Add MonoFont support to font viewer

eg-bdf-examples/examples/font_viewer.rs

@@ -2,20 +2,28 @@ use anyhow::{anyhow, Context, Result};
 use eg_bdf::BdfTextStyle;
 use eg_font_converter::{FontConverter, Mapping};
 use embedded_graphics::{
+    geometry::AnchorPoint,
+    mono_font::{ascii::FONT_6X10, MonoTextStyle},
     pixelcolor::Rgb888,
     prelude::*,
     primitives::{Line, PrimitiveStyle},
-    text::{Baseline, Text},
+    text::{renderer::TextRenderer, Alignment, Baseline, Text, TextStyleBuilder},
+};
+use embedded_graphics_simulator::{
+    sdl2::Keycode, OutputSettingsBuilder, SimulatorDisplay, SimulatorEvent, Window,
 };
-use embedded_graphics_simulator::{OutputSettingsBuilder, SimulatorDisplay, Window};
 
 fn main() {
     if let Err(e) = try_main() {
         eprintln!("Error: {e:#}");
     }
 }
 
-fn draw_text(display: &mut SimulatorDisplay<Rgb888>, text: &Text<BdfTextStyle<Rgb888>>) -> Point {
+/// Draws a text and its bounding box.
+fn draw_text<S: TextRenderer<Color = Rgb888>>(
+    display: &mut SimulatorDisplay<Rgb888>,
+    text: &Text<S>,
+) -> Point {
     text.bounding_box()
         .into_styled(PrimitiveStyle::with_stroke(Rgb888::CSS_DARK_ORANGE, 1))
         .draw(display)
@@ -24,25 +32,11 @@ fn draw_text(display: &mut SimulatorDisplay<Rgb888>, text: &Text<BdfTextStyle<Rg
     text.draw(display).unwrap()
 }
 
-fn try_main() -> Result<()> {
-    let file = std::env::args()
-        .nth(1)
-        .ok_or_else(|| anyhow!("missing filename"))?;
-
-    let output = FontConverter::with_file(&file, "BDF_FILE")
-        .glyphs(Mapping::Ascii)
-        .missing_glyph_substitute('?')
-        .convert_eg_bdf()
-        .with_context(|| "couldn't convert font")?;
-
-    let font = output.as_font();
-    let style = BdfTextStyle::new(&font, Rgb888::WHITE);
-
-    let settings = OutputSettingsBuilder::new().scale(3).build();
-    let mut window = Window::new("Font viewer", &settings);
-
-    let mut display = SimulatorDisplay::<Rgb888>::new(Size::new(600, 200));
-
+fn draw<S: TextRenderer<Color = Rgb888> + Copy>(
+    display: &mut SimulatorDisplay<Rgb888>,
+    style: S,
+    line_height: u32,
+) {
     let abc = ('a'..='z').collect::<String>();
     let digits = ('0'..='9').collect::<String>();
     let string = format!(
@@ -52,30 +46,31 @@ fn try_main() -> Result<()> {
         digits
     );
 
-    let position = Point::new(20, 20);
+    let position = Point::new(5, 5 + line_height as i32);
 
     Line::with_delta(position.y_axis(), Point::zero() + display.size().x_axis())
         .into_styled(PrimitiveStyle::with_stroke(Rgb888::CSS_DIM_GRAY, 1))
-        .draw(&mut display)
+        .draw(display)
         .unwrap();
 
     let text = Text::new(&string, position, style);
-    draw_text(&mut display, &text);
+    draw_text(display, &text);
 
-    let position = Point::new(20, 150);
+    let position = display.bounding_box().anchor_point(AnchorPoint::BottomLeft)
+        + Point::new(5, -(line_height as i32) * 3 / 2);
 
