toby/worlds-history-sim-rs
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Tweak rainfall generation

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cc4e5c393f1090b85f6be38d98a58e0899309c70
This commit is contained in:
Tobias Berger 2022-09-04 20:49:44 +02:00
parent 2c1697fae6
commit 99f4caab54
Signed by: toby
GPG key ID: 2D05EFAB764D6A88
2 changed files with 102 additions and 24 deletions
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110
save/src/world.rs
View file

@ -1,7 +1,7 @@
use std::{
error::Error,
f32::consts::{PI, TAU},
fmt::Display,
fmt::{Debug, Display},
};
use bevy::{math::Vec3A, prelude::Vec2, utils::default};
@ -32,26 +32,50 @@ impl Error for WorldGenError {
impl Display for WorldGenError {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
match self {
WorldGenError::CartesianError(err) => err.fmt(f),
WorldGenError::CartesianError(err) => Display::fmt(err, f),
}
}
}
#[derive(Debug, Clone)]
#[derive(Clone)]
pub struct World {
pub width: i32,
pub height: i32,
pub seed: u32,
pub terrain: Vec<Vec<TerrainCell>>,
contintent_offsets: [Vec2; World::NUM_CONTINENTS as usize],
continent_offsets: [Vec2; World::NUM_CONTINENTS as usize],
continent_widths: [f32; World::NUM_CONTINENTS as usize],
perlin: Perlin,
}
impl Debug for World {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("World")
.field("width", &self.width)
.field("height", &self.height)
.field("seed", &self.seed)
.field(
"Average Rainfall",
&(self
.terrain
.iter()
.flatten()
.map(|cell| cell.rainfall)
.sum::<f32>()
/ (self.width * self.height) as f32),
)
.field("continent_offsets", &self.continent_offsets)
.field("continent_widths", &self.continent_widths)
.field("perlin", &self.perlin)
.finish()
}
}
#[derive(Debug, Copy, Clone, Default)]
pub struct TerrainCell {
pub altitude: f32,
pub rainfall: f32,
pub rain_accumulated: f32,
}
impl World {
@ -64,14 +88,16 @@ impl World {
vec![TerrainCell::default(); width.try_into().unwrap()];
height.try_into().unwrap()
],
contintent_offsets: [default(); Self::NUM_CONTINENTS as usize],
continent_offsets: [default(); Self::NUM_CONTINENTS as usize],
continent_widths: [default(); Self::NUM_CONTINENTS as usize],
perlin: Perlin::new().set_seed(seed),
}
}
pub const NUM_CONTINENTS: u8 = 7;
pub const CONTINENT_FACTOR: f32 = 0.7;
pub const CONTINENT_WIDTH_FACTOR: f32 = 5.0;
pub const CONTINENT_MIN_WIDTH_FACTOR: f32 = 3.0;
pub const CONTINENT_MAX_WIDTH_FACTOR: f32 = 7.0;
pub const MIN_ALTITUDE: f32 = -10000.0;
pub const MAX_ALTITUDE: f32 = 10000.0;
@ -93,9 +119,9 @@ impl World {
if let Err(err) = self.generate_altitude() {
return Err(WorldGenError::CartesianError(err));
}
// if let Err(err) = self.generate_rainfall() {
// return Err(WorldGenError::CartesianError(err));
// }
if let Err(err) = self.generate_rainfall_alt() {
return Err(WorldGenError::CartesianError(err));
}
Ok(())
}
@ -104,11 +130,16 @@ impl World {
let mut rng = rand::thread_rng();
let width = self.width as f32;
let height = self.height as f32;
for (idx, continent_offset) in self.contintent_offsets.iter_mut().enumerate() {
continent_offset.x = rng
.gen_range(width * idx as f32 * 2.0 / 5.0..width * (idx as f32 + 2.0) * 2.0 / 5.0)
for i in 0..Self::NUM_CONTINENTS {
self.continent_offsets[i as usize].x = rng
.gen_range(width * i as f32 * 2.0 / 5.0..width * (i as f32 + 2.0) * 2.0 / 5.0)
.repeat(width);
continent_offset.y = rng.gen_range(height * 1.0 / 6.0..height * 5.0 / 6.0);
self.continent_offsets[i as usize].y =
rng.gen_range(height * 1.0 / 6.0..height * 5.0 / 6.0);
self.continent_widths[i as usize] =
rng.gen_range(Self::CONTINENT_MIN_WIDTH_FACTOR..Self::CONTINENT_MAX_WIDTH_FACTOR);
}
}
@ -121,21 +152,23 @@ impl World {
let mut max_value = 0.0;
let beta_factor = f32::sin(PI * y / height);
for Vec2 {
x: continent_x,
y: contintent_y,
} in self.contintent_offsets
{
for i in 0..Self::NUM_CONTINENTS {
let idx = i as usize;
let Vec2 {
x: continent_x,
y: continent_y,
} = self.continent_offsets[idx];
let distance_x = f32::min(
f32::min((continent_x - x).abs(), (width + continent_x - x).abs()),
(continent_x - x - width).abs(),
) * beta_factor;
let distance_y = f32::abs(contintent_y - y);
let distance_y = f32::abs(continent_y - y);
let distance = (distance_x * distance_x + distance_y * distance_y).sqrt();
let value = f32::max(0.0, 1.0 - Self::CONTINENT_WIDTH_FACTOR * distance / width);
let value = f32::max(0.0, 1.0 - self.continent_widths[idx] * distance / width);
max_value = f32::max(max_value, value);
}
@ -246,6 +279,43 @@ impl World {
Self::MIN_ALTITUDE + (raw_altitude * Self::ALTITUDE_SPAN)
}
fn generate_rainfall_alt(&mut self) -> Result<(), CartesianError> {
const MAX_CYCLES: u8 = 25;
const ACCUMULATED_RAIN_FACTOR: f32 = 2.0;
const RAINFALL_FACTOR: f32 = 0.1;
for _ in 0..MAX_CYCLES {
for x in 0..self.width {
let prev_x = (x + 1) % self.width;
for y in 0..self.height {
let width_factor = f32::sin(PI * y as f32 / self.height as f32);
let mut cell = self.terrain[y as usize][x as usize];
cell.rain_accumulated = 0.0;
if cell.altitude <= 0.0 {
cell.rain_accumulated +=
width_factor * ACCUMULATED_RAIN_FACTOR * Self::MAX_RAINFALL;
}
let prev_cell = self.terrain[y as usize][prev_x as usize];
cell.rain_accumulated += prev_cell.rain_accumulated;
cell.rainfall += cell.rain_accumulated * RAINFALL_FACTOR;
cell.rain_accumulated -= cell.rainfall;
cell.rain_accumulated = f32::max(cell.rain_accumulated, 0.0);
self.terrain[y as usize][x as usize] = cell;
}
}
}
Ok(())
}
fn generate_rainfall(&mut self) -> Result<(), CartesianError> {
let offset = Self::random_offset_vector();
const RADIUS: f32 = 2.0;

