a bunch of docs

cbindgen.toml

@@ -35,8 +35,8 @@ include = []
 exclude = ["BitVec"]
 
 [export.rename]
-"SpByteSlice" = "ByteSlice"
+"SPCommand" = "Command"
-"SpCommand" = "Command"
+"DisplayBitVec" = "BitVec"
 
 [enum]
 rename_variants = "QualifiedScreamingSnakeCase"

include/servicepoint.h

@@ -346,7 +346,7 @@ typedef struct Cp437GridCommand Cp437GridCommand;
 /**
  * This is a type only used by cbindgen to have a type for pointers.
  */
-typedef struct DisplayBitVec DisplayBitVec;
+typedef struct BitVec BitVec;
 
 /**
  * <div class="warning">Untested</div>
@@ -569,7 +569,7 @@ typedef struct {
      * The pointer to the command struct
      */
     CommandUnion data;
-} SPCommand;
+} Command;
 
 /**
  * A raw header.
@@ -637,7 +637,7 @@ void sp_bitmap_free(Bitmap */*notnull*/ bitmap);
  *
  * Returns NULL in case of error.
  */
-Bitmap *sp_bitmap_from_bitvec(size_t width, DisplayBitVec */*notnull*/ bitvec);
+Bitmap *sp_bitmap_from_bitvec(size_t width, BitVec */*notnull*/ bitvec);
 
 /**
  * Gets the current value at the specified position in the [Bitmap].
@@ -665,7 +665,7 @@ size_t sp_bitmap_height(Bitmap */*notnull*/ bitmap);
 /**
  * Consumes the Bitmap and returns the contained BitVec
  */
-DisplayBitVec */*notnull*/ sp_bitmap_into_bitvec(Bitmap */*notnull*/ bitmap);
+BitVec */*notnull*/ sp_bitmap_into_bitvec(Bitmap */*notnull*/ bitmap);
 
 /**
  * Creates a [BitmapCommand] and immediately turns that into a [Packet].
@@ -771,7 +771,7 @@ size_t sp_bitmap_width(Bitmap */*notnull*/ bitmap);
 /**
  * Clones a [DisplayBitVec].
  */
-DisplayBitVec */*notnull*/ sp_bitvec_clone(DisplayBitVec */*notnull*/ bit_vec);
+BitVec */*notnull*/ sp_bitvec_clone(BitVec */*notnull*/ bit_vec);
 
 /**
  * Sets the value of all bits in the [DisplayBitVec].
@@ -781,12 +781,12 @@ DisplayBitVec */*notnull*/ sp_bitvec_clone(DisplayBitVec */*notnull*/ bit_vec);
  * - `bit_vec`: instance to write to
  * - `value`: the value to set all bits to
  */
-void sp_bitvec_fill(DisplayBitVec */*notnull*/ bit_vec, bool value);
+void sp_bitvec_fill(BitVec */*notnull*/ bit_vec, bool value);
 
 /**
  * Deallocates a [DisplayBitVec].
  */
-void sp_bitvec_free(DisplayBitVec */*notnull*/ bit_vec);
+void sp_bitvec_free(BitVec */*notnull*/ bit_vec);
 
 /**
  * Gets the value of a bit from the [DisplayBitVec].
@@ -802,7 +802,7 @@ void sp_bitvec_free(DisplayBitVec */*notnull*/ bit_vec);
  *
  * - when accessing `index` out of bounds
  */
-bool sp_bitvec_get(DisplayBitVec */*notnull*/ bit_vec, size_t index);
+bool sp_bitvec_get(BitVec */*notnull*/ bit_vec, size_t index);
 
