fix c api, add usage example

.gitignore

@@ -1,2 +1,3 @@
 target
 .idea
+cmake-*

examples/lang_c/CMakeLists.txt

@@ -0,0 +1,23 @@
+cmake_minimum_required(VERSION 3.28)
+project(lang_c C)
+set(CMAKE_C_STANDARD 17)
+
+include(FetchContent)
+FetchContent_Declare(
+        Corrosion
+        GIT_REPOSITORY https://github.com/corrosion-rs/corrosion.git
+        GIT_TAG v0.5 # Optionally specify a commit hash, version tag or branch here
+)
+FetchContent_MakeAvailable(Corrosion)
+
+# Import targets defined in a package or workspace manifest `Cargo.toml` file
+corrosion_import_crate(
+        MANIFEST_PATH ../../servicepoint2/Cargo.toml
+        PROFILE release
+        FEATURES c-api
+        ALL_FEATURES)
+
+add_executable(lang_c main.c)
+
+target_link_libraries(lang_c PRIVATE servicepoint2)
+

examples/lang_c/main.c

@@ -0,0 +1,25 @@
+#include <stdio.h>
+#include "../../servicepoint2/sp2-bindings.h"
+
+int main(void) {
+    sp2_Connection *connection = sp2_connection_open("localhost:2342");
+    if (connection == NULL)
+        return 1;
+
+    sp2_Command *command = sp2_command_clear();
+    if (command == NULL)
+        return 2;
+    if (!sp2_connection_send(connection, command))
+        return 3;
+
+    sp2_PixelGrid *pixels = sp2_pixel_grid_new(sp2_PIXEL_WIDTH, sp2_PIXEL_HEIGHT);
+    sp2_pixel_grid_fill(pixels, true);
+    command = sp2_command_bitmap_linear_win(0, 0, pixels);
+    if (command == NULL)
+        return 4;
+    if (!sp2_connection_send(connection, command))
+        return 5;
+
+    sp2_connection_dealloc(connection);
+    return 0;
+}

servicepoint2/Cargo.toml

@@ -9,6 +9,9 @@ homepage = "https://docs.rs/crate/servicepoint2"
 repository = "https://github.com/kaesaecracker/servicepoint"
 readme = "../README.md"
 
+[lib]
+crate-type = ["staticlib", "rlib"]
+
 [dependencies]
 log = "0.4"
 flate2 = { version = "1.0", optional = true }
@@ -23,6 +26,7 @@ compression-bz = ["dep:bzip2", "compression"]
 compression-lz = ["dep:lz4", "compression"]
 compression-zs = ["dep:zstd", "compression"]
 compression = []
+c-api = []
 
 [build-dependencies]
 cbindgen = "0.26.0"

