use NotNull for parameters

Cargo.lock

@@ -1,6 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-version = 3
+version = 4
 
 [[package]]
 name = "adler2"
@@ -98,9 +98,9 @@ dependencies = [
 
 [[package]]
 name = "cbindgen"
-version = "0.27.0"
+version = "0.28.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fce8dd7fcfcbf3a0a87d8f515194b49d6135acab73e18bd380d1d93bb1a15eb"
+checksum = "eadd868a2ce9ca38de7eeafdcec9c7065ef89b42b32f0839278d55f35c54d1ff"
 dependencies = [
  "clap",
  "heck",
@@ -407,9 +407,8 @@ dependencies = [
 
 [[package]]
 name = "servicepoint"
-version = "0.13.1"
+version = "0.13.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+source = "git+https://git.berlin.ccc.de/servicepoint/servicepoint/?branch=next#971bee5065139f220022e8108cfaa9c263b8a8a0"
-checksum = "93b52049be55a15fe37c13249d7f96aa8a5de56e1a41838e74a822ee8316a0c4"
 dependencies = [
  "bitvec",
  "bzip2",

Cargo.toml

@@ -15,14 +15,31 @@ keywords = ["cccb", "cccb-servicepoint", "cbindgen"]
 crate-type = ["staticlib", "cdylib", "rlib"]
 
 [build-dependencies]
-cbindgen = "0.27.0"
+cbindgen = "0.28.0"
 
 [dependencies.servicepoint]
-version = "0.13.1"
+package = "servicepoint"
-features = ["all_compressions"]
+version = "0.13.2"
+default-features = false
+features = ["protocol_udp"]
+git = "https://git.berlin.ccc.de/servicepoint/servicepoint/"
+branch = "next"
+
+[features]
+full = ["servicepoint/all_compressions", "servicepoint/default"]
+default = ["full"]
 
 [lints.rust]
 missing-docs = "warn"
+unsafe_op_in_unsafe_fn = "warn"
 
 [package.metadata.docs.rs]
 all-features = true
+
+[profile.size-optimized]
+inherits = "release"
+opt-level = 'z'     # Optimize for size
+lto = true          # Enable link-time optimization
+codegen-units = 1   # Reduce number of codegen units to increase optimizations
+panic = 'abort'     # Abort on panic
+strip = true        # Strip symbols from binary

build.rs

@@ -6,21 +6,20 @@
 
 use std::{env, fs::copy};
 
-use cbindgen::{generate_with_config, Config};
-
 fn main() {
     let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
     println!("cargo::rerun-if-changed={crate_dir}");
 
     let config =
-        Config::from_file(crate_dir.clone() + "/cbindgen.toml").unwrap();
+        cbindgen::Config::from_file(crate_dir.clone() + "/cbindgen.toml")
+            .unwrap();
 
     let output_dir = env::var("OUT_DIR").unwrap();
     let header_file = output_dir.clone() + "/servicepoint.h";
 
-    generate_with_config(crate_dir, config)
+    if let Ok(bindings) = cbindgen::generate_with_config(crate_dir, config) {
-        .unwrap()
+        bindings.write_to_file(&header_file);
-        .write_to_file(&header_file);
+
         println!("cargo:include={output_dir}");
 
         println!("cargo::rerun-if-env-changed=SERVICEPOINT_HEADER_OUT");
@@ -30,4 +29,7 @@ fn main() {
             copy(header_file, &header_copy).unwrap();
             println!("cargo::rerun-if-changed={header_copy}");
         }
+    } else {
+        eprintln!("cargo:warning=Servicepoint header could not be generated");
+    }
 }

cbindgen.toml

@@ -19,18 +19,26 @@ line_endings = "LF"
 style = "type"
 usize_is_size_t = true
 
-# this is needed because otherwise the order in the C# bindings is different on different machines
+# this is needed because otherwise the order in the C bindings is different on different machines
 sort_by = "Name"
 
 [parse]
-parse_deps = false
+parse_deps = true
+include = ["servicepoint"]
+extra_bindings = ["servicepoint"]
 
 [parse.expand]
-all_features = true
+features = ["full"]
 
 [export]
 include = []
 exclude = []
 
+[export.rename]
+"TypedCommand" = "Command"
+
 [enum]
 rename_variants = "QualifiedScreamingSnakeCase"
+
+[ptr]
+non_null_attribute = "/*notnull*/"

examples/lang_c/Makefile

@@ -1,7 +1,47 @@
 CC := gcc
+CARGO := rustup run nightly cargo
 
 THIS_DIR := $(dir $(realpath $(lastword $(MAKEFILE_LIST))))
-REPO_ROOT := $(THIS_DIR)/../../../..
+REPO_ROOT := $(THIS_DIR)/../../
+RUST_TARGET_DIR := $(REPO_ROOT)/target/x86_64-unknown-linux-musl/size-optimized
+
+RUSTFLAGS := -Zlocation-detail=none \
+	-Zfmt-debug=none \
+	-C linker=musl-gcc \
+	-C link-arg=-s \
+	-C link-arg=--gc-sections \
+	-C link-arg=-z,norelro \
+	-C link-arg=--hash-style=gnu \
+	--crate-type=staticlib \
+	-C panic=abort
+
+CARGOFLAGS := --manifest-path=$(REPO_ROOT)/Cargo.toml \
+	--profile=size-optimized \
+	--no-default-features \
+	--target=x86_64-unknown-linux-musl \
+	-Zbuild-std="core,std,alloc,proc_macro,panic_abort" \
+	-Zbuild-std-features="panic_immediate_abort" \
+
+CCFLAGS := -static -Os \
+	-ffunction-sections -fdata-sections \
+	-fwrapv -fomit-frame-pointer -fno-stack-protector\
+	-fwhole-program \
+	-nodefaultlibs -lservicepoint_binding_c -lc \
+	-Wl,--gc-sections \
+	-fno-unroll-loops \
+	-fno-unwind-tables -fno-asynchronous-unwind-tables \
+	-fmerge-all-constants \
+	-Wl,-z,norelro \
+	-Wl,--hash-style=gnu \
+	-fvisibility=hidden \
+	-Bsymbolic \
+	-Wl,--exclude-libs,ALL \
+	-fno-ident
+	#-fuse-ld=gold \
+	-fno-exceptions
+	#-Wl,--icf=all \
+
+export SERVICEPOINT_HEADER_OUT := $(THIS_DIR)/include
 
 build: out/lang_c
 
@@ -15,20 +55,19 @@ run: out/lang_c
 
 PHONY: build clean dependencies run
 
-out/lang_c: dependencies src/main.c
+out/lang_c_unstripped: dependencies src/main.c
 	mkdir -p out || true
 	${CC} src/main.c \
-		-I include \
+		-I $(SERVICEPOINT_HEADER_OUT) \
-		-L $(REPO_ROOT)/target/release \
+		-L $(RUST_TARGET_DIR)\
-		-Wl,-Bstatic -lservicepoint_binding_c \
+		$(CCFLAGS) \
-		-Wl,-Bdynamic -llzma \
+		-o out/lang_c_unstripped
-		-o out/lang_c
+out/lang_c: out/lang_c_unstripped
+	strip -s -R .comment -R .gnu.version --strip-unneeded out/lang_c_unstripped -o out/lang_c
+#strip -S --strip-unneeded --remove-section=.note.gnu.gold-version --remove-section=.comment --remove-section=.note --remove-section=.note.gnu.build-id --remove-section=.note.ABI-tag
 
 dependencies: FORCE
 	mkdir -p include || true
 	# generate servicepoint header and binary to link against
-	SERVICEPOINT_HEADER_OUT=$(THIS_DIR)/include cargo build \
+	${CARGO} rustc $(CARGOFLAGS) -- $(RUSTFLAGS)
-		--manifest-path=$(REPO_ROOT)/crates/servicepoint_binding_c/Cargo.toml \
-		--release
-
 FORCE: ;

examples/lang_c/src/main.c

@@ -2,15 +2,26 @@
 #include "servicepoint.h"
 
 int main(void) {
-    SPConnection *connection = sp_connection_open("localhost:2342");
+    UdpConnection *connection = sp_connection_open("localhost:2342");
     if (connection == NULL)
         return 1;
 
-    SPBitmap *pixels = sp_bitmap_new(SP_PIXEL_WIDTH, SP_PIXEL_HEIGHT);
+    Bitmap *pixels = sp_bitmap_new(PIXEL_WIDTH, PIXEL_HEIGHT);
+    if (pixels == NULL)
+      return 1;
+
     sp_bitmap_fill(pixels, true);
 
