From d63a2592b4caa7ccfc0d78d643e032e1d4665bcf Mon Sep 17 00:00:00 2001
From: Zac Wilson <zac@zacjw.com>
Date: Mon, 7 Jul 2025 23:00:28 +0100
Subject: [PATCH] Started keyboard rewrite

---
 cardputer-bsc/src/keyboard.rs | 111 +++++++++++++++++++++++++++++++++-
 1 file changed, 110 insertions(+), 1 deletion(-)

diff --git a/cardputer-bsc/src/keyboard.rs b/cardputer-bsc/src/keyboard.rs
index 63a71b1..42c4a42 100644
--- a/cardputer-bsc/src/keyboard.rs
+++ b/cardputer-bsc/src/keyboard.rs
@@ -38,7 +38,10 @@
 // SOFTWARE.
 
 use esp_idf_hal::{
-    gpio::{Gpio11, Gpio13, Gpio15, Gpio3, Gpio4, Gpio5, Gpio6, Gpio7, Gpio8, Gpio9, Input, InputOutput, Level, Output, PinDriver},
+    gpio::{
+        Gpio11, Gpio13, Gpio15, Gpio3, Gpio4, Gpio5, Gpio6, Gpio7, Gpio8, Gpio9, Input,
+        InputOutput, Level, Output, PinDriver,
+    },
     peripheral::Peripheral,
 };
 use esp_idf_sys::EspError;
@@ -104,6 +107,112 @@ pub enum KeyImprint {
     Space,
 }
 
+impl KeyImprint {
+    fn from_packed_address(i: usize, j: usize) -> Self {
+        match (i,j) {
+            (0, 0) => KeyImprint::Backquote,
+            (0, 1) => KeyImprint::Two,
+            (0, 2) => KeyImprint::Four,
+            (0, 3) => KeyImprint::Six,
+            (0, 4) => KeyImprint::Eight,
+            (0, 5) => KeyImprint::Zero,
+            (0, 6) => KeyImprint::Equal,
+            
+            (1, 0) => KeyImprint::Tab,
+            (1, 1) => KeyImprint::W,
+            (1, 2) => KeyImprint::R,
+            (1, 3) => KeyImprint::Y,
+            (1, 4) => KeyImprint::I,
+            (1, 5) => KeyImprint::P,
+            (1, 6) => KeyImprint::CloseSquareBracket,
+
+            (2, 0) => KeyImprint::LeftFn,
+            (2, 1) => KeyImprint::A,
+            (2, 2) => KeyImprint::D,
+            (2, 3) => KeyImprint::G,
+            (2, 4) => KeyImprint::J,
+            (2, 5) => KeyImprint::L,
+            (2, 6) => KeyImprint::Quote,
+
+            (3, 0) => KeyImprint::LeftCtrl,
+            (3, 1) => KeyImprint::LeftAlt,
+            (3, 2) => KeyImprint::X,
+            (3, 3) => KeyImprint::V,
+            (3, 4) => KeyImprint::N,
+            (3, 5) => KeyImprint::Comma,
+            (3, 6) => KeyImprint::Slash,
+
+            (4, 0) => KeyImprint::One,
+            (4, 1) => KeyImprint::Three,
+            (4, 2) => KeyImprint::Five,
+            (4, 3) => KeyImprint::Seven,
+            (4, 4) => KeyImprint::Nine,
+            (4, 5) => KeyImprint::Minus,
+            (4, 6) => KeyImprint::Backspace,
+
+            (5, 0) => KeyImprint::Q,
+            (5, 1) => KeyImprint::E,
+            (5, 2) => KeyImprint::T,
+            (5, 3) => KeyImprint::U,
+            (5, 4) => KeyImprint::O,
+            (5, 5) => KeyImprint::OpenSquareBracket,
+            (5, 6) => KeyImprint::Backslash,
+
+            (6, 0) => KeyImprint::LeftShift,
+            (6, 1) => KeyImprint::S,
+            (6, 2) => KeyImprint::F,
+            (6, 3) => KeyImprint::H,
+            (6, 4) => KeyImprint::K,
+            (6, 5) => KeyImprint::SemiColon,
+            (6, 6) => KeyImprint::Enter,
+
+            (7, 0) => KeyImprint::LeftOpt,
+            (7, 1) => KeyImprint::Z,
+            (7, 2) => KeyImprint::C,
+            (7, 3) => KeyImprint::B,
+            (7, 4) => KeyImprint::M,
+            (7, 5) => KeyImprint::Period,
+            (7, 6) => KeyImprint::Space,
+
+            _ => unreachable!()
+        }
+    }
+}
+
+struct FullKeyboardState {
+    packed_state: [u8; 7],
+}
+
+enum KeyAction {
+    Pressed,
+    Released,
+}
+
+impl FullKeyboardState {
+    fn changes<'a>(&'a self, old: &'a Self) -> impl Iterator<Item = (KeyImprint, KeyAction)> + 'a {
+        self.packed_state
+            .iter()
+            .zip(old.packed_state.iter())
+            .enumerate()
+            .flat_map(|(i, (new, old))| {
+                let diff = new ^ old; // XOR to find what changed
+                (0..8).filter_map(move |j| {
+                    if (1 << j) & diff != 0 {
+                        let key = KeyImprint::from_packed_address(i, j);
+                        let action = if (1 << j) & new == 0 {
+                            KeyAction::Released
+                        } else {
+                            KeyAction::Pressed
+                        };
+                        Some((key, action))
+                    } else {
+                        None
+                    }
+                })
+            })
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub enum Modified {
     Graph(char),