limit brightness to valid levels, optional rand dependency to implement Distribution trait

fixup! limit brightness to valid levels, optional rand dependency to implement Distribution trait

crates/servicepoint/Cargo.toml

@@ -19,6 +19,7 @@ flate2 = { version = "1.0", optional = true }
 bzip2 = { version = "0.4", optional = true }
 zstd = { version = "0.13", optional = true }
 rust-lzma = { version = "0.6.0", optional = true }
+rand = { version = "0.8", optional = true }
 
 [features]
 default = ["compression_lzma"]
@@ -27,6 +28,11 @@ compression_bzip2 = ["dep:bzip2"]
 compression_lzma = ["dep:rust-lzma"]
 compression_zstd = ["dep:zstd"]
 all_compressions = ["compression_zlib", "compression_bzip2", "compression_lzma", "compression_zstd"]
+rand = ["dep:rand"]
+
+[[example]]
+name = "random_brightness"
+required-features = ["rand"]
 
 [dev-dependencies]
 # for examples

crates/servicepoint/examples/random_brightness.rs

@@ -32,7 +32,7 @@ fn main() {
         filled_grid.fill(true);
 
         let command =
-            BitmapLinearWin(Origin(0, 0), filled_grid, CompressionCode::Lzma);
+            BitmapLinearWin(Origin::new(0, 0), filled_grid, CompressionCode::Lzma);
         connection.send(command).expect("send failed");
     }
 
@@ -49,7 +49,7 @@ fn main() {
         let w = rng.gen_range(min_size..=TILE_WIDTH - x);
         let h = rng.gen_range(min_size..=TILE_HEIGHT - y);
 
-        let origin = Origin(x, y);
+        let origin = Origin::new(x, y);
         let mut luma = ByteGrid::new(w, h);
 
         for y in 0..h {

crates/servicepoint/src/brightness.rs

@@ -0,0 +1,41 @@
+use rand::distributions::Standard;
+#[cfg(feature = "rand")]
+use rand::prelude::Distribution;
+#[cfg(feature = "rand")]
+use rand::Rng;
+
+/// A display brightness value, checked for correct value range
+#[derive(Debug, Copy, Clone, PartialEq)]
+pub struct Brightness(u8);
+
+impl From<Brightness> for u8 {
+    fn from(brightness: Brightness) -> Self {
+        brightness.0
+    }
+}
+
+impl TryFrom<u8> for Brightness {
+    type Error = ();
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        if value > Self::MAX.0 {
+            Err(())
+        } else {
+            Ok(Brightness(value))
+        }
+    }
+}
+
+impl Brightness {
+    /// highest possible brightness value, 11
+    pub const MAX: Brightness = Brightness(11);
+    /// lowest possible brightness value, 0
+    pub const MIN: Brightness = Brightness(0);
+}
+
+#[cfg(feature = "rand")]
+impl Distribution<Brightness> for Standard {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> Brightness {
+        Brightness(rng.gen_range(Brightness::MIN.0..(Brightness::MAX.0 + 1)))
+    }
+}

crates/servicepoint/src/command.rs

@@ -3,8 +3,8 @@ use bitvec::prelude::BitVec;
 use crate::command_code::CommandCode;
 use crate::compression::{into_compressed, into_decompressed};
 use crate::{
-    ByteGrid, CompressionCode, Grid, Header, Packet, PixelGrid, SpBitVec,
+    Brightness, ByteGrid, CompressionCode, Grid, Header, Packet, PixelGrid,
-    TILE_SIZE,
+    SpBitVec, TILE_SIZE,
 };
 
 /// An origin marks the top left position of a window sent to the display.
@@ -24,9 +24,6 @@ impl std::ops::Add<Origin> for Origin {
 /// Type alias for documenting the meaning of the u16 in enum values
 pub type Offset = usize;
 
-/// Type alias for documenting the meaning of the u16 in enum values
-pub type Brightness = u8;
-
 /// A command to send to the display.
 #[derive(Debug, Clone, PartialEq)]
 pub enum Command {
@@ -95,7 +92,7 @@ impl From<Command> for Packet {
                     0x0000,
                     0x0000,
                 ),
-                vec![brightness],
+                vec![brightness.into()],
             ),
             Command::BitmapLinearWin(origin, pixels, compression) => {
                 bitmap_win_into_packet(origin, pixels, compression)
@@ -196,6 +193,8 @@ pub enum TryFromPacketError {
     InvalidCompressionCode(u16),
     /// Decompression of the payload failed. This can be caused by corrupted packets.
     DecompressionFailed,
+    /// The given brightness value is out of bounds
+    InvalidBrightness(u8),
 }
 
 impl TryFrom<Packet> for Command {
@@ -227,9 +226,12 @@ impl TryFrom<Packet> for Command {
 
                 let Header(_, a, b, c, d) = header;
                 if a != 0 || b != 0 || c != 0 || d != 0 {
-                    Err(TryFromPacketError::ExtraneousHeaderValues)
+                    return Err(TryFromPacketError::ExtraneousHeaderValues)
-                } else {
+                }
-                    Ok(Command::Brightness(payload[0]))
+
+                match Brightness::try_from(payload[0]) {
+                    Ok(b) => Ok(Command::Brightness(b)),
+                    Err(_) => Err(TryFromPacketError::InvalidBrightness(payload[0]))
                 }
             }
             CommandCode::HardReset => match Self::check_command_only(packet) {
@@ -399,9 +401,7 @@ mod tests {
 
     use crate::command::TryFromPacketError;
     use crate::command_code::CommandCode;
-    use crate::{
+    use crate::{Brightness, ByteGrid, Command, CompressionCode, Header, Origin, Packet, PixelGrid};
-        ByteGrid, Command, CompressionCode, Header, Origin, Packet, PixelGrid,
-    };
 
     fn round_trip(original: Command) {
         let packet: Packet = original.clone().into();
@@ -443,7 +443,7 @@ mod tests {
 
     #[test]
     fn round_trip_brightness() {
-        round_trip(Command::Brightness(6));
+        round_trip(Command::Brightness(Brightness::try_from(6).unwrap()));
     }
 
     #[test]

crates/servicepoint/src/lib.rs

@@ -5,8 +5,9 @@ use std::time::Duration;
 pub use bitvec;
 use bitvec::prelude::{BitVec, Msb0};
 
+pub use crate::brightness::Brightness;
 pub use crate::byte_grid::ByteGrid;
-pub use crate::command::{Brightness, Command, Offset, Origin};
+pub use crate::command::{Command, Offset, Origin};
 pub use crate::compression_code::CompressionCode;
 pub use crate::connection::Connection;
 pub use crate::data_ref::DataRef;
@@ -16,6 +17,7 @@ pub use crate::pixel_grid::PixelGrid;
 
 type SpBitVec = BitVec<u8, Msb0>;
 
+mod brightness;
 mod byte_grid;
 mod command;
 mod command_code;