-    SPCommand *command = sp_command_bitmap_linear_win(0, 0, pixels, SP_COMPRESSION_CODE_UNCOMPRESSED);
+    Command *command = sp_command_bitmap_linear_win(0, 0, pixels, COMPRESSION_CODE_UNCOMPRESSED);
-    sp_connection_send_command(connection, command);
+    if (command == NULL)
+      return 1;
+
+    Packet *packet = sp_packet_from_command(command);
+
+    Header *header = sp_packet_get_header(packet);
+    printf("[%d, %d, %d, %d, %d]\n", header->command_code, header->a, header->b, header->c, header->d);
+
+    sp_connection_send_packet(connection, packet);
 
     sp_connection_free(connection);
     return 0;

flake.nix

@@ -33,25 +33,35 @@
         { pkgs, system }:
         {
           default = pkgs.mkShell rec {
-            packages = with pkgs; [
+            buildInputs = with pkgs;[
+              xe
+              xz
+              libgcc
+              #glibc.static
+              musl
+              libunwind
+              ];
+
+            nativeBuildInputs = with pkgs;[
               (pkgs.symlinkJoin {
                 name = "rust-toolchain";
                 paths = with pkgs; [
-                  rustc
+                  #rustc
-                  cargo
+                  #cargo
-                  rustPlatform.rustcSrc
+                  #rustPlatform.rustcSrc
-                  rustfmt
+                  #rustfmt
-                  clippy
+                  #clippy
                   cargo-expand
                   cargo-tarpaulin
+                  rustup
                 ];
               })
               gcc
               gnumake
-              xe
-              xz
               pkg-config
+
             ];
+
             RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
           };
         }

src/bitmap.rs

@@ -1,24 +1,23 @@
 //! C functions for interacting with [SPBitmap]s
 //!
 //! prefix `sp_bitmap_`
+//!
+//! A grid of pixels.
+//!
+//! # Examples
+//!
+//! ```C
+//! Cp437Grid grid = sp_bitmap_new(8, 3);
+//! sp_bitmap_fill(grid, true);
+//! sp_bitmap_set(grid, 0, 0, false);
+//! sp_bitmap_free(grid);
+//! ```
 
-use servicepoint::{DataRef, Grid};
+use servicepoint::{Bitmap, DataRef, Grid};
 use std::ptr::NonNull;
 
 use crate::byte_slice::SPByteSlice;
 
-/// A grid of pixels.
-///
-/// # Examples
-///
-/// ```C
-/// Cp437Grid grid = sp_bitmap_new(8, 3);
-/// sp_bitmap_fill(grid, true);
-/// sp_bitmap_set(grid, 0, 0, false);
-/// sp_bitmap_free(grid);
-/// ```
-pub struct SPBitmap(pub(crate) servicepoint::Bitmap);
-
 /// Creates a new [SPBitmap] with the specified dimensions.
 ///
 /// # Arguments
@@ -26,9 +25,11 @@ pub struct SPBitmap(pub(crate) servicepoint::Bitmap);
 /// - `width`: size in pixels in x-direction
 /// - `height`: size in pixels in y-direction
 ///
-/// returns: [SPBitmap] initialized to all pixels off. Will never return NULL.
+/// returns: [SPBitmap] initialized to all pixels off, or NULL in case of an error.
 ///
-/// # Panics
+/// # Errors
+///
+/// In the following cases, this function will return NULL:
 ///
 /// - when the width is not dividable by 8
 ///
@@ -42,9 +43,12 @@ pub struct SPBitmap(pub(crate) servicepoint::Bitmap);
 pub unsafe extern "C" fn sp_bitmap_new(
     width: usize,
     height: usize,
-) -> NonNull<SPBitmap> {
+) -> *mut Bitmap {
-    let result = Box::new(SPBitmap(servicepoint::Bitmap::new(width, height)));
+    if let Some(bitmap) = Bitmap::new(width, height) {
-    NonNull::from(Box::leak(result))
+        Box::leak(Box::new(bitmap))
+    } else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Creates a new [SPBitmap] with a size matching the screen.
@@ -58,8 +62,8 @@ pub unsafe extern "C" fn sp_bitmap_new(
 /// - the returned instance is freed in some way, either by using a consuming function or
 ///   by explicitly calling [sp_bitmap_free].
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_new_screen_sized() -> NonNull<SPBitmap> {
+pub unsafe extern "C" fn sp_bitmap_new_screen_sized() -> NonNull<Bitmap> {
-    let result = Box::new(SPBitmap(servicepoint::Bitmap::max_sized()));
+    let result = Box::new(Bitmap::max_sized());
     NonNull::from(Box::leak(result))
 }
 
@@ -70,13 +74,18 @@ pub unsafe extern "C" fn sp_bitmap_new_screen_sized() -> NonNull<SPBitmap> {
 /// - `width`: size in pixels in x-direction
 /// - `height`: size in pixels in y-direction
 ///
-/// returns: [SPBitmap] that contains a copy of the provided data. Will never return NULL.
+/// returns: [SPBitmap] that contains a copy of the provided data, or NULL in case of an error.
+///
+/// # Errors
+///
+/// In the following cases, this function will return NULL:
+///
+/// - when the dimensions and data size do not match exactly.
+/// - when the width is not dividable by 8
 ///
 /// # Panics
 ///
 /// - when `data` is NULL
-/// - when the dimensions and data size do not match exactly.
-/// - when the width is not dividable by 8
 ///
 /// # Safety
 ///
@@ -89,14 +98,14 @@ pub unsafe extern "C" fn sp_bitmap_new_screen_sized() -> NonNull<SPBitmap> {
 pub unsafe extern "C" fn sp_bitmap_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: SPByteSlice,
-    data_length: usize,
+) -> *mut Bitmap {
-) -> NonNull<SPBitmap> {
+    let data = unsafe { data.as_slice() };
-    assert!(!data.is_null());
+    if let Ok(bitmap) = Bitmap::load(width, height, data) {
-    let data = std::slice::from_raw_parts(data, data_length);
+        Box::leak(Box::new(bitmap))
-    let result =
+    } else {
-        Box::new(SPBitmap(servicepoint::Bitmap::load(width, height, data)));
+        std::ptr::null_mut()
-    NonNull::from(Box::leak(result))
+    }
 }
 
 /// Clones a [SPBitmap].
@@ -117,10 +126,9 @@ pub unsafe extern "C" fn sp_bitmap_load(
 ///   by explicitly calling `sp_bitmap_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_clone(
-    bitmap: *const SPBitmap,
+    bitmap: NonNull<Bitmap>,
-) -> NonNull<SPBitmap> {
+) -> NonNull<Bitmap> {
-    assert!(!bitmap.is_null());
+    let result = Box::new(unsafe { bitmap.as_ref().clone() });
-    let result = Box::new(SPBitmap((*bitmap).0.clone()));
     NonNull::from(Box::leak(result))
 }
 
@@ -135,14 +143,11 @@ pub unsafe extern "C" fn sp_bitmap_clone(
 /// The caller has to make sure that:
 ///
 /// - `bitmap` points to a valid [SPBitmap]
-/// - `bitmap` is not used concurrently or after bitmap call
-/// - `bitmap` was not passed to another consuming function, e.g. to create a [SPCommand]
 ///
 /// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_free(bitmap: *mut SPBitmap) {
+pub unsafe extern "C" fn sp_bitmap_free(bitmap: NonNull<Bitmap>) {
-    assert!(!bitmap.is_null());
+    _ = unsafe { Box::from_raw(bitmap.as_ptr()) };
-    _ = Box::from_raw(bitmap);
 }
 
 /// Gets the current value at the specified position in the [SPBitmap].
@@ -165,12 +170,11 @@ pub unsafe extern "C" fn sp_bitmap_free(bitmap: *mut SPBitmap) {
 /// - `bitmap` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_get(
-    bitmap: *const SPBitmap,
+    bitmap: NonNull<Bitmap>,
     x: usize,
     y: usize,
 ) -> bool {
-    assert!(!bitmap.is_null());
+    unsafe { bitmap.as_ref().get(x, y) }
-    (*bitmap).0.get(x, y)
 }
 
 /// Sets the value of the specified position in the [SPBitmap].
@@ -196,13 +200,12 @@ pub unsafe extern "C" fn sp_bitmap_get(
 /// - `bitmap` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_set(
-    bitmap: *mut SPBitmap,
+    bitmap: NonNull<Bitmap>,
     x: usize,
     y: usize,
     value: bool,
 ) {
-    assert!(!bitmap.is_null());
+    unsafe { (*bitmap.as_ptr()).set(x, y, value) };
-    (*bitmap).0.set(x, y, value);
 }
 
 /// Sets the state of all pixels in the [SPBitmap].
@@ -223,9 +226,8 @@ pub unsafe extern "C" fn sp_bitmap_set(
 /// - `bitmap` points to a valid [SPBitmap]
 /// - `bitmap` is not written to or read from concurrently
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_fill(bitmap: *mut SPBitmap, value: bool) {
+pub unsafe extern "C" fn sp_bitmap_fill(bitmap: NonNull<Bitmap>, value: bool) {
-    assert!(!bitmap.is_null());
+    unsafe { (*bitmap.as_ptr()).fill(value) };
-    (*bitmap).0.fill(value);
 }
 
 /// Gets the width in pixels of the [SPBitmap] instance.
@@ -244,9 +246,8 @@ pub unsafe extern "C" fn sp_bitmap_fill(bitmap: *mut SPBitmap, value: bool) {
 ///
 /// - `bitmap` points to a valid [SPBitmap]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_width(bitmap: *const SPBitmap) -> usize {
+pub unsafe extern "C" fn sp_bitmap_width(bitmap: NonNull<Bitmap>) -> usize {
-    assert!(!bitmap.is_null());
+    unsafe { bitmap.as_ref().width() }
-    (*bitmap).0.width()
 }
 
 /// Gets the height in pixels of the [SPBitmap] instance.
@@ -265,9 +266,8 @@ pub unsafe extern "C" fn sp_bitmap_width(bitmap: *const SPBitmap) -> usize {
 ///
 /// - `bitmap` points to a valid [SPBitmap]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitmap_height(bitmap: *const SPBitmap) -> usize {
+pub unsafe extern "C" fn sp_bitmap_height(bitmap: NonNull<Bitmap>) -> usize {
-    assert!(!bitmap.is_null());
+    unsafe { bitmap.as_ref().height() }
-    (*bitmap).0.height()
 }
 
