From f30e0b7dc4d7a9e44f940eaaae0c4d5587c46610 Mon Sep 17 00:00:00 2001
From: Zac Wilson <zac@zacjw.com>
Date: Mon, 15 Dec 2025 11:59:07 +0000
Subject: [PATCH] Started writing frame drawing

---
 src/lib.rs | 90 +++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 69 insertions(+), 21 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index b1ef66f..8ef85bb 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -2,12 +2,13 @@
 
 use embedded_hal::{
     delay::DelayNs,
-    digital::{InputPin, OutputPin}, spi::{Operation, SpiDevice},
+    digital::{InputPin, OutputPin},
+    spi::{Operation, SpiDevice},
 };
 
-const EPD_WIDTH: u32 = 240;
-const EPD_HEIGHT: u32 = 320;
-const EPD_ARRAY: u32 = EPD_WIDTH * EPD_HEIGHT / 8;
+const EPD_WIDTH: usize = 240;
+const EPD_HEIGHT: usize = 320;
+const EPD_ARRAY: usize = EPD_WIDTH * EPD_HEIGHT / 8;
 
 pub struct EPaperDisplay<BusyPin, ResetPin, DcPin, SpiDevice, Delay> {
     busy: BusyPin,
@@ -27,13 +28,40 @@ pub enum WriteError<DcError, SpiError> {
     SpiError(SpiError),
 }
 
-impl<
-    BusyPin: InputPin,
-    ResetPin: OutputPin,
-    DcPin: OutputPin,
-    Spi: SpiDevice,
-    Delay: DelayNs,
-> EPaperDisplay<BusyPin, ResetPin, DcPin, Spi, Delay>
+pub struct Frame([u8; EPD_ARRAY]);
+
+impl Frame {
+    pub const fn new_white() -> Self {
+        Self([0xff; EPD_ARRAY])
+    }
+
+    pub const fn new_black() -> Self {
+        Self([0x00; EPD_ARRAY])
+    }
+}
+
+pub struct DoubleFrame {
+    old: Frame,
+    new: Frame,
+}
+
+pub enum PixelColour {
+    Black = 0,
+    White = 1,
+}
+
+impl DoubleFrame {
+    pub fn new(old: Frame, new: Frame) -> Self {
+        Self { old, new }
+    }
+
+    pub fn draw_pixel(&mut self, x: usize, y: usize, colour: PixelColour) {
+
+    }
+}
+
+impl<BusyPin: InputPin, ResetPin: OutputPin, DcPin: OutputPin, Spi: SpiDevice, Delay: DelayNs>
+    EPaperDisplay<BusyPin, ResetPin, DcPin, Spi, Delay>
 {
     pub fn new(
         busy: BusyPin,
@@ -54,22 +82,26 @@ impl<
 
     fn write_command(&mut self, byte: u8) -> Result<(), WriteError<DcPin::Error, Spi::Error>> {
         self.dc.set_low().map_err(WriteError::DcError)?;
-        self.spi.transaction(&mut [
-            Operation::DelayNs(60),
-            Operation::Write(&[byte]),
-            Operation::DelayNs(20),
-        ]).map_err(WriteError::SpiError)?;
+        self.spi
+            .transaction(&mut [
+                Operation::DelayNs(60),
+                Operation::Write(&[byte]),
+                Operation::DelayNs(20),
+            ])
+            .map_err(WriteError::SpiError)?;
         self.delay.delay_ns(40);
         Ok(())
     }
 
     fn write_data(&mut self, byte: u8) -> Result<(), WriteError<DcPin::Error, Spi::Error>> {
         self.dc.set_high().map_err(WriteError::DcError)?;
-        self.spi.transaction(&mut [
-            Operation::DelayNs(60),
-            Operation::Write(&[byte]),
-            Operation::DelayNs(20),
-        ]).map_err(WriteError::SpiError)?;
+        self.spi
+            .transaction(&mut [
+                Operation::DelayNs(60),
+                Operation::Write(&[byte]),
+                Operation::DelayNs(20),
+            ])
+            .map_err(WriteError::SpiError)?;
         self.delay.delay_ns(40);
         Ok(())
     }
@@ -107,4 +139,20 @@ impl<
         self.delay.delay_ms(1);
         self.wait_for_display();
     }
+
+    pub fn draw_full_frame(&mut self, double_frame: &mut DoubleFrame) {
+        self.write_command(0x10);
+        for byte in double_frame.old.0 {
+            self.write_data(byte);
+        }
+        self.write_command(0x13);
+        for byte in double_frame.new.0 {
+            self.write_data(byte);
+        }
+        self.write_command(0x12);
+        double_frame.old.0 = double_frame.new.0;
+
+        self.delay.delay_ms(1);
+        self.wait_for_display();
+    }
 }