implement Drop for deallocation

README.md

@@ -10,10 +10,13 @@ A small library to provide bindings for the [Nuked-OPL3 library](https://github.
 # Usage
 
 Nuked-OPL3 is not a turn-key implementation of the OPL3 chip - functions such as the status register, timers and
-interrupts are left as implementation details. Eventually this library will aim to provide a wrapper type that will
-provide example implementations for easier integrations with emulators.
+interrupts are left as implementation details.
 
-For now, you can access the Nuked-OPL3 API via the `Opl3Chip` struct.
+You can access the Nuked-OPL3 API via the `Opl3Chip` struct, if needed, but with the caveat that directly writing
+registers to Nuked-OPL3 will prevent you from reading the OPL registers correctly.
+
+If you intend to utilize `opl3-rs` in an emulator, you will probably want to use the `Opl3Device` wrapper which provides
+a full, device-oriented OPL3 implementation including the status, address and data registers, plus the OPL3 timers.
 
 # Docs
 
@@ -24,6 +27,9 @@ Documentation can be found on [docs.rs](https://docs.rs/opl3-rs/latest/opl3_rs/)
 An example of music playback is provided in the play_tune directory under /examples.
 This example uses the rodio library for audio playback and crossbeam channels for inter-thread communication.
 
+opl3-rs was primarily built for use with the [MartyPC PC emulator](https://github.com/dbalsom/martypc). It is used to
+implement an AdLib Music Card device.
+
 # Credits
 
 [Nuked-OPL3](https://github.com/nukeykt/Nuked-OPL3) is (C) 2013-2020 Nuke.YKT and licensed under LGPL 2.1

src/docs.md

@@ -1,12 +1,18 @@
 # opl3-rs
+
 `opl3-rs` is a small library to provide bindings for the [Nuked-OPL3 library](https://github.com/nukeykt/Nuked-OPL3).
 
 # Usage
+
 Nuked-OPL3 is not a turn-key implementation of the OPL3 chip - functions such as the status register, timers and
-interrupts are left as implementation details. Eventually this library will aim to provide a wrapper type that will
-provide example implementations for easier integrations with emulators.
+interrupts are left as implementation details.
 
-For now, you can access the Nuked-OPL3 API via the `Opl3Chip` struct.
+You can access the Nuked-OPL3 API via the `Opl3Chip` struct, if needed, but with the caveat that directly writing
+registers to Nuked-OPL3 will prevent you from reading the OPL registers correctly.
+
+If you intend to utilize `opl3-rs` in an emulator, you will probably want to use the `Opl3Device` wrapper which provides
+a full OPL3 implementation including the status registers and timers.
 
 # Credits
+
 [Nuked-OPL3](https://github.com/nukeykt/Nuked-OPL3) is (C) 2013-2020 Nuke.YKT and licensed under LGPL 2.1

src/lib.rs

@@ -456,6 +456,16 @@ pub struct Opl3Chip {
     chip: *mut bindings::Opl3Chip,
 }
 
+impl Drop for Opl3Chip {
+    /// Drop the Opl3Chip instance by deallocating the memory used by the Nuked-OPL3 instance.
+    fn drop(&mut self) {
+        unsafe {
+            let layout = std::alloc::Layout::new::<bindings::Opl3Chip>();
+            std::alloc::dealloc(self.chip as *mut u8, layout);
+        }
+    }
+}
+
 impl Opl3Chip {
     /// Creates a new OPL3 chip instance. The chip is initialized with the given sample rate.
     /// The internal chip device is Pinned to ensure that it is not moved in memory. The Nuked-OPL3