Add ability to draw text

Cargo.toml

@@ -12,4 +12,4 @@ exclude = ["src/main.rs"]
 
 [dependencies.sdl2]
 version = "0.35.2"
-features = ["image"]
+features = ["image", "ttf"]

src/lib.rs

@@ -57,7 +57,7 @@ use sdl2::{
     rwops::RWops,
     surface::Surface,
     video::{Window, WindowBuildError, WindowContext},
-    EventPump, IntegerOrSdlError,
+    EventPump, IntegerOrSdlError, ttf::{Sdl2TtfContext, Font, FontError},
 };
 
 #[doc(no_inline)]
@@ -109,6 +109,12 @@ impl From<TextureValueError> for CatboxError {
     }
 }
 
+impl From<FontError> for CatboxError {
+    fn from(e: FontError) -> Self {
+        CatboxError(format!("{}", e))
+    }
+}
+
 pub type Result<T> = std::result::Result<T, CatboxError>;
 
 /// Wrapper type around SDL's [`EventPump`](sdl2::EventPump). See those docs for more info.
@@ -233,20 +239,32 @@ impl Sprite {
     }
 }
 
+pub enum TextMode {
+    Transparent {
+        colour: (u8, u8, u8)
+    },
+    Shaded {
+        foreground: (u8, u8, u8),
+        background: (u8, u8, u8)
+    }
+}
+
 /// Game context.
 ///
 /// In most cases, this should never actually be used; instead, just pass it around to the various cat-box functions such as [`Sprite::draw()`].
 pub struct Context {
     canvas: Canvas<Window>,
     texture_creator: TextureCreator<WindowContext>,
+    ttf_subsystem: Sdl2TtfContext
 }
 
 impl Context {
-    fn new(canvas: Canvas<Window>) -> Self {
+    fn new(canvas: Canvas<Window>, ttf_subsystem: Sdl2TtfContext) -> Self {
         let creator = canvas.texture_creator();
         Self {
             canvas,
             texture_creator: creator,
+            ttf_subsystem
         }
     }
 
@@ -271,6 +289,27 @@ impl Context {
     }
 }
 
+pub fn draw_text(ctx: &mut Context, text: &str, font: &str, size: u16, pos: (i32, i32), mode: TextMode) -> Result<()> {
+    let font =  ctx.ttf_subsystem.load_font(font, size)?;
+    let renderer = font.render(text);
+
+    let surf = match mode {
+        TextMode::Transparent { colour: (r, g, b) } => renderer.solid(Color::RGB(r, g, b)),
+        TextMode::Shaded { foreground: (fr, fg, fb), background: (br, bg, bb) } => renderer.shaded(Color::RGB(fr, fg, fb), Color::RGB(br, bg, bb)),
+    }?;
+
+    drop(font);
+    let (creator, canvas) = ctx.inner();
+    let texture = creator.create_texture_from_surface(&surf)?;
+
+    let srect = surf.rect();
+    let dest_rect: Rect = Rect::from_center(pos, srect.width(), srect.height());
+
+    canvas.copy_ex(&texture, None, dest_rect, 0.0, None, false, false)?;
+
+    Ok(())
+}
+
 /// Representation of the game.
 pub struct Game {
     /// The title that the window displays.
@@ -322,12 +361,13 @@ impl Game {
             .build()?;
 
         let canvas = window.into_canvas().build()?;
+        let s = sdl2::ttf::init().unwrap();
 
         let event_pump = sdl_context.event_pump()?;
 
         let mut events = Events { pump: event_pump };
 
-        let mut ctx = Context::new(canvas);
+        let mut ctx = Context::new(canvas, s);
 
         loop {
             if self.stopped.get() {

src/main.rs

@@ -1,4 +1,4 @@
-use cat_box::{Event, Game, Keycode, Sprite};
+use cat_box::{Event, Game, Keycode, Sprite, draw_text};
 
 fn main() {
     let game = Game::new("catbox demo", 1000, 800);
@@ -10,6 +10,8 @@ fn main() {
         i = (i + 1.0) % 360.0;
         ctx.set_background_colour(i as u8, 64, 255);
 
+        draw_text(ctx, "this is a test", "cozette_bitmap.ttf", 65535, (300, 300), cat_box::TextMode::Shaded {foreground: (255, 255, 255), background: (0, 0, 0)}).unwrap();
+
         let (start_x, start_y) = s.position();
         let m = sdl2::mouse::MouseState::new(event_pump.as_ref());
         let x_diff = m.x() - start_x;