refact: macos, comments, resolution list (rustdesk#11830)

Signed-off-by: fufesou <linlong1266@gmail.com>

Author: fufesou

src/platform/macos.mm

@@ -240,6 +240,13 @@ static bool setDisplayToMode(CGDirectDisplayID display, CGDisplayModeRef mode) {
     return true;
 }
 
+// Set the display to a specific mode based on width and height.
+// Returns true if the display mode was successfully changed, false otherwise.
+// If no such mode is available, it will not change the display mode.
+//
+// If `tryHiDPI` is true, it will try to set the display to a HiDPI mode if available.
+// If no HiDPI mode is available, it will fall back to a non-HiDPI mode with the same resolution.
+// If `tryHiDPI` is false, it sets the display to the first mode with the same resolution, no matter if it's HiDPI or not.
 extern "C" bool MacSetMode(CGDirectDisplayID display, uint32_t width, uint32_t height, bool tryHiDPI)
 {
     bool ret = false;

src/platform/macos.rs

@@ -890,6 +890,17 @@ pub fn handle_application_should_open_untitled_file() {
     }
 }
 
+/// Get all resolutions of the display. The resolutions are:
+/// 1. Sorted by width and height in descending order, with duplicates removed.
+/// 2. Filtered out if the width is less than 800 (800x600) if there are too many (e.g., >15).
+/// 3. Contain HiDPI resolutions and the real resolutions.
+///
+/// We don't need to distinguish between HiDPI and real resolutions.
+/// When the controlling side changes the resolution, it will call `change_resolution_directly()`.
+/// `change_resolution_directly()` will try to use the HiDPI resolution first.
+/// This is how teamviewer does it for now.
+///
+/// If we need to distinguish HiDPI and real resolutions, we can add a flag to the `Resolution` struct.
 pub fn resolutions(name: &str) -> Vec<Resolution> {
     let mut v = vec![];
     if let Ok(display) = name.parse::<u32>() {