add experimental null char handling

Cargo.lock

@@ -760,17 +760,6 @@ dependencies = [
  "hashbrown",
 ]
 
-[[package]]
-name = "inherent"
-version = "1.0.12"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6c38228f24186d9cc68c729accb4d413be9eaed6ad07ff79e0270d9e56f3de13"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
-
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.1"
@@ -1521,14 +1510,13 @@ dependencies = [
 
 [[package]]
 name = "servicepoint"
-version = "0.15.2"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d1e88713031e003dc3ee708dbb282e36714eee466a12d311d0e2e24c61c7118"
+checksum = "9b04582e916474f1bc1605cad3773262c425d9062b487e49a0df59662f2cca8d"
 dependencies = [
  "bitvec",
  "bzip2",
  "flate2",
- "inherent",
  "log",
  "once_cell",
  "rust-lzma",
@@ -1538,7 +1526,7 @@ dependencies = [
 
 [[package]]
 name = "servicepoint-simulator"
-version = "0.2.3"
+version = "0.2.4"
 dependencies = [
  "clap",
  "env_logger",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "servicepoint-simulator"
-version = "0.2.3"
+version = "0.2.4"
 edition = "2021"
 publish = true
 license = "GPL-3.0-or-later"
@@ -19,9 +19,6 @@ env_logger = "0.11"
 clap = { version = "4.5", features = ["derive"] }
 thiserror = "2.0"
 
-# package parsing
-servicepoint = { features = ["all_compressions"], version = "0.15.2" }
-
 # font rendering
 font-kit = "0.14.2"
 # I should not need this as a direct dependency, but then I cannot spell the types needed to use font-kit...
@@ -32,6 +29,10 @@ winit = "0.30"
 # for drawing pixels onto the surface of the window
 softbuffer = "0.4.6"
 
+[dependencies.servicepoint]
+version = "0.16.0"
+features = ["all_compressions"]
+
 [profile.release]
 lto = true          # Enable link-time optimization
 codegen-units = 1   # Reduce number of codegen units to increase optimizations

README.md

@@ -42,14 +42,24 @@ Make sure to run a release build, because a debug build _way_ slower.
 Usage: servicepoint-simulator [OPTIONS]
 
