From 222324d954bde8b11066cb6895b173385f3df57f Mon Sep 17 00:00:00 2001
From: Joe Ardent <code@ardent.nebcorp.com>
Date: Tue, 1 Aug 2023 13:48:34 -0700
Subject: [PATCH] add qr module

---
 src/lib.rs  |  1 +
 src/main.rs |  2 +-
 src/qr.rs   | 38 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100644 src/lib.rs
 create mode 100644 src/qr.rs

diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..bae46d1
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1 @@
+mod qr;
diff --git a/src/main.rs b/src/main.rs
index 9c59d23..17d8aa0 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -58,7 +58,7 @@ impl eframe::App for Flasher {
                 .build()
                 .unwrap();
             let bytes = ImageBuilder::default()
-                .fit_width(1200)
+                .fit_width(1100)
                 .to_pixmap(&qr)
                 .encode_png()
                 .unwrap();
diff --git a/src/qr.rs b/src/qr.rs
new file mode 100644
index 0000000..e97a850
--- /dev/null
+++ b/src/qr.rs
@@ -0,0 +1,38 @@
+use fast_qr::ECL;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
+pub enum Mode {
+    Ascii,
+    Binary,
+}
+
+pub fn get_size(len: usize, mode: Mode) -> usize {
+    if mode == Mode::Ascii {
+        // alphanumeric mode is only 5.5 bits per character, so 5.5 / 8 = 0.6875
+        (len as f64 * 0.6875).ceil() as usize
+    } else {
+        len
+    }
+}
+
+pub fn choose_version(size: usize, ecl: ECL) -> fast_qr::Version {
+    use fast_qr::Version::*;
+    let ecl = match ecl {
+        ECL::L => 0.7,
+        ECL::M => 0.15,
+        ECL::Q => 0.25,
+        ECL::H => 0.30,
+    };
+
+    let size = (size as f64 / ecl) as usize;
+
+    match size {
+        0..=7 => V01,
+        8..=14 => V02,
+        15..=24 => V03,
+        25..=78 => V04,
+
+        //
+        _ => V40,
+    }
+}