Fix IMaterialSystem vtable offsets (#15)

Co-authored-by: Vurv <56230599+Vurv78@users.noreply.github.com>

Author: yogwoggf

examples/interfaces/README.md

@@ -0,0 +1,5 @@
+## ``interfaces``
+Generic binary module to display usage of a few source interfaces.
+
+## interfaces.reloadTextures()
+Reloads gmod's texture system

examples/interfaces/src/lib.rs

@@ -1,23 +1,31 @@
 use rglua::prelude::*;
-use rglua::interface::{self, LuaShared};
+use rglua::interface;
 
-#[derive(Debug, thiserror::Error)]
-enum GenericError {
-	#[error("Couldn't get interface {0}")]
-	NoInterface(String),
+#[lua_function]
+fn reload_textures(_l: LuaState) -> Result<i32, interface::Error> {
+	let matsys = iface!(MaterialSystem)?;
+	matsys.ReloadTextures();
 
-	#[error("Couldn't get interface as reference {0}")]
-	AsMut(String)
+	Ok(0)
 }
 
 #[gmod_open]
-fn open(l: LuaState) -> Result<i32, GenericError> {
+fn open(l: LuaState) -> Result<i32, interface::Error> {
 	// Access the lua state when you aren't directly given it.
 	let lua_shared = iface!(LuaShared)?;
-	let menu = unsafe { lua_shared.GetLuaInterface(2).as_mut() }
+
+	// 0 to get client state. this will error if you try and run the binary module on the server or menu realms.
+	let client = unsafe { lua_shared.GetLuaInterface(0).as_mut() }
 		.ok_or(interface::Error::AsMut)?;
 
-	printgm!(menu.base as _, "Hello from ILuaShared!");
+	printgm!(client.base as _, "Hello from ILuaShared!");
+
+	let lib = reg! [
+		"reloadTextures" => reload_textures
+	];
+
+	luaL_register(l, cstr!("interfaces"), lib.as_ptr());
+
 	Ok(0)
 }
 

rglua/src/interface/materials.rs

@@ -32,7 +32,7 @@ pub type MaterialHandle = c_ushort;
 /// "materialsystem.dll"
 #[vtable]
 pub struct MaterialSystem {
-	#[offset(70)]
+	#[offset(72)]
 	pub ReloadTextures: extern "C" fn(),
 	pub ReloadMaterials: extern "C" fn(pSubString: *const c_char),
 
@@ -45,7 +45,7 @@ pub struct MaterialSystem {
 		complain_prefix: *const c_char
 	) -> *mut c_void,
 
-	#[offset(75)]
+	#[offset(77)]
 	pub FirstMaterial: extern "C" fn() -> MaterialHandle,
 	pub NextMaterial: extern "C" fn(handle: MaterialHandle) -> MaterialHandle,
 	pub InvalidMaterial: extern "C" fn() -> MaterialHandle,