 Options:
-      --bind <BIND>  address and port to bind to [default: 0.0.0.0:2342]
-  -f, --font <FONT>  The name of the font family to use. This defaults to the system monospace font.
-  -s, --spacers      add spacers between tile rows to simulate gaps in real display
-  -r, --red          Use the red color channel
-  -g, --green        Use the green color channel
-  -b, --blue         Use the blue color channel
-  -v, --verbose      Set default log level lower. You can also change this via the RUST_LOG environment variable.
-  -h, --help         Print help
+      --bind <BIND>
+          address and port to bind to [default: 0.0.0.0:2342]
+  -f, --font <FONT>
+          The name of the font family to use. This defaults to the system monospace font.
+  -s, --spacers
+          add spacers between tile rows to simulate gaps in real display
+  -r, --red
+          Use the red color channel
+  -g, --green
+          Use the green color channel
+  -b, --blue
+          Use the blue color channel
+  -v, --verbose
+          Set default log level lower. You can also change this via the RUST_LOG environment variable.
+      --experimental-null-char-handling
+          When receiving a null byte as a char in the CharGridCommand, do not overwrite any pixels instead of clearing all pixels.
+  -h, --help
+          Print help
 ```
 
 See [env_logger](https://docs.rs/env_logger/latest/env_logger/) to configure logging.

flake.nix

@@ -75,6 +75,7 @@
             NIX_LD_LIBRARY_PATH = LD_LIBRARY_PATH;
             NIX_LD = pkgs.stdenv.cc.bintools.dynamicLinker;
             RUST_SRC_PATH = "${pkgs.rust.packages.stable.rustPlatform.rustLibSrc}";
+            RUST_BACKTRACE = "1";
           };
         }
       );

src/cli.rs

@@ -22,6 +22,11 @@ pub struct Cli {
         help = "Set default log level lower. You can also change this via the RUST_LOG environment variable."
     )]
     pub verbose: bool,
+    #[arg(
+        long,
+        help = "When receiving a null byte as a char in the CharGridCommand, do not overwrite any pixels instead of clearing all pixels."
+    )]
+    pub experimental_null_char_handling: bool,
 }
 
 #[derive(Parser, Debug)]

src/command_executor.rs

@@ -5,10 +5,11 @@ use crate::{
 };
 use log::{debug, error, info, trace, warn};
 use servicepoint::{
-    BinaryOperation, BitVecCommand, Bitmap, BitmapCommand, GlobalBrightnessCommand,
-    BrightnessGrid, BrightnessGridCommand, CharGridCommand, ClearCommand,
-    CompressionCode, Cp437GridCommand, FadeOutCommand, Grid, HardResetCommand,
-    Origin, TypedCommand, PIXEL_COUNT, PIXEL_WIDTH, TILE_SIZE,
+    BinaryOperation, BitVecCommand, Bitmap, BitmapCommand, BrightnessGrid,
+    BrightnessGridCommand, CharGridCommand, ClearCommand, CompressionCode,
+    Cp437GridCommand, FadeOutCommand, GlobalBrightnessCommand, Grid, GridMut,
+    HardResetCommand, Origin, TypedCommand, PIXEL_COUNT, PIXEL_WIDTH,
+    TILE_SIZE,
 };
 use std::{
     ops::{BitAnd, BitOr, BitXor},
@@ -21,6 +22,7 @@ pub struct CommandExecutionContext<'t> {
     luma: &'t RwLock<BrightnessGrid>,
     cp437_font: Cp437Font,
     font_renderer: FontRenderer8x8,
+    experimental_null_char_handling: bool,
 }
 
 #[must_use]
@@ -192,16 +194,30 @@ impl CommandExecute for CharGridCommand {
         for char_y in 0usize..grid.height() {
             for char_x in 0usize..grid.width() {
                 let char = grid.get(char_x, char_y);
+                let mut bitmap_window = {
+                    let pixel_x = (char_x + x) * TILE_SIZE;
+                    let pixel_y = (char_y + y) * TILE_SIZE;
+                    display
+                        .window_mut(
+                            pixel_x..pixel_x + TILE_SIZE,
+                            pixel_y..pixel_y + TILE_SIZE,
+                        )
+                        .unwrap()
+                };
+
+                if char == '\0' {
+                    if context.experimental_null_char_handling {
+                        trace!("skipping {char:?}");
+                    } else {
+                        bitmap_window.fill(false);
+                    }
+                    continue;
+                }
+
                 trace!("drawing {char}");
-
-                let tile_x = char_x + x;
-                let tile_y = char_y + y;
-
-                if let Err(e) = context.font_renderer.render(
-                    char,
