diff --git a/CHANGELOG.md b/CHANGELOG.md
index a92c0b596ec916a3de2d1d80f27cfa11680b3e0f..290c3c3bccd6b56ba8f3799684049075f842ee09 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
* Support for Python 3 API - [#36](https://gitlab.stage.hive.pt/joamag/boytacean/-/issues/36)
* `next_frame()` method for frame by frame navigation
+* Support for palette switching option in Libretro - [#37](https://gitlab.stage.hive.pt/joamag/boytacean/-/issues/37)
### Changed
diff --git a/frontends/libretro/src/consts.rs b/frontends/libretro/src/consts.rs
index 9b35e0e2bb2d641653465026d5dc0879f5614a15..51082f85836ab04d04548a52920830b50769f4ff 100644
--- a/frontends/libretro/src/consts.rs
+++ b/frontends/libretro/src/consts.rs
@@ -2,6 +2,9 @@ pub const RETRO_API_VERSION: u32 = 1;
pub const REGION_NTSC: u32 = 0;
pub const RETRO_ENVIRONMENT_SET_PIXEL_FORMAT: u32 = 10;
+pub const RETRO_ENVIRONMENT_GET_VARIABLE: u32 = 15;
+pub const RETRO_ENVIRONMENT_SET_VARIABLES: u32 = 16;
+pub const RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE: u32 = 17;
pub const RETRO_PIXEL_FORMAT_0RGB1555: usize = 0;
pub const RETRO_PIXEL_FORMAT_XRGB8888: usize = 1;
diff --git a/frontends/libretro/src/lib.rs b/frontends/libretro/src/lib.rs
index 3893b0d27d15c49fd12a6fab91f92160fe17d413..cb8d838fce9cf50f6eafd31e3293570cbbc4e8d8 100644
--- a/frontends/libretro/src/lib.rs
+++ b/frontends/libretro/src/lib.rs
@@ -1,6 +1,7 @@
#![allow(clippy::uninlined_format_args)]
pub mod consts;
+pub mod palettes;
use boytacean::{
debugln,
@@ -19,8 +20,11 @@ use consts::{
RETRO_DEVICE_ID_JOYPAD_R2, RETRO_DEVICE_ID_JOYPAD_R3, RETRO_DEVICE_ID_JOYPAD_RIGHT,
RETRO_DEVICE_ID_JOYPAD_SELECT, RETRO_DEVICE_ID_JOYPAD_START, RETRO_DEVICE_ID_JOYPAD_UP,
RETRO_DEVICE_ID_JOYPAD_X, RETRO_DEVICE_ID_JOYPAD_Y, RETRO_DEVICE_JOYPAD,
- RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, RETRO_PIXEL_FORMAT_XRGB8888,
+ RETRO_ENVIRONMENT_GET_VARIABLE, RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE,
+ RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, RETRO_ENVIRONMENT_SET_VARIABLES,
+ RETRO_PIXEL_FORMAT_XRGB8888,
};
+use palettes::get_palette;
use std::{
collections::HashMap,
ffi::CStr,
@@ -60,6 +64,11 @@ static mut INPUT_POLL_CALLBACK: Option<extern "C" fn()> = None;
static mut INPUT_STATE_CALLBACK: Option<
extern "C" fn(port: u32, device: u32, index: u32, id: u32) -> i16,
> = None;
+static mut UPDATED: bool = false;
+static mut VARIABLE: RetroVariable = RetroVariable {
+ key: "palette\0".as_ptr() as *const c_char,
+ value: std::ptr::null(),
+};
const KEYS: [RetroJoypad; 8] = [
RetroJoypad::RetroDeviceIdJoypadUp,
@@ -71,6 +80,17 @@ const KEYS: [RetroJoypad; 8] = [
RetroJoypad::RetroDeviceIdJoypadA,
RetroJoypad::RetroDeviceIdJoypadB,
];
