added fast partial update to embedded_linux example

examples/embedded_linux/src/main.rs

@@ -111,7 +111,7 @@ fn main() {
     graphics.draw_line(&mut buffer, 0,0,400,300, &Color::Black); 
 
     graphics.draw_filled_rectangle(&mut buffer, 200,200, 230, 230, &Color::Black); 
-    graphics.draw_line(&mut buffer, 200,200,200,230, &Color::White);
+    graphics.draw_line(&mut buffer, 202,202,218,228, &Color::White);
 
     graphics.draw_circle(&mut buffer, 200, 150, 130, &Color::Black);
 
@@ -125,6 +125,28 @@ fn main() {
  
     epd4in2.delay_ms(3000);
 
+    epd4in2.clear_frame(None).expect("clear frame error");
+
+    let mut small_buffer = [0xff; 128];
+    let circle_graphics = Graphics::new(32,32);
+    graphics.draw_circle(&mut small_buffer, 16,16, 10, &Color::Black);
+
+    epd4in2.set_partial_window(&small_buffer, 16,16, 32,32, 2, false);
+    epd4in2.display_frame_quick();
+
+    epd4in2.set_partial_window(&small_buffer, 128,64, 32,32, 2, false);
+    epd4in2.display_frame_quick();
+
+    epd4in2.set_partial_window(&small_buffer, 320,24, 32,32, 2, false);
+    epd4in2.display_frame_quick();
+
+    epd4in2.set_partial_window(&small_buffer, 160,240, 32,32, 2, false);
+    epd4in2.display_frame_quick();
+
+    epd4in2.delay_ms(3000);
+
+    
+
     epd4in2.clear_frame(None).expect("clear frame error");
 
     epd4in2.sleep().expect("sleeping error");

src/epd4in2/mod.rs

@@ -211,6 +211,9 @@ where
     /// Transmit partial data to the SRAM of the EPD,
     /// the final parameter dtm chooses between the 2
     /// internal buffers 
+    /// 
+    /// Normally it should be dtm2, so use false
+    /// 
     /// BUFFER needs to be of size: w / 8 * l !
     pub fn set_partial_window(&mut self, buffer: &[u8], x: u16, y: u16, w: u16, l: u16, is_dtm1: bool) -> Result<(), E> {
         if buffer.len() as u16 != w / 8 * l {