 /// Gets an unsafe reference to the data of the [SPBitmap] instance.
@@ -285,12 +285,7 @@ pub unsafe extern "C" fn sp_bitmap_height(bitmap: *const SPBitmap) -> usize {
 /// - the returned memory range is never accessed concurrently, either via the [SPBitmap] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitmap_unsafe_data_ref(
-    bitmap: *mut SPBitmap,
+    mut bitmap: NonNull<Bitmap>,
 ) -> SPByteSlice {
-    assert!(!bitmap.is_null());
+    unsafe { SPByteSlice::from_slice(bitmap.as_mut().data_ref_mut()) }
-    let data = (*bitmap).0.data_ref_mut();
-    SPByteSlice {
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
-        length: data.len(),
-    }
 }

src/bitvec.rs

@@ -13,19 +13,7 @@ use std::ptr::NonNull;
 /// sp_bitvec_set(vec, 5, true);
 /// sp_bitvec_free(vec);
 /// ```
-pub struct SPBitVec(servicepoint::BitVec);
+pub struct SPBitVec(pub(crate) servicepoint::BitVecU8Msb0);
-
-impl From<servicepoint::BitVec> for SPBitVec {
-    fn from(actual: servicepoint::BitVec) -> Self {
-        Self(actual)
-    }
-}
-
-impl From<SPBitVec> for servicepoint::BitVec {
-    fn from(value: SPBitVec) -> Self {
-        value.0
-    }
-}
 
 impl Clone for SPBitVec {
     fn clone(&self) -> Self {
@@ -53,7 +41,8 @@ impl Clone for SPBitVec {
 ///   by explicitly calling `sp_bitvec_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_new(size: usize) -> NonNull<SPBitVec> {
-    let result = Box::new(SPBitVec(servicepoint::BitVec::repeat(false, size)));
+    let result =
+        Box::new(SPBitVec(servicepoint::BitVecU8Msb0::repeat(false, size)));
     NonNull::from(Box::leak(result))
 }
 
@@ -75,12 +64,11 @@ pub unsafe extern "C" fn sp_bitvec_new(size: usize) -> NonNull<SPBitVec> {
 ///   by explicitly calling `sp_bitvec_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_load(
-    data: *const u8,
+    data: SPByteSlice,
-    data_length: usize,
 ) -> NonNull<SPBitVec> {
-    assert!(!data.is_null());
+    let data = unsafe { data.as_slice() };
-    let data = std::slice::from_raw_parts(data, data_length);
+    let result =
-    let result = Box::new(SPBitVec(servicepoint::BitVec::from_slice(data)));
+        Box::new(SPBitVec(servicepoint::BitVecU8Msb0::from_slice(data)));
     NonNull::from(Box::leak(result))
 }
 
@@ -102,10 +90,9 @@ pub unsafe extern "C" fn sp_bitvec_load(
 ///   by explicitly calling `sp_bitvec_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_clone(
-    bit_vec: *const SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
 ) -> NonNull<SPBitVec> {
-    assert!(!bit_vec.is_null());
+    let result = Box::new(unsafe { bit_vec.as_ref().clone() });
-    let result = Box::new((*bit_vec).clone());
     NonNull::from(Box::leak(result))
 }
 
@@ -125,9 +112,8 @@ pub unsafe extern "C" fn sp_bitvec_clone(
 ///
 /// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_free(bit_vec: *mut SPBitVec) {
+pub unsafe extern "C" fn sp_bitvec_free(bit_vec: NonNull<SPBitVec>) {
-    assert!(!bit_vec.is_null());
+    _ = unsafe { Box::from_raw(bit_vec.as_ptr()) };
-    _ = Box::from_raw(bit_vec);
 }
 
 /// Gets the value of a bit from the [SPBitVec].
@@ -152,11 +138,10 @@ pub unsafe extern "C" fn sp_bitvec_free(bit_vec: *mut SPBitVec) {
 /// - `bit_vec` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_get(
-    bit_vec: *const SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
     index: usize,
 ) -> bool {
-    assert!(!bit_vec.is_null());
+    unsafe { *bit_vec.as_ref().0.get(index).unwrap() }
-    *(*bit_vec).0.get(index).unwrap()
 }
 
 /// Sets the value of a bit in the [SPBitVec].
@@ -180,12 +165,11 @@ pub unsafe extern "C" fn sp_bitvec_get(
 /// - `bit_vec` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_set(
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
     index: usize,
     value: bool,
 ) {
-    assert!(!bit_vec.is_null());
+    unsafe { (*bit_vec.as_ptr()).0.set(index, value) }
-    (*bit_vec).0.set(index, value)
 }
 
 /// Sets the value of all bits in the [SPBitVec].
@@ -206,9 +190,11 @@ pub unsafe extern "C" fn sp_bitvec_set(
 /// - `bit_vec` points to a valid [SPBitVec]
 /// - `bit_vec` is not written to or read from concurrently
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_fill(bit_vec: *mut SPBitVec, value: bool) {
+pub unsafe extern "C" fn sp_bitvec_fill(
-    assert!(!bit_vec.is_null());
+    bit_vec: NonNull<SPBitVec>,
-    (*bit_vec).0.fill(value)
+    value: bool,
+) {
+    unsafe { (*bit_vec.as_ptr()).0.fill(value) }
 }
 
 /// Gets the length of the [SPBitVec] in bits.
@@ -227,9 +213,8 @@ pub unsafe extern "C" fn sp_bitvec_fill(bit_vec: *mut SPBitVec, value: bool) {
 ///
 /// - `bit_vec` points to a valid [SPBitVec]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_len(bit_vec: *const SPBitVec) -> usize {
+pub unsafe extern "C" fn sp_bitvec_len(bit_vec: NonNull<SPBitVec>) -> usize {
-    assert!(!bit_vec.is_null());
+    unsafe { bit_vec.as_ref().0.len() }
-    (*bit_vec).0.len()
 }
 
 /// Returns true if length is 0.
@@ -248,9 +233,10 @@ pub unsafe extern "C" fn sp_bitvec_len(bit_vec: *const SPBitVec) -> usize {
 ///
 /// - `bit_vec` points to a valid [SPBitVec]
 #[no_mangle]
-pub unsafe extern "C" fn sp_bitvec_is_empty(bit_vec: *const SPBitVec) -> bool {
+pub unsafe extern "C" fn sp_bitvec_is_empty(
-    assert!(!bit_vec.is_null());
+    bit_vec: NonNull<SPBitVec>,
-    (*bit_vec).0.is_empty()
+) -> bool {
+    unsafe { bit_vec.as_ref().0.is_empty() }
 }
 
 /// Gets an unsafe reference to the data of the [SPBitVec] instance.
@@ -272,12 +258,7 @@ pub unsafe extern "C" fn sp_bitvec_is_empty(bit_vec: *const SPBitVec) -> bool {
 /// - the returned memory range is never accessed concurrently, either via the [SPBitVec] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_bitvec_unsafe_data_ref(
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
 ) -> SPByteSlice {
-    assert!(!bit_vec.is_null());
+    unsafe { SPByteSlice::from_slice((*bit_vec.as_ptr()).0.as_raw_mut_slice()) }
-    let data = (*bit_vec).0.as_raw_mut_slice();
-    SPByteSlice {
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
-        length: data.len(),
-    }
 }

src/brightness_grid.rs

@@ -1,11 +1,28 @@
 //! C functions for interacting with [SPBrightnessGrid]s
 //!
 //! prefix `sp_brightness_grid_`
+//!
+//!
+//! A grid containing brightness values.
+//!
+//! # Examples
+//! ```C
+//! SPConnection connection = sp_connection_open("127.0.0.1:2342");
+//! if (connection == NULL)
+//!     return 1;
+//!
+//! SPBrightnessGrid grid = sp_brightness_grid_new(2, 2);
+//! sp_brightness_grid_set(grid, 0, 0, 0);
+//! sp_brightness_grid_set(grid, 1, 1, 10);
+//!
+//! SPCommand command = sp_command_char_brightness(grid);
+//! sp_connection_free(connection);
+//! ```
 
 use crate::SPByteSlice;
-use servicepoint::{DataRef, Grid};
+use servicepoint::{BrightnessGrid, DataRef, Grid};
 use std::convert::Into;
-use std::intrinsics::transmute;
+use std::mem::transmute;
 use std::ptr::NonNull;
 
 /// see [servicepoint::Brightness::MIN]
@@ -15,24 +32,6 @@ pub const SP_BRIGHTNESS_MAX: u8 = 11;
 /// Count of possible brightness values
 pub const SP_BRIGHTNESS_LEVELS: u8 = 12;
 
-/// A grid containing brightness values.
-///
-/// # Examples
-/// ```C
-/// SPConnection connection = sp_connection_open("127.0.0.1:2342");
-/// if (connection == NULL)
-///     return 1;
-///
-/// SPBrightnessGrid grid = sp_brightness_grid_new(2, 2);
-/// sp_brightness_grid_set(grid, 0, 0, 0);
-/// sp_brightness_grid_set(grid, 1, 1, 10);
-///
-/// SPCommand command = sp_command_char_brightness(grid);
-/// sp_connection_free(connection);
-/// ```
-#[derive(Clone)]
-pub struct SPBrightnessGrid(pub(crate) servicepoint::BrightnessGrid);
-
 /// Creates a new [SPBrightnessGrid] with the specified dimensions.
 ///
 /// returns: [SPBrightnessGrid] initialized to 0. Will never return NULL.
@@ -47,10 +46,8 @@ pub struct SPBrightnessGrid(pub(crate) servicepoint::BrightnessGrid);
 pub unsafe extern "C" fn sp_brightness_grid_new(
     width: usize,
     height: usize,
-) -> NonNull<SPBrightnessGrid> {
+) -> NonNull<BrightnessGrid> {
-    let result = Box::new(SPBrightnessGrid(servicepoint::BrightnessGrid::new(
+    let result = Box::new(BrightnessGrid::new(width, height));
-        width, height,
-    )));
     NonNull::from(Box::leak(result))
 }
 