+const VARIABLES: [RetroVariable; 2] = [
+ RetroVariable {
+ key: "palette\0".as_ptr() as *const c_char,
+ value: "DMG color palette; basic|hogwards|christmas|goldsilver|pacman|mariobros|pokemon\0"
+ .as_ptr() as *const c_char,
+ },
+ RetroVariable {
+ key: std::ptr::null(),
+ value: std::ptr::null(),
+ },
+];
#[derive(Clone, Copy, PartialEq, Eq, Hash)]
pub enum RetroJoypad {
@@ -159,6 +179,12 @@ pub struct RetroSystemTiming {
sample_rate: f64,
}
+#[repr(C)]
+pub struct RetroVariable {
+ key: *const c_char,
+ value: *const c_char,
+}
+
#[no_mangle]
pub extern "C" fn retro_api_version() -> c_uint {
debugln!("retro_api_version()");
@@ -233,6 +259,11 @@ pub extern "C" fn retro_set_environment(
debugln!("retro_set_environment()");
unsafe {
ENVIRONMENT_CALLBACK = callback;
+ let environment_cb = ENVIRONMENT_CALLBACK.as_ref().unwrap();
+ environment_cb(
+ RETRO_ENVIRONMENT_SET_VARIABLES,
+ &VARIABLES as *const _ as *const c_void,
+ );
}
}
@@ -244,6 +275,7 @@ pub extern "C" fn retro_set_controller_port_device() {
#[no_mangle]
pub extern "C" fn retro_run() {
let emulator = unsafe { EMULATOR.as_mut().unwrap() };
+ let environment_cb = unsafe { ENVIRONMENT_CALLBACK.as_ref().unwrap() };
let video_refresh_cb = unsafe { VIDEO_REFRESH_CALLBACK.as_ref().unwrap() };
let sample_batch_cb = unsafe { AUDIO_SAMPLE_BATCH_CALLBACK.as_ref().unwrap() };
let input_poll_cb = unsafe { INPUT_POLL_CALLBACK.as_ref().unwrap() };
@@ -257,6 +289,20 @@ pub extern "C" fn retro_run() {
/ GameBoy::VISUAL_FREQ)
.round() as u32;
+ // determines if any of the variable has changed value
+ // if that's the case all of them must be polled for
+ // update, and if needed action is triggered
+ unsafe {
+ environment_cb(
+ RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE,
+ &UPDATED as *const _ as *const c_void,
+ );
+ if UPDATED {
+ update_vars();
+ UPDATED = false;
+ }
+ }
+
loop {
// limits the number of ticks to the typical number
// of cycles expected for the current logic cycle
@@ -340,6 +386,7 @@ pub unsafe extern "C" fn retro_load_game(game: *const RetroGameInfo) -> bool {
instance.reset();
instance.load(true);
instance.load_cartridge(rom);
+ update_vars();
true
}
@@ -488,6 +535,25 @@ pub extern "C" fn retro_set_input_state(
}
}
+unsafe fn update_vars() {
+ update_palette();
+}
+
+unsafe fn update_palette() {
+ let emulator = EMULATOR.as_mut().unwrap();
+ let environment_cb = ENVIRONMENT_CALLBACK.as_ref().unwrap();
+ environment_cb(
+ RETRO_ENVIRONMENT_GET_VARIABLE,
+ &VARIABLE as *const _ as *const c_void,
+ );
+ if VARIABLE.value.is_null() {
+ return;
+ }
+ let palette_name = String::from(CStr::from_ptr(VARIABLE.value).to_str().unwrap());
+ let palette_info: boytacean::ppu::PaletteInfo = get_palette(palette_name);