     Line::with_delta(position.y_axis(), Point::zero() + display.size().x_axis())
         .into_styled(PrimitiveStyle::with_stroke(Rgb888::CSS_DIM_GRAY, 1))
-        .draw(&mut display)
+        .draw(display)
         .unwrap();
 
     let p = draw_text(
-        &mut display,
+        display,
         &Text::with_baseline("Top ", position, style, Baseline::Top),
     );
 
     let p = draw_text(
-        &mut display,
+        display,
         &Text::with_baseline(
             "Middle ",
             Point::new(p.x, position.y),
@@ -85,7 +80,7 @@ fn try_main() -> Result<()> {
     );
 
     let p = draw_text(
-        &mut display,
+        display,
         &Text::with_baseline(
             "Bottom ",
             Point::new(p.x, position.y),
@@ -95,16 +90,95 @@ fn try_main() -> Result<()> {
     );
 
     draw_text(
-        &mut display,
+        display,
         &Text::with_baseline(
             "Alphabetic",
             Point::new(p.x, position.y),
             style,
             Baseline::Alphabetic,
         ),
     );
+}
+
+fn try_main() -> Result<()> {
+    let file = std::env::args()
+        .nth(1)
+        .ok_or_else(|| anyhow!("missing filename"))?;
+
+    let converted_font = FontConverter::with_file(&file, "BDF_FILE")
+        .glyphs(Mapping::Ascii)
+        .missing_glyph_substitute('?');
+
+    let output = converted_font
+        .convert_eg_bdf()
+        .with_context(|| "couldn't convert font")?;
+    let bdf_font = output.as_font();
 
-    window.show_static(&display);
+    let output = converted_font
+        .convert_mono_font()
+        .with_context(|| "couldn't convert font")?;
+    let mono_font = output.as_font();
+
+    let hints_style = MonoTextStyle::new(&FONT_6X10, Rgb888::CSS_DIM_GRAY);
+    let bottom_right = TextStyleBuilder::new()
+        .baseline(Baseline::Bottom)
+        .alignment(Alignment::Right)
+        .build();
+
+    // TODO: add metrics getter
+    let line_height = bdf_font.ascent + bdf_font.descent;
+    let display_height = line_height * 8;
+    let display_width = (line_height * 25).max(display_height);
+    let display_size = Size::new(display_width, display_height);
+
+    let mut display = SimulatorDisplay::<Rgb888>::new(display_size);
+
+    let scale = (1200 / display_size.width).max(1);
+
+    let settings = OutputSettingsBuilder::new().scale(scale).build();
+    let mut window = Window::new("Font viewer", &settings);
+
+    let mut use_mono_font = false;
+
+    'main_loop: loop {
+        window.update(&display);
+
+        for event in window.events() {
+            match event {
+                SimulatorEvent::KeyDown { keycode, .. } => match keycode {
+                    Keycode::M => {
+                        use_mono_font = !use_mono_font;
+                    }
+                    _ => {}
+                },
+                SimulatorEvent::Quit => break 'main_loop,
+                _ => {}
+            }
+        }
+
+        let mut hint = "Press M to toggle".to_string();
+
+        display.clear(Rgb888::BLACK).unwrap();
+        if use_mono_font {
+            let style = MonoTextStyle::new(&mono_font, Rgb888::WHITE);
+            draw(&mut display, style, line_height);
+
+            hint.insert_str(0, "Mono | ");
+        } else {
+            let style = BdfTextStyle::new(&bdf_font, Rgb888::WHITE);
+            draw(&mut display, style, line_height);
+
+            hint.insert_str(0, "Bdf | ");
+        }
+
+        let corner = display
+            .bounding_box()
+            .offset(-3)
+            .anchor_point(AnchorPoint::BottomRight);
+        Text::with_text_style(&hint, corner, hints_style, bottom_right)
+            .draw(&mut display)
+            .unwrap();
+    }
 
     Ok(())
 }

eg-font-converter/src/lib.rs

@@ -312,15 +312,15 @@ impl<'a> FontConverter<'a> {
             .try_get::<i32>(Property::FontAscent)
             .ok()
             .filter(|v| *v >= 0)
-            .unwrap() as u32; //TODO: convert to error
+            .unwrap_or_default() as u32; //TODO: convert to error
 
         let descent = bdf
             .metadata
             .properties
             .try_get::<i32>(Property::FontDescent)
             .ok()
             .filter(|v| *v >= 0)
-            .unwrap() as u32; //TODO: convert to error
+            .unwrap_or_default() as u32; //TODO: convert to error
 
         // TODO: read from BDF and use correct fallbacks (https://www.x.org/docs/XLFD/xlfd.pdf 3.2.30)
         let underline_position = ascent + 1;