@@ -75,16 +72,18 @@ pub unsafe extern "C" fn sp_brightness_grid_new(
 pub unsafe extern "C" fn sp_brightness_grid_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: SPByteSlice,
-    data_length: usize,
+) -> *mut BrightnessGrid {
-) -> NonNull<SPBrightnessGrid> {
+    let data = unsafe { data.as_slice() };
-    assert!(!data.is_null());
+    let grid = match servicepoint::ByteGrid::load(width, height, data) {
-    let data = std::slice::from_raw_parts(data, data_length);
+        None => return std::ptr::null_mut(),
-    let grid = servicepoint::ByteGrid::load(width, height, data);
+        Some(grid) => grid,
-    let grid = servicepoint::BrightnessGrid::try_from(grid)
+    };
-        .expect("invalid brightness value");
+    if let Ok(grid) = BrightnessGrid::try_from(grid) {
-    let result = Box::new(SPBrightnessGrid(grid));
+        Box::leak(Box::new(grid))
-    NonNull::from(Box::leak(result))
+    } else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Clones a [SPBrightnessGrid].
@@ -109,10 +108,9 @@ pub unsafe extern "C" fn sp_brightness_grid_load(
 ///   by explicitly calling `sp_brightness_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_clone(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
-) -> NonNull<SPBrightnessGrid> {
+) -> NonNull<BrightnessGrid> {
-    assert!(!brightness_grid.is_null());
+    let result = Box::new(unsafe { brightness_grid.as_ref().clone() });
-    let result = Box::new((*brightness_grid).clone());
     NonNull::from(Box::leak(result))
 }
 
@@ -137,10 +135,9 @@ pub unsafe extern "C" fn sp_brightness_grid_clone(
 /// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_free(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) {
-    assert!(!brightness_grid.is_null());
+    _ = unsafe { Box::from_raw(brightness_grid.as_ptr()) };
-    _ = Box::from_raw(brightness_grid);
 }
 
 /// Gets the current value at the specified position.
@@ -165,12 +162,11 @@ pub unsafe extern "C" fn sp_brightness_grid_free(
 /// - `brightness_grid` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_get(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
     x: usize,
     y: usize,
 ) -> u8 {
-    assert!(!brightness_grid.is_null());
+    unsafe { brightness_grid.as_ref().get(x, y) }.into()
-    (*brightness_grid).0.get(x, y).into()
 }
 
 /// Sets the value of the specified position in the [SPBrightnessGrid].
@@ -197,15 +193,14 @@ pub unsafe extern "C" fn sp_brightness_grid_get(
 /// - `brightness_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_set(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
     x: usize,
     y: usize,
     value: u8,
 ) {
-    assert!(!brightness_grid.is_null());
     let brightness = servicepoint::Brightness::try_from(value)
         .expect("invalid brightness value");
-    (*brightness_grid).0.set(x, y, brightness);
+    unsafe { (*brightness_grid.as_ptr()).set(x, y, brightness) };
 }
 
 /// Sets the value of all cells in the [SPBrightnessGrid].
@@ -228,13 +223,12 @@ pub unsafe extern "C" fn sp_brightness_grid_set(
 /// - `brightness_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_fill(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
     value: u8,
 ) {
-    assert!(!brightness_grid.is_null());
     let brightness = servicepoint::Brightness::try_from(value)
         .expect("invalid brightness value");
-    (*brightness_grid).0.fill(brightness);
+    unsafe { (*brightness_grid.as_ptr()).fill(brightness) };
 }
 
 /// Gets the width of the [SPBrightnessGrid] instance.
@@ -256,10 +250,9 @@ pub unsafe extern "C" fn sp_brightness_grid_fill(
 /// - `brightness_grid` points to a valid [SPBrightnessGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_width(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) -> usize {
-    assert!(!brightness_grid.is_null());
+    unsafe { brightness_grid.as_ref().width() }
-    (*brightness_grid).0.width()
 }
 
 /// Gets the height of the [SPBrightnessGrid] instance.
@@ -281,10 +274,9 @@ pub unsafe extern "C" fn sp_brightness_grid_width(
 /// - `brightness_grid` points to a valid [SPBrightnessGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_height(
-    brightness_grid: *const SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) -> usize {
-    assert!(!brightness_grid.is_null());
+    unsafe { brightness_grid.as_ref().height() }
-    (*brightness_grid).0.height()
 }
 
 /// Gets an unsafe reference to the data of the [SPBrightnessGrid] instance.
@@ -308,15 +300,10 @@ pub unsafe extern "C" fn sp_brightness_grid_height(
 /// - the returned memory range is never accessed concurrently, either via the [SPBrightnessGrid] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_brightness_grid_unsafe_data_ref(
-    brightness_grid: *mut SPBrightnessGrid,
+    brightness_grid: NonNull<BrightnessGrid>,
 ) -> SPByteSlice {
-    assert!(!brightness_grid.is_null());
+    assert_eq!(size_of::<servicepoint::Brightness>(), 1);
-    assert_eq!(core::mem::size_of::<servicepoint::Brightness>(), 1);
+    let data = unsafe { (*brightness_grid.as_ptr()).data_ref_mut() };
-    let data = (*brightness_grid).0.data_ref_mut();
     // this assumes more about the memory layout than rust guarantees. yikes!
-    let data: &mut [u8] = transmute(data);
+    unsafe { SPByteSlice::from_slice(transmute(data)) }
-    SPByteSlice {
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
-        length: data.len(),
-    }
 }

src/byte_slice.rs

@@ -2,7 +2,6 @@
 
 use std::ptr::NonNull;
 
-#[repr(C)]
 /// Represents a span of memory (`&mut [u8]` ) as a struct usable by C code.
 ///
 /// You should not create an instance of this type in your C code.
@@ -16,9 +15,29 @@ use std::ptr::NonNull;
 ///   the function returning this type.
 /// - an instance of this created from C is never passed to a consuming function, as the rust code
 ///   will try to free the memory of a potentially separate allocator.
+#[repr(C)]
 pub struct SPByteSlice {
     /// The start address of the memory
     pub start: NonNull<u8>,
     /// The amount of memory in bytes
     pub length: usize,
 }
+
+impl SPByteSlice {
+    pub(crate) unsafe fn as_slice(&self) -> &[u8] {
+        unsafe { std::slice::from_raw_parts(self.start.as_ptr(), self.length) }
+    }
+
+    pub(crate) unsafe fn as_slice_mut(&self) -> &mut [u8] {
+        unsafe {
+            std::slice::from_raw_parts_mut(self.start.as_ptr(), self.length)
+        }
+    }
+
+    pub(crate) unsafe fn from_slice(slice: &mut [u8]) -> Self {
+        Self {
+            start: NonNull::new(slice.as_mut_ptr()).unwrap(),
+            length: slice.len(),
+        }
+    }
+}

src/char_grid.rs

@@ -1,33 +1,27 @@
 //! C functions for interacting with [SPCharGrid]s
 //!
 //! prefix `sp_char_grid_`
+//!
+//! A C-wrapper for grid containing UTF-8 characters.
+//!
+//! As the rust [char] type is not FFI-safe, characters are passed in their UTF-32 form as 32bit unsigned integers.
+//!
+//! The encoding is enforced in most cases by the rust standard library
+//! and will panic when provided with illegal characters.
+//!
+//! # Examples
+//!
+//! ```C
+//! CharGrid grid = sp_char_grid_new(4, 3);
+//! sp_char_grid_fill(grid, '?');
+//! sp_char_grid_set(grid, 0, 0, '!');
+//! sp_char_grid_free(grid);
+//! ```
 
-use servicepoint::Grid;
+use crate::SPByteSlice;
+use servicepoint::{CharGrid, Grid};
 use std::ptr::NonNull;
 
-/// A C-wrapper for grid containing UTF-8 characters.
-///
-/// As the rust [char] type is not FFI-safe, characters are passed in their UTF-32 form as 32bit unsigned integers.
-///
-/// The encoding is enforced in most cases by the rust standard library
-/// and will panic when provided with illegal characters.
-///
-/// # Examples
-///
-/// ```C
-/// CharGrid grid = sp_char_grid_new(4, 3);
-/// sp_char_grid_fill(grid, '?');
-/// sp_char_grid_set(grid, 0, 0, '!');
-/// sp_char_grid_free(grid);
-/// ```
-pub struct SPCharGrid(pub(crate) servicepoint::CharGrid);
-
-impl Clone for SPCharGrid {
-    fn clone(&self) -> Self {
-        SPCharGrid(self.0.clone())
-    }
-}
-
 /// Creates a new [SPCharGrid] with the specified dimensions.
 ///
 /// returns: [SPCharGrid] initialized to 0. Will never return NULL.
@@ -42,9 +36,8 @@ impl Clone for SPCharGrid {
 pub unsafe extern "C" fn sp_char_grid_new(
     width: usize,
     height: usize,
-) -> NonNull<SPCharGrid> {
+) -> NonNull<CharGrid> {
-    let result =
+    let result = Box::new(CharGrid::new(width, height));
-        Box::new(SPCharGrid(servicepoint::CharGrid::new(width, height)));
     NonNull::from(Box::leak(result))
 }
 
