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        god_rays: 0.0,
41    };
42
43    // Cámara baja, en 3/4, para leer el llano + los cactus recortados contra el cielo.
44    let camera = Camera3d::orbit(
45        Vec3::new(0.0, dy as f32 * -0.18, 0.0),
46        38_f32.to_radians(),
47        14_f32.to_radians(),
48        dim_xz as f32 * 1.5,
49    );
50
51    let mut scene = Scene3d::new();
52    let pixels = render(&hal, &mut renderer, &mut scene, &mut vr, &camera);
53    write_png(&pixels, "/tmp/desert.png");
54    eprintln!("escrito /tmp/desert.png (desierto {dim_xz}³ seed {seed})");
55}
56
57fn render(
58    hal: &Hal,
59    renderer: &mut Renderer,
60    scene: &mut Scene3d,
61    vr: &mut VoxelRenderer,
62    camera: &Camera3d,
63) -> Vec<u8> {
64    let inter = hal.device.create_texture(&wgpu::TextureDescriptor {
65        label: Some("inter"),
66        size: wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
67        mip_level_count: 1,
68        sample_count: 1,
69        dimension: wgpu::TextureDimension::D2,
70        format: FMT,
71        usage: wgpu::TextureUsages::STORAGE_BINDING
72            | wgpu::TextureUsages::TEXTURE_BINDING
73            | wgpu::TextureUsages::RENDER_ATTACHMENT
74            | wgpu::TextureUsages::COPY_SRC,
75        view_formats: &[],
76    });
77    let view = inter.create_view(&wgpu::TextureViewDescriptor::default());
78    renderer
79        .render_to_view(hal, &vello::Scene::new(), &view, W, H, Color::from_rgba8(0, 0, 0, 255))
80        .expect("base");
81    let mut enc = hal
82        .device
83        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: Some("desert") });
84    scene.render(&hal.device, &hal.queue, &mut enc, &view, (W, H), camera, Some(vr), &[]);
85    hal.queue.submit(std::iter::once(enc.finish()));
86    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
87    readback(hal, &inter)
88}
89
90fn readback(hal: &Hal, target: &wgpu::Texture) -> Vec<u8> {
91    let unpadded = (W * 4) as usize;
92    let align = wgpu::COPY_BYTES_PER_ROW_ALIGNMENT as usize;
93    let padded = unpadded.div_ceil(align) * align;
94    let buf = hal.device.create_buffer(&wgpu::BufferDescriptor {
95        label: Some("readback"),
96        size: (padded * H as usize) as u64,
97        usage: wgpu::BufferUsages::MAP_READ | wgpu::BufferUsages::COPY_DST,
98        mapped_at_creation: false,
99    });
100    let mut enc = hal
101        .device
102        .create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
103    enc.copy_texture_to_buffer(
104        wgpu::TexelCopyTextureInfo {
105            texture: target,
106            mip_level: 0,
107            origin: wgpu::Origin3d::ZERO,
108            aspect: wgpu::TextureAspect::All,
109        },
110        wgpu::TexelCopyBufferInfo {
111            buffer: &buf,
112            layout: wgpu::TexelCopyBufferLayout {
113                offset: 0,
114                bytes_per_row: Some(padded as u32),
115                rows_per_image: Some(H),
116            },
117        },
118        wgpu::Extent3d { width: W, height: H, depth_or_array_layers: 1 },
119    );
120    hal.queue.submit(std::iter::once(enc.finish()));
121    let slice = buf.slice(..);
122    let (tx, rx) = std::sync::mpsc::channel();
123    slice.map_async(wgpu::MapMode::Read, move |r| {
124        let _ = tx.send(r);
125    });
126    let _ = hal.device.poll(wgpu::PollType::wait_indefinitely());
127    rx.recv().unwrap().unwrap();
128    let data = slice.get_mapped_range();
129    let mut pixels = Vec::with_capacity((W * H * 4) as usize);
130    for row in 0..H as usize {
131        let s = row * padded;
132        pixels.extend_from_slice(&data[s..s + unpadded]);
133    }
134    drop(data);
135    buf.unmap();
136    pixels
137}
138
139fn write_png(pixels: &[u8], path: &str) {
140    let file = File::create(path).expect("png");
141    let mut enc = png::Encoder::new(BufWriter::new(file), W, H);
142    enc.set_color(png::ColorType::Rgba);
143    enc.set_depth(png::BitDepth::Eight);
144    let mut wtr = enc.write_header().unwrap();
145    wtr.write_image_data(pixels).unwrap();
146}