tawasuyu/llimphi

1//! Demo headless del **creador de mundos**: rinde la receta del **desierto**
2//! ([`WorldRecipe::desert`]) — llano de arena, pocas montañas, pocos ríos, cactus.
3//! Es el mundo de apertura del corto.
4//!
5//! `cargo run -p llimphi-voxel --example desert_demo --release -- [dim_xz] [seed]`
6//! → `/tmp/desert.png`
7
8use std::fs::File;
9use std::io::BufWriter;
10
11use llimphi_3d::glam::Vec3;
12use llimphi_3d::{Atmosphere, Camera3d, Scene3d, VoxelRenderer};
13use llimphi_hal::{wgpu, Hal};
14use llimphi_raster::peniko::Color;
15use llimphi_raster::{vello, Renderer};
16use llimphi_voxel::Project;
17
18const W: u32 = 960;
19const H: u32 = 540;
20const FMT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba8Unorm;
21
22fn main() {
23    let dim_xz: u32 = std::env::args().nth(1).and_then(|s| s.parse().ok()).unwrap_or(160);
24    let seed: u32 = std::env::args().nth(2).and_then(|s| s.parse().ok()).unwrap_or(7);
25    let dy: u32 = (dim_xz * 4 / 10).max(48);
26    let dim = [dim_xz, dy, dim_xz];
27
28    let hal = pollster::block_on(Hal::new(None)).expect("hal");
29    let mut renderer = Renderer::new(&hal).expect("renderer");
30
31    // El bioma de desierto del proyecto de arranque, resuelto a su paleta; la
32    // semilla del CLI manda (en vez de la del mundo).
33    let project = Project::starter();
34    let bioma = project.biomas.iter().find(|b| b.name == "desierto").expect("bioma desierto");
35    let palette = project.bioma_palette(bioma);
36    let grid = bioma.generate_window(seed, &palette, dim, [0, 0]);
37
38    let mut vr = VoxelRenderer::new(&hal.device, &hal.queue, FMT, &grid);
39    vr.sun_dir = [0.62, 0.42, 0.28]; // sol más bajo → relieve/sombras de las dunas y cactus
40    vr.atmosphere = Atmosphere {
41        sky_zenith: [92, 146, 208],
42        sky_horizon: [228, 206, 162], // horizonte arenoso/caluroso
43        fog_density: 0.22 / dim_xz as f32, // niebla suave: no lavar el llano
44        god_rays: 0.0,
45    };
46
47    // Cámara baja, en 3/4, para leer el llano + los cactus recortados contra el cielo.
48    let camera = Camera3d::orbit(
49        Vec3::new(0.0, dy as f32 * -0.18, 0.0),
50        38_f32.to_radians(),
51        14_f32.to_radians(),
52        dim_xz as f32 * 1.5,
53    );
54
55    let mut scene = Scene3d::new();
56    let pixels = render(&hal, &mut renderer, &mut scene, &mut vr, &camera);
57    write_png(&pixels, "/tmp/desert.png");
58    eprintln!("escrito /tmp/desert.png (desierto {dim_xz}³ seed {seed})");
59}
60
61fn render(
62    hal: &Hal,
63    renderer: &mut Renderer,
64    scene: &mut Scene3d,
65    vr: &mut VoxelRenderer,
66    camera: &Camera3d,
67) -> Vec<u8> {
68    let inter = hal.device.create_texture(&wgpu::TextureDescriptor {
69        label: Some("inter"),
70        size: wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
71        mip_level_count: 1,
72        sample_count: 1,
73        dimension: wgpu::TextureDimension::D2,
74        format: FMT,
75        usage: wgpu::TextureUsages::STORAGE_BINDING
76            | wgpu::TextureUsages::TEXTURE_BINDING
77            | wgpu::TextureUsages::RENDER_ATTACHMENT
78            | wgpu::TextureUsages::COPY_SRC,
79        view_formats: &[],
80    });
81    let view = inter.create_view(&wgpu::TextureViewDescriptor::default());
82    renderer
83        .render_to_view(hal, &vello::Scene::new(), &view, W, H, Color::from_rgba8(0, 0, 0, 255))
84        .expect("base");
85    let mut enc = hal
86        .device
87        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: Some("desert") });
88    scene.render(&hal.device, &hal.queue, &mut enc, &view, (W, H), camera, Some(vr), &[]);
89    hal.queue.submit(std::iter::once(enc.finish()));
90    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
91    readback(hal, &inter)
92}
93
94fn readback(hal: &Hal, target: &wgpu::Texture) -> Vec<u8> {
95    let unpadded = (W * 4) as usize;
96    let align = wgpu::COPY_BYTES_PER_ROW_ALIGNMENT as usize;
97    let padded = unpadded.div_ceil(align) * align;
98    let buf = hal.device.create_buffer(&wgpu::BufferDescriptor {
99        label: Some("readback"),
100        size: (padded * H as usize) as u64,
101        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
102        mapped_at_creation: false,
103    });
104    let mut enc = hal
105        .device
106        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
107    enc.copy_texture_to_buffer(
108        wgpu::TexelCopyTextureInfo {
109            texture: target,
110            mip_level: 0,
111            origin: wgpu::Origin3d::ZERO,
112            aspect: wgpu::TextureAspect::All,
113        },
114        wgpu::TexelCopyBufferInfo {
115            buffer: &buf,
116            layout: wgpu::TexelCopyBufferLayout {
117                offset: 0,
118                bytes_per_row: Some(padded as u32),
119                rows_per_image: Some(H),
120            },
121        },
122        wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
123    );
124    hal.queue.submit(std::iter::once(enc.finish()));
125    let slice = buf.slice(..);
126    let (tx, rx) = std::sync::mpsc::channel();
127    slice.map_async(wgpu::MapMode::Read, move |r| {
128        let _ = tx.send(r);
129    });
130    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
131    rx.recv().unwrap().unwrap();
132    let data = slice.get_mapped_range();
133    let mut pixels = Vec::with_capacity((W * H * 4) as usize);
134    for row in 0..H as usize {
135        let s = row * padded;
136        pixels.extend_from_slice(&data[s..s + unpadded]);
137    }
138    drop(data);
139    buf.unmap();
140    pixels
141}
142
143fn write_png(pixels: &[u8], path: &str) {
144    let file = File::create(path).expect("png");
145    let mut enc = png::Encoder::new(BufWriter::new(file), W, H);
146    enc.set_color(png::ColorType::Rgba);
147    enc.set_depth(png::BitDepth::Eight);
148    let mut wtr = enc.write_header().unwrap();
149    wtr.write_image_data(pixels).unwrap();
150}