@@ -70,15 +63,12 @@ pub unsafe extern "C" fn sp_char_grid_new(
 pub unsafe extern "C" fn sp_char_grid_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: SPByteSlice,
-    data_length: usize,
+) -> NonNull<CharGrid> {
-) -> NonNull<SPCharGrid> {
+    let data = unsafe { data.as_slice() };
-    assert!(data.is_null());
+    // TODO remove unwrap
-    let data = std::slice::from_raw_parts(data, data_length);
+    let result =
-    let result = Box::new(SPCharGrid(
+        Box::new(CharGrid::load_utf8(width, height, data.to_vec()).unwrap());
-        servicepoint::CharGrid::load_utf8(width, height, data.to_vec())
-            .unwrap(),
-    ));
     NonNull::from(Box::leak(result))
 }
 
@@ -100,10 +90,9 @@ pub unsafe extern "C" fn sp_char_grid_load(
 ///   by explicitly calling `sp_char_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_clone(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
-) -> NonNull<SPCharGrid> {
+) -> NonNull<CharGrid> {
-    assert!(!char_grid.is_null());
+    let result = Box::new(unsafe { char_grid.as_ref().clone() });
-    let result = Box::new((*char_grid).clone());
     NonNull::from(Box::leak(result))
 }
 
@@ -123,9 +112,8 @@ pub unsafe extern "C" fn sp_char_grid_clone(
 ///
 /// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_char_grid_free(char_grid: *mut SPCharGrid) {
+pub unsafe extern "C" fn sp_char_grid_free(char_grid: NonNull<CharGrid>) {
-    assert!(!char_grid.is_null());
+    _ = unsafe { Box::from_raw(char_grid.as_ptr()) };
-    _ = Box::from_raw(char_grid);
 }
 
 /// Gets the current value at the specified position.
@@ -148,12 +136,11 @@ pub unsafe extern "C" fn sp_char_grid_free(char_grid: *mut SPCharGrid) {
 /// - `char_grid` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_get(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
     x: usize,
     y: usize,
 ) -> u32 {
-    assert!(!char_grid.is_null());
+    unsafe { char_grid.as_ref().get(x, y) as u32 }
-    (*char_grid).0.get(x, y) as u32
 }
 
 /// Sets the value of the specified position in the [SPCharGrid].
@@ -181,13 +168,12 @@ pub unsafe extern "C" fn sp_char_grid_get(
 /// [SPBitVec]: [crate::SPBitVec]
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_set(
-    char_grid: *mut SPCharGrid,
+    char_grid: NonNull<CharGrid>,
     x: usize,
     y: usize,
     value: u32,
 ) {
-    assert!(!char_grid.is_null());
+    unsafe { (*char_grid.as_ptr()).set(x, y, char::from_u32(value).unwrap()) };
-    (*char_grid).0.set(x, y, char::from_u32(value).unwrap());
 }
 
 /// Sets the value of all cells in the [SPCharGrid].
@@ -209,11 +195,10 @@ pub unsafe extern "C" fn sp_char_grid_set(
 /// - `char_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_fill(
-    char_grid: *mut SPCharGrid,
+    char_grid: NonNull<CharGrid>,
     value: u32,
 ) {
-    assert!(!char_grid.is_null());
+    unsafe { (*char_grid.as_ptr()).fill(char::from_u32(value).unwrap()) };
-    (*char_grid).0.fill(char::from_u32(value).unwrap());
 }
 
 /// Gets the width of the [SPCharGrid] instance.
@@ -233,10 +218,9 @@ pub unsafe extern "C" fn sp_char_grid_fill(
 /// - `char_grid` points to a valid [SPCharGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_width(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
 ) -> usize {
-    assert!(!char_grid.is_null());
+    unsafe { char_grid.as_ref().width() }
-    (*char_grid).0.width()
 }
 
 /// Gets the height of the [SPCharGrid] instance.
@@ -256,8 +240,7 @@ pub unsafe extern "C" fn sp_char_grid_width(
 /// - `char_grid` points to a valid [SPCharGrid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_char_grid_height(
-    char_grid: *const SPCharGrid,
+    char_grid: NonNull<CharGrid>,
 ) -> usize {
-    assert!(!char_grid.is_null());
+    unsafe { char_grid.as_ref().height() }
-    (*char_grid).0.height()
 }

src/command.rs

@@ -2,12 +2,12 @@
 //!
 //! prefix `sp_command_`
 
-use std::ptr::{null_mut, NonNull};
+use crate::SPBitVec;
-
+use servicepoint::{
-use crate::{
+    BinaryOperation, Bitmap, BrightnessGrid, CharGrid, CompressionCode,
-    SPBitVec, SPBitmap, SPBrightnessGrid, SPCharGrid, SPCompressionCode,
+    Cp437Grid, GlobalBrightnessCommand, Packet, TypedCommand,
-    SPCp437Grid, SPPacket,
 };
+use std::ptr::NonNull;
 
 /// A low-level display command.
 ///
@@ -23,13 +23,6 @@ use crate::{
 /// ```
 ///
 /// [SPConnection]: [crate::SPConnection]
-pub struct SPCommand(pub(crate) servicepoint::Command);
-
-impl Clone for SPCommand {
-    fn clone(&self) -> Self {
-        SPCommand(self.0.clone())
-    }
-}
 
 /// Tries to turn a [SPPacket] into a [SPCommand].
 ///
@@ -52,12 +45,12 @@ impl Clone for SPCommand {
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_try_from_packet(
-    packet: *mut SPPacket,
+    packet: NonNull<Packet>,
-) -> *mut SPCommand {
+) -> *mut TypedCommand {
-    let packet = *Box::from_raw(packet);
+    let packet = *unsafe { Box::from_raw(packet.as_ptr()) };
-    match servicepoint::Command::try_from(packet.0) {
+    match servicepoint::TypedCommand::try_from(packet) {
-        Err(_) => null_mut(),
+        Err(_) => std::ptr::null_mut(),
-        Ok(command) => Box::into_raw(Box::new(SPCommand(command))),
+        Ok(command) => Box::into_raw(Box::new(command)),
     }
 }
 
@@ -79,10 +72,9 @@ pub unsafe extern "C" fn sp_command_try_from_packet(
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_clone(
-    command: *const SPCommand,
+    command: NonNull<TypedCommand>,
-) -> NonNull<SPCommand> {
+) -> NonNull<TypedCommand> {
-    assert!(!command.is_null());
+    let result = Box::new(unsafe { command.as_ref().clone() });
-    let result = Box::new((*command).clone());
     NonNull::from(Box::leak(result))
 }
 
@@ -105,8 +97,8 @@ pub unsafe extern "C" fn sp_command_clone(
 /// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
-pub unsafe extern "C" fn sp_command_clear() -> NonNull<SPCommand> {
+pub unsafe extern "C" fn sp_command_clear() -> NonNull<TypedCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::Clear));
+    let result = Box::new(servicepoint::ClearCommand.into());
     NonNull::from(Box::leak(result))
 }
 
@@ -123,8 +115,8 @@ pub unsafe extern "C" fn sp_command_clear() -> NonNull<SPCommand> {
 /// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
-pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<SPCommand> {
+pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<TypedCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::HardReset));
+    let result = Box::new(servicepoint::HardResetCommand.into());
     NonNull::from(Box::leak(result))
 }
 
@@ -139,8 +131,8 @@ pub unsafe extern "C" fn sp_command_hard_reset() -> NonNull<SPCommand> {
 /// - the returned [SPCommand] instance is freed in some way, either by using a consuming function or
 ///   by explicitly calling `sp_command_free`.
 #[no_mangle]
-pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<SPCommand> {
+pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<TypedCommand> {
-    let result = Box::new(SPCommand(servicepoint::Command::FadeOut));
+    let result = Box::new(servicepoint::FadeOutCommand.into());
     NonNull::from(Box::leak(result))
 }
 
@@ -161,11 +153,10 @@ pub unsafe extern "C" fn sp_command_fade_out() -> NonNull<SPCommand> {
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_brightness(
     brightness: u8,
-) -> NonNull<SPCommand> {
+) -> NonNull<TypedCommand> {
     let brightness = servicepoint::Brightness::try_from(brightness)
         .expect("invalid brightness");
-    let result =
+    let result = Box::new(GlobalBrightnessCommand::from(brightness).into());
-        Box::new(SPCommand(servicepoint::Command::Brightness(brightness)));
     NonNull::from(Box::leak(result))
 }
 
@@ -191,14 +182,16 @@ pub unsafe extern "C" fn sp_command_brightness(
 pub unsafe extern "C" fn sp_command_char_brightness(
     x: usize,
     y: usize,
-    grid: *mut SPBrightnessGrid,
+    grid: NonNull<BrightnessGrid>,
-) -> NonNull<SPCommand> {
+) -> NonNull<TypedCommand> {
-    assert!(!grid.is_null());
+    let grid = unsafe { *Box::from_raw(grid.as_ptr()) };
-    let byte_grid = *Box::from_raw(grid);
+    let result = Box::new(
-    let result = Box::new(SPCommand(servicepoint::Command::CharBrightness(
+        servicepoint::BrightnessGridCommand {
-        servicepoint::Origin::new(x, y),
+            origin: servicepoint::Origin::new(x, y),
-        byte_grid.0,
+            grid,
-    )));
+        }
+        .into(),
+    );
     NonNull::from(Box::leak(result))
 }
 
@@ -230,17 +223,17 @@ pub unsafe extern "C" fn sp_command_char_brightness(
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_bitmap_linear(
     offset: usize,
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
-    compression: SPCompressionCode,
+    compression: CompressionCode,
-) -> NonNull<SPCommand> {
+) -> *mut TypedCommand {
-    assert!(!bit_vec.is_null());
+    unsafe {
-    let bit_vec = *Box::from_raw(bit_vec);
+        sp_command_bitmap_linear_internal(
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinear(
             offset,
-        bit_vec.into(),
+            bit_vec,
-        compression.try_into().expect("invalid compression code"),
+            compression,
-    )));
+            BinaryOperation::Overwrite,
-    NonNull::from(Box::leak(result))
+        )
+    }
 }
 
