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::WorldRecipe;
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    let recipe = WorldRecipe::desert(seed);
32    let grid = recipe.generate(dim);
33
34    let mut vr = VoxelRenderer::new(&hal.device, &hal.queue, FMT, &grid);
35    vr.sun_dir = [0.62, 0.42, 0.28]; // sol más bajo → relieve/sombras de las dunas y cactus
36    vr.atmosphere = Atmosphere {
37        sky_zenith: [92, 146, 208],
38        sky_horizon: [228, 206, 162], // horizonte arenoso/caluroso
39        fog_density: 0.22 / dim_xz as f32, // niebla suave: no lavar el llano
40    };
41
42    // Cámara baja, en 3/4, para leer el llano + los cactus recortados contra el cielo.
43    let camera = Camera3d::orbit(
44        Vec3::new(0.0, dy as f32 * -0.18, 0.0),
45        38_f32.to_radians(),
46        14_f32.to_radians(),
47        dim_xz as f32 * 1.5,
48    );
49
50    let mut scene = Scene3d::new();
51    let pixels = render(&hal, &mut renderer, &mut scene, &mut vr, &camera);
52    write_png(&pixels, "/tmp/desert.png");
53    eprintln!("escrito /tmp/desert.png (desierto {dim_xz}³ seed {seed})");
54}
55
56fn render(
57    hal: &Hal,
58    renderer: &mut Renderer,
59    scene: &mut Scene3d,
60    vr: &mut VoxelRenderer,
61    camera: &Camera3d,
62) -> Vec<u8> {
63    let inter = hal.device.create_texture(&wgpu::TextureDescriptor {
64        label: Some("inter"),
65        size: wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
66        mip_level_count: 1,
67        sample_count: 1,
68        dimension: wgpu::TextureDimension::D2,
69        format: FMT,
70        usage: wgpu::TextureUsages::STORAGE_BINDING
71            | wgpu::TextureUsages::TEXTURE_BINDING
72            | wgpu::TextureUsages::RENDER_ATTACHMENT
73            | wgpu::TextureUsages::COPY_SRC,
74        view_formats: &[],
75    });
76    let view = inter.create_view(&wgpu::TextureViewDescriptor::default());
77    renderer
78        .render_to_view(hal, &vello::Scene::new(), &view, W, H, Color::from_rgba8(0, 0, 0, 255))
79        .expect("base");
80    let mut enc = hal
81        .device
82        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: Some("desert") });
83    scene.render(&hal.device, &hal.queue, &mut enc, &view, (W, H), camera, Some(vr), &[]);
84    hal.queue.submit(std::iter::once(enc.finish()));
85    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
86    readback(hal, &inter)
87}
88
89fn readback(hal: &Hal, target: &wgpu::Texture) -> Vec<u8> {
90    let unpadded = (W * 4) as usize;
91    let align = wgpu::COPY_BYTES_PER_ROW_ALIGNMENT as usize;
92    let padded = unpadded.div_ceil(align) * align;
93    let buf = hal.device.create_buffer(&wgpu::BufferDescriptor {
94        label: Some("readback"),
95        size: (padded * H as usize) as u64,
96        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
97        mapped_at_creation: false,
98    });
99    let mut enc = hal
100        .device
101        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
102    enc.copy_texture_to_buffer(
103        wgpu::TexelCopyTextureInfo {
104            texture: target,
105            mip_level: 0,
106            origin: wgpu::Origin3d::ZERO,
107            aspect: wgpu::TextureAspect::All,
108        },
109        wgpu::TexelCopyBufferInfo {
110            buffer: &buf,
111            layout: wgpu::TexelCopyBufferLayout {
112                offset: 0,
113                bytes_per_row: Some(padded as u32),
114                rows_per_image: Some(H),
115            },
116        },
117        wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
118    );
119    hal.queue.submit(std::iter::once(enc.finish()));
120    let slice = buf.slice(..);
121    let (tx, rx) = std::sync::mpsc::channel();
122    slice.map_async(wgpu::MapMode::Read, move |r| {
123        let _ = tx.send(r);
124    });
125    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
126    rx.recv().unwrap().unwrap();
127    let data = slice.get_mapped_range();
128    let mut pixels = Vec::with_capacity((W * H * 4) as usize);
129    for row in 0..H as usize {
130        let s = row * padded;
131        pixels.extend_from_slice(&data[s..s + unpadded]);
132    }
133    drop(data);
134    buf.unmap();
135    pixels
136}
137
138fn write_png(pixels: &[u8], path: &str) {
139    let file = File::create(path).expect("png");
140    let mut enc = png::Encoder::new(BufWriter::new(file), W, H);
141    enc.set_color(png::ColorType::Rgba);
142    enc.set_depth(png::BitDepth::Eight);
143    let mut wtr = enc.write_header().unwrap();
144    wtr.write_image_data(pixels).unwrap();
145}