From 5aa308f695358a08e43b40b262f583cdf6178c68 Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Wed, 15 Mar 2023 13:15:32 +1100
Subject: [PATCH] save state restore

---
 gb-vst/src/lib.rs      | 49 +++++++++++++++++++++++++-----------------
 lib/src/connect/mod.rs |  1 +
 2 files changed, 30 insertions(+), 20 deletions(-)

diff --git a/gb-vst/src/lib.rs b/gb-vst/src/lib.rs
index 0805235..c4389d9 100644
--- a/gb-vst/src/lib.rs
+++ b/gb-vst/src/lib.rs
@@ -1,7 +1,7 @@
 use async_ringbuf::AsyncHeapConsumer;
 use futures::executor;
 use gb_emu_lib::{
-    connect::{AudioOutput, DownsampleType, EmulatorMessage, JoypadButtons, RomFile},
+    connect::{AudioOutput, CpuSaveState, DownsampleType, EmulatorMessage, JoypadButtons, RomFile},
     EmulatorCore,
 };
 use nih_plug::prelude::*;
@@ -27,6 +27,7 @@ pub struct GameboyEmu {
     vars: Option<EmuVars>,
     frame_receiver: Arc<FrameReceiver>,
     key_handler: Arc<JoypadSender>,
+    last_save_state: Option<CpuSaveState<[u8; 4]>>,
 }
 
 type FrameReceiver = Mutex<Option<Receiver<Vec<[u8; 4]>>>>;
@@ -36,6 +37,9 @@ const FRAMES_TO_BUFFER: usize = 1;
 const INCLUDE_BOOTROM: bool = false;
 const DOWNSAMPLE_TYPE: DownsampleType = DownsampleType::ZeroOrderHold;
 
+const ROM: &[u8; 65536] = include_bytes!("../../test-roms/mGB1_3_0.gb");
+const BOOTROM: &[u8; 256] = include_bytes!("../../bootrom/dmg_boot.bin");
+
 impl Plugin for GameboyEmu {
     const NAME: &'static str = "Gameboy";
 
@@ -48,7 +52,7 @@ impl Plugin for GameboyEmu {
     const VERSION: &'static str = "0.1";
 
     const AUDIO_IO_LAYOUTS: &'static [AudioIOLayout] = &[AudioIOLayout {
-        main_input_channels: NonZeroU32::new(2),
+        main_input_channels: None,
         main_output_channels: NonZeroU32::new(2),
 
         aux_input_ports: &[],
@@ -60,6 +64,9 @@ impl Plugin for GameboyEmu {
         names: PortNames::const_default(),
     }];
 
+    const MIDI_INPUT: MidiConfig = MidiConfig::MidiCCs;
+    const SAMPLE_ACCURATE_AUTOMATION: bool = true;
+
     type SysExMessage = ();
 
     type BackgroundTask = ();
@@ -118,25 +125,12 @@ impl Plugin for GameboyEmu {
             vars.rx = rx;
         } else {
             let bootrom = if INCLUDE_BOOTROM {
-                Some(RomFile::Raw(
-                    include_bytes!("../../bootrom/dmg_boot.bin").to_vec(),
-                ))
+                Some(RomFile::Raw(BOOTROM.to_vec()))
             } else {
                 None
             };
 
-            let options = gb_emu_lib::Options {
-                rom: RomFile::Raw(
-                    include_bytes!("../../test-roms/Tetris.gb")
-                        .to_vec()
-                        .to_vec(),
-                ),
-                save_path: None,
-                no_save: true,
-                bootrom,
-                connect_serial: false,
-                verbose: false,
-            };
+            let rom = RomFile::Raw(ROM.to_vec());
 
             let (sender, receiver) = channel::<EmulatorMessage>();
 
@@ -152,8 +146,22 @@ impl Plugin for GameboyEmu {
             *self.frame_receiver.lock().unwrap() = Some(frame_receiver);
             *self.key_handler.lock().unwrap() = Some(key_handler);
 
-            let mut emulator_core =
-                EmulatorCore::init(receiver, options, Box::new(renderer), output, None);
+            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,
+                };
+
+                EmulatorCore::init(receiver, options, window, output, None)
+            };
             emulator_core.run_until_buffer_full();
 
             self.vars = Some(EmuVars {
@@ -169,6 +177,7 @@ impl Plugin for GameboyEmu {
     fn deactivate(&mut self) {
         nih_log!("deactivating");
         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"),
@@ -181,7 +190,7 @@ impl Vst3Plugin for GameboyEmu {
     const VST3_CLASS_ID: [u8; 16] = *b"alexjankagbemula";
 
     const VST3_SUBCATEGORIES: &'static [Vst3SubCategory] =
-        &[Vst3SubCategory::Distortion, Vst3SubCategory::Dynamics];
+        &[Vst3SubCategory::Instrument, Vst3SubCategory::Synth];
 }
 
 nih_export_vst3!(GameboyEmu);
diff --git a/lib/src/connect/mod.rs b/lib/src/connect/mod.rs
index b8fcc2e..d89e41f 100644
--- a/lib/src/connect/mod.rs
+++ b/lib/src/connect/mod.rs
@@ -1,5 +1,6 @@
 use crate::processor::memory::mmio::gpu::Colour;
 pub use crate::processor::memory::mmio::joypad::{JoypadButtons, JoypadState};
+pub use crate::processor::CpuSaveState;
 pub use crate::{HEIGHT, WIDTH};
 use async_ringbuf::{AsyncHeapConsumer, AsyncHeapProducer, AsyncHeapRb};