 /// Set pixel data according to an and-mask starting at the offset.
@@ -271,17 +264,17 @@ pub unsafe extern "C" fn sp_command_bitmap_linear(
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_bitmap_linear_and(
     offset: usize,
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
-    compression: SPCompressionCode,
+    compression: CompressionCode,
-) -> NonNull<SPCommand> {
+) -> *mut TypedCommand {
-    assert!(!bit_vec.is_null());
+    unsafe {
-    let bit_vec = *Box::from_raw(bit_vec);
+        sp_command_bitmap_linear_internal(
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearAnd(
             offset,
-        bit_vec.into(),
+            bit_vec,
-        compression.try_into().expect("invalid compression code"),
+            compression,
-    )));
+            BinaryOperation::Xor,
-    NonNull::from(Box::leak(result))
+        )
+    }
 }
 
 /// Set pixel data according to an or-mask starting at the offset.
@@ -312,17 +305,17 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_and(
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_bitmap_linear_or(
     offset: usize,
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
-    compression: SPCompressionCode,
+    compression: CompressionCode,
-) -> NonNull<SPCommand> {
+) -> *mut TypedCommand {
-    assert!(!bit_vec.is_null());
+    unsafe {
-    let bit_vec = *Box::from_raw(bit_vec);
+        sp_command_bitmap_linear_internal(
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearOr(
             offset,
-        bit_vec.into(),
+            bit_vec,
-        compression.try_into().expect("invalid compression code"),
+            compression,
-    )));
+            BinaryOperation::Or,
-    NonNull::from(Box::leak(result))
+        )
+    }
 }
 
 /// Set pixel data according to a xor-mask starting at the offset.
@@ -353,17 +346,39 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_or(
 #[no_mangle]
 pub unsafe extern "C" fn sp_command_bitmap_linear_xor(
     offset: usize,
-    bit_vec: *mut SPBitVec,
+    bit_vec: NonNull<SPBitVec>,
-    compression: SPCompressionCode,
+    compression: CompressionCode,
-) -> NonNull<SPCommand> {
+) -> *mut TypedCommand {
-    assert!(!bit_vec.is_null());
+    unsafe {
-    let bit_vec = *Box::from_raw(bit_vec);
+        sp_command_bitmap_linear_internal(
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearXor(
             offset,
-        bit_vec.into(),
+            bit_vec,
-        compression.try_into().expect("invalid compression code"),
+            compression,
-    )));
+            BinaryOperation::Xor,
-    NonNull::from(Box::leak(result))
+        )
+    }
+}
+
+#[inline]
+unsafe fn sp_command_bitmap_linear_internal(
+    offset: usize,
+    bit_vec: NonNull<SPBitVec>,
+    compression: CompressionCode,
+    operation: BinaryOperation,
+) -> *mut TypedCommand {
+    let bit_vec = unsafe { *Box::from_raw(bit_vec.as_ptr()) };
+    let compression = match compression.try_into() {
+        Ok(compression) => compression,
+        Err(_) => return std::ptr::null_mut(),
+    };
+    let command = servicepoint::BitVecCommand {
+        offset,
+        operation,
+        bitvec: bit_vec.0,
+        compression,
+    }
+    .into();
+    Box::leak(Box::new(command))
 }
 
 /// Show codepage 437 encoded text on the screen.
@@ -388,14 +403,16 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_xor(
 pub unsafe extern "C" fn sp_command_cp437_data(
     x: usize,
     y: usize,
-    grid: *mut SPCp437Grid,
+    grid: NonNull<Cp437Grid>,
-) -> NonNull<SPCommand> {
+) -> NonNull<TypedCommand> {
-    assert!(!grid.is_null());
+    let grid = *unsafe { Box::from_raw(grid.as_ptr()) };
-    let grid = *Box::from_raw(grid);
+    let result = Box::new(
-    let result = Box::new(SPCommand(servicepoint::Command::Cp437Data(
+        servicepoint::Cp437GridCommand {
-        servicepoint::Origin::new(x, y),
+            origin: servicepoint::Origin::new(x, y),
-        grid.0,
+            grid,
-    )));
+        }
+        .into(),
+    );
     NonNull::from(Box::leak(result))
 }
 
@@ -421,14 +438,16 @@ pub unsafe extern "C" fn sp_command_cp437_data(
 pub unsafe extern "C" fn sp_command_utf8_data(
     x: usize,
     y: usize,
-    grid: *mut SPCharGrid,
+    grid: NonNull<CharGrid>,
-) -> NonNull<SPCommand> {
+) -> NonNull<TypedCommand> {
-    assert!(!grid.is_null());
+    let grid = unsafe { *Box::from_raw(grid.as_ptr()) };
-    let grid = *Box::from_raw(grid);
+    let result = Box::new(
-    let result = Box::new(SPCommand(servicepoint::Command::Utf8Data(
+        servicepoint::CharGridCommand {
-        servicepoint::Origin::new(x, y),
+            origin: servicepoint::Origin::new(x, y),
-        grid.0,
+            grid,
-    )));
+        }
+        .into(),
+    );
     NonNull::from(Box::leak(result))
 }
 
@@ -456,19 +475,21 @@ pub unsafe extern "C" fn sp_command_utf8_data(
 pub unsafe extern "C" fn sp_command_bitmap_linear_win(
     x: usize,
     y: usize,
-    bitmap: *mut SPBitmap,
+    bitmap: NonNull<Bitmap>,
-    compression_code: SPCompressionCode,
+    compression: CompressionCode,
-) -> NonNull<SPCommand> {
+) -> *mut TypedCommand {
-    assert!(!bitmap.is_null());
+    let bitmap = unsafe { *Box::from_raw(bitmap.as_ptr()) };
-    let byte_grid = (*Box::from_raw(bitmap)).0;
+    let compression = match compression.try_into() {
-    let result = Box::new(SPCommand(servicepoint::Command::BitmapLinearWin(
+        Ok(compression) => compression,
-        servicepoint::Origin::new(x, y),
+        Err(_) => return std::ptr::null_mut(),
-        byte_grid,
+    };
-        compression_code
+    let command = servicepoint::BitmapCommand {
-            .try_into()
+        origin: servicepoint::Origin::new(x, y),
-            .expect("invalid compression code"),
+        bitmap,
-    )));
+        compression,
-    NonNull::from(Box::leak(result))
+    }
+    .into();
+    Box::leak(Box::new(command))
 }
 
 /// Deallocates a [SPCommand].
@@ -492,7 +513,6 @@ pub unsafe extern "C" fn sp_command_bitmap_linear_win(
 /// - `command` is not used concurrently or after this call
 /// - `command` was not passed to another consuming function, e.g. to create a [SPPacket]
 #[no_mangle]
-pub unsafe extern "C" fn sp_command_free(command: *mut SPCommand) {
+pub unsafe extern "C" fn sp_command_free(command: NonNull<TypedCommand>) {
-    assert!(!command.is_null());
+    _ = unsafe { Box::from_raw(command.as_ptr()) };
-    _ = Box::from_raw(command);
 }

src/connection.rs

@@ -1,22 +1,20 @@
 //! C functions for interacting with [SPConnection]s
 //!
 //! prefix `sp_connection_`
+//!
+//! A connection to the display.
+//!
+//! # Examples
+//!
+//! ```C
+//! CConnection connection = sp_connection_open("172.23.42.29:2342");
+//! if (connection != NULL)
+//!     sp_connection_send_command(connection, sp_command_clear());
+//! ```
 
+use servicepoint::{Connection, Packet, TypedCommand, UdpConnection};
 use std::ffi::{c_char, CStr};
-use std::ptr::{null_mut, NonNull};
+use std::ptr::NonNull;
-
-use crate::{SPCommand, SPPacket};
-
-/// A connection to the display.
-///
-/// # Examples
-///
-/// ```C
-/// CConnection connection = sp_connection_open("172.23.42.29:2342");
-/// if (connection != NULL)
-///     sp_connection_send_command(connection, sp_command_clear());
-/// ```
-pub struct SPConnection(pub(crate) servicepoint::Connection);
 
 /// Creates a new instance of [SPConnection].
 ///
@@ -34,33 +32,46 @@ pub struct SPConnection(pub(crate) servicepoint::Connection);
 ///   by explicitly calling `sp_connection_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_connection_open(
-    host: *const c_char,
+    host: NonNull<c_char>,
-) -> *mut SPConnection {
+) -> *mut UdpConnection {
-    assert!(!host.is_null());
+    let host = unsafe { CStr::from_ptr(host.as_ptr()) }
-    let host = CStr::from_ptr(host).to_str().expect("Bad encoding");
+        .to_str()
-    let connection = match servicepoint::Connection::open(host) {
+        .expect("Bad encoding");
-        Err(_) => return null_mut(),
+    let connection = match UdpConnection::open(host) {
+        Err(_) => return std::ptr::null_mut(),
         Ok(value) => value,
     };
 
-    Box::into_raw(Box::new(SPConnection(connection)))
+    Box::into_raw(Box::new(connection))
 }
 
