Various improvements (#25)

- Added is_busy to Waveshare_Interface
- Added IS_BUSY_LOW const for all supported epds
- Added is_busy to DisplayInterface
- moved width, height and default_background_color directly to epd4in2 module
- Added VarDisplay (a variable buffersize display/graphic driver)
- Removed all Buffers (Buffer1in54,...) and instead made specialised Displays (Display1in54,...) with included Buffers
- Updated and added more examples
- Cargo fmt/clippy
- Improved Docs/Readmes

src/epd4in2/constants.rs

@@ -1,9 +1,3 @@
-use crate::color::Color;
-
-pub const WIDTH: u32 = 400;
-pub const HEIGHT: u32 = 300;
-pub const DEFAULT_BACKGROUND_COLOR: Color = Color::White;
-
 #[rustfmt::skip]
 pub(crate) const LUT_VCOM0: [u8; 44] = [
 0x00, 0x17, 0x00, 0x00, 0x00, 0x02,        

src/epd4in2/graphics.rs

@@ -1,22 +1,54 @@
-use crate::epd4in2::constants::{DEFAULT_BACKGROUND_COLOR, HEIGHT, WIDTH};
+use crate::epd4in2::{DEFAULT_BACKGROUND_COLOR, HEIGHT, WIDTH};
+use crate::graphics::{Display, DisplayRotation};
+use crate::prelude::*;
+use embedded_graphics::prelude::*;
 
 /// Full size buffer for use with the 4in2 EPD
 ///
 /// Can also be manuall constructed:
 /// `buffer: [DEFAULT_BACKGROUND_COLOR.get_byte_value(); WIDTH / 8 * HEIGHT]`
-pub struct Buffer4in2 {
-    pub buffer: [u8; WIDTH as usize * HEIGHT as usize / 8],
+pub struct Display4in2 {
+    buffer: [u8; WIDTH as usize * HEIGHT as usize / 8],
+    rotation: DisplayRotation,
 }
 
-impl Default for Buffer4in2 {
+impl Default for Display4in2 {
     fn default() -> Self {
-        Buffer4in2 {
+        Display4in2 {
             buffer: [DEFAULT_BACKGROUND_COLOR.get_byte_value();
                 WIDTH as usize * HEIGHT as usize / 8],
+            rotation: DisplayRotation::default(),
         }
     }
 }
 
+impl Drawing<Color> for Display4in2 {
+    fn draw<T>(&mut self, item_pixels: T)
+    where
+        T: Iterator<Item = Pixel<Color>>,
+    {
+        self.draw_helper(WIDTH, HEIGHT, item_pixels);
+    }
+}
+
+impl Display for Display4in2 {
+    fn buffer(&self) -> &[u8] {
+        &self.buffer
+    }
+
+    fn get_mut_buffer(&mut self) -> &mut [u8] {
+        &mut self.buffer
+    }
+
+    fn set_rotation(&mut self, rotation: DisplayRotation) {
+        self.rotation = rotation;
+    }
+
+    fn rotation(&self) -> DisplayRotation {
+        self.rotation
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -24,35 +56,27 @@ mod tests {
     use crate::epd4in2;
     use crate::graphics::{Display, DisplayRotation};
     use embedded_graphics::coord::Coord;
-    use embedded_graphics::prelude::*;
     use embedded_graphics::primitives::Line;
 
     // test buffer length
     #[test]
     fn graphics_size() {
-        let mut display4in2 = Buffer4in2::default();
-        let display = Display::new(WIDTH, HEIGHT, &mut display4in2.buffer);
+        let display = Display4in2::default();
         assert_eq!(display.buffer().len(), 15000);
     }
 
     // test default background color on all bytes
     #[test]
     fn graphics_default() {
-        let mut display4in2 = Buffer4in2::default();
-        let display = Display::new(WIDTH, HEIGHT, &mut display4in2.buffer);
-        use crate::epd4in2;
+        let display = Display4in2::default();
         for &byte in display.buffer() {
-            assert_eq!(
-                byte,
-                epd4in2::constants::DEFAULT_BACKGROUND_COLOR.get_byte_value()
-            );
+            assert_eq!(byte, epd4in2::DEFAULT_BACKGROUND_COLOR.get_byte_value());
         }
     }
 