servicepoint2/bindings.h

@@ -1,186 +0,0 @@
-#include <stdarg.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdlib.h>
-
-/**
- * size of a single tile in one dimension
- */
-#define sp2_TILE_SIZE 8
-
-/**
- * tile count in the x-direction
- */
-#define sp2_TILE_WIDTH 56
-
-/**
- * tile count in the y-direction
- */
-#define sp2_TILE_HEIGHT 20
-
-/**
- * screen width in pixels
- */
-#define sp2_PIXEL_WIDTH (sp2_TILE_WIDTH * sp2_TILE_SIZE)
-
-/**
- * screen height in pixels
- */
-#define sp2_PIXEL_HEIGHT (sp2_TILE_HEIGHT * sp2_TILE_SIZE)
-
-/**
- * pixel count on whole screen
- */
-#define sp2_PIXEL_COUNT ((uintptr_t)sp2_PIXEL_WIDTH * (uintptr_t)sp2_PIXEL_HEIGHT)
-
-/**
- * Specifies the kind of compression to use. Availability depends on features.
- */
-enum sp2_CompressionCode {
-  Uncompressed = 0,
-  Gz = 26490,
-  Bz = 25210,
-  Lz = 27770,
-  Zs = 31347,
-};
-typedef uint16_t sp2_CompressionCode;
-
-/**
- * A vector of bits
- */
-typedef struct sp2_BitVec sp2_BitVec;
-
-/**
- * A grid of bytes
- */
-typedef struct sp2_ByteGrid sp2_ByteGrid;
-
-/**
- * A command to send to the display.
- */
-typedef struct sp2_Command sp2_Command;
-
-/**
- * A connection to the display.
- */
-typedef struct sp2_Connection sp2_Connection;
-
-/**
- * A grid of pixels stored in packed bytes.
- */
-typedef struct sp2_PixelGrid sp2_PixelGrid;
-
-typedef uint8_t sp2_Brightness;
-
-typedef uint16_t sp2_Offset;
-
-/**
- * Tries to load a command from the passed array with the specified length.
- *
- * returns: NULL in case of an error, pointer to the allocated command otherwise
- */
-struct sp2_Command *command_try_load(const uint8_t *data, uintptr_t length);
-
-/**
- * Clones a `Command` instance
- */
-struct sp2_Command *command_clone(const struct sp2_Command *original);
-
-/**
- * Allocates a new `Command::Clear` instance
- */
-struct sp2_Command *command_clear(void);
-
-/**
- * Allocates a new `Command::HardReset` instance
- */
-struct sp2_Command *command_hard_reset(void);
-
-/**
- * Allocates a new `Command::FadeOut` instance
- */
-struct sp2_Command *command_fade_out(void);
-
-/**
- * Allocates a new `Command::Brightness` instance
- */
-struct sp2_Command *command_brightness(sp2_Brightness brightness);
-
-/**
- * Allocates a new `Command::CharBrightness` instance.
- * The passed `ByteGrid` gets deallocated in the process.
- */
-struct sp2_Command *command_char_brightness(uint16_t x, uint16_t y, struct sp2_ByteGrid *byte_grid);
-
-/**
- * Allocates a new `Command::BitmapLinear` instance.
- * The passed `BitVec` gets deallocated in the process.
- */
-struct sp2_Command *command_bitmap_linear(sp2_Offset offset,
-                                          struct sp2_BitVec *bit_vec,
-                                          sp2_CompressionCode compression);
-
-/**
- * Allocates a new `Command::BitmapLinearAnd` instance.
- * The passed `BitVec` gets deallocated in the process.
- */
-struct sp2_Command *command_bitmap_linear_and(sp2_Offset offset,
-                                              struct sp2_BitVec *bit_vec,
-                                              sp2_CompressionCode compression);
-
-/**
- * Allocates a new `Command::BitmapLinearOr` instance.
- * The passed `BitVec` gets deallocated in the process.
- */
-struct sp2_Command *command_bitmap_linear_or(sp2_Offset offset,
-                                             struct sp2_BitVec *bit_vec,
-                                             sp2_CompressionCode compression);
-
-/**
- * Allocates a new `Command::BitmapLinearXor` instance.
- * The passed `BitVec` gets deallocated in the process.
- */
-struct sp2_Command *command_bitmap_linear_xor(sp2_Offset offset,
-                                              struct sp2_BitVec *bit_vec,
-                                              sp2_CompressionCode compression);
-
-/**
- * Allocates a new `Command::Cp437Data` instance.
- * The passed `ByteGrid` gets deallocated in the process.
- */
-struct sp2_Command *command_cp437_data(uint16_t x, uint16_t y, struct sp2_ByteGrid *byte_grid);
-
-/**
- * Allocates a new `Command::BitmapLinearWin` instance.
- * The passed `PixelGrid` gets deallocated in the process.
- */
-struct sp2_Command *command_bitmap_linear_win(uint16_t x,
-                                              uint16_t y,
-                                              struct sp2_PixelGrid *byte_grid);
-
-/**
- * Deallocates a command. Note that connection_send does this implicitly, so you only need
- * to do this if you use the library for parsing commands.
- */
-void command_dealloc(struct sp2_Command *ptr);
-
-/**
- * Creates a new instance of Connection.
- * The returned instance has to be deallocated with `connection_dealloc`.
- *
- * returns: NULL if connection fails or connected instance
- *
- * Panics: bad string encoding
- */
-struct sp2_Connection *connection_open(const char *host);
-
-/**
- * Sends the command instance. The instance is consumed / destroyed and cannot be used after this call.
- */
-bool connection_send(const struct sp2_Connection *connection,
-                     struct sp2_Command *command_ptr);
-
-/**
- * Closes and deallocates a connection instance
- */
-void connection_dealloc(struct sp2_Connection *ptr);

servicepoint2/build.rs

@@ -6,11 +6,15 @@ use cbindgen::Language;
 fn main() {
     let crate_dir = env::var("CARGO_MANIFEST_DIR").unwrap();
 
+    println!("cargo:rerun-if-changed=src");
+
     cbindgen::Builder::new()
         .with_crate(crate_dir)
         .with_item_prefix("sp2_")
         .with_language(Language::C)
+        .with_cpp_compat(true)
+        .with_parse_expand_all_features(true)
         .generate()
         .expect("Unable to generate bindings")
-        .write_to_file("bindings.h");
+        .write_to_file("sp2-bindings.h");
 }

