Libretro frontend

Cargo.toml

@@ -3,10 +3,11 @@ members = [
     "sdl",
     "core",
     "rpi",
-    "common"
+    "common", 
+    "libretro"
 ]
 
 [workspace.package]
 version = "4.0.0"
 authors = ["alloncm <alloncm@gmail.com>"]
-rust-version = "1.70"   # cause of once cell
+rust-version = "1.73"   # cause of cargo-ndk used to build for android platform

Makefile.toml

@@ -2,7 +2,7 @@
 default_to_workspace = false
 
 [tasks.all]
-dependencies = ["test", "sdl", "rpios", "rpibm"]
+dependencies = ["test", "sdl", "rpios", "rpibm", "libretro"]
 
 [tasks.test]
 command = "cargo"
@@ -57,4 +57,14 @@ install_crate = {rustup_component_name = "llvm-tools-preview"}
 [tasks.install_rust_src]
 toolchain = "nightly"
 command = "rustup"
-args = ["component", "add", "rust-src"]
+args = ["component", "add", "rust-src"]
+
+[tasks.libretro]
+command = "cargo"
+args = ["build", "--release", "--package", "magenboy_libretro"]
+dependencies = ["libretro_android"]
+
+[tasks.libretro_android]
+install_crate = {crate_name = "cargo-ndk", binary = "cargo", test_arg = "ndk"}
+command = "cargo"
+args = ["ndk", "--target=aarch64-linux-android", "build", "--release", "--package", "magenboy_libretro"]

README.md

@@ -79,6 +79,10 @@ rustup component add llvm-tools-preview
 
 3. Builds the image
 
+### Libretro
+
+See - [LibretroDocs](docs/Libretro.md)
+
 ## Running
 
 ### Desktop

sdl/src/audio/audio_resampler.rs → common/src/audio/audio_resampler.rs

@@ -6,14 +6,12 @@ pub trait AudioResampler{
 }
 
 pub trait ResampledAudioDevice<AR:AudioResampler> : AudioDevice{
-    const VOLUME:Sample = 10 as Sample;
-
     fn push_buffer(&mut self, buffer:&[StereoSample; BUFFER_SIZE]){
         let resample = self.get_resampler().resample(buffer);
         for sample in resample{
             let(buffer, index) = self.get_audio_buffer();
-            buffer[*index] = sample.left_sample * Self::VOLUME;
-            buffer[*index + 1] = sample.left_sample * Self::VOLUME;
+            buffer[*index] = sample.left_sample;
+            buffer[*index + 1] = sample.right_sample;
             *index += 2;
             if *index == BUFFER_SIZE{
                 *index = 0;

sdl/src/audio/manual_audio_resampler.rs → common/src/audio/manual_audio_resampler.rs

@@ -1,4 +1,4 @@
-use magenboy_core::apu::audio_device::{BUFFER_SIZE, DEFAULT_SAPMPLE, Sample, StereoSample};
+use magenboy_core::apu::audio_device::{BUFFER_SIZE, StereoSample};
 use super::audio_resampler::AudioResampler;
 
 
@@ -12,15 +12,6 @@ pub struct ManualAudioResampler{
     skip_to_use:u32,
 }
 
-impl ManualAudioResampler{
-    fn interpolate_sample(samples:&[StereoSample])->StereoSample{
-        let interpulated_left_sample = samples.iter().fold(DEFAULT_SAPMPLE, |acc, x| acc + x.left_sample) / samples.len() as Sample;
-        let interpulated_right_sample = samples.iter().fold(DEFAULT_SAPMPLE, |acc, x| acc + x.right_sample) / samples.len() as Sample;
-
-        return StereoSample{left_sample: interpulated_left_sample, right_sample: interpulated_right_sample};
-    }
-}
-
 impl AudioResampler for ManualAudioResampler{
     fn new(original_frequency:u32, target_frequency:u32)->Self{
         // Calling round in order to get the nearest integer and resample as precise as possible
@@ -59,7 +50,7 @@ impl AudioResampler for ManualAudioResampler{
             self.sampling_counter += 1;
 
