text from rust

front/index.js

@@ -1,34 +1,55 @@
+var ctx;
+var image;
+var memory;
+const width = 256;
+const height = 224;
+
+function blit_frame() {
+    ctx.putImageData(image, 0, 0);
+}
+
+function blit_text(text, len, x, y, size) {
+    let decoded = (new TextDecoder())
+        .decode(new Uint8Array(memory.buffer, text, len));
+    ctx.font = size +'vh serif'
+    ctx.fillText(decoded,x,y);
+}
+
 async function init() {
-    const { instance } = await WebAssembly.instantiateStreaming(
-        fetch("./index.wasm")
-    );
-
-    const width = 600;
-    const height = 600;
-
     const canvas = document.getElementById("window");
     canvas.width = width;
     canvas.height = height;
 
+    ctx = canvas.getContext("2d");
+
+    const { instance } = await WebAssembly.instantiateStreaming(
+        fetch("./index.wasm"),
+        {
+            "env" : {
+                "js_sin": Math.sin,
+                "blit_frame": blit_frame,
+                "blit_text": blit_text,
+            },
+        }
+    );
+
+    memory = instance.exports.memory
     const buffer_address = instance.exports.BUFFER.value;
-    const image = new ImageData(
+    image = new ImageData(
         new Uint8ClampedArray(
-            instance.exports.memory.buffer,
+            memory.buffer,
             buffer_address,
             4 * width * height,
         ),
         width,
     );
 
-    const ctx = canvas.getContext("2d");
+    instance.exports.frame_entry();
+    ctx.textBaseline = 'top'
+    ctx.textAlign = 'left';
 
     const render = () => {
         instance.exports.frame_entry();
-        ctx.putImageData(image, 0, 0);
-        ctx.font = '84px sans-serif'
-        ctx.textBaseline = 'top'
-        ctx.textAlign = 'left';
-        ctx.fillText("demo",12,12);
 
         requestAnimationFrame(render);
     }

justfile

@@ -7,10 +7,11 @@ build: minify-js minify-rust minify-html
 
 build-rust:
     cargo build --manifest-path pirates/Cargo.toml --target wasm32-unknown-unknown --release
+    cp pirates/target/wasm32-unknown-unknown/release/pirates.wasm front/index.wasm
 
 minify-rust: build-rust build-dir
-    wasm-strip pirates/target/wasm32-unknown-unknown/release/pirates.wasm
+    wasm-strip front/index.wasm
-    wasm-opt -o build/index.wasm -Oz pirates/target/wasm32-unknown-unknown/release/pirates.wasm
+    wasm-opt -o build/index.wasm -Oz front/index.wasm
    
 minify-js: build-dir
     #minify-js -m module --output build/index.js front/index.js
@@ -29,7 +30,7 @@ check-size: build
 check-zip: zip
     unzip -v build/release.zip | awk '{printf ("%5s\t%s\n", $3,  $8)}'
 
-    @cat build/release.zip | wc -c | xargs -I {} python3 -c "print(str(round({}/(13*1024),2))+'%')"
+    @cat build/release.zip | wc -c | xargs -I {} python3 -c "print(str(round({}/(13*1024)*100,2))+'%')"
 
 zip: build
     zip -r build/release.zip build -x release.zip

pirates/src/lib.rs

@@ -7,8 +7,22 @@ fn handle_panic(_: &core::panic::PanicInfo) -> ! {
     loop {}
 }
 
-const WIDTH: usize = 600;
+extern {
-const HEIGHT: usize = 600;
+    fn blit_frame();
+    fn blit_text(text: *const u8, len: u32, x: i32, y: i32, size: u8);
+}
+
+fn draw_text(text: &str, x: i32, y: i32, size: u8) {
+    unsafe {
+        blit_text(
+            (*text).as_ptr(),
+            text.len() as u32,
+            x, y, size)
+    }
+}
+
+const WIDTH: usize = 256;
+const HEIGHT: usize = 224;
 
 #[no_mangle]
 static mut BUFFER: [u32; WIDTH * HEIGHT] = [0; WIDTH * HEIGHT];
@@ -28,6 +42,9 @@ fn render_frame(buffer: &mut [u32; WIDTH*HEIGHT]) {
             buffer[y*WIDTH + x] = frame.wrapping_add((x^y) as u32) | 0xFF000000;
         }
     }
+    unsafe { blit_frame(); }
+
+    draw_text("hi from rust", 0,100,1);
 }
 
 #[cfg(test)]