     #[test]
     fn graphics_rotation_0() {
-        let mut display4in2 = Buffer4in2::default();
-        let mut display = Display::new(WIDTH, HEIGHT, &mut display4in2.buffer);
+        let mut display = Display4in2::default();
         display.draw(
             Line::new(Coord::new(0, 0), Coord::new(7, 0))
                 .with_stroke(Some(Color::Black))
@@ -64,17 +88,13 @@ mod tests {
         assert_eq!(buffer[0], Color::Black.get_byte_value());
 
         for &byte in buffer.iter().skip(1) {
-            assert_eq!(
-                byte,
-                epd4in2::constants::DEFAULT_BACKGROUND_COLOR.get_byte_value()
-            );
+            assert_eq!(byte, epd4in2::DEFAULT_BACKGROUND_COLOR.get_byte_value());
         }
     }
 
     #[test]
     fn graphics_rotation_90() {
-        let mut display4in2 = Buffer4in2::default();
-        let mut display = Display::new(WIDTH, HEIGHT, &mut display4in2.buffer);
+        let mut display = Display4in2::default();
         display.set_rotation(DisplayRotation::Rotate90);
         display.draw(
             Line::new(Coord::new(0, 392), Coord::new(0, 399))
@@ -87,17 +107,13 @@ mod tests {
         assert_eq!(buffer[0], Color::Black.get_byte_value());
 
         for &byte in buffer.iter().skip(1) {
-            assert_eq!(
-                byte,
-                epd4in2::constants::DEFAULT_BACKGROUND_COLOR.get_byte_value()
-            );
+            assert_eq!(byte, epd4in2::DEFAULT_BACKGROUND_COLOR.get_byte_value());
         }
     }
 
     #[test]
     fn graphics_rotation_180() {
-        let mut display4in2 = Buffer4in2::default();
-        let mut display = Display::new(WIDTH, HEIGHT, &mut display4in2.buffer);
+        let mut display = Display4in2::default();
         display.set_rotation(DisplayRotation::Rotate180);
         display.draw(
             Line::new(Coord::new(392, 299), Coord::new(399, 299))
@@ -113,17 +129,13 @@ mod tests {
         assert_eq!(buffer[0], Color::Black.get_byte_value());
 
         for &byte in buffer.iter().skip(1) {
-            assert_eq!(
-                byte,
-                epd4in2::constants::DEFAULT_BACKGROUND_COLOR.get_byte_value()
-            );
+            assert_eq!(byte, epd4in2::DEFAULT_BACKGROUND_COLOR.get_byte_value());
         }
     }
 
     #[test]
     fn graphics_rotation_270() {
-        let mut display4in2 = Buffer4in2::default();
-        let mut display = Display::new(WIDTH, HEIGHT, &mut display4in2.buffer);
+        let mut display = Display4in2::default();
         display.set_rotation(DisplayRotation::Rotate270);
         display.draw(
             Line::new(Coord::new(299, 0), Coord::new(299, 7))
@@ -139,10 +151,7 @@ mod tests {
         assert_eq!(buffer[0], Color::Black.get_byte_value());
 
         for &byte in buffer.iter().skip(1) {
-            assert_eq!(
-                byte,
-                epd4in2::constants::DEFAULT_BACKGROUND_COLOR.get_byte_value()
-            );
+            assert_eq!(byte, epd4in2::DEFAULT_BACKGROUND_COLOR.get_byte_value());
         }
     }
 }

src/epd4in2/mod.rs

@@ -56,15 +56,22 @@ use crate::traits::{InternalWiAdditions, RefreshLUT, WaveshareDisplay};
 
 //The Lookup Tables for the Display
 mod constants;
-pub use self::constants::*;
+use crate::epd4in2::constants::*;
+
+pub const WIDTH: u32 = 400;
+pub const HEIGHT: u32 = 300;
+pub const DEFAULT_BACKGROUND_COLOR: Color = Color::White;
+const IS_BUSY_LOW: bool = true;
 
 use crate::color::Color;
 
 pub(crate) mod command;
 use self::command::Command;
 
+#[cfg(feature = "graphics")]
 mod graphics;
-pub use self::graphics::Buffer4in2;
+#[cfg(feature = "graphics")]
+pub use self::graphics::Display4in2;
 
 /// EPD4in2 driver
 ///
@@ -322,6 +329,10 @@ where
             ),
         }
     }
+
+    fn is_busy(&self) -> bool {
+        self.interface.is_busy(IS_BUSY_LOW)
+    }
 }
 
 impl<SPI, CS, BUSY, DC, RST> EPD4in2<SPI, CS, BUSY, DC, RST>
@@ -350,7 +361,7 @@ where
     }
 
     fn wait_until_idle(&mut self) {
-        self.interface.wait_until_idle(true)
+        self.interface.wait_until_idle(IS_BUSY_LOW)
     }
 
     fn send_resolution(&mut self, spi: &mut SPI) -> Result<(), SPI::Error> {