harenae-rs/src/falling_sand/systems.rs

59 lines
1.8 KiB
Rust

use bevy::{
asset::{Assets, Handle},
ecs::system::{Query, Res, ResMut},
render::texture::Image,
};
use rand::Rng;
use super::{element::Element, rules::FallingSandRules, Chunk};
pub fn place_sand(mut query: Query<&mut Chunk>) {
for mut chunk in &mut query {
let frac = chunk.width / 2;
let x = (chunk.width - frac) / 2 + rand::thread_rng().gen_range(0..frac);
let y = chunk.height - 1;
chunk.set_cell(x, y, Element::Sand);
}
}
pub fn simulate_chunk(rules: Res<FallingSandRules>, mut query: Query<&mut Chunk>) {
for mut chunk in &mut query {
chunk.update(&rules);
}
}
pub fn update_chunk_texture(
mut images: ResMut<Assets<Image>>,
mut query: Query<(&mut Chunk, &Handle<Image>)>,
) {
for (mut chunk, image_handle) in &mut query {
if !chunk.dirty_rect.is_dirty() {
return;
}
if let Some(image) = images.get_mut(image_handle) {
for y in chunk.dirty_rect.range_y() {
for x in chunk.dirty_rect.range_x() {
let mut colour = (0, 0, 0);
if let Some(element) = chunk.get_cell(x, y) {
match element {
Element::Air => colour = (25, 24, 26),
Element::Sand => colour = (255, 216, 102),
Element::Water => colour = (120, 220, 232),
_ => {}
}
}
let index = (x + y * chunk.width) * 4;
image.data[index] = colour.0;
image.data[index + 1] = colour.1;
image.data[index + 2] = colour.2;
image.data[index + 3] = 255;
}
}
}
chunk.dirty_rect.reset();
}
}