roguelike-game/src/camera.rs

//! Handle rendering of the viewport
use ::rltk::{Point, Rltk};
use ::specs::prelude::*;

use crate::components::{Hidden, Position, Renderable, TileSize};
use crate::map::tile_glyph;
use crate::{colors, Map};

/// Whether to render an outline of the current map's boundaries
const SHOW_BOUNDARIES: bool = false;

/// Get the rectangle representing the current viewport
pub fn get_screen_bounds(ecs: &World, _ctx: &mut Rltk) -> (i32, i32, i32, i32) {
    let player_pos = ecs.fetch::<Point>();
    // let (x_chars, y_chars) = ctx.get_char_size();
    let (x_chars, y_chars) = (48, 44);

    let center_x = (x_chars / 2) as i32;
    let center_y = (y_chars / 2) as i32;

    let min_x = player_pos.x - center_x;
    let max_x = min_x + x_chars as i32;
    let min_y = player_pos.y - center_y;
    let max_y = min_y + y_chars as i32;

    (min_x, max_x, min_y, max_y)
}

/// Render the current viewport
pub fn render_camera(ecs: &World, ctx: &mut Rltk) {
    let map = ecs.fetch::<Map>();
    let (min_x, max_x, min_y, max_y) = get_screen_bounds(ecs, ctx);

    // Render the Map
    let map_width = map.width - 1;
    let map_height = map.height - 1;

    let mut y = 0;
    #[allow(clippy::explicit_counter_loop)]
    for ty in min_y..max_y {
        let mut x = 0;
        for tx in min_x..max_x {
            if tx > 0 && tx < map_width && ty > 0 && ty < map_height {
                let idx = map.xy_idx(tx, ty);
                if map.revealed_tiles[idx] {
                    let (glyph, fg, bg) = tile_glyph(idx, &*map);
                    ctx.set(x, y, fg, bg, glyph);
                }
            } else if SHOW_BOUNDARIES {
                ctx.set(x, y, colors::GRAY, colors::BLACK, rltk::to_cp437('·'));
            }
            x += 1;
        }
        y += 1;
    }

    // Render entities
    let positions = ecs.read_storage::<Position>();
    let renderables = ecs.read_storage::<Renderable>();
    let hidden = ecs.read_storage::<Hidden>();
    let map = ecs.fetch::<Map>();
    let sizes = ecs.read_storage::<TileSize>();
    let entities = ecs.entities();

    let mut data = (&positions, &renderables, &entities, !&hidden)
        .join()
        .collect::<Vec<_>>();
    data.sort_by(|&a, &b| b.1.render_order.cmp(&a.1.render_order));
    for (pos, render, entity, _hidden) in data.iter() {
        if let Some(size) = sizes.get(*entity) {
            for cy in 0..size.y {
                for cx in 0..size.x {
                    let tile_x = cx + pos.x;
                    let tile_y = cy + pos.y;
                    let idx = map.xy_idx(tile_x, tile_y);
                    if map.visible_tiles[idx] {
                        let entity_screen_x = (cx + pos.x) - min_x;
                        let entity_screen_y = (cy + pos.y) - min_y;
                        if entity_screen_x > 0
                            && entity_screen_x < map_width
                            && entity_screen_y > 0
                            && entity_screen_y < map_height
                        {
                            ctx.set(
                                entity_screen_x + 1,
                                entity_screen_y + 1,
                                render.fg,
                                render.bg,
                                render.glyph,
                            );
                        }
                    }
                }
            }
        } else {
            let idx = map.xy_idx(pos.x, pos.y);
            if map.visible_tiles[idx] {
                let entity_screen_x = pos.x - min_x;
                let entity_screen_y = pos.y - min_y;
                if entity_screen_x > 0
                    && entity_screen_x < map_width
                    && entity_screen_y > 0
                    && entity_screen_y < map_height
                {
                    ctx.set(
                        entity_screen_x,
                        entity_screen_y,
                        render.fg,
                        render.bg,
                        render.glyph,
                    );
                }
            }
        }
    }
}

pub fn render_debug_map(map: &Map, ctx: &mut Rltk) {
    let player_pos = Point::new(map.width / 2, map.height / 2);
    let (x_chars, y_chars) = ctx.get_char_size();

    let center_x = (x_chars / 2) as i32;
    let center_y = (y_chars / 2) as i32;

    let min_x = player_pos.x - center_x;
    let max_x = min_x + x_chars as i32;
    let min_y = player_pos.y - center_y;
    let max_y = min_y + y_chars as i32;

    let map_width = map.width - 1;
    let map_height = map.height - 1;

    let mut y = 0;
    #[allow(clippy::explicit_counter_loop)]
    for ty in min_y..max_y {
        let mut x = 0;
        for tx in min_x..max_x {
            if tx > 0 && tx < map_width && ty > 0 && ty < map_height {
                let idx = map.xy_idx(tx, ty);
                if map.revealed_tiles[idx] {
                    let (glyph, fg, bg) = tile_glyph(idx, &*map);
                    ctx.set(x, y, fg, bg, glyph);
                }
            } else if SHOW_BOUNDARIES {
                ctx.set(x, y, colors::GRAY, colors::BLACK, rltk::to_cp437('·'));
            }
            x += 1;
        }
        y += 1;
    }
}