+ emulator.ppu().set_palette_colors(palette_info.colors());
+}
+
fn retro_key_to_pad(retro_key: RetroJoypad) -> Option<PadKey> {
match retro_key {
RetroJoypad::RetroDeviceIdJoypadUp => Some(PadKey::Up),
diff --git a/frontends/libretro/src/palettes.rs b/frontends/libretro/src/palettes.rs
new file mode 100644
index 0000000000000000000000000000000000000000..f0340a59d7c351bf90f64dffebe9fed8dabc08ca
--- /dev/null
+++ b/frontends/libretro/src/palettes.rs
@@ -0,0 +1,91 @@
+use boytacean::ppu::{Palette, PaletteInfo};
+
+pub struct PaletteInfoStatic {
+ name: &'static str,
+ colors: Palette,
+}
+
+impl PaletteInfoStatic {
+ pub fn into_palette_info(&self) -> PaletteInfo {
+ PaletteInfo::new(self.name, self.colors)
+ }
+}
+
+static PALETTES: [PaletteInfoStatic; 7] = [
+ PaletteInfoStatic {
+ name: "basic",
+ colors: [
+ [0xff, 0xff, 0xff],
+ [0xc0, 0xc0, 0xc0],
+ [0x60, 0x60, 0x60],
+ [0x00, 0x00, 0x00],
+ ],
+ },
+ PaletteInfoStatic {
+ name: "hogwards",
+ colors: [
+ [0xb6, 0xa5, 0x71],
+ [0x8b, 0x7e, 0x56],
+ [0x55, 0x4d, 0x35],
+ [0x20, 0x1d, 0x13],
+ ],
+ },
+ PaletteInfoStatic {
+ name: "christmas",
+ colors: [
+ [0xe8, 0xe7, 0xdf],
+ [0x8b, 0xab, 0x95],
+ [0x9e, 0x5c, 0x5e],
+ [0x53, 0x4d, 0x57],
+ ],
+ },
+ PaletteInfoStatic {
+ name: "goldsilver",
+ colors: [
+ [0xc5, 0xc6, 0x6d],
+ [0x97, 0xa1, 0xb0],
+ [0x58, 0x5e, 0x67],
+ [0x23, 0x52, 0x29],
+ ],
+ },
+ PaletteInfoStatic {
+ name: "pacman",
+ colors: [
+ [0xff, 0xff, 0x00],
+ [0xff, 0xb8, 0x97],
+ [0x37, 0x32, 0xff],
+ [0x00, 0x00, 0x00],
+ ],
+ },
+ PaletteInfoStatic {
+ name: "mariobros",
+ colors: [
+ [0xf7, 0xce, 0xc3],
+ [0xcc, 0x9e, 0x22],
+ [0x92, 0x34, 0x04],
+ [0x00, 0x00, 0x00],
+ ],
+ },
+ PaletteInfoStatic {
+ name: "pokemon",
+ colors: [
+ [0xf8, 0x78, 0x00],
+ [0xb8, 0x60, 0x00],
+ [0x78, 0x38, 0x00],
+ [0x00, 0x00, 0x00],
+ ],
+ },
+];
+
+pub fn get_palette_names() -> Vec<String> {
+ PALETTES.iter().map(|p| p.name.to_string()).collect()
+}
+
+pub fn get_palette(name: String) -> PaletteInfo {
+ for palette in PALETTES.iter() {
+ if palette.name == name {
+ return palette.into_palette_info();
+ }
+ }
+ PALETTES[0].into_palette_info()
+}
diff --git a/src/ppu.rs b/src/ppu.rs
index 542d92d365bf4a6586e140308e8cb870ad71bde8..87287b576e22bc98faae3b840c743d467886a4e0 100644
--- a/src/ppu.rs
+++ b/src/ppu.rs
@@ -127,8 +127,8 @@ pub type Palette = [Pixel; PALETTE_SIZE];
/// with alpha within the Game Boy context.
pub type PaletteAlpha = [PixelAlpha; PALETTE_SIZE];
-/// Represents a palette with the metadata that is
-/// associated with it.
+/// Represents a palette together with the metadata
+/// that is associated with it.
#[cfg_attr(feature = "wasm", wasm_bindgen)]
#[derive(Clone, PartialEq, Eq)]
pub struct PaletteInfo {