add macos with_disallow_hidpi

CHANGELOG.md

@@ -2,6 +2,7 @@
 - On macOS, drop the run closure on exit.
 - On Windows, location of `WindowEvent::Touch` are window client coordinates instead of screen coordinates.
 - On X11, fix delayed events after window redraw.
+- On macOS, add `WindowBuilderExt::with_disallow_hidpi` to have the option to turn off best resolution openGL surface.
 
 # 0.20.0 Alpha 2 (2019-07-09)
 

src/platform/macos.rs

@@ -129,6 +129,7 @@ pub trait WindowBuilderExtMacOS {
     fn with_fullsize_content_view(self, fullsize_content_view: bool) -> WindowBuilder;
     /// Build window with `resizeIncrements` property. Values must not be 0.
     fn with_resize_increments(self, increments: LogicalSize) -> WindowBuilder;
+    fn with_disallow_hidpi(self, disallow_hidpi: bool) -> WindowBuilder;
 }
 
 impl WindowBuilderExtMacOS for WindowBuilder {
@@ -182,6 +183,12 @@ impl WindowBuilderExtMacOS for WindowBuilder {
         self.platform_specific.resize_increments = Some(increments.into());
         self
     }
+
+    #[inline]
+    fn with_disallow_hidpi(mut self, disallow_hidpi: bool) -> WindowBuilder {
+        self.platform_specific.disallow_hidpi = disallow_hidpi;
+        self
+    }
 }
 
 /// Additional methods on `MonitorHandle` that are specific to MacOS.

src/platform_impl/macos/window.rs

@@ -66,6 +66,7 @@ pub struct PlatformSpecificWindowBuilderAttributes {
     pub titlebar_buttons_hidden: bool,
     pub fullsize_content_view: bool,
     pub resize_increments: Option<LogicalSize>,
+    pub disallow_hidpi: bool,
 }
 
 fn create_app(activation_policy: ActivationPolicy) -> Option<id> {
@@ -86,10 +87,15 @@ fn create_app(activation_policy: ActivationPolicy) -> Option<id> {
     }
 }
 
-unsafe fn create_view(ns_window: id) -> Option<(IdRef, Weak<Mutex<util::Cursor>>)> {
+unsafe fn create_view(
+    ns_window: id,
+    pl_attribs: &PlatformSpecificWindowBuilderAttributes,
+) -> Option<(IdRef, Weak<Mutex<util::Cursor>>)> {
     let (ns_view, cursor) = new_view(ns_window);
     ns_view.non_nil().map(|ns_view| {
-        ns_view.setWantsBestResolutionOpenGLSurface_(YES);
+        if !pl_attribs.disallow_hidpi {
+            ns_view.setWantsBestResolutionOpenGLSurface_(YES);
+        }
 
         // On Mojave, views automatically become layer-backed shortly after being added to
         // a window. Changing the layer-backedness of a view breaks the association between
@@ -301,10 +307,11 @@ impl UnownedWindow {
             os_error!(OsError::CreationError("Couldn't create `NSWindow`"))
         })?;
 
-        let (ns_view, cursor) = unsafe { create_view(*ns_window) }.ok_or_else(|| {
-            unsafe { pool.drain() };
-            os_error!(OsError::CreationError("Couldn't create `NSView`"))
-        })?;
+        let (ns_view, cursor) =
+            unsafe { create_view(*ns_window, &pl_attribs) }.ok_or_else(|| {
+                unsafe { pool.drain() };
+                os_error!(OsError::CreationError("Couldn't create `NSView`"))
+            })?;
 
         let input_context = unsafe { util::create_input_context(*ns_view) };