bracket-terminal 0.8.1

use super::events::*;
use super::*;
use crate::hal::*;
use crate::prelude::{BTerm, GameState, BACKEND_INTERNAL};
use crate::{clear_input_state, Result};
use glow::HasContext;

pub fn main_loop<GS: GameState>(mut bterm: BTerm, mut gamestate: GS) -> Result<()> {
    use glow::HasRenderLoop;

    std::panic::set_hook(Box::new(console_error_panic_hook::hook));

    {
        let be = BACKEND.lock();
        let gl = be.gl.as_ref().unwrap();
        let mut bit = BACKEND_INTERNAL.lock();
        for f in bit.fonts.iter_mut() {
            f.setup_gl_texture(gl)?;
        }

        for s in bit.sprite_sheets.iter_mut() {
            let mut f = Font::new(&s.filename.to_string(), 1, 1, (1, 1));
            f.setup_gl_texture(gl)?;
            s.backing = Some(f);
        }
    }

    let now = wasm_timer::Instant::now();
    let mut prev_seconds = now.elapsed().as_secs();
    let mut prev_ms = now.elapsed().as_millis();
    let mut frames = 0;

    let render_loop = glow::RenderLoop::from_request_animation_frame();
    render_loop.run(move |_running: &mut bool| {
        // Read in event results
        unsafe {
            bterm.key = GLOBAL_KEY;
            bterm.mouse_pos = (GLOBAL_MOUSE_POS.0, GLOBAL_MOUSE_POS.1);
            bterm.left_click = GLOBAL_LEFT_CLICK;
            bterm.shift = GLOBAL_MODIFIERS.0;
            bterm.control = GLOBAL_MODIFIERS.1;
            bterm.alt = GLOBAL_MODIFIERS.2;
            bterm.web_button = GLOBAL_BUTTON.clone();
            bterm.on_mouse_position(GLOBAL_MOUSE_POS.0 as f64, GLOBAL_MOUSE_POS.1 as f64);
        }

        // Call the tock function
        tock(
            &mut bterm,
            &mut gamestate,
            &mut frames,
            &mut prev_seconds,
            &mut prev_ms,
            &now,
        );

        // Clear any input
        clear_input_state(&mut bterm);
        unsafe {
            GLOBAL_KEY = None;
            GLOBAL_MODIFIERS = (false, false, false);
            GLOBAL_LEFT_CLICK = false;
            GLOBAL_BUTTON = None;
        }
    });
    Ok(())
}

fn tock<GS: GameState>(
    bterm: &mut BTerm,
    gamestate: &mut GS,
    frames: &mut i32,
    prev_seconds: &mut u64,
    prev_ms: &mut u128,
    now: &wasm_timer::Instant,
) {
    // Check that the console backings match our actual consoles
    check_console_backing();

    let now_seconds = now.elapsed().as_secs();
    *frames += 1;

    if now_seconds > *prev_seconds {
        bterm.fps = *frames as f32 / (now_seconds - *prev_seconds) as f32;
        *frames = 0;
        *prev_seconds = now_seconds;
    }

    let now_ms = now.elapsed().as_millis();
    if now_ms > *prev_ms {
        bterm.frame_time_ms = (now_ms - *prev_ms) as f32;
        *prev_ms = now_ms;
    }

    gamestate.tick(bterm);

    // Console structure - doesn't really have to be every frame...
    rebuild_consoles();

    // Bind to the backing buffer
    if bterm.post_scanlines {
        let be = BACKEND.lock();
        be.backing_buffer
            .as_ref()
            .unwrap()
            .bind(be.gl.as_ref().unwrap());
    }

    // Clear the screen
    unsafe {
        let be = BACKEND.lock();
        be.gl.as_ref().unwrap().clear_color(0.0, 0.0, 0.0, 1.0);
        be.gl.as_ref().unwrap().clear(glow::COLOR_BUFFER_BIT);
    }

    // Tell each console to draw itself
    render_consoles().unwrap();

    // If there is a GL callback, call it now
    {
        let be = BACKEND.lock();
        if let Some(callback) = be.gl_callback.as_ref() {
            let gl = be.gl.as_ref().unwrap();
            callback(gamestate, gl);
        }
    }

    if bterm.post_scanlines {
        // Now we return to the primary screen
        let be = BACKEND.lock();
        be.backing_buffer
            .as_ref()
            .unwrap()
            .default(be.gl.as_ref().unwrap());
        unsafe {
            let bi = BACKEND_INTERNAL.lock();
            if bterm.post_scanlines {
                bi.shaders[3].useProgram(be.gl.as_ref().unwrap());
                bi.shaders[3].setVec3(
                    be.gl.as_ref().unwrap(),
                    "screenSize",
                    bterm.width_pixels as f32,
                    bterm.height_pixels as f32,
                    0.0,
                );
                bi.shaders[3].setBool(be.gl.as_ref().unwrap(), "screenBurn", bterm.post_screenburn);
            } else {
                bi.shaders[2].useProgram(be.gl.as_ref().unwrap());
            }
            be.gl
                .as_ref()
                .unwrap()
                .bind_vertex_array(Some(be.quad_vao.unwrap()));
            be.gl.as_ref().unwrap().bind_texture(
                glow::TEXTURE_2D,
                Some(be.backing_buffer.as_ref().unwrap().texture),
            );
            be.gl.as_ref().unwrap().draw_arrays(glow::TRIANGLES, 0, 6);
        }
    }
}