 /**
  * Creates a [BitVecCommand] and immediately turns that into a [Packet].
@@ -811,7 +811,7 @@ bool sp_bitvec_get(DisplayBitVec */*notnull*/ bit_vec, size_t index);
  *
  * Returns NULL in case of an error.
  */
-Packet *sp_bitvec_into_packet(DisplayBitVec */*notnull*/ bitvec,
+Packet *sp_bitvec_into_packet(BitVec */*notnull*/ bitvec,
                               size_t offset,
                               BinaryOperation operation,
                               CompressionCode compression);
@@ -823,7 +823,7 @@ Packet *sp_bitvec_into_packet(DisplayBitVec */*notnull*/ bitvec,
  *
  * - `bit_vec`: instance to write to
  */
-bool sp_bitvec_is_empty(DisplayBitVec */*notnull*/ bit_vec);
+bool sp_bitvec_is_empty(BitVec */*notnull*/ bit_vec);
 
 /**
  * Gets the length of the [DisplayBitVec] in bits.
@@ -832,14 +832,14 @@ bool sp_bitvec_is_empty(DisplayBitVec */*notnull*/ bit_vec);
  *
  * - `bit_vec`: instance to write to
  */
-size_t sp_bitvec_len(DisplayBitVec */*notnull*/ bit_vec);
+size_t sp_bitvec_len(BitVec */*notnull*/ bit_vec);
 
 /**
  * Interpret the data as a series of bits and load then into a new [DisplayBitVec] instance.
  *
  * returns: [DisplayBitVec] instance containing data.
  */
-DisplayBitVec */*notnull*/ sp_bitvec_load(ByteSlice data);
+BitVec */*notnull*/ sp_bitvec_load(ByteSlice data);
 
 /**
  * Creates a new [DisplayBitVec] instance.
@@ -854,7 +854,7 @@ DisplayBitVec */*notnull*/ sp_bitvec_load(ByteSlice data);
  *
  * - when `size` is not divisible by 8.
  */
-DisplayBitVec */*notnull*/ sp_bitvec_new(size_t size);
+BitVec */*notnull*/ sp_bitvec_new(size_t size);
 
 /**
  * Sets the value of a bit in the [DisplayBitVec].
@@ -869,9 +869,7 @@ DisplayBitVec */*notnull*/ sp_bitvec_new(size_t size);
  *
  * - when accessing `index` out of bounds
  */
-void sp_bitvec_set(DisplayBitVec */*notnull*/ bit_vec,
+void sp_bitvec_set(BitVec */*notnull*/ bit_vec, size_t index, bool value);
-                   size_t index,
-                   bool value);
 
 /**
  * Gets an unsafe reference to the data of the [DisplayBitVec] instance.
@@ -882,7 +880,7 @@ void sp_bitvec_set(DisplayBitVec */*notnull*/ bit_vec,
  *
  * - `bit_vec`: instance to write to
  */
-ByteSlice sp_bitvec_unsafe_data_ref(DisplayBitVec */*notnull*/ bit_vec);
+ByteSlice sp_bitvec_unsafe_data_ref(BitVec */*notnull*/ bit_vec);
 
 /**
  * Clones a [BrightnessGrid].
@@ -1126,6 +1124,11 @@ void sp_char_grid_set(CharGrid */*notnull*/ char_grid,
  */
 size_t sp_char_grid_width(CharGrid */*notnull*/ char_grid);
 
+/**
+ * Clones an [BitmapCommand] instance.
+ *
+ * returns: a new [BitmapCommand] instance.
+ */
 BitmapCommand */*notnull*/ sp_cmd_bitmap_clone(BitmapCommand */*notnull*/ command);
 
 void sp_cmd_bitmap_free(BitmapCommand */*notnull*/ command);
@@ -1181,11 +1184,19 @@ void sp_cmd_bitmap_set_origin(BitmapCommand */*notnull*/ command,
                               size_t origin_x,
                               size_t origin_y);
 
+/**
+ * Clones an [BitVecCommand] instance.
+ *
+ * returns: a new [BitVecCommand] instance.
+ */
 BitVecCommand */*notnull*/ sp_cmd_bitvec_clone(BitVecCommand */*notnull*/ command);
 
+/**
+ * Deallocates a [BitVecCommand].
+ */
 void sp_cmd_bitvec_free(BitVecCommand */*notnull*/ command);
 