             if self.sampling_counter == self.skip_to_use {
-                let interpolated_sample = Self::interpolate_sample(&self.sampling_buffer);
+                let interpolated_sample = StereoSample::interpolate(&self.sampling_buffer);
                 self.sampling_counter = 0;
                 self.sampling_buffer.clear();
 

common/src/lib.rs

@@ -4,6 +4,12 @@ cfg_if::cfg_if!{ if #[cfg(feature = "std")] {
     pub mod mbc_handler;
     pub mod mpmc_gfx_device;
     pub mod logging;
+    pub mod audio{
+        mod audio_resampler;
+        mod manual_audio_resampler;
+        pub use audio_resampler::*;
+        pub use manual_audio_resampler::*;
+    }
 }}
 
 pub mod menu;

common/src/mbc_handler.rs

@@ -20,7 +20,7 @@ fn try_get_save_data(name:&String)->Option<Vec<u8>>{
     }
 }
 
-pub fn release_mbc<'a>(program_name:&String, mbc: &'a dyn Mbc){
+pub fn release_mbc<'a>(program_name:&String, mbc: &'a mut dyn Mbc){
     if mbc.has_battery(){
         while fs::write(format!("{}{}", program_name, ".sav"), mbc.get_ram()).is_err() {}       
         info!("saved succesfully");

common/src/scale.c

@@ -40,7 +40,7 @@ extern void scale_buffer(const uint16_t* input_buffer, int input_buffer_width, i
             const uint16_t pixel = ((uint16_t)blue) | (((uint16_t)green) << 5) | (((uint16_t)red) << 11);
 
             output_buffer[output_offset_counter * 2] = (uint8_t)(pixel >> 8);
-            output_buffer[(output_offset_counter * 2) + 1] = (uint8_t)(pixel && 0xFF);
+            output_buffer[(output_offset_counter * 2) + 1] = (uint8_t)(pixel & 0xFF);
             output_offset_counter++;
         }
     }

core/src/apu/apu_registers_updater.rs

@@ -10,7 +10,7 @@ use super::{
     square_sample_producer::SquareSampleProducer, 
     volume_envelop::VolumeEnvlope, 
     wave_sample_producer::WaveSampleProducer,
-    sound_utils::NUMBER_OF_CHANNELS
+    NUMBER_OF_CHANNELS
 };
 
 

core/src/apu/audio_device.rs

@@ -1,8 +1,13 @@
+use super::NUMBER_OF_CHANNELS;
+
 pub type Sample = i16;
 pub const DEFAULT_SAPMPLE:Sample = 0 as Sample;
+const MAX_MASTER_VOLUME:Sample = 8;
+pub const SAMPLE_MAX: Sample = Sample::MAX / (MAX_MASTER_VOLUME * NUMBER_OF_CHANNELS as Sample);
 
-pub const BUFFER_SIZE:usize = 2048;
+pub const BUFFER_SIZE:usize = 0x2000;
 
+#[derive(Clone, Copy)]
 #[repr(C, packed)]
 pub struct StereoSample{
     pub left_sample:Sample,
@@ -13,11 +18,12 @@ impl StereoSample{
     pub const fn const_defualt()->Self{
         Self{left_sample:DEFAULT_SAPMPLE, right_sample:DEFAULT_SAPMPLE}
     }
-}
 