-                    &mut display,
-                    Origin::new(tile_x * TILE_SIZE, tile_y * TILE_SIZE),
-                ) {
+                if let Err(e) =
+                    context.font_renderer.render(char, &mut bitmap_window)
+                {
                     error!(
                         "stopping drawing text because char draw failed: {e}"
                     );
@@ -251,12 +267,14 @@ impl<'t> CommandExecutionContext<'t> {
         display: &'t RwLock<Bitmap>,
         luma: &'t RwLock<BrightnessGrid>,
         font_renderer: FontRenderer8x8,
+        experimental_null_char_handling: bool,
     ) -> Self {
         CommandExecutionContext {
             display,
             luma,
             font_renderer,
             cp437_font: Cp437Font::default(),
+            experimental_null_char_handling,
         }
     }
 }

src/font_renderer.rs

@@ -12,8 +12,11 @@ use pathfinder_geometry::{
     transform2d::Transform2F,
     vector::{vec2f, vec2i},
 };
-use servicepoint::{Bitmap, Grid, Origin, Pixels, TILE_SIZE};
-use std::sync::{Mutex, MutexGuard};
+use servicepoint::{Bitmap, GridMut, WindowMut, TILE_SIZE};
+use std::{
+    collections::HashMap,
+    sync::{Mutex, MutexGuard},
+};
 
 #[derive(Debug)]
 struct SendFont(Font);
@@ -32,6 +35,7 @@ pub struct FontRenderer8x8 {
     font: SendFont,
     canvas: Mutex<Canvas>,
     fallback_char: Option<u32>,
+    cache: Mutex<HashMap<char, Bitmap>>,
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -56,6 +60,7 @@ impl FontRenderer8x8 {
             font: SendFont(font),
             fallback_char,
             canvas: Mutex::new(canvas),
+            cache: Mutex::new(HashMap::new()),
         }
     }
 
@@ -74,9 +79,13 @@ impl FontRenderer8x8 {
     pub fn render(
         &self,
         char: char,
-        bitmap: &mut Bitmap,
-        offset: Origin<Pixels>,
+        target: &mut WindowMut<bool, Bitmap>,
     ) -> Result<(), RenderError> {
+        let cache = &mut *self.cache.lock().unwrap();
+        if let Some(drawn_char) = cache.get(&char) {
+            target.deref_assign(drawn_char);
+        }
+
         let glyph_id = self.get_glyph(char)?;
 
         let mut canvas = self.canvas.lock().unwrap();
@@ -91,20 +100,21 @@ impl FontRenderer8x8 {
             RasterizationOptions::Bilevel,
         )?;
 
-        Self::copy_to_bitmap(canvas, bitmap, offset)
+        let mut bitmap = Bitmap::new(TILE_SIZE, TILE_SIZE).unwrap();
+        Self::copy_to_bitmap(canvas, &mut bitmap)?;
+        target.deref_assign(&bitmap);
+        cache.insert(char, bitmap);
+        Ok(())
     }
 
     fn copy_to_bitmap(
         canvas: MutexGuard<Canvas>,
         bitmap: &mut Bitmap,
-        offset: Origin<Pixels>,
     ) -> Result<(), RenderError> {
         for y in 0..TILE_SIZE {
             for x in 0..TILE_SIZE {
                 let canvas_val = canvas.pixels[x + y * TILE_SIZE] != 0;
-                let bitmap_x = offset.x + x;
-                let bitmap_y = offset.y + y;
-                if !bitmap.set_optional(bitmap_x, bitmap_y, canvas_val) {
+                if !bitmap.set_optional(x, y, canvas_val) {
                     return Err(OutOfBounds(x, y));
                 }
             }

src/gui.rs

@@ -24,6 +24,7 @@ const PIXEL_HEIGHT_WITH_SPACERS: usize =
     PIXEL_HEIGHT + NUM_SPACERS * SPACER_HEIGHT;
 
 const OFF_COLOR: u32 = u32::from_ne_bytes([0u8, 0, 0, 0]);
+const SPACER_COLOR: u32 = u32::from_ne_bytes([100u8, 100, 100, 0]);
 
 #[derive(Debug)]
 pub enum AppEvents {
@@ -61,7 +62,7 @@ impl<'t> Gui<'t> {
             if self.options.spacers && tile_y != 0 {
                 // cannot just frame.skip(PIXEL_WIDTH as usize * SPACER_HEIGHT as usize) because of typing
                 for _ in 0..PIXEL_WIDTH * SPACER_HEIGHT {
-                    frame.next().unwrap();
+                    *frame.next().unwrap() = SPACER_COLOR;
                 }
             }
 

src/main.rs

@@ -39,7 +39,12 @@ fn main() {
         .font
         .map(FontRenderer8x8::from_name)
         .unwrap_or_else(FontRenderer8x8::default);
-    let context = CommandExecutionContext::new(&display, &luma, font_renderer);
+    let context = CommandExecutionContext::new(
+        &display,
+        &luma,
+        font_renderer,
+        cli.experimental_null_char_handling,
+    );
     let mut udp_server = UdpServer::new(
         cli.bind,
         stop_udp_rx,