servicepoint2/sp2-bindings.h

@@ -0,0 +1,353 @@
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/**
+ * size of a single tile in one dimension
+ */
+#define sp2_TILE_SIZE 8
+
+/**
+ * tile count in the x-direction
+ */
+#define sp2_TILE_WIDTH 56
+
+/**
+ * tile count in the y-direction
+ */
+#define sp2_TILE_HEIGHT 20
+
+/**
+ * screen width in pixels
+ */
+#define sp2_PIXEL_WIDTH (sp2_TILE_WIDTH * sp2_TILE_SIZE)
+
+/**
+ * screen height in pixels
+ */
+#define sp2_PIXEL_HEIGHT (sp2_TILE_HEIGHT * sp2_TILE_SIZE)
+
+/**
+ * pixel count on whole screen
+ */
+#define sp2_PIXEL_COUNT ((uintptr_t)sp2_PIXEL_WIDTH * (uintptr_t)sp2_PIXEL_HEIGHT)
+
+/**
+ * Specifies the kind of compression to use. Availability depends on features.
+ */
+enum sp2_CompressionCode
+#ifdef __cplusplus
+  : uint16_t
+#endif // __cplusplus
+ {
+  Uncompressed = 0,
+  Gz = 26490,
+  Bz = 25210,
+  Lz = 27770,
+  Zs = 31347,
+};
+#ifndef __cplusplus
+typedef uint16_t sp2_CompressionCode;
+#endif // __cplusplus
+
+/**
+ * A vector of bits
+ */
+typedef struct sp2_BitVec sp2_BitVec;
+
+/**
+ * A grid of bytes
+ */
+typedef struct sp2_ByteGrid sp2_ByteGrid;
+
+/**
+ * A command to send to the display.
+ */
+typedef struct sp2_Command sp2_Command;
+
+/**
+ * A connection to the display.
+ */
+typedef struct sp2_Connection sp2_Connection;
+
+/**
+ * A grid of pixels stored in packed bytes.
+ */
+typedef struct sp2_PixelGrid sp2_PixelGrid;
+
+typedef uint8_t sp2_Brightness;
+
+typedef uint16_t sp2_Offset;
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+/**
+ * Creates a new `BitVec` instance.
+ * The returned instance has to be freed with `bit_vec_dealloc`.
+ */
+struct sp2_BitVec *sp2_bit_vec_new(uintptr_t size);
+
+/**
+ * Loads a `BitVec` from the provided data.
+ * The returned instance has to be freed with `bit_vec_dealloc`.
+ */
+struct sp2_BitVec *sp2_bit_vec_load(const uint8_t *data, uintptr_t data_length);
+
+/**
+ * Clones a `BitVec`.
+ * The returned instance has to be freed with `bit_vec_dealloc`.
+ */
+struct sp2_BitVec *sp2_bit_vec_clone(const struct sp2_BitVec *this_);
+
+/**
+ * Deallocates a `BitVec`.
+ *
+ * Note: do not call this if the grid has been consumed in another way, e.g. to create a command.
+ */
+void sp2_bit_vec_dealloc(struct sp2_BitVec *this_);
+
+/**
+ * Gets the value of a bit from the `BitVec`.
+ */
+bool sp2_bit_vec_get(const struct sp2_BitVec *this_, uintptr_t index);
+
+/**
+ * Sets the value of a bit in the `BitVec`.
+ */
+bool sp2_bit_vec_set(struct sp2_BitVec *this_, uintptr_t index, bool value);
+
+/**
+ * Sets the value of all bits in the `BitVec`.
+ */
+void sp2_bit_vec_fill(struct sp2_BitVec *this_, bool value);
+
+/**
+ * Gets the length of the `BitVec` in bits.
+ */
+uintptr_t sp2_bit_vec_len(const struct sp2_BitVec *this_);
+
+/**
+ * Creates a new `ByteGrid` instance.
+ * The returned instance has to be freed with `byte_grid_dealloc`.
+ */
+struct sp2_ByteGrid *sp2_byte_grid_new(uintptr_t width, uintptr_t height);
+
+/**
+ * Loads a `ByteGrid` with the specified dimensions from the provided data.
+ * The returned instance has to be freed with `byte_grid_dealloc`.
+ */
+struct sp2_ByteGrid *sp2_byte_grid_load(uintptr_t width,
+                                        uintptr_t height,
+                                        const uint8_t *data,
+                                        uintptr_t data_length);
+
+/**
+ * Clones a `ByteGrid`.
+ * The returned instance has to be freed with `byte_grid_dealloc`.
+ */
+struct sp2_ByteGrid *sp2_byte_grid_clone(const struct sp2_ByteGrid *this_);
+
+/**
+ * Deallocates a `ByteGrid`.
+ *
+ * Note: do not call this if the grid has been consumed in another way, e.g. to create a command.
+ */
+void sp2_byte_grid_dealloc(struct sp2_ByteGrid *this_);
+
+/**
+ * Get the current value at the specified position
+ */
+uint8_t sp2_byte_grid_get(const struct sp2_ByteGrid *this_, uintptr_t x, uintptr_t y);
+
+/**
+ * Sets the current value at the specified position
+ */
+void sp2_byte_grid_set(struct sp2_ByteGrid *this_, uintptr_t x, uintptr_t y, uint8_t value);
+
+/**
+ * Fills the whole `ByteGrid` with the specified value
+ */
+void sp2_byte_grid_fill(struct sp2_ByteGrid *this_, uint8_t value);
+
+/**
+ * Gets the width in pixels of the `ByteGrid` instance.
+ */
+uintptr_t sp2_byte_grid_width(const struct sp2_PixelGrid *this_);
+
+/**
+ * Gets the height in pixels of the `ByteGrid` instance.
+ */
+uintptr_t sp2_byte_grid_height(const struct sp2_PixelGrid *this_);
+
+/**
+ * Tries to load a command from the passed array with the specified length.
+ *
+ * returns: NULL in case of an error, pointer to the allocated command otherwise
+ */
+struct sp2_Command *sp2_command_try_load(const uint8_t *data, uintptr_t length);
+
+/**
+ * Clones a `Command` instance
+ */
+struct sp2_Command *sp2_command_clone(const struct sp2_Command *original);
+
+/**
+ * Allocates a new `Command::Clear` instance
+ */
+struct sp2_Command *sp2_command_clear(void);
+
+/**
+ * Allocates a new `Command::HardReset` instance
+ */
+struct sp2_Command *sp2_command_hard_reset(void);
+
+/**