-DisplayBitVec *sp_cmd_bitvec_get(BitVecCommand */*notnull*/ command);
+BitVec *sp_cmd_bitvec_get(BitVecCommand */*notnull*/ command);
 
 CompressionCode sp_cmd_bitvec_get_compression(BitVecCommand */*notnull*/ command);
 
@@ -1209,7 +1220,7 @@ Packet *sp_cmd_bitvec_into_packet(BitVecCommand */*notnull*/ command);
  *
  * The contained [`DisplayBitVec`] is always uncompressed.
  */
-BitVecCommand */*notnull*/ sp_cmd_bitvec_new(DisplayBitVec */*notnull*/ bitvec,
+BitVecCommand */*notnull*/ sp_cmd_bitvec_new(BitVec */*notnull*/ bitvec,
                                              size_t offset,
                                              BinaryOperation operation,
                                              CompressionCode compression);
@@ -1218,7 +1229,7 @@ BitVecCommand */*notnull*/ sp_cmd_bitvec_new(DisplayBitVec */*notnull*/ bitvec,
  * Moves the provided bitmap to be contained in the command.
  */
 void sp_cmd_bitvec_set(BitVecCommand */*notnull*/ command,
-                       DisplayBitVec */*notnull*/ bitvec);
+                       BitVec */*notnull*/ bitvec);
 
 void sp_cmd_bitvec_set_compression(BitVecCommand */*notnull*/ command,
                                    CompressionCode compression);
@@ -1229,14 +1240,24 @@ void sp_cmd_bitvec_set_offset(BitVecCommand */*notnull*/ command,
 void sp_cmd_bitvec_set_operation(BitVecCommand */*notnull*/ command,
                                  BinaryOperation operation);
 
+/**
+ * Clones an [GlobalBrightnessCommand] instance.
+ *
+ * returns: a new [GlobalBrightnessCommand] instance.
+ */
 GlobalBrightnessCommand */*notnull*/ sp_cmd_brightness_global_clone(GlobalBrightnessCommand */*notnull*/ command);
 
 void sp_cmd_brightness_global_free(BitmapCommand */*notnull*/ command);
 
 Brightness *sp_cmd_brightness_global_get(GlobalBrightnessCommand */*notnull*/ command);
 
-Packet *sp_cmd_brightness_global_into_packet(GlobalBrightnessCommand */*notnull*/ command);
+Packet */*notnull*/ sp_cmd_brightness_global_into_packet(GlobalBrightnessCommand */*notnull*/ command);
 
+/**
+ * Set the brightness of all tiles to the same value.
+ *
+ * Returns: a new [GlobalBrightnessCommand] instance.
+ */
 GlobalBrightnessCommand */*notnull*/ sp_cmd_brightness_global_new(Brightness brightness);
 
 /**
@@ -1245,10 +1266,22 @@ GlobalBrightnessCommand */*notnull*/ sp_cmd_brightness_global_new(Brightness bri
 void sp_cmd_brightness_global_set(GlobalBrightnessCommand */*notnull*/ command,
                                   Brightness brightness);
 
+/**
+ * Clones an [BrightnessGridCommand] instance.
+ *
+ * returns: a new [BrightnessGridCommand] instance.
+ */
 BrightnessGridCommand */*notnull*/ sp_cmd_brightness_grid_clone(BrightnessGridCommand */*notnull*/ command);
 
+/**
+ * Deallocates a [BitmapCommand].
+ */
 void sp_cmd_brightness_grid_free(BitmapCommand */*notnull*/ command);
 
+/**
+ * Moves the provided [BrightnessGrid] into a new [BrightnessGridCommand],
+ * leaving other fields as their default values.
+ */
 BrightnessGridCommand */*notnull*/ sp_cmd_brightness_grid_from_grid(BrightnessGrid */*notnull*/ grid);
 
 BrightnessGrid *sp_cmd_brightness_grid_get(BrightnessGridCommand */*notnull*/ command);
@@ -1259,6 +1292,13 @@ void sp_cmd_brightness_grid_get_origin(BrightnessGridCommand */*notnull*/ comman
 
