Wrote more doc comments

src/lib.rs

@@ -64,12 +64,20 @@ pub struct DoubleFrame<PartialWindow> {
     partial_window: PartialWindow,
 }
 
+/// The colour of a given pixel.
+/// 
+/// Since the GDEQ031T10 is pure black-and-white (no greyscale), this is just a two-state enum.S
 pub enum PixelColour {
     Black = 0,
     White = 1,
 }
 
+/// A trait for partial window strategies for use with [DoubleFrame].
+/// 
+/// This trait is sealed, so the only strategies available are [NoPartialWindow]
+/// and [AutomaticPartialWindow].
 pub trait ApplyPartialWindow: private::Sealed {
+    /// Applies the given window to the display so that its next update will only refresh part of the display.
     fn apply<
         BusyPin: InputPin,
         ResetPin: OutputPin,
@@ -81,8 +89,13 @@ pub trait ApplyPartialWindow: private::Sealed {
         display: &mut EPaperDisplay<BusyPin, ResetPin, DcPin, Spi, Delay>,
     );
 
+    /// Add a new bounding box which must be covered by the partial window.
+    /// 
+    /// Calls to this method accumulate, meaning all bounding boxes will be covered by the
+    /// partial window until [ApplyPartialWindow::reset_partial_window] is called.
     fn update_partial_window(&mut self, min_x: u16, max_x: u16, min_y: u16, max_y: u16);
 
+    /// Resets the partial window to be empty.
     fn reset_partial_window(&mut self);
 }
 
@@ -94,6 +107,8 @@ mod private {
     impl Sealed for super::AutomaticPartialWindow {}
 }
 
+/// A partial window strategy which doesn't do any window tracking and simply updates
+/// the entire display.
 pub struct NoPartialWindow;
 
 impl ApplyPartialWindow for NoPartialWindow {
@@ -114,6 +129,8 @@ impl ApplyPartialWindow for NoPartialWindow {
     fn reset_partial_window(&mut self) {}
 }
 
+/// A partial window strategy which tracks the bounding box of all changes made to the display
+/// since the last display update and only updates that region.
 pub struct AutomaticPartialWindow {
     min_x: u16,
     max_x: u16,
@@ -301,10 +318,12 @@ impl<BusyPin: InputPin, ResetPin: OutputPin, DcPin: OutputPin, Spi: SpiDevice, D
         self.write_data(0xA5);
     }
 
+    /// Enables partial updates based on whichever strategy was chosen at time of display initialisation.
     pub fn enable_partial_mode(&mut self) {
         self.write_command(0x91);
     }
 
+    /// Disable partial updates; all updates will refresh the entire display.
     pub fn disable_partial_mode(&mut self) {
         self.write_command(0x92);
     }