example.rs

extern crate olc_pixel_game_engine;

use crate::olc_pixel_game_engine as olc;

// Very simple example application that prints "Hello, World!" on screen.

struct ExampleProgram {}

impl olc::Application for ExampleProgram {
  fn on_user_create(&mut self) -> Result<(), olc::Error> {
    // Mirrors `olcPixelGameEngine::onUserCreate`. Your code goes here.
    Ok(())
  }

  fn on_user_update(&mut self, _elapsed_time: f32) -> Result<(), olc::Error> {
    // Mirrors `olcPixelGameEngine::onUserUpdate`. Your code goes here.

    // Clears screen and sets black colour.
    olc::clear(olc::BLACK);
    // Prints the string starting at the position (40, 40) and using white colour.
    olc::draw_string(40, 40, "Hello, World!", olc::WHITE)?;
    Ok(())
  }

  fn on_user_destroy(&mut self) -> Result<(), olc::Error> {
    // Mirrors `olcPixelGameEngine::onUserDestroy`. Your code goes here.
    Ok(())
  }
}

fn main() {
  let mut example = ExampleProgram {};
  // Launches the program in 200x100 "pixels" screen, where each "pixel" is 4x4 pixel square,
  // and starts the main game loop.
  olc::start("Hello, World!", &mut example, 200, 100, 4, 4).unwrap();
}