gridcursor.rs

use crate::{
    assets::GRIDCURSOR_TEXTURE,
    components::{GridCursor, GridPos},
    machine::{Machine, MACHINE_SIZE},
    RENDER_ORDER,
};

use bevy::prelude::*;

pub struct GridCursorPlugin;

pub struct GridCursorTexture {
    pub handle: Handle<Image>,
}

/// TEMPORARY
/// simple index to decide on type of machine to be placed
struct SelectedMachine(pub Machine);

impl Plugin for GridCursorPlugin {
    fn build(&self, app: &mut App) {
        app.add_startup_system_to_stage(StartupStage::PostStartup, gridcursor_setup_system)
            .add_system(gridcursor_follow_mouse_system)
            .add_system(cursor_handle_click_system)
            .insert_resource(SelectedMachine(Machine::Wall))
            .add_system(key_input_system);
    }
}

fn gridcursor_setup_system(mut commands: Commands, texture: Res<GridCursorTexture>) {
    commands
        .spawn_bundle(SpriteBundle {
            texture: texture.handle.clone(),
            transform: Transform {
                scale: (MACHINE_SIZE / GRIDCURSOR_TEXTURE.size).extend(1.0),
                ..default()
            },
            ..default()
        })
        .insert(GridPos::new(3, 3, 0))
        .insert(GridCursor);
}

fn gridcursor_follow_mouse_system(
    mut cursor_moved: EventReader<CursorMoved>,
    mut query: Query<(&mut Transform, &mut GridPos), With<GridCursor>>,
    camera_query: Query<(&Camera, &GlobalTransform)>,
    windows: Res<Windows>,
) {
    let window = windows.get_primary().unwrap();

    for event in cursor_moved.iter() {
        if let Ok((mut transform, mut grid_pos)) = query.get_single_mut() {
            let new_grid_pos =
                GridPos::from_screen_pos(event.position, window, camera_query.single(), 0);

            *grid_pos = new_grid_pos;
            transform.translation = new_grid_pos.to_world_pos().extend(RENDER_ORDER.gridcursor)
        }
    }
}

fn cursor_handle_click_system(
    mut commands: Commands,
    slected_machine: Res<SelectedMachine>,
    mouse_button: Res<Input<MouseButton>>,
    cursor_query: Query<&GridPos, With<GridCursor>>,
) {
    if let Ok(pos) = cursor_query.get_single() {
        if mouse_button.just_pressed(MouseButton::Left) {
            commands.spawn_bundle((*pos, slected_machine.0));
        }
    }
}

fn key_input_system(mut slected_machine: ResMut<SelectedMachine>, kb: Res<Input<KeyCode>>) {
    for key in kb.get_just_pressed() {
        match key {
            KeyCode::Key1 => {
                slected_machine.0 = Machine::Wall;
            }
            KeyCode::Key2 => {
                slected_machine.0 = Machine::Turbine;
            }
            KeyCode::Key3 => {
                slected_machine.0 = Machine::Cable;
            }
            _ => (),
        };
    }
}