Implement image_to_cursor to avoid redundant code

diff --git a/src/main.rs b/src/main.rs
index f502a9d47ea87b78b235d63035bd848661d59cc6..6e06fabc7f90c8b124f08ac2df26e9bf8a6a8b66 100644 (file)
--- a/src/main.rs
+++ b/src/main.rs
@@ -223,6 +223,22 @@ fn make_png(dim_x: u32, dim_y: u32, scale: u32, data: &mut dyn Iterator<Item = u
     Ok(cursor)
 }
 
+fn image_to_cursor(img: RgbImage, scale: u32) -> Result<Cursor<Vec<u8>>, ImageError> {
+    let (dim_x, dim_y) = img.dimensions();
+    let (dim_x, dim_y) = (dim_x * scale, dim_y * scale);
+
+    // Image must not be larger than 1 megapixel
+    if dim_x * dim_y > 1048576 {
+        return Err(ImageError::dimension_error())
+    }
+
+    let mut cursor = Cursor::new(Vec::new());
+    let img = resize(&img, dim_x, dim_y, FilterType::Nearest);
+    to_imageresult(write_buffer_with_format(&mut cursor, &img, dim_x, dim_y, ColorType::Rgb8, Png))?;
+    Ok(cursor)
+}
+
+
 #[get("/gen/0/{data}")]
 async fn img_gen0(req: HttpRequest) -> Result<impl Responder> {
     let data = req.uri().path().split("/").skip(3).next().unwrap();
@@ -245,16 +261,12 @@ async fn img_gen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>) -> Result<
 #[get("/pgen/0/{data}")]
 async fn img_pgen0(req: HttpRequest, canvas0: web::Data<Arc<Mutex<Canvas0>>>) -> Result<impl Responder> {
     let data = req.uri().path().split("/").skip(3).next().unwrap();
-    let mut cursor = Cursor::new(Vec::new());
     let scale = 16;
     let img: RgbImage = ({
         let canvas_option = &mut *canvas0.lock().unwrap();
         Ok(apply_to_canvas( |c, d| to_canvasresult(rgb_encode_to_canvas(c, d)), &mut canvas_option.0, None, data)?.img.clone())
     } as Result<RgbImage, CanvasError>)?;
-    let (tdim_x, tdim_y) = img.dimensions();
-    let (tdim_x, tdim_y) = (tdim_x * scale, tdim_y * scale);
-    let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
-    to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
+    let cursor = image_to_cursor(img, scale)?;
     Ok(HttpResponse::build(StatusCode::OK)
        .content_type("image/png")
        .body(cursor.into_inner()))
@@ -268,11 +280,7 @@ async fn img_pgen1(req: HttpRequest, path: web::Path<(u32, u32, u32)>, canvas1:
         let canvas_option = &mut *canvas1.lock().unwrap();
         Ok(apply_to_canvas( |c, d| to_canvasresult(rgb_encode_to_canvas(c, d)), &mut canvas_option.0, Some((dim_x, dim_y)), data)?.img.clone())
     } as Result<RgbImage, CanvasError>)?;
-    let (tdim_x, tdim_y) = img.dimensions();
-    let (tdim_x, tdim_y) = (tdim_x * scale, tdim_y * scale);
-    let img = resize(&img, tdim_x, tdim_y, FilterType::Nearest);
-    let mut cursor = Cursor::new(Vec::new());
-    to_imageresult(write_buffer_with_format(&mut cursor, &img, tdim_x, tdim_y, ColorType::Rgb8, Png))?;
+    let cursor = image_to_cursor(img, scale)?;
     Ok(HttpResponse::build(StatusCode::OK)
        .content_type("image/png")
        .body(cursor.into_inner()))