16
save/src/world_manager.rs
View file

@ -27,7 +27,7 @@ impl WorldManager {
let altitude_color = Self::altitude_contour_color(cell.altitude);
let rainfall_color = Self::rainfall_color(cell.rainfall);
let normalized_rainfall = f32::max(cell.rainfall / World::MAX_RAINFALL, 0.0);
let normalized_rainfall = Self::normalize_rainfall(cell.rainfall);
let r = (altitude_color.r() * (1.0 - normalized_rainfall))
+ (rainfall_color.r() * normalized_rainfall);
@ -36,7 +36,7 @@ impl WorldManager {
let b = (altitude_color.b() * (1.0 - normalized_rainfall))
+ (rainfall_color.b() * normalized_rainfall);
Color::rgb(r, g, b)
Color::rgb_linear(r, g, b)
}
fn altitude_color(altitude: f32) -> Color {
@ -64,11 +64,19 @@ impl WorldManager {
}
fn rainfall_color(rainfall: f32) -> Color {
if rainfall < 0.0 {
if rainfall <= 0.0 {
Color::BLACK
} else {
let mult = rainfall / World::MAX_RAINFALL;
Color::GREEN * mult
Color::rgb(0.0, mult, 0.0)
}
}
fn normalize_rainfall(rainfall: f32) -> f32 {
if rainfall <= 0.0 {
rainfall
} else {
rainfall / World::MAX_ALTITUDE
}
}