 Packet *sp_cmd_brightness_grid_into_packet(BrightnessGridCommand */*notnull*/ command);
 
+/**
+ * Set the brightness of individual tiles in a rectangular area of the display.
+ *
+ * The passed [BrightnessGrid] gets consumed.
+ *
+ * Returns: a new [BrightnessGridCommand] instance.
+ */
 BrightnessGridCommand */*notnull*/ sp_cmd_brightness_grid_new(BrightnessGrid */*notnull*/ grid,
                                                               size_t origin_x,
                                                               size_t origin_y);
@@ -1273,10 +1313,22 @@ void sp_cmd_brightness_grid_set_origin(BrightnessGridCommand */*notnull*/ comman
                                        size_t origin_x,
                                        size_t origin_y);
 
+/**
+ * Clones an [CharGridCommand] instance.
+ *
+ * returns: a new [CharGridCommand] instance.
+ */
 CharGridCommand */*notnull*/ sp_cmd_char_grid_clone(CharGridCommand */*notnull*/ command);
 
+/**
+ * Deallocates a [BitmapCommand].
+ */
 void sp_cmd_char_grid_free(BitmapCommand */*notnull*/ command);
 
+/**
+ * Moves the provided [CharGrid] into a new [CharGridCommand],
+ * leaving other fields as their default values.
+ */
 CharGridCommand */*notnull*/ sp_cmd_char_grid_from_grid(CharGrid */*notnull*/ grid);
 
 CharGrid *sp_cmd_char_grid_get(CharGridCommand */*notnull*/ command);
@@ -1287,6 +1339,13 @@ void sp_cmd_char_grid_get_origin(CharGridCommand */*notnull*/ command,
 
 Packet *sp_cmd_char_grid_into_packet(CharGridCommand */*notnull*/ command);
 
+/**
+ * Show UTF-8 encoded text on the screen.
+ *
+ * The passed [CharGrid] gets consumed.
+ *
+ * Returns: a new [CharGridCommand] instance.
+ */
 CharGridCommand */*notnull*/ sp_cmd_char_grid_new(CharGrid */*notnull*/ grid,
                                                   size_t origin_x,
                                                   size_t origin_y);
@@ -1301,6 +1360,9 @@ void sp_cmd_char_grid_set_origin(CharGridCommand */*notnull*/ command,
                                  size_t origin_x,
                                  size_t origin_y);
 
+/**
+ * Deallocates a [ClearCommand].
+ */
 void sp_cmd_clear_free(ClearCommand */*notnull*/ command);
 
 /**
@@ -1309,21 +1371,35 @@ void sp_cmd_clear_free(ClearCommand */*notnull*/ command);
  * Does not affect brightness.
  *
  * Returns: a new [ClearCommand] instance.
- *
- * # Examples
- *
- * ```C
- * sp_udp_send_command(connection, sp_cmd_clear());
- * ```
  */
 ClearCommand */*notnull*/ sp_cmd_clear_new(void);
 
+/**
+ * Clones an [Cp437GridCommand] instance.
+ *
+ * returns: a new [Cp437GridCommand] instance.
+ */
 Cp437GridCommand */*notnull*/ sp_cmd_cp437_grid_clone(Cp437GridCommand */*notnull*/ command);
 
+/**
+ * Deallocates a [Cp437GridCommand].
+ */
 void sp_cmd_cp437_grid_free(BitmapCommand */*notnull*/ command);
 
+/**
+ * Moves the provided [Cp437Grid] into a new [Cp437GridCommand],
+ * leaving other fields as their default values.
+ */
 Cp437GridCommand */*notnull*/ sp_cmd_cp437_grid_from_grid(Cp437Grid */*notnull*/ grid);
 
+/**
+ * Show text on the screen.
+ *
+ * The text is sent in the form of a 2D grid of [CP-437] encoded characters.
+ * For sending UTF-8 encoded characters, see [servicepoint::CharGridCommand].
+ *
+ * [CP-437]: https://en.wikipedia.org/wiki/Code_page_437
+ */
 Cp437Grid *sp_cmd_cp437_grid_get(Cp437GridCommand */*notnull*/ command);
 
