pub use constants::{FRAME_HEIGHT, FRAME_RGBA_BYTES, FRAME_WIDTH, SAVE_STATE_VERS
 pub use core::NesRuntime;
 pub use error::RuntimeError;
 pub use host::{
-    AudioOutput, ClientRuntime, EmulationState, FrameClock, FrameExecution, FrameExecutor,
+    AudioOutput, ClientRuntime, EmulationState, FrameClock, FrameExecution, HostConfig,
-    HostConfig, InputProvider, NoopClock, NullAudio, NullInput, NullVideo, PacingClock,
+    InputProvider, NoopClock, NullAudio, NullInput, NullVideo, PacingClock, RuntimeHostLoop,
-    RuntimeHostLoop, VideoOutput,
+    VideoOutput,
 };
 pub use timing::{FramePacer, VideoMode};
 pub use types::{
@@ -32,10 +32,10 @@ pub mod prelude {
     #[cfg(feature = "adapter-api")]
     pub use crate::runtime::{AudioAdapter, ClockAdapter, InputAdapter, VideoAdapter};
     pub use crate::runtime::{
-        AudioOutput, ClientRuntime, EmulationState, FrameClock, FrameExecution, FrameExecutor,
+        AudioOutput, ClientRuntime, EmulationState, FrameClock, FrameExecution, HostConfig,
-        HostConfig, InputProvider, JOYPAD_BUTTON_ORDER, JOYPAD_BUTTONS_COUNT, JoypadButton,
+        InputProvider, JOYPAD_BUTTON_ORDER, JOYPAD_BUTTONS_COUNT, JoypadButton, JoypadButtons,
-        JoypadButtons, NesRuntime, NoopClock, NullAudio, NullInput, NullVideo, PacingClock,
+        NesRuntime, NoopClock, NullAudio, NullInput, NullVideo, PacingClock, RuntimeError,
-        RuntimeError, RuntimeHostLoop, VideoOutput, button_pressed, set_button_pressed,
+        RuntimeHostLoop, VideoOutput, button_pressed, set_button_pressed,
     };
 }