Add code to render text, refactor render into OOPish

src/renderer/mod.rs

@@ -1,36 +1,57 @@
 
 pub mod structs;
-use sdl3::{pixels::Color};
-use structs::{Prefs, Screen};
 
-/// Initialize video, allocate buffers and load fonts
-/// Based on https://github.com/vhspace/sdl3-rs/blob/master/examples/ttf-demo.rs
+use sdl3::{pixels::Color, rect::Rect, render::Canvas, sys::metadata::render, ttf::Font, video::Window};
+use structs::{Prefs};
 
-pub fn init(prefs: &Prefs) -> &mut structs::Screen {
-    // Initialize the screen   
-    let sdl_context = sdl3::init().unwrap();
-    let video_subsys = sdl_context.video().unwrap();
+pub struct Screen<'a> {
+    canvas: Box<Canvas<Window>>,
+    font: Box<Font<'a>>
+}
 
-    let window = video_subsys
-    .window("Dublin Bus", prefs.screen_width, prefs.screen_height)
-    .position_centered()
-    .borderless()
-    //.fullscreen()
-    .build().unwrap();
+impl Screen<'_> {
 
-    // Load font
-    let ttf_context = sdl3::ttf::init().unwrap();
-    let mut font = ttf_context.load_font(&prefs.font_path, 128.0).unwrap();
+    pub fn print(&mut self, line: u32, text: &str) {
+        let rendered_text = self.font.render(text).solid(Color::RED).unwrap();
+        let texture_creator = self.canvas.texture_creator();
+        let texture = rendered_text.as_texture(&texture_creator).unwrap();
+        let _ = self.canvas.copy(&texture, 
+            Rect::new(0, 0, rendered_text.width(), rendered_text.height()), 
+            Rect::new(0, (line * rendered_text.height()).try_into().unwrap(), rendered_text.width(), rendered_text.height()));
+        self.canvas.present();
+    }
 
-    // Clear screen
-    let mut canvas = window.into_canvas();
-    canvas.set_draw_color(Color::BLACK);
-    canvas.clear();
-    canvas.present();
 
-    let screen = Screen { 
-        canvas:  &canvas, 
-        font: &font,
-    };
-    return &mut &screen;
+    pub fn clear(&mut self) {
+        self.canvas.set_draw_color(Color::BLACK);
+        self.canvas.clear();
+        self.canvas.present();
+    }
+
+    /// Initialize video, allocate buffers and load fonts
+    /// Based on https://github.com/vhspace/sdl3-rs/blob/master/examples/ttf-demo.rs
+    pub fn init(prefs: &Prefs) -> Screen {
+        // Initialize the screen   
+        let sdl_context = sdl3::init().unwrap();
+        let video_subsys = sdl_context.video().unwrap();
+
+        let window = video_subsys
+        .window("Dublin Bus", prefs.screen_width, prefs.screen_height)
+        .position_centered()
+        .borderless()
+        //.fullscreen()
+        .build().unwrap();
+
+        // Load font
+        let ttf_context = sdl3::ttf::init().unwrap();
+        let font = ttf_context.load_font(&prefs.font_path, 128.0).unwrap();
+
+        let mut screen: Screen = Screen {
+            canvas:  Box::new(window.into_canvas()), 
+            font: Box::new(font),
+        };
+
+        screen.clear();
+        return screen;
+    }
 }

src/renderer/structs.rs

@@ -1,13 +1,7 @@
 use sdl3::{render::Canvas, ttf::Font, video::Window};
 
-
 pub struct Prefs {
     pub font_path: String,
     pub screen_width: u32,
     pub screen_height: u32,
 }
-
-pub struct Screen<'a> {
-    pub canvas: &'a Canvas<Window>,
-    pub font: &'a Font<'a>,
-}