 /**
@@ -1337,6 +1413,13 @@ void sp_cmd_cp437_grid_get_origin(Cp437GridCommand */*notnull*/ command,
 
 Packet *sp_cmd_cp437_grid_into_packet(Cp437GridCommand */*notnull*/ command);
 
+/**
+ * Show text on the screen.
+ *
+ * The text is sent in the form of a 2D grid of [CP-437] encoded characters.
+ *
+ * The origin is relative to the top-left of the display.
+ */
 Cp437GridCommand */*notnull*/ sp_cmd_cp437_grid_new(Cp437Grid */*notnull*/ grid,
                                                     size_t origin_x,
                                                     size_t origin_y);
@@ -1358,6 +1441,9 @@ void sp_cmd_cp437_grid_set_origin(Cp437GridCommand */*notnull*/ command,
                                   size_t origin_x,
                                   size_t origin_y);
 
+/**
+ * Deallocates a [FadeOutCommand].
+ */
 void sp_cmd_fade_out_free(ClearCommand */*notnull*/ command);
 
 /**
@@ -1368,41 +1454,44 @@ void sp_cmd_fade_out_free(ClearCommand */*notnull*/ command);
 FadeOutCommand */*notnull*/ sp_cmd_fade_out_new(void);
 
 /**
- * Clones a [SPCommand] instance.
+ * Clones an [SPCommand] instance.
  *
- * returns: new [SPCommand] instance.
+ * returns: a new [SPCommand] instance.
  */
-SPCommand sp_cmd_generic_clone(SPCommand command);
+Command sp_cmd_generic_clone(Command command);
 
 /**
- * Deallocates a [SPCommand].
+ * Deallocates an [SPCommand].
  *
  * # Examples
  *
  * ```C
- * TypedCommand c = sp_command_clear();
+ * SPCommand c = sp_cmd_clear_into_generic(sp_cmd_clear_new());
  * sp_command_free(c);
  * ```
  */
-void sp_cmd_generic_free(SPCommand command);
+void sp_cmd_generic_free(Command command);
 
 /**
- * Turns a [TypedCommand] into a [Packet].
+ * Tries to turn a [SPCommand] into a [Packet].
- * The [TypedCommand] gets consumed.
+ * The [SPCommand] gets consumed.
  *
- * Returns NULL in case of an error.
+ * Returns tag [CommandTag::Invalid] in case of an error.
  */
-Packet *sp_cmd_generic_into_packet(SPCommand command);
+Packet *sp_cmd_generic_into_packet(Command command);
 
 /**
- * Tries to turn a [Packet] into a [TypedCommand].
+ * Tries to turn a [Packet] into a [SPCommand].
  *
- * The packet is deallocated in the process.
+ * The packet is dropped in the process.
  *
- * Returns: pointer to new [TypedCommand] instance or NULL if parsing failed.
+ * Returns: pointer to new [SPCommand] instance or NULL if parsing failed.
  */
-SPCommand *sp_cmd_generic_try_from_packet(Packet */*notnull*/ packet);
+Command *sp_cmd_generic_try_from_packet(Packet */*notnull*/ packet);
 
+/**
+ * Deallocates a [HardResetCommand].
+ */
 void sp_cmd_hard_reset_free(ClearCommand */*notnull*/ command);
 
 /**
@@ -1520,6 +1609,8 @@ size_t sp_cp437_grid_width(Cp437Grid */*notnull*/ cp437_grid);
 
 /**
  * Clones a [Packet].
+ *
+ * returns: a new [Packet] instance.
  */
 Packet */*notnull*/ sp_packet_clone(Packet */*notnull*/ packet);
 
