RustMessingWithSdl2/src/main.rs

use sdl2::pixels::Color;
use sdl2::event::Event;
use sdl2::keyboard::Keycode;
use sdl2::keyboard::Scancode;
use std::collections::HashSet;
use std::time::Duration;
use sdl2::rect::Point;
use sdl2::rect::Rect;

const WINDOW_HEIGHT:i32 = 800;
const WINDOW_WIDTH:i32 = 1000;
const BLOC_SPEED:f32 = 3.0;
const MAX_SPEED:f32 = 20.0;
const GRAVITY:f32 = 10.0;

const BOUNCE_RATIO:f32 = 110.0;

pub struct Game{
    main_bloc:Entity,
}
impl Game{
    pub fn render(&mut self,ctx:&mut sdl2::render::Canvas<sdl2::video::Window>){
        ctx.set_draw_color(Color::RGB(0x6D, 0x6D, 0x64));
        ctx.clear();

        //Rendering main_bloc
        ctx.set_draw_color(Color::RGB(0x33, 0x33, 0x33));
        ctx.fill_rect(self.main_bloc.shape).expect("Could not fill the rectangle");
        //ctx.set_draw_color(Color::RGB(0xFF, 0xFF, 0xFF));
        //ctx.draw_rect(self.main_bloc.shape).expect("Could not outline the rectangle");
    }
    pub fn up(&mut self){
        // 'w' or the up arrow has been pressed
        //println!("DEBUG: Up is pressed");
        self.main_bloc.velocity.y -= BLOC_SPEED as i32;
        if self.main_bloc.velocity.y < -MAX_SPEED as i32{
            self.main_bloc.velocity.y = -MAX_SPEED as i32;
        }
    }
    pub fn down(&mut self){
        // 's' or the down arrow has been pressed
        //println!("DEBUG: Down is pressed");
        self.main_bloc.velocity.y += BLOC_SPEED as i32;
        if self.main_bloc.velocity.y > MAX_SPEED as i32{
            self.main_bloc.velocity.y = MAX_SPEED as i32;
        }
    }
    pub fn left(&mut self){
        // 'a' or the left arrow has been pressed
        //println!("DEBUG: Left is pressed");
        self.main_bloc.velocity.x -= BLOC_SPEED as i32;
        if self.main_bloc.velocity.x < -MAX_SPEED as i32{
            self.main_bloc.velocity.x = -MAX_SPEED as i32;
        }
    }
    pub fn right(&mut self){
        // 'd' or the right arrow has been pressed
        //println!("DEBUG: Right is pressed");
        self.main_bloc.velocity.x += BLOC_SPEED as i32;
        if self.main_bloc.velocity.y > MAX_SPEED as i32{
            self.main_bloc.velocity.y = MAX_SPEED as i32;
        }
    }
    pub fn update(&mut self){
        let bloc = &mut self.main_bloc;
        let mut posx = bloc.shape.x;
        let mut posy = bloc.shape.y;
        let width = bloc.shape.width() as i32;
        let height = bloc.shape.height() as i32;

        if posy + height >= WINDOW_HEIGHT{
            //we hit rock bottom
            posy = WINDOW_HEIGHT - height;
            bloc.velocity.y = -(bloc.velocity.y as f32 / 100.0 * BOUNCE_RATIO) as i32;
        }
        if posy <= 0{
            //we hit top
            posy = 0;
            bloc.velocity.y = -(bloc.velocity.y as f32 / 100.0 * BOUNCE_RATIO) as i32;
        }
        if posx + width >= WINDOW_WIDTH{
            //we hit right
            posx = WINDOW_WIDTH - width;
            bloc.velocity.x = -(bloc.velocity.x as f32 / 100.0 * BOUNCE_RATIO) as i32;
        }
        if posx <= 0{
            //we hit left
            posx = 0;
            bloc.velocity.x = -(bloc.velocity.x as f32 / 100.0 * BOUNCE_RATIO) as i32;
        }

        if bloc.velocity.x > MAX_SPEED as i32{
            bloc.velocity.x = MAX_SPEED as i32;
        }
        if bloc.velocity.x < -MAX_SPEED as i32{
            bloc.velocity.x = -MAX_SPEED as i32;
        }
        if bloc.velocity.y > MAX_SPEED as i32{
            bloc.velocity.y = MAX_SPEED as i32;
        }
        if bloc.velocity.y < -MAX_SPEED as i32{
            bloc.velocity.y = -MAX_SPEED as i32;
        }

        posx += bloc.velocity.x;
        posy += bloc.velocity.y;
        bloc.shape.set_x(posx);
        bloc.shape.set_y(posy);
    }
}

pub struct Entity{
    shape:Rect,
    velocity:Point,
}

pub fn main_loop(canvas: &mut sdl2::render::Canvas<sdl2::video::Window>,event_pump:&mut sdl2::EventPump,game:&mut Game){
    'running: loop {
        for event in event_pump.poll_iter() {
            match event {
                Event::Quit {..} |
                Event::KeyDown { keycode: Some(Keycode::Escape), .. } => {
                    break 'running
                },
                Event::KeyDown { keycode: Some(Keycode::W), .. } | Event::KeyDown {keycode: Some(Keycode::Up), ..} => {
                    //pressed up
                    game.up();
                },
                Event::KeyDown { keycode: Some(Keycode::S), .. } | Event::KeyDown { keycode: Some(Keycode::Down), .. } => {
                    //pressed up
                    game.down();
                },
                Event::KeyDown { keycode: Some(Keycode::A), .. } | Event::KeyDown { keycode: Some(Keycode::Left), .. } => {
                    //pressed up
                    game.left();
                },
                Event::KeyDown { keycode: Some(Keycode::D), .. } | Event::KeyDown { keycode: Some(Keycode::Right), .. } => {
                    //pressed up
                    game.right();
                },
                _ => {}
            }
        }
        
        // MAIN LOOP
        game.update();
        game.render(canvas);
        // MAIN LOOP

        canvas.present();
        ::std::thread::sleep(Duration::new(0, 1_000_000_000u32 / 60));
    }
}

pub fn main() {
    let sdl_context = sdl2::init().unwrap();
    let video_subsystem = sdl_context.video().unwrap();

    let window = video_subsystem.window("Test SDL Rust", WINDOW_WIDTH as u32, WINDOW_HEIGHT as u32)
        .position_centered()
        .build()
        .unwrap();

    let mut canvas = window.into_canvas().build().unwrap();
    let mut event_pump = sdl_context.event_pump().unwrap();

    canvas.set_draw_color(Color::RGB(0x6D, 0x6D, 0x64));

    let main_bloc_width:i32 = 50;
    let main_bloc_height:i32 = 50;
    let main_bloc_position:Point = Point::new(WINDOW_WIDTH / 2 - main_bloc_width / 2,WINDOW_HEIGHT / 2 - main_bloc_height / 2);
    let main_bloc_rectangle = Rect::new(main_bloc_position.x,main_bloc_position.y, main_bloc_width as u32, main_bloc_height as u32);
    let main_bloc_velocity = Point::new(0,0);
    let main_entity = Entity{
        shape:main_bloc_rectangle,
        velocity:main_bloc_velocity
    };
    let mut game = Game{main_bloc:main_entity};
    main_loop(&mut canvas,&mut event_pump,&mut game);
}