feat/jni: Add rustboyadvance-jni crate to export some simple JNI bindings

Former-commit-id: d4e7a622a97215a8c1b7b50bb7f08d18cb9c5716

Cargo.toml

@@ -8,6 +8,7 @@ edition = "2018"
 members = [
     "rustboyadvance-sdl2",
     "rustboyadvance-minifb",
+    "rustboyadvance-jni",
 ]
 
 [dependencies]
@@ -24,7 +25,7 @@ hexdump = "0.1.0"
 time = "0.2.6"
 bitfield = "0.13.1"
 bitflags = "1.2.1"
-zip = "0.5.4"
+zip = {version = "0.5.4", default-features = false, features = ["deflate", "time"]}
 ctrlc = "3.1.3"
 bit-set = "0.5.1"
 debug_stub_derive = "0.3.0"

rustboyadvance-jni/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "rustboyadvance-jni"
+version = "0.1.0"
+authors = ["Michel Heily <michelheily@gmail.com>"]
+edition = "2018"
+description = "JNI bindings for rustboyadvance core"
+publish = false
+
+[lib]
+crate-type = ["staticlib", "cdylib"]
+
+[dependencies]
+rustboyadvance-ng = {path = "../"}
+jni = { version = "0.14", default-features = false }
+log = "0.4.8"
+env_logger = "0.7.1"

rustboyadvance-jni/src/lib.rs

@@ -0,0 +1,159 @@
+/// JNI Bindings to rustboyadvance
+/// For use with the following java class
+///
+/// package com.mrmichel.rustboyadvance;
+////
+/// public class EmulatorInterface {
+///
+///     public static native int loadRom(String romPath);
+///
+///     public static native int openEmulator(String biosPath);
+///
+///     public static native void closeEmulator();
+///
+///     public static native int runFrame(int[] frame_buffer);
+///
+///     static {
+///         System.loadLibrary("rustboyadvance_jni");
+///     }
+/// }
+use std::cell::RefCell;
+use std::os::raw::c_void;
+use std::rc::Rc;
+
+#[macro_use]
+extern crate log;
+
+use env_logger;
+
+use rustboyadvance_ng::prelude::*;
+
+struct Hardware {
+    frame_buffer: [u32; DISPLAY_WIDTH * DISPLAY_HEIGHT],
+}
+
+impl Hardware {
+    fn new() -> Hardware {
+        Hardware {
+            frame_buffer: [0; DISPLAY_WIDTH * DISPLAY_HEIGHT],
+        }
+    }
+}
+
+impl VideoInterface for Hardware {
+    fn render(&mut self, buffer: &[u32]) {
+        self.frame_buffer[..].clone_from_slice(buffer);
+    }
+}
+
+impl AudioInterface for Hardware {}
+impl InputInterface for Hardware {}
+
+struct Emulator {
+    hwif: Rc<RefCell<Hardware>>,
+    gba: GameBoyAdvance,
+}
+
+#[allow(non_snake_case)]
+pub mod android {
+    use super::*;
+
+    use std::path::Path;
+
+    use jni;
+
+    use jni::objects::{JClass, JString};
+    use jni::sys::{jint, jintArray, JNI_VERSION_1_6};
+    use jni::{JNIEnv, JavaVM};
+
+    static mut EMULATOR: Option<Emulator> = None;
+    static mut ROM: Option<Cartridge> = None;
+
+    #[no_mangle]
+    pub unsafe extern "C" fn JNI_OnLoad(_vm: *mut JavaVM, _reserved: *mut c_void) -> jint {
+        env_logger::init();
+        debug!("library loaded!");
+
+        JNI_VERSION_1_6
+    }
+
+    #[no_mangle]
+    pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_EmulatorInterface_loadRom(
+        env: JNIEnv,
+        _: JClass,
+        rom_path: JString,
+    ) -> jint {
+        if EMULATOR.is_some() {
+            error!("can't load rom while emulator is running");
+            return -1;
+        }
+
+        let rom_path: String = env
+            .get_string(rom_path)
+            .expect("invalid rom path object")
+            .into();
+        let gamepak = GamepakBuilder::new()
+            .file(&Path::new(&rom_path))
+            .build()
+            .expect("failed to load rom");
+
+        info!("Loaded ROM file {:?}", gamepak.header);
+        ROM = Some(gamepak);
+
+        0
+    }
+
+    #[no_mangle]
+    pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_EmulatorInterface_openEmulator(
+        env: JNIEnv,
+        _: JClass,
+        bios_path: JString,
+    ) -> jint {
+        if let Some(cartridge) = ROM.clone() {
+            let bios_path: String = env
+                .get_string(bios_path)
+                .expect("invalid bios path object")
+                .into();
+            let hw = Rc::new(RefCell::new(Hardware::new()));
+
+            let bios_rom = read_bin_file(&Path::new(&bios_path)).expect("failed to load bios file");
+
+            EMULATOR = Some(Emulator {
+                hwif: hw.clone(),
+                gba: GameBoyAdvance::new(bios_rom, cartridge, hw.clone(), hw.clone(), hw.clone()),
+            });
+
+            return 0;
+        } else {
+            error!("please call loadRom first");
+            return -1;
+        }
+    }
+
+    #[no_mangle]
+    pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_EmulatorInterface_closeEmulator(
+        env: JNIEnv,
+        _: JClass,
+    ) {
+        EMULATOR = None;
+    }
+
+    #[no_mangle]
+    pub unsafe extern "C" fn Java_com_mrmichel_rustboyadvance_EmulatorInterface_runFrame(
+        env: JNIEnv,
+        _: JClass,
+        frame_buffer: jintArray,
+    ) -> jint {
+        if let Some(emu) = &mut EMULATOR {
+            emu.gba.frame();
+            let our_buffer =
+                std::mem::transmute::<&[u32], &[i32]>(&emu.hwif.borrow().frame_buffer as &[u32]);
+            env.set_int_array_region(frame_buffer, 0, our_buffer)
+                .expect("failed to copy frame buffer to java");
+
+            return 0;
+        }
+        error!("emulator is not initalized");
+        return -1;
+    }
+}

src/lib.rs

@@ -58,7 +58,8 @@ pub trait InputInterface {
 
 pub mod prelude {
     pub use super::core::arm7tdmi;
-    pub use super::core::cartridge::GamepakBuilder;
+    pub use super::core::cartridge::{Cartridge, GamepakBuilder};
+    pub use super::core::gpu::{DISPLAY_HEIGHT, DISPLAY_WIDTH};
     pub use super::core::Bus;
     pub use super::core::{GBAError, GBAResult, GameBoyAdvance};
     #[cfg(feature = "debugger")]