-/// Creates a new instance of [SPConnection] for testing that does not actually send anything.
+//#[no_mangle]
-///
+//pub unsafe extern "C" fn sp_connection_open_ipv4(
-/// returns: a new instance. Will never return NULL.
+//    host: SocketAddrV4,
-///
+//) -> *mut SPConnection {
-/// # Safety
+//    let connection = match servicepoint::UdpConnection::open(host) {
-///
+//        Err(_) => return std::ptr::null_mut(),
-/// The caller has to make sure that:
+//        Ok(value) => value,
-///
+//    };
-/// - the returned instance is freed in some way, either by using a consuming function or
+//
-///   by explicitly calling `sp_connection_free`.
+//    Box::into_raw(Box::new(SPConnection(connection)))
-#[no_mangle]
+//}
-pub unsafe extern "C" fn sp_connection_fake() -> NonNull<SPConnection> {
+
-    let result = Box::new(SPConnection(servicepoint::Connection::Fake));
+// /// Creates a new instance of [SPUdpConnection] for testing that does not actually send anything.
-    NonNull::from(Box::leak(result))
+// ///
-}
+// /// returns: a new instance. Will never return NULL.
+// ///
+// /// # Safety
+// ///
+// /// The caller has to make sure that:
+// ///
+// /// - the returned instance is freed in some way, either by using a consuming function or
+// ///   by explicitly calling `sp_connection_free`.
+// #[no_mangle]
+// pub unsafe extern "C" fn sp_connection_fake() -> NonNull<SPUdpConnection> {
+//     let result = Box::new(SPUdpConnection(servicepoint::Connection::Fake));
+//     NonNull::from(Box::leak(result))
+// }
 
 /// Sends a [SPPacket] to the display using the [SPConnection].
 ///
@@ -82,13 +93,11 @@ pub unsafe extern "C" fn sp_connection_fake() -> NonNull<SPConnection> {
 /// - `packet` is not used concurrently or after this call
 #[no_mangle]
 pub unsafe extern "C" fn sp_connection_send_packet(
-    connection: *const SPConnection,
+    connection: NonNull<UdpConnection>,
-    packet: *mut SPPacket,
+    packet: NonNull<Packet>,
 ) -> bool {
-    assert!(!connection.is_null());
+    let packet = unsafe { Box::from_raw(packet.as_ptr()) };
-    assert!(!packet.is_null());
+    unsafe { connection.as_ref().send(*packet) }.is_ok()
-    let packet = Box::from_raw(packet);
-    (*connection).0.send((*packet).0).is_ok()
 }
 
 /// Sends a [SPCommand] to the display using the [SPConnection].
@@ -111,13 +120,11 @@ pub unsafe extern "C" fn sp_connection_send_packet(
 /// - `command` is not used concurrently or after this call
 #[no_mangle]
 pub unsafe extern "C" fn sp_connection_send_command(
-    connection: *const SPConnection,
+    connection: NonNull<UdpConnection>,
-    command: *mut SPCommand,
+    command: NonNull<TypedCommand>,
 ) -> bool {
-    assert!(!connection.is_null());
+    let command = *unsafe { Box::from_raw(command.as_ptr()) };
-    assert!(!command.is_null());
+    unsafe { connection.as_ref().send(command) }.is_ok()
-    let command = (*Box::from_raw(command)).0;
-    (*connection).0.send(command).is_ok()
 }
 
 /// Closes and deallocates a [SPConnection].
@@ -133,7 +140,8 @@ pub unsafe extern "C" fn sp_connection_send_command(
 /// - `connection` points to a valid [SPConnection]
 /// - `connection` is not used concurrently or after this call
 #[no_mangle]
-pub unsafe extern "C" fn sp_connection_free(connection: *mut SPConnection) {
+pub unsafe extern "C" fn sp_connection_free(
-    assert!(!connection.is_null());
+    connection: NonNull<UdpConnection>,
-    _ = Box::from_raw(connection);
+) {
+    _ = unsafe { Box::from_raw(connection.as_ptr()) };
 }

src/constants.rs

@@ -1,48 +0,0 @@
-//! re-exported constants for use in C
-
-use servicepoint::CompressionCode;
-use std::time::Duration;
-
-/// size of a single tile in one dimension
-pub const SP_TILE_SIZE: usize = 8;
-
-/// Display tile count in the x-direction
-pub const SP_TILE_WIDTH: usize = 56;
-
-/// Display tile count in the y-direction
-pub const SP_TILE_HEIGHT: usize = 20;
-
-/// Display width in pixels
-pub const SP_PIXEL_WIDTH: usize = SP_TILE_WIDTH * SP_TILE_SIZE;
-
-/// Display height in pixels
-pub const SP_PIXEL_HEIGHT: usize = SP_TILE_HEIGHT * SP_TILE_SIZE;
-
-/// pixel count on whole screen
-pub const SP_PIXEL_COUNT: usize = SP_PIXEL_WIDTH * SP_PIXEL_HEIGHT;
-
-/// Actual hardware limit is around 28-29ms/frame. Rounded up for less dropped packets.
-pub const SP_FRAME_PACING_MS: u128 = Duration::from_millis(30).as_millis();
-
-/// Specifies the kind of compression to use.
-#[repr(u16)]
-pub enum SPCompressionCode {
-    /// no compression
-    Uncompressed = 0x0,
-    /// compress using flate2 with zlib header
-    Zlib = 0x677a,
-    /// compress using bzip2
-    Bzip2 = 0x627a,
-    /// compress using lzma
-    Lzma = 0x6c7a,
-    /// compress using Zstandard
-    Zstd = 0x7a73,
-}
-
-impl TryFrom<SPCompressionCode> for CompressionCode {
-    type Error = ();
-
-    fn try_from(value: SPCompressionCode) -> Result<Self, Self::Error> {
-        CompressionCode::try_from(value as u16)
-    }
-}

src/cp437_grid.rs

@@ -1,31 +1,25 @@
 //! C functions for interacting with [SPCp437Grid]s
 //!
 //! prefix `sp_cp437_grid_`
+//!
+//!
+//! A C-wrapper for grid containing codepage 437 characters.
+//!
+//! The encoding is currently not enforced.
+//!
+//! # Examples
+//!
+//! ```C
+//! Cp437Grid grid = sp_cp437_grid_new(4, 3);
+//! sp_cp437_grid_fill(grid, '?');
+//! sp_cp437_grid_set(grid, 0, 0, '!');
+//! sp_cp437_grid_free(grid);
+//! ```
 
 use crate::SPByteSlice;
-use servicepoint::{DataRef, Grid};
+use servicepoint::{Cp437Grid, DataRef, Grid};
 use std::ptr::NonNull;
 
-/// A C-wrapper for grid containing codepage 437 characters.
-///
-/// The encoding is currently not enforced.
-///
-/// # Examples
-///
-/// ```C
-/// Cp437Grid grid = sp_cp437_grid_new(4, 3);
-/// sp_cp437_grid_fill(grid, '?');
-/// sp_cp437_grid_set(grid, 0, 0, '!');
-/// sp_cp437_grid_free(grid);
-/// ```
-pub struct SPCp437Grid(pub(crate) servicepoint::Cp437Grid);
-
-impl Clone for SPCp437Grid {
-    fn clone(&self) -> Self {
-        SPCp437Grid(self.0.clone())
-    }
-}
-
 /// Creates a new [SPCp437Grid] with the specified dimensions.
 ///
 /// returns: [SPCp437Grid] initialized to 0. Will never return NULL.
@@ -40,9 +34,8 @@ impl Clone for SPCp437Grid {
 pub unsafe extern "C" fn sp_cp437_grid_new(
     width: usize,
     height: usize,
-) -> NonNull<SPCp437Grid> {
+) -> NonNull<Cp437Grid> {
-    let result =
+    let result = Box::new(Cp437Grid::new(width, height));
-        Box::new(SPCp437Grid(servicepoint::Cp437Grid::new(width, height)));
     NonNull::from(Box::leak(result))
 }
 
@@ -67,15 +60,15 @@ pub unsafe extern "C" fn sp_cp437_grid_new(
 pub unsafe extern "C" fn sp_cp437_grid_load(
     width: usize,
     height: usize,
-    data: *const u8,
+    data: SPByteSlice,
-    data_length: usize,
+) -> *mut Cp437Grid {
-) -> NonNull<SPCp437Grid> {
+    let data = unsafe { data.as_slice() };
-    assert!(data.is_null());
+    let grid = Cp437Grid::load(width, height, data);
-    let data = std::slice::from_raw_parts(data, data_length);
+    if let Some(grid) = grid {
-    let result = Box::new(SPCp437Grid(servicepoint::Cp437Grid::load(
+        Box::leak(Box::new(grid))
-        width, height, data,
+    } else {
-    )));
+        std::ptr::null_mut()
-    NonNull::from(Box::leak(result))
+    }
 }
 
 /// Clones a [SPCp437Grid].
@@ -96,10 +89,9 @@ pub unsafe extern "C" fn sp_cp437_grid_load(
 ///   by explicitly calling `sp_cp437_grid_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_clone(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
-) -> NonNull<SPCp437Grid> {
+) -> NonNull<Cp437Grid> {
-    assert!(!cp437_grid.is_null());
+    let result = Box::new(unsafe { cp437_grid.as_ref().clone() });
-    let result = Box::new((*cp437_grid).clone());
     NonNull::from(Box::leak(result))
 }
 
@@ -119,9 +111,8 @@ pub unsafe extern "C" fn sp_cp437_grid_clone(
 ///
 /// [SPCommand]: [crate::SPCommand]
 #[no_mangle]
-pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: *mut SPCp437Grid) {
+pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: NonNull<Cp437Grid>) {
-    assert!(!cp437_grid.is_null());
+    _ = unsafe { Box::from_raw(cp437_grid.as_ptr()) };
-    _ = Box::from_raw(cp437_grid);
 }
 
