custom chars support

3 files changed, 85 insertions, 0 deletions

diff --git a/examples/custom_char.rs b/examples/custom_char.rs
new file mode 100644
index 0000000..059f173
--- /dev/null
+++ b/examples/custom_char.rs
@@ -0,0 +1,23 @@
+use charlcd::custom_char;
+use charlcd::Screen;
+use std::io::Write;
+
+fn main() -> std::io::Result<()> {
+    let mut screen = Screen::default()?;
+
+    // Alarm symbol
+    screen.custom_char(0, [0x04, 0x0E, 0x0E, 0x0E, 0x0E, 0x1F, 0x04, 0x00])?;
+
+    screen.custom_char(1, custom_char::RIGHT_ARROW)?;
+    screen.custom_char(2, custom_char::LEFT_ARROW)?;
+    screen.custom_char(3, custom_char::UP_ARROW)?;
+    screen.custom_char(4, custom_char::DOWN_ARROW)?;
+
+    screen.clear()?;
+    screen.write(b"\x00 Alarm 10:00\n")?;
+    screen.write(b"\x01\x02 X Arrows\n")?;
+    screen.write(b"\x03\x04 Y Arrow")?;
+    screen.flush()?;
+
+    Ok(())
+}
diff --git a/src/custom_char.rs b/src/custom_char.rs
new file mode 100644
index 0000000..47f99f5
--- /dev/null
+++ b/src/custom_char.rs
@@ -0,0 +1,50 @@
+/// X axis mirror of a custom LCD character
+pub const fn mirror_x(src: [u8; 8]) -> [u8; 8] {
+    // const fn do not support for loops currently, hence manual unroll
+    [
+        src[0].reverse_bits() >> 3,
+        src[1].reverse_bits() >> 3,
+        src[2].reverse_bits() >> 3,
+        src[3].reverse_bits() >> 3,
+        src[4].reverse_bits() >> 3,
+        src[5].reverse_bits() >> 3,
+        src[6].reverse_bits() >> 3,
+        src[7].reverse_bits() >> 3,
+    ]
+}
+
+/// Y axis mirror of a custom LCD character
+pub const fn mirror_y(src: [u8; 8]) -> [u8; 8] {
+    // const fn do not support for loops currently, hence manual unroll
+    [
+        src[7], src[6], src[5], src[4], src[3], src[2], src[1], src[0],
+    ]
+}
+
+#[cfg_attr(rustfmt, rustfmt_skip)]
+pub const RIGHT_ARROW: [u8; 8] = [
+    0b00000,
+    0b01000,
+    0b01100,
+    0b01110,
+    0b01100,
+    0b01000,
+    0b00000,
+    0b00000,
+];
+
+pub const LEFT_ARROW: [u8; 8] = mirror_x(RIGHT_ARROW);
+
+#[cfg_attr(rustfmt, rustfmt_skip)]
+pub const UP_ARROW: [u8; 8] = [
+    0b00000,
+    0b00000,
+    0b00100,
+    0b01110,
+    0b11111,
+    0b00000,
+    0b00000,
+    0b00000,
+];
+
+pub const DOWN_ARROW: [u8; 8] = mirror_y(UP_ARROW);
diff --git a/src/lib.rs b/src/lib.rs
index b573b1a..6b1d6e1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,5 @@
 mod codes;
+pub mod custom_char;
 mod of_node;
 
 use std::fs::{File, OpenOptions};
@@ -288,6 +289,17 @@ where
         write_simple_code!(self, SpecialCode::LargeFont)
     }
 
+    /// Custom character create
+    pub fn custom_char(&mut self, code: u8, value: [u8; 8]) -> std::io::Result<()> {
+        let mut res = 0u64;
+        let mut i = 0;
+        for b in value.iter().rev() {
+            res |= (*b as u64) << i;
+            i += 8;
+        }
+        write_simple_code!(self, SpecialCode::Generator(code, res))
+    }
+
     pub fn gotoxy(&mut self, x: u32, y: u32) -> std::io::Result<()> {
         write_simple_code!(self, SpecialCode::GotoXY(Some(x), Some(y)))
     }