//! Bounded orthographic production rendering. GPU work runs on the native
//! current context, one request per UI update; sampling/filtering/PNG I/O run
//! on the worker. The worker never waits for a preview acknowledgment.
use crate::{
    equipment,
    preview::{self, Mat4, PreviewCharacter, PreviewControls},
    project::CameraFraming,
    render_job::{ImageBuf, RenderEvent},
};
use glow::HasContext;
use std::{
    path::{Path, PathBuf},
    sync::{
        atomic::{AtomicBool, Ordering},
        mpsc, Arc, Mutex,
    },
    thread,
};

pub const SCALE: u32 = 8;
pub const MAX_HIGHRES: u32 = 2048;
pub const PASSES: [&str; 6] = [
    "highres",
    "detail",
    "target-res / diffuse",
    "depth",
    "normal",
    "specular",
];
pub const NEAR: f32 = 0.05;
pub const FAR: f32 = 40.;
#[derive(Clone)]
pub struct Draw {
    pub positions: Arc<Vec<[f32; 3]>>,
    pub normals: Arc<Vec<[f32; 3]>>,
    pub uvs: Arc<Vec<[f32; 2]>>,
    pub vertex_colors: Arc<Vec<[f32; 4]>>,
    pub indices: Vec<u32>,
    pub color: [f32; 4],
    pub albedo: Option<Arc<equipment::Texture>>,
    pub shiny: Option<Arc<equipment::Texture>>,
    pub specular: f32,
    pub cutoff: f32,
    pub flat_normals: bool,
}
#[derive(Clone)]
pub struct Scene {
    pub draws: Vec<Draw>,
    pub view: Mat4,
    pub projection: Mat4,
    pub width: u32,
    pub height: u32,
}
#[derive(Debug)]
pub struct Buffers {
    pub width: u32,
    pub height: u32,
    pub diffuse: Vec<u8>,
    pub normal: Vec<u8>,
    pub specular: Vec<u8>,
    pub depth: Vec<f32>,
}
#[derive(Debug)]
pub struct Target {
    pub diffuse: ImageBuf,
    pub normal: ImageBuf,
    pub specular: ImageBuf,
    pub depth: Vec<u16>,
    pub depth_preview: ImageBuf,
}
#[derive(Clone)]
pub struct RenderJob {
    pub character: PreviewCharacter,
    pub sex: String,
    pub preset: Option<equipment::Preset>,
    pub target_width: u32,
    pub target_height: u32,
    pub fps: u32,
    pub framing: CameraFraming,
    pub output: PathBuf,
}
#[derive(Debug, Clone, PartialEq)]
pub struct ClipPlan {
    pub source_name: String,
    pub token: String,
    pub frames: u32,
}
#[derive(Debug, Clone, PartialEq)]
pub struct Plan {
    pub clips: Vec<ClipPlan>,
    pub images: u32,
    pub passes: u32,
    pub files: u32,
}
pub fn plan(body: &PreviewCharacter, fps: u32) -> Result<Plan, String> {
    if fps == 0 || fps > 240 {
        return Err("fps moet 1–240 zijn".into());
    }
    let clips = if body.clips.is_empty() {
        vec![ClipPlan {
            source_name: String::new(),
            token: "clip000-bind".into(),
            frames: 1,
        }]
    } else {
        body.clips
            .iter()
            .enumerate()
            .map(|(i, c)| {
                let duration = c.duration;
                if !duration.is_finite() || duration < 0. || duration * fps as f32 > 100000. {
                    return Err("ongeldige of te lange animatie".into());
                }
                // Exporter float timestamps commonly put a nominal 1-second
                // endpoint one ULP above 1. Do not duplicate that terminal pose.
                let samples = f64::from(duration) * f64::from(fps);
                let nearest = samples.round();
                let samples = if (samples - nearest).abs()
                    <= 4. * f64::from(f32::EPSILON) * samples.max(1.)
                {
                    nearest
                } else {
                    samples
                };
                Ok(ClipPlan {
                    source_name: c.name.clone(),
                    token: clip_token(i, &c.name),
                    frames: samples.ceil().max(1.) as u32,
                })
            })
            .collect::<Result<Vec<_>, String>>()?
