From b5fa2e6690551eb2048c276ce79c5cbf27827576 Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Wed, 15 Mar 2023 14:05:19 +1100
Subject: [PATCH] should restore from save state... doesn't, but should

---
 gb-vst/src/lib.rs | 68 ++++++++++++++++++++++++++++++++++-------------
 lib/src/lib.rs    | 39 +++++++++++++++++++++++++++
 2 files changed, 89 insertions(+), 18 deletions(-)

diff --git a/gb-vst/src/lib.rs b/gb-vst/src/lib.rs
index c4389d9..1d5b0e3 100644
--- a/gb-vst/src/lib.rs
+++ b/gb-vst/src/lib.rs
@@ -5,6 +5,7 @@ use gb_emu_lib::{
     EmulatorCore,
 };
 use nih_plug::prelude::*;
+use nih_plug::{midi::MidiResult::Basic, params::persist::PersistentField};
 use std::sync::{
     mpsc::{channel, Receiver, Sender},
     Arc, Mutex,
@@ -13,8 +14,29 @@ use ui::{Emulator, EmulatorRenderer};
 
 mod ui;
 
+#[derive(Default)]
+struct SaveStateParam {
+    state: Arc<Mutex<Option<CpuSaveState<[u8; 4]>>>>,
+}
+
+impl PersistentField<'_, Option<CpuSaveState<[u8; 4]>>> for SaveStateParam {
+    fn set(&self, new_value: Option<CpuSaveState<[u8; 4]>>) {
+        *self.state.lock().unwrap() = new_value;
+    }
+
+    fn map<F, R>(&self, f: F) -> R
+    where
+        F: Fn(&Option<CpuSaveState<[u8; 4]>>) -> R,
+    {
+        f(&self.state.lock().unwrap())
+    }
+}
+
 #[derive(Params, Default)]
-struct EmuParams {}
+struct EmuParams {
+    #[persist = "save_state"]
+    last_save_state: SaveStateParam,
+}
 
 struct EmuVars {
     rx: AsyncHeapConsumer<[f32; 2]>,
@@ -27,7 +49,7 @@ pub struct GameboyEmu {
     vars: Option<EmuVars>,
     frame_receiver: Arc<FrameReceiver>,
     key_handler: Arc<JoypadSender>,
-    last_save_state: Option<CpuSaveState<[u8; 4]>>,
+    params: Arc<EmuParams>,
 }
 
 type FrameReceiver = Mutex<Option<Receiver<Vec<[u8; 4]>>>>;
@@ -72,15 +94,18 @@ impl Plugin for GameboyEmu {
     type BackgroundTask = ();
 
     fn params(&self) -> Arc<dyn Params> {
-        Arc::new(EmuParams::default())
+        self.params.clone()
     }
 
     fn process(
         &mut self,
         buffer: &mut Buffer,
         _: &mut AuxiliaryBuffers,
-        _: &mut impl ProcessContext<Self>,
+        _c: &mut impl ProcessContext<Self>,
     ) -> ProcessStatus {
+        while let Some(event) = _c.next_event() {
+            if let Some(Basic(_midi)) = event.as_midi() {}
+        }
         if let Some(ref mut vars) = self.vars {
             if buffer.channels() != 2 {
                 panic!()
@@ -97,6 +122,7 @@ impl Plugin for GameboyEmu {
             }
             vars.emulator_core.run_until_buffer_full();
         }
+        self.update_save_state();
         ProcessStatus::KeepAlive
     }
 
@@ -148,20 +174,16 @@ impl Plugin for GameboyEmu {
 
             let window = Box::new(renderer);
 
-            let mut emulator_core = if let Some(state) = self.last_save_state.take() {
-                EmulatorCore::from_save_state(state, rom, receiver, window, output)
-            } else {
-                let options = gb_emu_lib::Options {
-                    rom,
-                    save_path: None,
-                    no_save: true,
-                    bootrom,
-                    connect_serial: false,
-                    verbose: false,
-                };
+            let mut emulator_core =
+                if let Some(state) = self.params.last_save_state.state.lock().unwrap().take() {
+                    EmulatorCore::from_save_state(state, rom, receiver, window, output)
+                } else {
+                    let options = gb_emu_lib::Options::new(rom)
+                        .with_bootrom(bootrom)
+                        .force_no_save();
 
-                EmulatorCore::init(receiver, options, window, output, None)
-            };
+                    EmulatorCore::init(receiver, options, window, output, None)
+                };
             emulator_core.run_until_buffer_full();
 
             self.vars = Some(EmuVars {
@@ -169,6 +191,7 @@ impl Plugin for GameboyEmu {
                 sender,
                 emulator_core,
             });
+            self.update_save_state();
         }
 
         true
@@ -176,8 +199,8 @@ impl Plugin for GameboyEmu {
 
     fn deactivate(&mut self) {
         nih_log!("deactivating");
+        self.update_save_state();
         if let Some(ref mut vars) = self.vars {
-            self.last_save_state = Some(vars.emulator_core.get_save_state());
             match vars.sender.send(EmulatorMessage::Stop) {
                 Ok(_) => self.vars = None,
                 Err(e) => nih_log!("error {e} sending message to emulator"),
@@ -186,6 +209,15 @@ impl Plugin for GameboyEmu {
     }
 }
 
+impl GameboyEmu {
+    fn update_save_state(&mut self) {
+        if let Some(ref mut vars) = self.vars {
+            *self.params.last_save_state.state.lock().unwrap() =
+                Some(vars.emulator_core.get_save_state());
+        }
+    }
+}
+
 impl Vst3Plugin for GameboyEmu {
     const VST3_CLASS_ID: [u8; 16] = *b"alexjankagbemula";
 
diff --git a/lib/src/lib.rs b/lib/src/lib.rs
index c87f729..01e5edb 100644
--- a/lib/src/lib.rs
+++ b/lib/src/lib.rs
@@ -22,6 +22,7 @@ mod constants;
 mod processor;
 pub mod util;
 
+#[non_exhaustive]
 pub struct Options {
     pub rom: RomFile,
     pub save_path: Option<String>,
@@ -31,6 +32,44 @@ pub struct Options {
     pub verbose: bool,
 }
 
+impl Options {
+    pub fn new(rom: RomFile) -> Self {
+        Self {
+            rom,
+            save_path: None,
+            no_save: false,
+            bootrom: None,
+            connect_serial: false,
+            verbose: false,
+        }
+    }
+
+    pub fn with_save_path(mut self, path: String) -> Self {
+        self.save_path = Some(path);
+        self
+    }
+
+    pub fn force_no_save(mut self) -> Self {
+        self.no_save = true;
+        self
+    }
+
+    pub fn with_bootrom(mut self, bootrom: Option<RomFile>) -> Self {
+        self.bootrom = bootrom;
+        self
+    }
+
+    pub fn with_serial(mut self) -> Self {
+        self.connect_serial = true;
+        self
+    }
+
+    pub fn with_verbose(mut self) -> Self {
+        self.verbose = true;
+        self
+    }
+}
+
 static mut PAUSE_ENABLED: bool = false;
 static mut PAUSE_QUEUED: bool = false;