+ * Allocates a new `Command::FadeOut` instance
+ */
+struct sp2_Command *sp2_command_fade_out(void);
+
+/**
+ * Allocates a new `Command::Brightness` instance
+ */
+struct sp2_Command *sp2_command_brightness(sp2_Brightness brightness);
+
+/**
+ * Allocates a new `Command::CharBrightness` instance.
+ * The passed `ByteGrid` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_char_brightness(uint16_t x,
+                                                uint16_t y,
+                                                struct sp2_ByteGrid *byte_grid);
+
+/**
+ * Allocates a new `Command::BitmapLinear` instance.
+ * The passed `BitVec` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_bitmap_linear(sp2_Offset offset,
+                                              struct sp2_BitVec *bit_vec,
+                                              sp2_CompressionCode compression);
+
+/**
+ * Allocates a new `Command::BitmapLinearAnd` instance.
+ * The passed `BitVec` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_bitmap_linear_and(sp2_Offset offset,
+                                                  struct sp2_BitVec *bit_vec,
+                                                  sp2_CompressionCode compression);
+
+/**
+ * Allocates a new `Command::BitmapLinearOr` instance.
+ * The passed `BitVec` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_bitmap_linear_or(sp2_Offset offset,
+                                                 struct sp2_BitVec *bit_vec,
+                                                 sp2_CompressionCode compression);
+
+/**
+ * Allocates a new `Command::BitmapLinearXor` instance.
+ * The passed `BitVec` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_bitmap_linear_xor(sp2_Offset offset,
+                                                  struct sp2_BitVec *bit_vec,
+                                                  sp2_CompressionCode compression);
+
+/**
+ * Allocates a new `Command::Cp437Data` instance.
+ * The passed `ByteGrid` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_cp437_data(uint16_t x, uint16_t y, struct sp2_ByteGrid *byte_grid);
+
+/**
+ * Allocates a new `Command::BitmapLinearWin` instance.
+ * The passed `PixelGrid` gets deallocated in the process.
+ */
+struct sp2_Command *sp2_command_bitmap_linear_win(uint16_t x,
+                                                  uint16_t y,
+                                                  struct sp2_PixelGrid *byte_grid);
+
+/**
+ * Deallocates a command. Note that connection_send does this implicitly, so you only need
+ * to do this if you use the library for parsing commands.
+ */
+void sp2_command_dealloc(struct sp2_Command *ptr);
+
+/**
+ * Creates a new instance of Connection.
+ * The returned instance has to be deallocated with `connection_dealloc`.
+ *
+ * returns: NULL if connection fails or connected instance
+ *
+ * Panics: bad string encoding
+ */
+struct sp2_Connection *sp2_connection_open(const char *host);
+
+/**
+ * Sends the command instance. The instance is consumed / destroyed and cannot be used after this call.
+ */
+bool sp2_connection_send(const struct sp2_Connection *connection,
+                         struct sp2_Command *command_ptr);
+
+/**
+ * Closes and deallocates a connection instance
+ */
+void sp2_connection_dealloc(struct sp2_Connection *ptr);
+
+/**
+ * Creates a new `PixelGrid` instance.
+ * The returned instance has to be freed with `pixel_grid_dealloc`.
+ */
+struct sp2_PixelGrid *sp2_pixel_grid_new(uintptr_t width, uintptr_t height);
+
+/**
+ * Loads a `PixelGrid` with the specified dimensions from the provided data.
+ * The returned instance has to be freed with `pixel_grid_dealloc`.
+ */
+struct sp2_PixelGrid *sp2_pixel_grid_load(uintptr_t width,
+                                          uintptr_t height,
+                                          const uint8_t *data,
+                                          uintptr_t data_length);
+
+/**
+ * Clones a `PixelGrid`.
+ * The returned instance has to be freed with `pixel_grid_dealloc`.
+ */
+struct sp2_PixelGrid *sp2_pixel_grid_clone(const struct sp2_PixelGrid *this_);
+
+/**
+ * Deallocates a `PixelGrid`.
+ *
+ * Note: do not call this if the grid has been consumed in another way, e.g. to create a command.
+ */
+void sp2_pixel_grid_dealloc(struct sp2_PixelGrid *this_);
+
+/**
+ * Get the current value at the specified position
+ */
+bool sp2_pixel_grid_get(const struct sp2_PixelGrid *this_, uintptr_t x, uintptr_t y);
+
+/**
+ * Sets the current value at the specified position
+ */
+void sp2_pixel_grid_set(struct sp2_PixelGrid *this_, uintptr_t x, uintptr_t y, bool value);
+
+/**
+ * Fills the whole `PixelGrid` with the specified value
+ */
+void sp2_pixel_grid_fill(struct sp2_PixelGrid *this_, bool value);
+
+/**
+ * Gets the width in pixels of the `PixelGrid` instance.
+ */
+uintptr_t sp2_pixel_grid_width(const struct sp2_PixelGrid *this_);
+
+/**
+ * Gets the height in pixels of the `PixelGrid` instance.
+ */
+uintptr_t sp2_pixel_grid_height(const struct sp2_PixelGrid *this_);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif // __cplusplus