 /// Gets the current value at the specified position.
@@ -144,12 +135,11 @@ pub unsafe extern "C" fn sp_cp437_grid_free(cp437_grid: *mut SPCp437Grid) {
 /// - `cp437_grid` is not written to concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_get(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
     x: usize,
     y: usize,
 ) -> u8 {
-    assert!(!cp437_grid.is_null());
+    unsafe { cp437_grid.as_ref().get(x, y) }
-    (*cp437_grid).0.get(x, y)
 }
 
 /// Sets the value of the specified position in the [SPCp437Grid].
@@ -177,13 +167,12 @@ pub unsafe extern "C" fn sp_cp437_grid_get(
 /// [SPBitVec]: [crate::SPBitVec]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_set(
-    cp437_grid: *mut SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
     x: usize,
     y: usize,
     value: u8,
 ) {
-    assert!(!cp437_grid.is_null());
+    unsafe { (*cp437_grid.as_ptr()).set(x, y, value) };
-    (*cp437_grid).0.set(x, y, value);
 }
 
 /// Sets the value of all cells in the [SPCp437Grid].
@@ -205,11 +194,10 @@ pub unsafe extern "C" fn sp_cp437_grid_set(
 /// - `cp437_grid` is not written to or read from concurrently
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_fill(
-    cp437_grid: *mut SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
     value: u8,
 ) {
-    assert!(!cp437_grid.is_null());
+    unsafe { (*cp437_grid.as_ptr()).fill(value) };
-    (*cp437_grid).0.fill(value);
 }
 
 /// Gets the width of the [SPCp437Grid] instance.
@@ -229,10 +217,9 @@ pub unsafe extern "C" fn sp_cp437_grid_fill(
 /// - `cp437_grid` points to a valid [SPCp437Grid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_width(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
 ) -> usize {
-    assert!(!cp437_grid.is_null());
+    unsafe { cp437_grid.as_ref().width() }
-    (*cp437_grid).0.width()
 }
 
 /// Gets the height of the [SPCp437Grid] instance.
@@ -252,10 +239,9 @@ pub unsafe extern "C" fn sp_cp437_grid_width(
 /// - `cp437_grid` points to a valid [SPCp437Grid]
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_height(
-    cp437_grid: *const SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
 ) -> usize {
-    assert!(!cp437_grid.is_null());
+    unsafe { cp437_grid.as_ref().height() }
-    (*cp437_grid).0.height()
 }
 
 /// Gets an unsafe reference to the data of the [SPCp437Grid] instance.
@@ -275,11 +261,7 @@ pub unsafe extern "C" fn sp_cp437_grid_height(
 /// - the returned memory range is never accessed concurrently, either via the [SPCp437Grid] or directly
 #[no_mangle]
 pub unsafe extern "C" fn sp_cp437_grid_unsafe_data_ref(
-    cp437_grid: *mut SPCp437Grid,
+    cp437_grid: NonNull<Cp437Grid>,
 ) -> SPByteSlice {
-    let data = (*cp437_grid).0.data_ref_mut();
+    unsafe { SPByteSlice::from_slice((*cp437_grid.as_ptr()).data_ref_mut()) }
-    SPByteSlice {
-        start: NonNull::new(data.as_mut_ptr_range().start).unwrap(),
-        length: data.len(),
-    }
 }

src/lib.rs

@@ -32,7 +32,6 @@ pub use crate::byte_slice::*;
 pub use crate::char_grid::*;
 pub use crate::command::*;
 pub use crate::connection::*;
-pub use crate::constants::*;
 pub use crate::cp437_grid::*;
 pub use crate::packet::*;
 
@@ -43,6 +42,10 @@ mod byte_slice;
 mod char_grid;
 mod command;
 mod connection;
-mod constants;
 mod cp437_grid;
 mod packet;
+
+use std::time::Duration;
+
+/// Actual hardware limit is around 28-29ms/frame. Rounded up for less dropped packets.
+pub const SP_FRAME_PACING_MS: u128 = Duration::from_millis(30).as_millis();

src/packet.rs

@@ -1,13 +1,13 @@
 //! C functions for interacting with [SPPacket]s
 //!
 //! prefix `sp_packet_`
+//!
+//!
+//! The raw packet
 
-use std::ptr::{null_mut, NonNull};
+use crate::SPByteSlice;
-
+use servicepoint::{Header, Packet, TypedCommand};
-use crate::SPCommand;
+use std::ptr::NonNull;
-
-/// The raw packet
-pub struct SPPacket(pub(crate) servicepoint::Packet);
 
 /// Turns a [SPCommand] into a [SPPacket].
 /// The [SPCommand] gets consumed.
@@ -28,12 +28,14 @@ pub struct SPPacket(pub(crate) servicepoint::Packet);
 ///   by explicitly calling `sp_packet_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_from_command(
-    command: *mut SPCommand,
+    command: NonNull<TypedCommand>,
-) -> NonNull<SPPacket> {
+) -> *mut Packet {
-    assert!(!command.is_null());
+    let command = unsafe { *Box::from_raw(command.as_ptr()) };
-    let command = *Box::from_raw(command);
+    if let Ok(packet) = command.try_into() {
-    let result = Box::new(SPPacket(command.0.into()));
+        Box::leak(Box::new(packet))
-    NonNull::from(Box::leak(result))
+    } else {
+        std::ptr::null_mut()
+    }
 }
 
 /// Tries to load a [SPPacket] from the passed array with the specified length.
@@ -53,15 +55,11 @@ pub unsafe extern "C" fn sp_packet_from_command(
 /// - the returned [SPPacket] instance is freed in some way, either by using a consuming function or
 ///   by explicitly calling `sp_packet_free`.
 #[no_mangle]
-pub unsafe extern "C" fn sp_packet_try_load(
+pub unsafe extern "C" fn sp_packet_try_load(data: SPByteSlice) -> *mut Packet {
-    data: *const u8,
+    let data = unsafe { data.as_slice() };
-    length: usize,
-) -> *mut SPPacket {
-    assert!(!data.is_null());
-    let data = std::slice::from_raw_parts(data, length);
     match servicepoint::Packet::try_from(data) {
-        Err(_) => null_mut(),
+        Err(_) => std::ptr::null_mut(),
-        Ok(packet) => Box::into_raw(Box::new(SPPacket(packet))),
+        Ok(packet) => Box::into_raw(Box::new(packet)),
     }
 }
 
@@ -91,35 +89,50 @@ pub unsafe extern "C" fn sp_packet_try_load(
 ///   by explicitly calling [sp_packet_free].
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_from_parts(
-    command_code: u16,
+    header: Header,
-    a: u16,
+    payload: *const SPByteSlice,
-    b: u16,
+) -> NonNull<Packet> {
-    c: u16,
-    d: u16,
-    payload: *const u8,
-    payload_len: usize,
-) -> NonNull<SPPacket> {
-    assert_eq!(payload.is_null(), payload_len == 0);
-
     let payload = if payload.is_null() {
         vec![]
     } else {
-        let payload = std::slice::from_raw_parts(payload, payload_len);
+        let payload = unsafe { (*payload).as_slice() };
         Vec::from(payload)
     };
 
-    let packet = servicepoint::Packet {
+    let packet = Box::new(Packet { header, payload });
-        header: servicepoint::Header {
+    NonNull::from(Box::leak(packet))
-            command_code,
+}
-            a,
+
-            b,
+#[no_mangle]
-            c,
+pub unsafe extern "C" fn sp_packet_get_header(
-            d,
+    packet: NonNull<Packet>,
-        },
+) -> NonNull<Header> {
-        payload,
+    NonNull::from(&mut unsafe { (*packet.as_ptr()).header })
-    };
+}
-    let result = Box::new(SPPacket(packet));
+
-    NonNull::from(Box::leak(result))
+#[no_mangle]
+pub unsafe extern "C" fn sp_packet_get_payload(
+    packet: NonNull<Packet>,
+) -> SPByteSlice {
+    unsafe { SPByteSlice::from_slice(&mut *(*packet.as_ptr()).payload) }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn sp_packet_set_payload(
+    packet: NonNull<Packet>,
+    data: SPByteSlice,
+) {
+    unsafe { (*packet.as_ptr()).payload = data.as_slice().to_vec() }
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn sp_packet_write_to(
+    packet: NonNull<Packet>,
+    buffer: SPByteSlice,
+) {
+    unsafe {
+        packet.as_ref().serialize_to(buffer.as_slice_mut());
+    }
 }
 
 /// Clones a [SPPacket].
@@ -140,10 +153,9 @@ pub unsafe extern "C" fn sp_packet_from_parts(
 ///   by explicitly calling `sp_packet_free`.
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_clone(
-    packet: *const SPPacket,
+    packet: NonNull<Packet>,
-) -> NonNull<SPPacket> {
+) -> NonNull<Packet> {
-    assert!(!packet.is_null());
+    let result = Box::new(unsafe { packet.as_ref().clone() });
-    let result = Box::new(SPPacket((*packet).0.clone()));
     NonNull::from(Box::leak(result))
 }
 
@@ -160,7 +172,6 @@ pub unsafe extern "C" fn sp_packet_clone(
 /// - `packet` points to a valid [SPPacket]
 /// - `packet` is not used concurrently or after this call
 #[no_mangle]
-pub unsafe extern "C" fn sp_packet_free(packet: *mut SPPacket) {
+pub unsafe extern "C" fn sp_packet_free(packet: NonNull<Packet>) {
-    assert!(!packet.is_null());
+    _ = unsafe { Box::from_raw(packet.as_ptr()) }
-    _ = Box::from_raw(packet)
 }