Allowing imported graphics to be exposed as pub mod (#738)

- [X] Changelog updated

This PR adds the possibility for graphics imported through
`include_background_gfx!` to be used as public modules, e.g.:
```rust
/// graphics.rs
agb::include_background_gfx!(pub background, "d77bba", tiles256 => 256 "map.aseprite");

/// main.rs
#![no_std]
#![no_main]

use agb::display::Priority;
use agb::display::tiled::RegularBackgroundSize::Background64x64;
use agb::display::tiled::{TiledMap, TileFormat};

mod graphics;


#[agb::entry]
fn main(mut gba: agb::Gba) -> ! {
    let (tiled, mut vram) = gba.display.video.tiled1();
    let vblank = agb::interrupt::VBlank::get();
    let tileset = &graphics::background::tiles256.tiles;

    vram.set_background_palettes(graphics::background::PALETTES);

    let mut bg = tiled.regular(Priority::P2, Background64x64, TileFormat::EightBpp);

    for y in 0..64u16 {
        for x in 0..64u16 {
            bg.set_tile(&mut vram, (x, y), tileset, graphics::background::tiles256.tile_settings[1]);
        }
    }
    bg.set_visible(true);
    bg.commit(&mut vram);

    loop {
        vblank.wait_for_vblank();
    }
}
```

CHANGELOG.md

@@ -19,6 +19,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 - There are no longer gaps between tiles in affine graphics modes.
 
+### Added
+- Added option to export imported background graphics from `include_background_gfx` as pub.
+
 ## [0.20.5] - 2024/06/18
 
 ### Fixed

agb-image-converter/src/lib.rs

@@ -109,6 +109,7 @@ impl Parse for BackgroundGfxOption {
 
 struct IncludeBackgroundGfxInput {
     module_name: syn::Ident,
+    as_pub: bool,
     crate_prefix: String,
     transparent_colour: Colour,
     background_gfx_options: Vec<BackgroundGfxOption>,
@@ -126,6 +127,15 @@ impl Parse for IncludeBackgroundGfxInput {
             format_ident!("agb")
         };
 
+        let lookahead = input.lookahead1();
+
+        let as_pub = if lookahead.peek(Token![pub]) {
+            let _: Token![pub] = input.parse()?;
+            true
+        } else {
+            false
+        };
+
         let module_name: syn::Ident = input.parse()?;
         let _: Token![,] = input.parse()?;
 
@@ -146,6 +156,7 @@ impl Parse for IncludeBackgroundGfxInput {
 
         Ok(Self {
             module_name,
+            as_pub,
             crate_prefix: crate_prefix.to_string(),
             transparent_colour,
             background_gfx_options: background_gfx_options.into_iter().collect(),
@@ -186,11 +197,13 @@ pub fn include_background_gfx(input: TokenStream) -> TokenStream {
     let root = std::env::var("CARGO_MANIFEST_DIR").expect("Failed to get cargo manifest dir");
 
     let module_name = config.module_name.clone();
-    include_gfx_from_config(config, module_name, Path::new(&root))
+    let as_pub = config.as_pub;
+    include_gfx_from_config(config, as_pub, module_name, Path::new(&root))
 }
 
 fn include_gfx_from_config(
     config: Box<dyn config::Config>,
+    as_pub: bool,
     module_name: syn::Ident,
     parent: &Path,
 ) -> TokenStream {
@@ -255,12 +268,22 @@ fn include_gfx_from_config(
     let palette_code =
         rust_generator::generate_palette_code(&optimisation_results, &config.crate_prefix());
 
-    let module = quote! {
+    let module = if as_pub {
+        quote! {
+            pub mod #module_name {
+                #palette_code
+
+                #(#image_code)*
+            }
+        }
+    } else {
+        quote! {
             mod #module_name {
                 #palette_code
 
                 #(#image_code)*
             }
+        }
     };
 
     TokenStream::from(module)

agb/src/lib.rs

@@ -105,6 +105,15 @@
 /// # use agb::include_background_gfx;
 /// include_background_gfx!(generated_background, "000000", DATA => "$OUT_DIR/generated_background.aseprite");
 /// ```
+///
+/// You can also make the exported background a public module which will allow other modules access them. The following
+/// will declare `water_tiles` as a `pub mod` rather than a `mod`.
+///
+/// ```rust,no_run
+/// ##![no_std]
+/// ##![no_main]
+/// agb::include_background_gfx!(pub water_tiles, tiles => "examples/water_tiles.png");
+/// ```
 pub use agb_image_converter::include_background_gfx;
 
 #[doc(hidden)]