@@ -1633,7 +1724,7 @@ UdpSocket *sp_udp_open_ipv4(uint8_t ip1,
  * sp_udp_send_command(connection, sp_command_brightness(5));
  * ```
  */
-bool sp_udp_send_command(UdpSocket */*notnull*/ connection, SPCommand command);
+bool sp_udp_send_command(UdpSocket */*notnull*/ connection, Command command);
 
 /**
  * Sends a [Header] to the display using the [UdpSocket].

src/commands/bitmap_command.rs

@@ -41,6 +41,9 @@ pub unsafe extern "C" fn sp_cmd_bitmap_into_packet(
     heap_move_ok(unsafe { heap_remove(command) }.try_into())
 }
 
+/// Clones an [BitmapCommand] instance.
+///
+/// returns: a new [BitmapCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_bitmap_clone(
     command: NonNull<BitmapCommand>,

src/commands/bitvec_command.rs

@@ -41,6 +41,9 @@ pub unsafe extern "C" fn sp_cmd_bitvec_into_packet(
     heap_move_ok(unsafe { heap_remove(command) }.try_into())
 }
 
+/// Clones an [BitVecCommand] instance.
+///
+/// returns: a new [BitVecCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_bitvec_clone(
     command: NonNull<BitVecCommand>,
@@ -48,6 +51,7 @@ pub unsafe extern "C" fn sp_cmd_bitvec_clone(
     unsafe { heap_clone(command) }
 }
 
+/// Deallocates a [BitVecCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_bitvec_free(command: NonNull<BitVecCommand>) {
     unsafe { heap_drop(command) }

src/commands/brightness_grid_command.rs

@@ -6,6 +6,11 @@ use servicepoint::{
 };
 use std::ptr::NonNull;
 
+/// Set the brightness of individual tiles in a rectangular area of the display.
+///
+/// The passed [BrightnessGrid] gets consumed.
+///
+/// Returns: a new [BrightnessGridCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_grid_new(
     grid: NonNull<BrightnessGrid>,
@@ -18,6 +23,8 @@ pub unsafe extern "C" fn sp_cmd_brightness_grid_new(
     })
 }
 
+/// Moves the provided [BrightnessGrid] into a new [BrightnessGridCommand],
+/// leaving other fields as their default values.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_grid_from_grid(
     grid: NonNull<BrightnessGrid>,
@@ -32,6 +39,9 @@ pub unsafe extern "C" fn sp_cmd_brightness_grid_into_packet(
     heap_move_ok(unsafe { heap_remove(command) }.try_into())
 }
 
+/// Clones an [BrightnessGridCommand] instance.
+///
+/// returns: a new [BrightnessGridCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_grid_clone(
     command: NonNull<BrightnessGridCommand>,
@@ -39,6 +49,7 @@ pub unsafe extern "C" fn sp_cmd_brightness_grid_clone(
     unsafe { heap_clone(command) }
 }
 
+/// Deallocates a [BitmapCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_grid_free(
     command: NonNull<BitmapCommand>,

src/commands/cc_only_commands.rs

@@ -7,17 +7,12 @@ use std::ptr::NonNull;
 /// Does not affect brightness.
 ///
 /// Returns: a new [ClearCommand] instance.
-///
-/// # Examples
-///
-/// ```C
-/// sp_udp_send_command(connection, sp_cmd_clear());
-/// ```
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_clear_new() -> NonNull<ClearCommand> {
     heap_move_nonnull(ClearCommand)
 }
 
+/// Deallocates a [ClearCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_clear_free(command: NonNull<ClearCommand>) {
     unsafe { heap_drop(command) }
@@ -33,6 +28,7 @@ pub unsafe extern "C" fn sp_cmd_hard_reset_new() -> NonNull<HardResetCommand> {
     heap_move_nonnull(HardResetCommand)
 }
 
+/// Deallocates a [HardResetCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_hard_reset_free(
     command: NonNull<ClearCommand>,
@@ -48,6 +44,7 @@ pub unsafe extern "C" fn sp_cmd_fade_out_new() -> NonNull<FadeOutCommand> {
     heap_move_nonnull(FadeOutCommand)
 }
 
