Allow setting fg/bg-color

src/display.rs

@@ -1,4 +1,4 @@
-use core::ops::Mul;
+use core::ops::{Add, Mul};
 
 use embedded_hal::{delay::DelayNs, spi::SpiBus};
 use esp_hal::{DriverMode, gpio::Output, spi::master::Spi};
@@ -64,6 +64,14 @@ impl Mul<f32> for Rgb565 {
     }
 }
 
+impl Add<Rgb565> for Rgb565 {
+    type Output = Rgb565;
+
+    fn add(self, rhs: Rgb565) -> Self::Output {
+        Rgb565(self.0 + rhs.0, self.1 + rhs.1, self.2 + rhs.2)
+    }
+}
+
 #[derive(Default, Clone, Copy, Debug)]
 pub struct Position {
     pub x: i16,

src/font.rs

@@ -6,7 +6,7 @@ use alloc::vec;
 use alloc::vec::Vec;
 use alloc::{borrow::ToOwned, string::String};
 
-use crate::display::{self, Display, Position, Rgb565};
+use crate::display::{self, Color, Display, Position, Rgb565};
 
 static OPEN_SANS: &'static [u8] = include_bytes!("./OpenSans_Condensed-Regular.ttf");
 
@@ -62,6 +62,8 @@ impl<'a> FontRenderer<'a> {
         position: Position,
         h_align: HorizontalAlignment,
         v_align: VerticalAlignment,
+        bg: Rgb565,
+        fg: Rgb565,
     ) {
         let text = text.into();
         let rows = text.split("\n").collect::<Vec<&str>>();
@@ -82,7 +84,7 @@ impl<'a> FontRenderer<'a> {
             };
             let y = start_y + (self.height * i as u32) as i16;
 
-            self.raw_render(display, data, Position { x, y });
+            self.raw_render(display, data, Position { x, y }, bg, fg);
         }
     }
 
@@ -112,6 +114,8 @@ impl<'a> FontRenderer<'a> {
         display: &mut Display<'d, DM, Delay>,
         data: RawRenderData<'a>,
         pos: Position,
+        bg: Rgb565,
+        fg: Rgb565,
     ) {
         let start_x = pos.x.clamp(0, 240);
         let start_y = pos.y.clamp(0, 240);
@@ -129,7 +133,7 @@ impl<'a> FontRenderer<'a> {
         let width = end_x - start_x;
         let height = end_y - start_y;
 
-        let mut pixel_data = vec![Rgb565::white(); height as usize * width as usize];
+        let mut pixel_data = vec![bg; height as usize * width as usize];
 
         for g in data.glyphs {
             if let Some(bb) = g.pixel_bounding_box() {
@@ -137,8 +141,8 @@ impl<'a> FontRenderer<'a> {
                     let x = bb.min.x + x as i32 - clip_left as i32;
                     let y = bb.min.y + y as i32 - clip_top as i32;
                     if x >= 0 && y >= 0 && x < width as i32 && y < height as i32 {
-                        let col = 255 - (255. * cov) as u8;
-                        pixel_data[(x + y * width as i32) as usize] = Rgb565(col, col, col);
+                        let col = bg * (1. - cov) + fg * cov;
+                        pixel_data[(x + y * width as i32) as usize] = col;
                     }
                 });
             }

src/main.rs

@@ -117,6 +117,8 @@ fn main() -> ! {
         Position::new(0, 0),
         HorizontalAlignment::LeftToRight,
         VerticalAlignment::TopToBottom,
+        Rgb565::black(),
+        Rgb565::white(),
     );
 
     let sim_rst = Output::new(peripherals.GPIO15, Level::High, OutputConfig::default());