servicepoint2/src/bit_vec.rs

@@ -106,53 +106,61 @@ impl std::fmt::Debug for BitVec {
     }
 }
 
-#[allow(unused)]
+#[cfg(feature = "c-api")]
 pub mod c_api {
     use crate::BitVec;
 
     /// Creates a new `BitVec` instance.
     /// The returned instance has to be freed with `bit_vec_dealloc`.
-    pub unsafe extern "C" fn bit_vec_new(size: usize) -> *mut BitVec {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_new(size: usize) -> *mut BitVec {
         Box::into_raw(Box::new(BitVec::new(size)))
     }
 
     /// Loads a `BitVec` from the provided data.
     /// The returned instance has to be freed with `bit_vec_dealloc`.
-    pub unsafe extern "C" fn byte_grid_load(data: *const u8, data_length: usize) -> *mut BitVec {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_load(data: *const u8, data_length: usize) -> *mut BitVec {
         let data = std::slice::from_raw_parts(data, data_length);
         Box::into_raw(Box::new(BitVec::from(data)))
     }
 
     /// Clones a `BitVec`.
     /// The returned instance has to be freed with `bit_vec_dealloc`.
-    pub unsafe extern "C" fn byte_grid_clone(this: *const BitVec) -> *mut BitVec {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_clone(this: *const BitVec) -> *mut BitVec {
         Box::into_raw(Box::new((*this).clone()))
     }
 
     /// Deallocates a `BitVec`.
     ///
     /// Note: do not call this if the grid has been consumed in another way, e.g. to create a command.
-    pub unsafe extern "C" fn byte_grid_dealloc(this: *mut BitVec) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_dealloc(this: *mut BitVec) {
         _ = Box::from_raw(this);
     }
 
     /// Gets the value of a bit from the `BitVec`.
-    pub unsafe extern "C" fn byte_grid_get(this: *const BitVec, index: usize) -> bool {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_get(this: *const BitVec, index: usize) -> bool {
         (*this).get(index)
     }
 
     /// Sets the value of a bit in the `BitVec`.
-    pub unsafe extern "C" fn byte_grid_set(this: *mut BitVec, index: usize, value: bool) -> bool {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_set(this: *mut BitVec, index: usize, value: bool) -> bool {
         (*this).set(index, value)
     }
 
     /// Sets the value of all bits in the `BitVec`.
-    pub unsafe extern "C" fn byte_grid_fill(this: *mut BitVec, value: bool) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_fill(this: *mut BitVec, value: bool) {
         (*this).fill(value)
     }
 
     /// Gets the length of the `BitVec` in bits.
-    pub unsafe extern "C" fn byte_grid_len(this: *const BitVec) -> usize{
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_bit_vec_len(this: *const BitVec) -> usize{
         (*this).len()
     }
 }

servicepoint2/src/byte_grid.rs

@@ -58,59 +58,68 @@ impl Into<Vec<u8>> for ByteGrid {
     }
 }
 
-#[allow(unused)]
+#[cfg(feature = "c-api")]
 pub mod c_api
 {
     use crate::{ByteGrid, PixelGrid};
 
