fix: autosize surface layout

Autosized surfaces perform the layout step to get the size and then again when building the interface, but sometimes the calculated size is not enough space when used as a bound, so we need to add a tiny amount to the calculated size. This also makes the event loop timeout duration configurable. Viewport physical size is calculated directly from the logical size now as well in iced-sctk to avoid inconsistencies that resulted from recalculating the logical size after using it to calculate the physical size.

graphics/src/viewport.rs

@@ -12,6 +12,23 @@ pub struct Viewport {
 }
 
 impl Viewport {
+    /// Creates a new [`Viewport`] with the given logical dimensions and scale factor
+    pub fn with_logical_size(size: Size<f32>, scale_factor: f64) -> Viewport {
+        let physical_size = Size::new(
+            (size.width as f64 * scale_factor).ceil() as u32,
+            (size.height as f64 * scale_factor).ceil() as u32,
+        );
+        Viewport {
+            physical_size,
+            logical_size: size,
+            scale_factor,
+            projection: Transformation::orthographic(
+                physical_size.width,
+                physical_size.height,
+            ),
+        }
+    }
+
     /// Creates a new [`Viewport`] with the given physical dimensions and scale
     /// factor.
     pub fn with_physical_size(size: Size<u32>, scale_factor: f64) -> Viewport {