+/// Deallocates a [FadeOutCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_fade_out_free(command: NonNull<ClearCommand>) {
     unsafe { heap_drop(command) }

src/commands/char_grid_command.rs

@@ -4,6 +4,11 @@ use crate::mem::{
 use servicepoint::{BitmapCommand, CharGrid, CharGridCommand, Origin, Packet};
 use std::ptr::NonNull;
 
+/// Show UTF-8 encoded text on the screen.
+///
+/// The passed [CharGrid] gets consumed.
+///
+/// Returns: a new [CharGridCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_char_grid_new(
     grid: NonNull<CharGrid>,
@@ -16,6 +21,8 @@ pub unsafe extern "C" fn sp_cmd_char_grid_new(
     })
 }
 
+/// Moves the provided [CharGrid] into a new [CharGridCommand],
+/// leaving other fields as their default values.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_char_grid_from_grid(
     grid: NonNull<CharGrid>,
@@ -30,6 +37,9 @@ pub unsafe extern "C" fn sp_cmd_char_grid_into_packet(
     heap_move_ok(unsafe { heap_remove(command) }.try_into())
 }
 
+/// Clones an [CharGridCommand] instance.
+///
+/// returns: a new [CharGridCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_char_grid_clone(
     command: NonNull<CharGridCommand>,
@@ -37,6 +47,7 @@ pub unsafe extern "C" fn sp_cmd_char_grid_clone(
     unsafe { heap_clone(command) }
 }
 
+/// Deallocates a [BitmapCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_char_grid_free(
     command: NonNull<BitmapCommand>,

src/commands/cp437_grid_command.rs

@@ -6,6 +6,11 @@ use servicepoint::{
 };
 use std::ptr::NonNull;
 
+/// Show text on the screen.
+///
+/// The text is sent in the form of a 2D grid of [CP-437] encoded characters.
+///
+/// The origin is relative to the top-left of the display.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_cp437_grid_new(
     grid: NonNull<Cp437Grid>,
@@ -18,6 +23,8 @@ pub unsafe extern "C" fn sp_cmd_cp437_grid_new(
     })
 }
 
+/// Moves the provided [Cp437Grid] into a new [Cp437GridCommand],
+/// leaving other fields as their default values.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_cp437_grid_from_grid(
     grid: NonNull<Cp437Grid>,
@@ -32,6 +39,9 @@ pub unsafe extern "C" fn sp_cmd_cp437_grid_into_packet(
     heap_move_ok(unsafe { heap_remove(command) }.try_into())
 }
 
+/// Clones an [Cp437GridCommand] instance.
+///
+/// returns: a new [Cp437GridCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_cp437_grid_clone(
     command: NonNull<Cp437GridCommand>,
@@ -39,6 +49,7 @@ pub unsafe extern "C" fn sp_cmd_cp437_grid_clone(
     unsafe { heap_clone(command) }
 }
 
+/// Deallocates a [Cp437GridCommand].
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_cp437_grid_free(
     command: NonNull<BitmapCommand>,
@@ -59,6 +70,12 @@ pub unsafe extern "C" fn sp_cmd_cp437_grid_set(
     }
 }
 
+/// Show text on the screen.
+///
+/// The text is sent in the form of a 2D grid of [CP-437] encoded characters.
+/// For sending UTF-8 encoded characters, see [servicepoint::CharGridCommand].
+///
+/// [CP-437]: https://en.wikipedia.org/wiki/Code_page_437
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_cp437_grid_get(
     mut command: NonNull<Cp437GridCommand>,

src/commands/generic_command.rs

@@ -1,5 +1,6 @@
 use crate::mem::{
-    heap_clone, heap_drop, heap_move_nonnull, heap_move_ok, heap_remove,
+    heap_clone, heap_drop, heap_move, heap_move_nonnull, heap_move_ok,
+    heap_remove,
 };
 use servicepoint::{
     BitVecCommand, BitmapCommand, BrightnessGridCommand, CharGridCommand,
@@ -229,7 +230,7 @@ pub unsafe extern "C" fn sp_cmd_generic_clone(command: SPCommand) -> SPCommand {