     /// Creates a new `ByteGrid` instance.
     /// The returned instance has to be freed with `byte_grid_dealloc`.
-    pub unsafe extern "C" fn byte_grid_new(width: usize, height: usize) -> *mut ByteGrid {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_new(width: usize, height: usize) -> *mut ByteGrid {
         Box::into_raw(Box::new(ByteGrid::new(width, height)))
     }
 
     /// Loads a `ByteGrid` with the specified dimensions from the provided data.
     /// The returned instance has to be freed with `byte_grid_dealloc`.
-    pub unsafe extern "C" fn byte_grid_load(width: usize, height: usize, data: *const u8, data_length: usize) -> *mut ByteGrid {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_load(width: usize, height: usize, data: *const u8, data_length: usize) -> *mut ByteGrid {
         let data = std::slice::from_raw_parts(data, data_length);
         Box::into_raw(Box::new(ByteGrid::load(width, height, data)))
     }
 
     /// Clones a `ByteGrid`.
     /// The returned instance has to be freed with `byte_grid_dealloc`.
-    pub unsafe extern "C" fn byte_grid_clone(this: *const ByteGrid) -> *mut ByteGrid {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_clone(this: *const ByteGrid) -> *mut ByteGrid {
         Box::into_raw(Box::new((*this).clone()))
     }
 
     /// Deallocates a `ByteGrid`.
     ///
     /// Note: do not call this if the grid has been consumed in another way, e.g. to create a command.
-    pub unsafe extern "C" fn byte_grid_dealloc(this: *mut ByteGrid) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_dealloc(this: *mut ByteGrid) {
         _ = Box::from_raw(this);
     }
 
     /// Get the current value at the specified position
-    pub unsafe extern "C" fn byte_grid_get(this: *const ByteGrid, x: usize, y: usize) -> u8 {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_get(this: *const ByteGrid, x: usize, y: usize) -> u8 {
         (*this).get(x, y)
     }
 
     /// Sets the current value at the specified position
-    pub unsafe extern "C" fn byte_grid_set(this: *mut ByteGrid, x: usize, y: usize, value: u8) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_set(this: *mut ByteGrid, x: usize, y: usize, value: u8) {
         (*this).set(x, y, value);
     }
 
     /// Fills the whole `ByteGrid` with the specified value
-    pub unsafe extern "C" fn byte_grid_fill(this: *mut ByteGrid, value: u8) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_fill(this: *mut ByteGrid, value: u8) {
         (*this).fill(value);
     }
 
     /// Gets the width in pixels of the `ByteGrid` instance.
-    pub unsafe extern "C" fn pixel_grid_width(this: *const PixelGrid) -> usize {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_width(this: *const PixelGrid) -> usize {
         (*this).width
     }
 
     /// Gets the height in pixels of the `ByteGrid` instance.
-    pub unsafe extern "C" fn pixel_grid_height(this: *const PixelGrid) -> usize {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_byte_grid_height(this: *const PixelGrid) -> usize {
         (*this).height
     }
 }

servicepoint2/src/command.rs

@@ -316,18 +316,18 @@ fn packet_into_linear_bitmap(
     Ok((BitVec::from(&*payload), sub))
 }
 
-#[allow(unused)]
+#[cfg(feature = "c-api")]
 pub mod c_api
 {
     use std::ptr::null_mut;
 
     use crate::{BitVec, Brightness, ByteGrid, Command, CompressionCode, Offset, Origin, Packet, PixelGrid};
 
-    /// Tries to load a command from the passed array with the specified length.
+    /// Tries to load a `Command` from the passed array with the specified length.
     ///
     /// returns: NULL in case of an error, pointer to the allocated command otherwise
     #[no_mangle]
-    pub unsafe extern "C" fn command_try_load(data: *const u8, length: usize) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_try_load(data: *const u8, length: usize) -> *mut Command {
         let data = std::slice::from_raw_parts(data, length);
         let packet = match Packet::try_from(data) {
             Err(_) => return null_mut(),
@@ -342,38 +342,38 @@ pub mod c_api
 
     /// Clones a `Command` instance
     #[no_mangle]
-    pub unsafe extern "C" fn command_clone(original: *const Command) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_clone(original: *const Command) -> *mut Command {
         Box::into_raw(Box::new((*original).clone()))
     }
 
     /// Allocates a new `Command::Clear` instance
     #[no_mangle]
-    pub unsafe extern "C" fn command_clear() -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_clear() -> *mut Command {
         Box::into_raw(Box::new(Command::Clear))
     }
 
