add line function to platform

platform/src/loader.cwa

@@ -3,7 +3,7 @@ import "env.memory" memory(4);
 global mut base_end: i32 = 0;
 
 export fn load_uw8(module_size: i32) -> i32 {
-    let lazy version = ?0 - 1;
+    let lazy version = 0?0 - 1;
     if version < 0 {
         return module_size;
     }
@@ -21,10 +21,10 @@ export fn load_uw8(module_size: i32) -> i32 {
     let src = 0x1e001;
 
     loop sections {
-        if src < module_end & (base_start >= base_end | ?src <= ?base_start) {
+        if src < module_end & (base_start >= base_end | src?0 <= base_start?0) {
             let lazy length2 = copy_section(dest, src);
             dest = dest + length2;
-            if base_start < base_end & ?src == ?base_start {
+            if base_start < base_end & src?0 == base_start?0 {
                 base_start = base_start + section_size(base_start);
             }
             src = src + length2;
@@ -47,7 +47,7 @@ fn section_size(ptr: i32) -> i32 {
     let l = 0;
     let shift = 0;
     loop size {
-        let lazy b = ?p;
+        let lazy b = p?0;
         l = l | ((b & 127) << shift);
         shift = shift + 7;
         p = p + 1;
@@ -65,7 +65,7 @@ fn copy_section(dest: i32, src: i32) -> i32 {
 fn copy(dest: i32, src: i32, len: i32) {
     if len > 0 {
         loop bytes {
-            ?(dest + (len := len - 1)) = ?(src + len);
+            (dest + (len := len - 1))?0 = (src + len)?0;
             branch_if len: bytes
         }
     }
@@ -142,7 +142,7 @@ fn upkr_bit(context_index: i32) -> i32 {
 
     loop refill {
         if upkr_state < 1<<16 {
-            upkr_state = (upkr_state << 8) | ?upkr_src_ptr;
+            upkr_state = (upkr_state << 8) | upkr_src_ptr?0;
             upkr_src_ptr = upkr_src_ptr + 1;
             branch refill;
         }

platform/src/main.rs

@@ -11,13 +11,13 @@ fn main() -> Result<()> {
     convert_font()?;
 
     println!("Compiling loader module");
-    let loader = curlywas::compile_file("src/loader.cwa")?;
+    let loader = curlywas::compile_file("src/loader.cwa", curlywas::Options::default())?;
     File::create("bin/loader.wasm")?.write_all(&loader)?;
 
     println!("Loader (including base module): {} bytes", loader.len());
 
     println!("Compiling platform module");
-    let platform = curlywas::compile_file("src/platform.cwa")?;
+    let platform = curlywas::compile_file("src/platform.cwa", curlywas::Options::default())?;
     println!("Compressing platform module");
     let platform = uw8_tool::pack(
         &platform,

platform/src/platform.cwa

@@ -135,6 +135,89 @@ export fn circle(cx: f32, cy: f32, radius: f32, col: i32) {
     }
 }
 
+export fn line(x1: f32, y1: f32, x2: f32, y2: f32, col: i32) {
+    let swapTmp: f32;
+    if x1 > x2 {
+        swapTmp = x1;
+        x1 = x2;
+        x2 = swapTmp;
+        swapTmp = y1;
+        y1 = y2;
+        y2 = swapTmp;
+    }
+    if x1 < 0 as f32 & x2 >= 0 as f32 {
+        y1 = y1 + (y2 - y1) * -x1 / (x2 - x1);
+        x1 = 0 as f32;
+    }
+    if x1 < 320 as f32 & x2 >= 320 as f32 {
+        y2 = y2 + (y2 - y1) * (320 as f32 - x2) / (x2 - x1);
+        x2 = 320 as f32;
+    }
+
+    if y1 > y2 {
+        swapTmp = x1;
+        x1 = x2;
+        x2 = swapTmp;
+        swapTmp = y1;
+        y1 = y2;
+        y2 = swapTmp;
+    }
+    if y1 < 0 as f32 & y2 >= 0 as f32 {
+        x1 = x1 + (x2 - x1) * -y1 / (y2 - y1);
+        y1 = 0 as f32;
+    }
+    if y1 < 240 as f32 & y2 >= 240 as f32 {
+        x2 = x2 + (x2 - x1) * (240 as f32 - y2) / (y2 - y1);
+        y2 = 240 as f32;
+    }
+
+    let lazy dx = x2 - x1;
+    let lazy dy = y2 - y1;
+    let max_axis: f32;
+    let p: f32;
+    if abs(dx) >= dy {
+        max_axis = dx;
+        p = x1;
+    } else {
+        max_axis = dy;
+        p = y1;
+    }
+
+    let steps = floor(p + max_axis) as i32 - floor(p) as i32;
+    p = floor(p) + 0.5 - p;
+    if max_axis < 0 as f32 {
+        steps = -steps;
+        p = -p;
+        max_axis = -max_axis;
+    }
+    dx = dx / max_axis;
+    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);
+
+    if !steps {
+        return;
+    }
+
+    x1 = x1 + (1 as f32 + p) * dx;
+    y1 = y1 + (1 as f32 + p) * dy;
+
+    p = p + steps as f32;
+
+    loop pixels {
+        if steps := steps - 1 {
+            setPixel(x1 as i32, y1 as i32, col);
+            x1 = x1 + dx;
+            y1 = y1 + dy;
+            branch pixels;
+        }
+    }
+
+    f = min(max_axis, p) - p;
+    setPixel((x1 + f * dx) as i32, (y1 + f * dy) as i32, col);
+}
+
 //////////
 // TEXT //
 //////////