-impl Clone for StereoSample{
-    fn clone(&self) -> Self {
-        Self{left_sample:self.left_sample,right_sample:self.right_sample}
+    pub fn interpolate(samples:&[StereoSample])->StereoSample{
+        let left_sample = (samples.iter().fold(0, |acc, x| acc + x.left_sample as i64) / samples.len() as i64) as Sample;
+        let right_sample = (samples.iter().fold(0, |acc, x| acc + x.right_sample as i64) / samples.len() as i64) as Sample;
+
+        return StereoSample{left_sample, right_sample};
     }
 }
 

core/src/apu/channel.rs

@@ -1,6 +1,4 @@
-use super::audio_device::{DEFAULT_SAPMPLE, Sample};
-use super::sample_producer::SampleProducer;
-use super::timer::Timer;
+use super::{audio_device::{Sample, DEFAULT_SAPMPLE, SAMPLE_MAX}, sample_producer::*, timer::Timer};
 
 pub struct Channel<Procuder: SampleProducer>{
     pub enabled:bool,
@@ -50,20 +48,24 @@ impl<Procuder: SampleProducer> Channel<Procuder>{
 
     pub fn get_audio_sample(&mut self)->Sample{
         if self.enabled{
-
-            let sample = if self.timer.cycle(){
+            if self.timer.cycle(){
                 self.timer.update_cycles_to_tick(self.sample_producer.get_updated_frequency_ticks(self.frequency));
-                self.sample_producer.produce() as Sample
+                let digital_sample = self.sample_producer.produce();
+                self.last_sample = Self::convert_digital_to_analog(digital_sample);
             }
-            else{
-                self.last_sample
-            };
-
-            self.last_sample = sample;
-
-            return self.last_sample;
         }
+        else{
+            self.last_sample = DEFAULT_SAPMPLE;
+        }
+
+        return self.last_sample;
+    }
+
+    fn convert_digital_to_analog(digital_sample:u8)->Sample{
+        const RATIO:Sample = SAMPLE_MAX / MAX_DIGITAL_SAMPLE as Sample;
 
-        return DEFAULT_SAPMPLE;
+        // Expandibg the sample to the full range of the Sample type while still 
+        // allowing furhter calculations without overflowing
+        return (digital_sample as Sample - (MAX_DIGITAL_SAMPLE as Sample / 2)) * RATIO;
     }
 }

core/src/apu/gb_apu.rs

@@ -7,7 +7,7 @@ use super::{
     sound_terminal::SoundTerminal,
     square_sample_producer::SquareSampleProducer, 
     wave_sample_producer::WaveSampleProducer,
-    sound_utils::NUMBER_OF_CHANNELS
+    NUMBER_OF_CHANNELS
 };
 
 pub struct GbApu<Device: AudioDevice>{

core/src/apu/mod.rs

@@ -11,8 +11,8 @@ pub mod freq_sweep;
 pub mod volume_envelop;
 pub mod noise_sample_producer;
 
-mod sound_utils;
 mod apu_registers_updater;
 
 pub use apu_registers_updater::*;
 
+pub(self) const NUMBER_OF_CHANNELS:usize = 4;

core/src/apu/sample_producer.rs

@@ -1,4 +1,8 @@
+/// Max value for digital sample according to the Pandocs
+pub const MAX_DIGITAL_SAMPLE:u8 = 0xF;
+
 pub trait SampleProducer{
+    /// Produces a digital sample in range of 0 to 0xF 
     fn produce(&mut self)->u8;
     fn get_updated_frequency_ticks(&self, freq:u16)->u16;
     fn reset(&mut self);

core/src/apu/sound_terminal.rs

@@ -1,4 +1,4 @@
-use super::{audio_device::{DEFAULT_SAPMPLE, Sample}, sound_utils::NUMBER_OF_CHANNELS};
+use super::{audio_device::{DEFAULT_SAPMPLE, Sample}, NUMBER_OF_CHANNELS};
 
 type ChannelMask = u16;
 

