fix

src/components/Canvas.vue

@@ -38,16 +38,23 @@ const render = () => {
   var rotationDelta = imageHeightPx / Math.tan(vRotation / 180 * Math.PI);
 
   if (ctx.value) {
+    var x = 0;
     var y = 0;
-    for (let i = 0; i < 100; i++) {
+
+    let i = 0;
+    while (y < imageHeightPx) {
       y += hMargins[i % 2] * ONE_MM;
       ctx.value.moveTo(0, y);
       ctx.value.lineTo(imageWidthPx, y);
       ctx.value.stroke();
+      i++;
     }
 
-    for (let i = 1; i < 100; i++) {
-      const x = i * vMarginPx;
+    x = 0;
+    y = 0;
+    i = 0;
+    while (x - rotationDelta < imageWidthPx) {
+      x = i * vMarginPx;
       var x0 = x;
       var y0 = 0;
       var x1 = x - rotationDelta;
@@ -55,6 +62,7 @@ const render = () => {
       ctx.value.moveTo(x0, y0);
       ctx.value.lineTo(x1, y1);
       ctx.value.stroke();
+      i++;
     }
   }
 };