Add EPD 4in2bc support

Author: yurinnick

src/color.rs

@@ -103,6 +103,7 @@ impl ColorType for Color {
 impl ColorType for TriColor {
     const BITS_PER_PIXEL_PER_BUFFER: usize = 1;
     const BUFFER_COUNT: usize = 2;
+
     fn bitmask(&self, bwrbit: bool, pos: u32) -> (u8, u16) {
         let bit = 0x80 >> (pos % 8);
         match self {
@@ -307,16 +308,16 @@ impl From<BinaryColor> for Color {
 impl From<embedded_graphics_core::pixelcolor::Rgb888> for Color {
     fn from(rgb: embedded_graphics_core::pixelcolor::Rgb888) -> Self {
         use embedded_graphics_core::pixelcolor::RgbColor;
-        if rgb == RgbColor::BLACK {
-            Color::Black
-        } else if rgb == RgbColor::WHITE {
-            Color::White
-        } else {
-            // choose closest color
-            if (rgb.r() as u16 + rgb.g() as u16 + rgb.b() as u16) > 255 * 3 / 2 {
-                Color::White
-            } else {
-                Color::Black
+        match rgb {
+            RgbColor::BLACK => Color::Black,
+            RgbColor::WHITE => Color::White,
+            _ => {
+                // choose closest color
+                if (rgb.r() as u16 + rgb.g() as u16 + rgb.b() as u16) > 255 * 3 / 2 {
+                    Color::White
+                } else {
+                    Color::Black
+                }
             }
         }
     }
@@ -369,13 +370,11 @@ impl From<BinaryColor> for TriColor {
 impl From<embedded_graphics_core::pixelcolor::Rgb888> for TriColor {
     fn from(rgb: embedded_graphics_core::pixelcolor::Rgb888) -> Self {
         use embedded_graphics_core::pixelcolor::RgbColor;
-        if rgb == RgbColor::BLACK {
-            TriColor::Black
-        } else if rgb == RgbColor::WHITE {
-            TriColor::White
-        } else {
+        match rgb {
+            RgbColor::BLACK => TriColor::Black,
+            RgbColor::WHITE => TriColor::White,
             // there is no good approximation here since we don't know which color is 'chromatic'
-            TriColor::Chromatic
+            _ => TriColor::Chromatic,
         }
     }
 }

src/epd4in2/mod.rs

@@ -58,7 +58,7 @@ use crate::interface::DisplayInterface;
 use crate::traits::{InternalWiAdditions, QuickRefresh, RefreshLut, WaveshareDisplay};
 
 //The Lookup Tables for the Display
-mod constants;
+pub(crate) mod constants;
 use crate::epd4in2::constants::*;
 
 /// Width of the display