V210 issue fix + correct packing

internal/generator/cpu_moving_square.go

@@ -45,6 +45,7 @@ func patchMovingSquare(
 	lastBlockX := min(width, (lastPixelX+5)/6*6)
 	firstY := max(0, int(math.Floor(bounds.minY)))
 	lastY := min(height, int(math.Ceil(bounds.maxY)))
+	stride := V210LineSize(width)
 
 	for y := firstY; y < lastY; y++ {
 		for x := firstBlockX; x < lastBlockX; x += 6 {
@@ -57,7 +58,7 @@ func patchMovingSquare(
 				}
 				pixels[i] = color
 			}
-			offset := (y*width + x) / 6 * 16
+			offset := y*stride + x/6*16
 			packV210Block(dst[offset:offset+16], pixels)
 		}
 	}