     /// Allocates a new `Command::HardReset` instance
     #[no_mangle]
-    pub unsafe extern "C" fn command_hard_reset() -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_hard_reset() -> *mut Command {
         Box::into_raw(Box::new(Command::HardReset))
     }
 
     /// Allocates a new `Command::FadeOut` instance
     #[no_mangle]
-    pub unsafe extern "C" fn command_fade_out() -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_fade_out() -> *mut Command {
         Box::into_raw(Box::new(Command::FadeOut))
     }
 
     /// Allocates a new `Command::Brightness` instance
     #[no_mangle]
-    pub unsafe extern "C" fn command_brightness(brightness: Brightness) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_brightness(brightness: Brightness) -> *mut Command {
         Box::into_raw(Box::new(Command::Brightness(brightness)))
     }
 
     /// Allocates a new `Command::CharBrightness` instance.
     /// The passed `ByteGrid` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_char_brightness(x: u16, y: u16, byte_grid: *mut ByteGrid) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_char_brightness(x: u16, y: u16, byte_grid: *mut ByteGrid) -> *mut Command {
         let byte_grid = *Box::from_raw(byte_grid);
         Box::into_raw(Box::new(Command::CharBrightness(Origin(x, y), byte_grid)))
     }
@@ -381,7 +381,7 @@ pub mod c_api
     /// Allocates a new `Command::BitmapLinear` instance.
     /// The passed `BitVec` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_bitmap_linear(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_bitmap_linear(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
         let bit_vec = *Box::from_raw(bit_vec);
         Box::into_raw(Box::new(Command::BitmapLinear(offset, bit_vec, compression)))
     }
@@ -389,7 +389,7 @@ pub mod c_api
     /// Allocates a new `Command::BitmapLinearAnd` instance.
     /// The passed `BitVec` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_bitmap_linear_and(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_bitmap_linear_and(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
         let bit_vec = *Box::from_raw(bit_vec);
         Box::into_raw(Box::new(Command::BitmapLinearAnd(offset, bit_vec, compression)))
     }
@@ -397,7 +397,7 @@ pub mod c_api
     /// Allocates a new `Command::BitmapLinearOr` instance.
     /// The passed `BitVec` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_bitmap_linear_or(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_bitmap_linear_or(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
         let bit_vec = *Box::from_raw(bit_vec);
         Box::into_raw(Box::new(Command::BitmapLinearOr(offset, bit_vec, compression)))
     }
@@ -405,7 +405,7 @@ pub mod c_api
     /// Allocates a new `Command::BitmapLinearXor` instance.
     /// The passed `BitVec` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_bitmap_linear_xor(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_bitmap_linear_xor(offset: Offset, bit_vec: *mut BitVec, compression: CompressionCode) -> *mut Command {
         let bit_vec = *Box::from_raw(bit_vec);
         Box::into_raw(Box::new(Command::BitmapLinearXor(offset, bit_vec, compression)))
     }
@@ -413,7 +413,7 @@ pub mod c_api
     /// Allocates a new `Command::Cp437Data` instance.
     /// The passed `ByteGrid` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_cp437_data(x: u16, y: u16, byte_grid: *mut ByteGrid) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_cp437_data(x: u16, y: u16, byte_grid: *mut ByteGrid) -> *mut Command {
         let byte_grid = *Box::from_raw(byte_grid);
         Box::into_raw(Box::new(Command::Cp437Data(Origin(x, y), byte_grid)))
     }
@@ -421,15 +421,15 @@ pub mod c_api
     /// Allocates a new `Command::BitmapLinearWin` instance.
     /// The passed `PixelGrid` gets deallocated in the process.
     #[no_mangle]
-    pub unsafe extern "C" fn command_bitmap_linear_win(x: u16, y: u16, byte_grid: *mut PixelGrid) -> *mut Command {
+    pub unsafe extern "C" fn sp2_command_bitmap_linear_win(x: u16, y: u16, byte_grid: *mut PixelGrid) -> *mut Command {
         let byte_grid = *Box::from_raw(byte_grid);
         Box::into_raw(Box::new(Command::BitmapLinearWin(Origin(x, y), byte_grid)))
     }
 
-    /// Deallocates a command. Note that connection_send does this implicitly, so you only need
+    /// Deallocates a `Command`. Note that connection_send does this implicitly, so you only need
     /// to do this if you use the library for parsing commands.
     #[no_mangle]
-    pub unsafe extern "C" fn command_dealloc(ptr: *mut Command) {
+    pub unsafe extern "C" fn sp2_command_dealloc(ptr: *mut Command) {
         _ = Box::from_raw(ptr);
     }
 }

servicepoint2/src/connection.rs

@@ -65,6 +65,7 @@ impl Connection {
     }
 }
 
+#[cfg(feature = "c-api")]
 pub mod c_api
 {
     use std::ffi::{c_char, CStr};
@@ -79,7 +80,7 @@ pub mod c_api
     ///
     /// Panics: bad string encoding
     #[no_mangle]
-    pub unsafe extern "C" fn connection_open(host: *const c_char) -> *mut Connection {
+    pub unsafe extern "C" fn sp2_connection_open(host: *const c_char) -> *mut Connection {
         let host = CStr::from_ptr(host).to_str().expect("Bad encoding");
         let connection = match Connection::open(host) {
             Err(_) => return null_mut(),
@@ -92,14 +93,14 @@ pub mod c_api
 