core/src/apu/square_sample_producer.rs

@@ -1,6 +1,11 @@
-use super::{sample_producer::SampleProducer, sound_utils::DUTY_TABLE};
-use super::freq_sweep::FreqSweep;
-use super::volume_envelop::VolumeEnvlope;
+use super::{freq_sweep::FreqSweep, sample_producer::SampleProducer, volume_envelop::VolumeEnvlope};
+
+const DUTY_TABLE:[[u8; 8]; 4] = [
+    [0,0,0,0,0,0,0,1],
+    [1,0,0,0,0,0,0,1],
+    [1,0,0,0,0,1,1,1],
+    [0,1,1,1,1,1,1,0],
+];
 
 pub struct SquareSampleProducer{
     pub wave_duty:u8,

core/src/keypad/joypad_handler.rs

@@ -3,8 +3,7 @@ use super::{joypad_provider::JoypadProvider, joypad::Joypad, button::Button};
 
 
 pub struct JoypadHandler<JP:JoypadProvider>{
-    pub register:u8,
-
+    register:u8,
     joypad:Joypad,
     joypad_provider:JP,
 }
@@ -20,7 +19,9 @@ impl<JP:JoypadProvider> JoypadHandler<JP>{
 
     pub fn poll_joypad_state(&mut self){
         self.joypad_provider.provide(&mut self.joypad);
+    }
 
+    pub fn get_register(&mut self) -> u8{
         let buttons = (self.register & BIT_5_MASK) == 0;
         let directions = (self.register & BIT_4_MASK) == 0;
 
@@ -36,8 +37,10 @@ impl<JP:JoypadProvider> JoypadHandler<JP>{
             flip_bit_u8(&mut self.register, 2, !self.joypad.buttons[Button::Up as usize]);
             flip_bit_u8(&mut self.register, 3, !self.joypad.buttons[Button::Down as usize]);
         }
-    }
 
+        return self.register;
+    }
+
     pub fn set_register(&mut self, value:u8){
         self.register &= 0b1100_1111;   // Reset bit 4 & 5
         self.register |= value & 0b0011_0000;   // Seting the bits

core/src/machine/gameboy.rs

@@ -53,9 +53,9 @@ impl<'a, JP:JoypadProvider, AD:AudioDevice, GFX:GfxDevice> GameBoy<'a, JP, AD, G
     }
 
     pub fn cycle_frame(&mut self){
-        while self.mmu.m_cycle_counter < CYCLES_PER_FRAME{
-            self.mmu.poll_joypad_state();
-
+        self.mmu.poll_joypad_state();
+
+        while !self.mmu.consume_vblank_event(){
             //CPU
             let mut cpu_cycles_passed = 1;
             if !self.cpu.halt && !self.mmu.dma_block_cpu(){
@@ -72,8 +72,6 @@ impl<'a, JP:JoypadProvider, AD:AudioDevice, GFX:GfxDevice> GameBoy<'a, JP, AD, G
                 self.mmu.cycle(interrupt_cycles);
             }
         }
-
-        self.mmu.m_cycle_counter = 0;
     }
 
     fn execute_opcode(&mut self)->u8{

core/src/mmu/carts/mbc1.rs

@@ -12,7 +12,7 @@ pub struct Mbc1<'a>{
 }
 
 impl<'a> Mbc for Mbc1<'a>{
-    fn get_ram(&self) ->&[u8] {
+    fn get_ram(&mut self) ->&mut [u8] {
         self.ram
     }
 

core/src/mmu/carts/mbc3.rs

@@ -16,7 +16,7 @@ pub struct Mbc3<'a>{
 
 impl<'a> Mbc for Mbc3<'a>{
 
-    fn get_ram(&self) ->&[u8] {
+    fn get_ram(&mut self) ->&mut [u8] {
         self.ram
     }
 

core/src/mmu/carts/mbc5.rs

@@ -12,8 +12,8 @@ pub struct Mbc5<'a>{
 }
 
 impl<'a> Mbc for Mbc5<'a> {
-    fn get_ram(&self)->&[u8] {
-        &self.ram
+    fn get_ram(&mut self)->&mut [u8] {
+        self.ram
     }
 
     fn has_battery(&self)->bool {