Running _spinning-square_ only prints ```"Hello, world!"``` message

[trevisanj]

Project compiles seamlessly, but when I run I get no graphics and following message instead:

$ cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 2.92s
     Running `target/debug/spinning-square`
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: "Error compiling vertex shader: 0:1(10): error: GLSL 1.50 is not supported. Supported versions are: 1.00 ES, 3.00 ES, 3.10 ES, and 3.20 ES\n"', /media/j/maca/Programs/cargo/registry/src/index.crates.io-6f17d22bba15001f/piston2d-opengl_graphics-0.82.0/src/back_end.rs:81:71
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[funtemple3000]

Can you show me the code please?

[trevisanj]

Sure! ... but also sorry, I am now getting a different error message (I updated it in the original message in this issue as well):

$ cargo run
    Finished dev [unoptimized + debuginfo] target(s) in 2.92s
     Running `target/debug/spinning-square`
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: "Error compiling vertex shader: 0:1(10): error: GLSL 1.50 is not supported. Supported versions are: 1.00 ES, 3.00 ES, 3.10 ES, and 3.20 ES\n"', /media/j/maca/Programs/cargo/registry/src/index.crates.io-6f17d22bba15001f/piston2d-opengl_graphics-0.82.0/src/back_end.rs:81:71
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

Code follows (spinning square):

extern crate glutin_window;
extern crate graphics;
extern crate opengl_graphics;
extern crate piston;

use glutin_window::GlutinWindow as Window;
use opengl_graphics::{GlGraphics, OpenGL};
use piston::event_loop::{EventSettings, Events};
use piston::input::{RenderArgs, RenderEvent, UpdateArgs, UpdateEvent};
use piston::window::WindowSettings;

pub struct App {
    gl: GlGraphics, // OpenGL drawing backend.
    rotation: f64,  // Rotation for the square.
}

impl App {
    fn render(&mut self, args: &RenderArgs) {
        use graphics::*;

        const GREEN: [f32; 4] = [0.0, 1.0, 0.0, 1.0];
        const RED: [f32; 4] = [1.0, 0.0, 0.0, 1.0];

        let square = rectangle::square(0.0, 0.0, 50.0);
        let rotation = self.rotation;
        let (x, y) = (args.window_size[0] / 2.0, args.window_size[1] / 2.0);

        self.gl.draw(args.viewport(), |c, gl| {
            // Clear the screen.
            clear(GREEN, gl);

            let transform = c
                .transform
                .trans(x, y)
                .rot_rad(rotation)
                .trans(-25.0, -25.0);

            // Draw a box rotating around the middle of the screen.
            rectangle(RED, square, transform, gl);
        });
    }

    fn update(&mut self, args: &UpdateArgs) {
        // Rotate 2 radians per second.
        self.rotation += 2.0 * args.dt;
    }
}

fn main() {
    // Change this to OpenGL::V2_1 if not working.
    let opengl = OpenGL::V3_2;

    // Create a Glutin window.
    let mut window: Window = WindowSettings::new("spinning-square", [200, 200])
        .graphics_api(opengl)
        .exit_on_esc(true)
        .build()
        .unwrap();

    // Create a new game and run it.
    let mut app = App {
        gl: GlGraphics::new(opengl),
        rotation: 0.0,
    };

    let mut events = Events::new(EventSettings::new());
    while let Some(e) = events.next(&mut window) {
        if let Some(args) = e.render_args() {
            app.render(&args);
        }

        if let Some(args) = e.update_args() {
            app.update(&args);
        }
    }
}