 pub unsafe extern "C" fn sp_cmd_generic_free(command: SPCommand) {
     unsafe {
         match command.tag {
-            CommandTag::Invalid => return,
+            CommandTag::Invalid => (),
             CommandTag::Bitmap => heap_drop(command.data.bitmap),
             CommandTag::BitVec => heap_drop(command.data.bitvec),
             CommandTag::BrightnessGrid => {
@@ -273,20 +274,20 @@ pub unsafe extern "C" fn sp_cmd_generic_into_packet(
         CommandTag::Cp437Grid => heap_move_ok(unsafe {
             heap_remove(command.data.cp437_grid).try_into()
         }),
-        CommandTag::GlobalBrightness => heap_move_ok(unsafe {
+        CommandTag::GlobalBrightness => heap_move(unsafe {
-            heap_remove(command.data.global_brightness).try_into()
+            heap_remove(command.data.global_brightness).into()
         }),
         CommandTag::Clear => {
-            heap_move_ok(unsafe { heap_remove(command.data.clear).try_into() })
+            heap_move(unsafe { heap_remove(command.data.clear).into() })
+        }
+        CommandTag::HardReset => {
+            heap_move(unsafe { heap_remove(command.data.hard_reset).into() })
+        }
+        CommandTag::FadeOut => {
+            heap_move(unsafe { heap_remove(command.data.fade_out).into() })
+        }
+        CommandTag::BitmapLegacy => {
+            heap_move(unsafe { heap_remove(command.data.bitmap_legacy).into() })
         }
-        CommandTag::HardReset => heap_move_ok(unsafe {
-            heap_remove(command.data.hard_reset).try_into()
-        }),
-        CommandTag::FadeOut => heap_move_ok(unsafe {
-            heap_remove(command.data.fade_out).try_into()
-        }),
-        CommandTag::BitmapLegacy => heap_move_ok(unsafe {
-            heap_remove(command.data.bitmap_legacy).try_into()
-        }),
     }
 }

src/commands/global_brightness_command.rs

@@ -1,11 +1,12 @@
-use crate::mem::{
+use crate::mem::{heap_clone, heap_drop, heap_move_nonnull, heap_remove};
-    heap_clone, heap_drop, heap_move_nonnull, heap_move_ok, heap_remove,
-};
 use servicepoint::{
     BitmapCommand, Brightness, GlobalBrightnessCommand, Packet,
 };
 use std::ptr::NonNull;
 
+/// Set the brightness of all tiles to the same value.
+///
+/// Returns: a new [GlobalBrightnessCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_global_new(
     brightness: Brightness,
@@ -16,10 +17,13 @@ pub unsafe extern "C" fn sp_cmd_brightness_global_new(
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_global_into_packet(
     command: NonNull<GlobalBrightnessCommand>,
-) -> *mut Packet {
+) -> NonNull<Packet> {
-    heap_move_ok(unsafe { heap_remove(command) }.try_into())
+    heap_move_nonnull(unsafe { heap_remove(command) }.into())
 }
 
+/// Clones an [GlobalBrightnessCommand] instance.
+///
+/// returns: a new [GlobalBrightnessCommand] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_cmd_brightness_global_clone(
     command: NonNull<GlobalBrightnessCommand>,

src/lib.rs

@@ -25,10 +25,14 @@
 //! }
 //! ```
 
+/// Functions related to commands.
 pub mod commands;
+/// Functions related to [servicepoint::Bitmap], [servicepoint::CharGrid] and friends.
 pub mod containers;
-pub mod mem;
+pub(crate) mod mem;
+/// Functions related to [Packet].
 pub mod packet;
+/// Functions related to [UdpSocket].
 pub mod udp;
 
 use std::time::Duration;

src/packet.rs

@@ -79,6 +79,8 @@ pub unsafe extern "C" fn sp_packet_serialize_to(
 }
 
 /// Clones a [Packet].
+///
+/// returns: a new [Packet] instance.
 #[no_mangle]
 pub unsafe extern "C" fn sp_packet_clone(
     packet: NonNull<Packet>,