add font.rs

src/font.rs

@@ -0,0 +1,90 @@
+use embedded_hal::delay::DelayNs;
+use esp_hal::DriverMode;
+use rusttype::{Font, Point, Scale};
+
+use alloc::string::String;
+use alloc::vec;
+use alloc::vec::Vec;
+
+use crate::display::{self, Display, Position, Rgb565};
+
+static OPEN_SANS: &'static [u8] = include_bytes!("./OpenSans_Condensed-Regular.ttf");
+
+pub struct FontRenderer<'a> {
+    font: Font<'a>,
+    height: u32,
+    scale: Scale,
+    offset: Point<f32>,
+}
+
+impl<'a> FontRenderer<'a> {
+    pub fn create(size: u32) -> FontRenderer<'a> {
+        let font = Font::try_from_bytes(OPEN_SANS).unwrap();
+        let scale = Scale {
+            x: size as f32 * 2.,
+            y: size as f32,
+        };
+
+        let v_metrics = font.v_metrics(scale);
+        let offset = rusttype::Point {
+            x: 0.0,
+            y: v_metrics.ascent,
+        };
+        FontRenderer {
+            font,
+            height: size,
+            scale,
+            offset,
+        }
+    }
+
+    pub fn render<'d, T: Into<String>, DM: DriverMode, Delay: DelayNs>(
+        &self,
+        display: &mut Display<'d, DM, Delay>,
+        text: T,
+        pos: Position,
+    ) {
+        let glyphs = self
+            .font
+            .layout(&text.into(), self.scale, self.offset)
+            .collect::<Vec<_>>();
+
+        let width = libm::ceil(
+            glyphs
+                .iter()
+                .rev()
+                .map(|g| g.position().x as f32 + g.unpositioned().h_metrics().advance_width)
+                .next()
+                .unwrap_or(0.0) as f64,
+        ) as usize;
+
+        let mut pixel_data = vec![Rgb565::white(); self.height as usize * width];
+
+        for g in glyphs {
+            if let Some(bb) = g.pixel_bounding_box() {
+                g.draw(|x, y, cov| {
+                    let x = bb.min.x + x as i32;
+                    let y = bb.min.y + y as i32;
+                    if x >= 0 && y >= 0 && x < width as i32 && y < self.height as i32 {
+                        let col = 255 - (255. * cov) as u8;
+                        pixel_data[(x + y * width as i32) as usize] = Rgb565(col, col, col);
+                    }
+                });
+            }
+        }
+
+        display.set_window(
+            pos,
+            Position {
+                x: pos.x + width as u16 - 1,
+                y: pos.y + self.height as u16 - 1,
+            },
+        );
+        display.write(display::Writeable::Data(
+            &pixel_data
+                .iter()
+                .flat_map(|p| p.as_color().bytes)
+                .collect::<Vec<_>>(),
+        ));
+    }
+}

src/main.rs

@@ -22,7 +22,10 @@ use esp_hal::{
 use esp_backtrace as _;
 use rusttype::Font;
 
-use crate::display::{Color, Display, Position, Rgb565, SetAddressMode};
+use crate::{
+    display::{Color, Display, Position, Rgb565, SetAddressMode},
+    font::FontRenderer,
+};
 use esp_alloc::HEAP;
 
 use alloc::vec;
@@ -30,6 +33,7 @@ use alloc::vec;
 extern crate alloc;
 
 mod display;
+mod font;
 
 static OPEN_SANS: &'static [u8] = include_bytes!("./OpenSans_Condensed-Regular.ttf");
 
@@ -106,65 +110,13 @@ fn main() -> ! {
         Rgb565::yellow().as_color(),
     );
 
-    let font = Font::try_from_bytes(OPEN_SANS).unwrap();
-    let glyph = font.glyph('a');
-    const SCALE: u16 = 30;
-    let scale = rusttype::Scale {
-        x: SCALE as f32 * 2.,
-        y: SCALE as f32,
-    };
-    let v_metrics = font.v_metrics(scale);
-    let offset = rusttype::Point {
-        x: 0.0,
-        y: v_metrics.ascent,
-    };
-    let glyphs = font
-        .layout("Hello world", scale, offset)
-        .collect::<Vec<_>>();
+    let font_renderer = FontRenderer::create(30);
 
-    let width = libm::ceil(
-        glyphs
-            .iter()
-            .rev()
-            .map(|g| g.position().x as f32 + g.unpositioned().h_metrics().advance_width)
-            .next()
-            .unwrap_or(0.0) as f64,
-    ) as usize;
-
-    let mut pixel_data = vec![Rgb565::white(); SCALE as usize * width];
-
-    for g in glyphs {
-        if let Some(bb) = g.pixel_bounding_box() {
-            g.draw(|x, y, cov| {
-                let x = bb.min.x + x as i32;
-                let y = bb.min.y + y as i32;
-                if x >= 0 && y >= 0 && x < width as i32 && y < SCALE as i32 {
-                    let col = 255 - (255. * cov) as u8;
-                    pixel_data[(x + y * width as i32) as usize] = Rgb565(col, col, col);
-                }
-            });
-        }
-    }
-
-    display.set_window(
-        Position { x: 0, y: 0 },
-        Position {
-            x: width as u16 - 1,
-            y: SCALE as u16 - 1,
-        },
-    );
-    display.write(display::Writeable::Data(
-        &pixel_data
-            .iter()
-            .flat_map(|p| p.as_color().bytes)
-            .collect::<Vec<_>>(),
-    ));
+    font_renderer.render(&mut display, "Hello World!", Position::new(0, 0));
 
     loop {
         let delay_start = Instant::now();
 
-        log::info!("Hello world");
-
         while delay_start.elapsed() < Duration::from_millis(100) {}
         // test_delay.delay_millis(1);
     }