fix #2: Crash when drawing zero sized line

platform/Cargo.lock

@@ -79,9 +79,9 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "chumsky"
-version = "0.5.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2d3efff85e8572b1c3fa0127706af58c4fff8458f8d9436d54b1e97573c7a3f"
+checksum = "8d02796e4586c6c41aeb68eae9bfb4558a522c35f1430c14b40136c3706e09e4"
 dependencies = [
  "ahash 0.3.8",
 ]
@@ -146,14 +146,14 @@ checksum = "7a81dae078cea95a014a339291cec439d2f232ebe854a9d672b796c6afafa9b7"
 [[package]]
 name = "curlywas"
 version = "0.1.0"
-source = "git+https://github.com/exoticorn/curlywas.git?rev=196719b#196719b35ef377cb7e001554b27ac5de013dcf2b"
+source = "git+https://github.com/exoticorn/curlywas.git?rev=89638565#896385654ab2c089200920b6dea4abec641c88d6"
 dependencies = [
  "anyhow",
  "ariadne",
  "chumsky",
  "pico-args",
- "wasm-encoder",
+ "wasm-encoder 0.10.0",
- "wasmparser",
+ "wasmparser 0.83.0",
 ]
 
 [[package]]
@@ -197,6 +197,21 @@ dependencies = [
  "ahash 0.7.6",
 ]
 
+[[package]]
+name = "heck"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
+dependencies = [
+ "unicode-segmentation",
+]
+
+[[package]]
+name = "id-arena"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25a2bc672d1148e28034f176e01fffebb08b35768468cc954630da77a1449005"
+
 [[package]]
 name = "lazy_static"
 version = "1.4.0"
@@ -227,6 +242,15 @@ dependencies = [
  "rgb",
 ]
 
+[[package]]
+name = "log"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51b9bbe6c47d51fc3e1a9b945965946b4c44142ab8792c50835a980d362c2710"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "miniz_oxide"
 version = "0.4.4"
@@ -286,6 +310,24 @@ version = "0.5.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "864d3e96a899863136fc6e99f3d7cae289dafe43bf2c5ac19b70df7210c0a145"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "rgb"
 version = "0.8.31"
@@ -304,6 +346,17 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "syn"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
 [[package]]
 name = "time"
 version = "0.1.43"
@@ -323,6 +376,18 @@ dependencies = [
  "crunchy",
 ]
 
+[[package]]
+name = "unicode-segmentation"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e8820f5d777f6224dc4be3632222971ac30164d4a258d595640799554ebfd99"
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+
 [[package]]
 name = "upkr"
 version = "0.1.0"
@@ -342,8 +407,9 @@ dependencies = [
  "pbr",
  "pico-args",
  "upkr",
- "wasm-encoder",
+ "walrus",
- "wasmparser",
+ "wasm-encoder 0.8.0",
+ "wasmparser 0.81.0",
 ]
 
 [[package]]
@@ -352,6 +418,32 @@ version = "0.9.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5fecdca9a5291cc2b8dcf7dc02453fee791a280f3743cb0905f8822ae463b3fe"
 
+[[package]]
+name = "walrus"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4eb08e48cde54c05f363d984bb54ce374f49e242def9468d2e1b6c2372d291f8"
+dependencies = [
+ "anyhow",
+ "id-arena",
+ "leb128",
+ "log",
+ "walrus-macro",
+ "wasmparser 0.77.0",
+]
+
+[[package]]
+name = "walrus-macro"
+version = "0.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0a6e5bd22c71e77d60140b0bd5be56155a37e5bd14e24f5f87298040d0cc40d7"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"
@@ -367,12 +459,33 @@ dependencies = [
  "leb128",
 ]
 
+[[package]]
+name = "wasm-encoder"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "aa9d9bf45fc46f71c407837c9b30b1e874197f2dc357588430b21e5017d290ab"
+dependencies = [
+ "leb128",
+]
+
+[[package]]
+name = "wasmparser"
+version = "0.77.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b35c86d22e720a07d954ebbed772d01180501afe7d03d464f413bb5f8914a8d6"
+
 [[package]]
 name = "wasmparser"
 version = "0.81.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "98930446519f63d00a836efdc22f67766ceae8dbcc1571379f2bcabc6b2b9abc"
 
+[[package]]
+name = "wasmparser"
+version = "0.83.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "718ed7c55c2add6548cca3ddd6383d738cd73b892df400e96b9aa876f0141d7a"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

platform/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-curlywas = { git="https://github.com/exoticorn/curlywas.git", rev="196719b" }
+curlywas = { git="https://github.com/exoticorn/curlywas.git", rev="89638565" }
 uw8-tool = { path="../uw8-tool" }
 anyhow = "1"
 lodepng = "3.4"

platform/src/main.rs

@@ -12,15 +12,15 @@ fn main() -> Result<()> {
 
     println!("Compiling loader module");
     let loader = curlywas::compile_file("src/loader.cwa", curlywas::Options::default())?;
-    File::create("bin/loader.wasm")?.write_all(&loader)?;
+    File::create("bin/loader.wasm")?.write_all(&loader.wasm)?;
 
-    println!("Loader (including base module): {} bytes", loader.len());
+    println!("Loader (including base module): {} bytes", loader.wasm.len());
 
     println!("Compiling platform module");
     let platform = curlywas::compile_file("src/platform.cwa", curlywas::Options::default())?;
     println!("Compressing platform module");
     let platform = uw8_tool::pack(
-        &platform,
+        &platform.wasm,
         &uw8_tool::PackConfig::default().with_compression_level(4),
     )?;
     File::create("bin/platform.uw8")?.write_all(&platform)?;

platform/src/platform.cwa

@@ -256,6 +256,11 @@ export fn line(x1: f32, y1: f32, x2: f32, y2: f32, col: i32) {
         p = y1;
     }
 
+    if max_axis == 0 as f32 {
+        setPixel(x1 as i32, y1 as i32, col);
+        return;
+    }
+
     let steps = floor(p + max_axis) as i32 - floor(p) as i32;
     p = floor(p) + 0.5 - p;
     if max_axis < 0 as f32 {
@@ -267,7 +272,7 @@ export fn line(x1: f32, y1: f32, x2: f32, y2: f32, col: i32) {
     dy = dy / max_axis;
 
     let f = min(max_axis, max(0 as f32, p));
-    setPixel((x1 + f * dx) as i32, (y1 + f * dy) as i32, col);
+    setPixel(i32.trunc_sat_f32_s(x1 + f * dx), i32.trunc_sat_f32_s(y1 + f * dy), col);
 
     if !steps {
         return;
@@ -280,7 +285,7 @@ export fn line(x1: f32, y1: f32, x2: f32, y2: f32, col: i32) {
 
     loop pixels {
         if steps := steps - 1 {
-            setPixel(x1 as i32, y1 as i32, col);
+            setPixel(i32.trunc_sat_f32_s(x1), i32.trunc_sat_f32_s(y1), col);
             x1 = x1 + dx;
             y1 = y1 + dy;
             branch pixels;
@@ -288,7 +293,7 @@ export fn line(x1: f32, y1: f32, x2: f32, y2: f32, col: i32) {
     }
 
     f = min(max_axis, p) - p;
-    setPixel((x1 + f * dx) as i32, (y1 + f * dy) as i32, col);
+    setPixel(i32.trunc_sat_f32_s(x1 + f * dx), i32.trunc_sat_f32_s(y1 + f * dy), col);
 }
 
 //////////