     /// Sends the command instance. The instance is consumed / destroyed and cannot be used after this call.
     #[no_mangle]
-    pub unsafe extern "C" fn connection_send(connection: *const Connection, command_ptr: *mut Command) -> bool{
+    pub unsafe extern "C" fn sp2_connection_send(connection: *const Connection, command_ptr: *mut Command) -> bool{
         let command = Box::from_raw(command_ptr);
         (*connection).send(*command).is_ok()
     }
 
     /// Closes and deallocates a connection instance
     #[no_mangle]
-    pub unsafe extern "C" fn connection_dealloc(ptr: *mut Connection) {
+    pub unsafe extern "C" fn sp2_connection_dealloc(ptr: *mut Connection) {
         _ = Box::from_raw(ptr);
     }
 }

servicepoint2/src/pixel_grid.rs

@@ -84,59 +84,68 @@ impl Into<Vec<u8>> for PixelGrid {
     }
 }
 
-#[allow(unused)]
+#[cfg(feature = "c-api")]
 pub mod c_api
 {
     use crate::PixelGrid;
 
     /// Creates a new `PixelGrid` instance.
     /// The returned instance has to be freed with `pixel_grid_dealloc`.
-    pub unsafe extern "C" fn pixel_grid_new(width: usize, height: usize) -> *mut PixelGrid {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_new(width: usize, height: usize) -> *mut PixelGrid {
         Box::into_raw(Box::new(PixelGrid::new(width, height)))
     }
 
     /// Loads a `PixelGrid` with the specified dimensions from the provided data.
     /// The returned instance has to be freed with `pixel_grid_dealloc`.
-    pub unsafe extern "C" fn pixel_grid_load(width: usize, height: usize, data: *const u8, data_length: usize) -> *mut PixelGrid {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_load(width: usize, height: usize, data: *const u8, data_length: usize) -> *mut PixelGrid {
         let data = std::slice::from_raw_parts(data, data_length);
         Box::into_raw(Box::new(PixelGrid::load(width, height, data)))
     }
 
     /// Clones a `PixelGrid`.
     /// The returned instance has to be freed with `pixel_grid_dealloc`.
-    pub unsafe extern "C" fn pixel_grid_clone(this: *const PixelGrid) -> *mut PixelGrid {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_clone(this: *const PixelGrid) -> *mut PixelGrid {
         Box::into_raw(Box::new((*this).clone()))
     }
 
     /// Deallocates a `PixelGrid`.
     ///
     /// Note: do not call this if the grid has been consumed in another way, e.g. to create a command.
-    pub unsafe extern "C" fn pixel_grid_dealloc(this: *mut PixelGrid) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_dealloc(this: *mut PixelGrid) {
         _ = Box::from_raw(this);
     }
 
     /// Get the current value at the specified position
-    pub unsafe extern "C" fn pixel_grid_get(this: *const PixelGrid, x: usize, y: usize) -> bool {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_get(this: *const PixelGrid, x: usize, y: usize) -> bool {
         (*this).get(x, y)
     }
 
     /// Sets the current value at the specified position
-    pub unsafe extern "C" fn pixel_grid_set(this: *mut PixelGrid, x: usize, y: usize, value: bool) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_set(this: *mut PixelGrid, x: usize, y: usize, value: bool) {
         (*this).set(x, y, value);
     }
 
     /// Fills the whole `PixelGrid` with the specified value
-    pub unsafe extern "C" fn pixel_grid_fill(this: *mut PixelGrid, value: bool) {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_fill(this: *mut PixelGrid, value: bool) {
         (*this).fill(value);
     }
 
     /// Gets the width in pixels of the `PixelGrid` instance.
-    pub unsafe extern "C" fn pixel_grid_width(this: *const PixelGrid) -> usize {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_width(this: *const PixelGrid) -> usize {
         (*this).width
     }
 
     /// Gets the height in pixels of the `PixelGrid` instance.
-    pub unsafe extern "C" fn pixel_grid_height(this: *const PixelGrid) -> usize {
+    #[no_mangle]
+    pub unsafe extern "C" fn sp2_pixel_grid_height(this: *const PixelGrid) -> usize {
         (*this).height
     }
 }