    };
    let frames = clips
        .iter()
        .try_fold(0u32, |n, c| n.checked_add(c.frames))
        .ok_or("te veel frames")?;
    let images = frames.checked_mul(36).ok_or("te veel beelden")?;
    let passes = images.checked_mul(6).ok_or("te veel passes")?;
    let files = images.checked_mul(4).ok_or("te veel bestanden")?;
    if files > 500000 {
        return Err("batch groter dan 500000 uitvoerbestanden".into());
    }
    Ok(Plan {
        clips,
        images,
        passes,
        files,
    })
}
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct Sample {
    pub clip: usize,
    pub frame: u32,
    pub pitch: i32,
    pub yaw: u32,
}
pub fn samples(plan: &Plan) -> impl Iterator<Item = Sample> + '_ {
    plan.clips.iter().enumerate().flat_map(|(clip, c)| {
        (0..c.frames).flat_map(move |frame| {
            [-30, 0, 30].into_iter().flat_map(move |pitch| {
                (0..12).map(move |y| Sample {
                    clip,
                    frame,
                    pitch,
                    yaw: y * 30,
                })
            })
        })
    })
}

pub fn clip_token(index: usize, name: &str) -> String {
    let slug: String = name
        .chars()
        .map(|c| {
            if c.is_ascii_alphanumeric() {
                c.to_ascii_lowercase()
            } else {
                '-'
            }
        })
        .take(48)
        .collect();
    format!(
        "clip{index:03}-{}",
        if slug.is_empty() { "animation" } else { &slug }
    )
}
pub fn output_path(
    sex: &str,
    set: &str,
    clip: &str,
    frame: u32,
    pitch: i32,
    yaw: u32,
    map: &str,
) -> Result<PathBuf, String> {
    if !["male", "female"].contains(&sex)
        || !(set == "body" || equipment::valid_name(set))
        || !equipment::valid_name(clip)
        || ![-30, 0, 30].contains(&pitch)
        || yaw >= 360
        || !yaw.is_multiple_of(30)
        || !["diffuse", "normal", "depth", "specular"].contains(&map)
    {
        return Err("ongeldig uitvoerpad/token".into());
    }
    Ok(PathBuf::from(sex)
        .join(set)
        .join(clip)
        .join(format!("f{frame:06}"))
        .join(format!("p{pitch:+03}_y{yaw:03}_{map}.png")))
}
pub fn camera(framing: CameraFraming, yaw: f32, pitch: f32, aspect: f32) -> (Mat4, Mat4) {
    let target = [0., framing.center_y_milli as f32 / 1000., 0.];
    let d = preview::eye_offset(yaw, pitch, 10.);
    let eye = [d[0], target[1] + d[1], d[2]];
    let half = framing.height_milli as f32 / 2000.;
    let mut p = preview::identity();
    p[0] = 1. / (half * aspect);
    p[5] = 1. / half;
    p[10] = -2. / (FAR - NEAR);
    p[14] = -(FAR + NEAR) / (FAR - NEAR);
    (preview::view_matrix(eye, target), p)
}
fn point(m: &Mat4, p: [f32; 3]) -> [f32; 3] {
    std::array::from_fn(|i| m[i] * p[0] + m[i + 4] * p[1] + m[i + 8] * p[2] + m[i + 12])
}
fn normalize(v: [f32; 3]) -> [f32; 3] {
    let l = v.iter().map(|x| x * x).sum::<f32>().sqrt();
    if l > 1e-10 {
        v.map(|x| x / l)
    } else {
        [0., 0., 1.]
    }
}
fn normal(m: &Mat4, n: [f32; 3]) -> [f32; 3] {
    let a = [m[0], m[1], m[2]];
    let b = [m[4], m[5], m[6]];
    let c = [m[8], m[9], m[10]];
    let cross = |a: [f32; 3], b: [f32; 3]| {
        [
            a[1] * b[2] - a[2] * b[1],
            a[2] * b[0] - a[0] * b[2],
            a[0] * b[1] - a[1] * b[0],
        ]
    };
    let x = cross(b, c);
    let y = cross(c, a);
    let z = cross(a, b);
    let det = a.iter().zip(x).map(|(a, b)| a * b).sum::<f32>();
    if det.abs() < 1e-12 {
        return normalize(n);
    }
    normalize(std::array::from_fn(|i| {
        (x[i] * n[0] + y[i] * n[1] + z[i] * n[2]) / det
    }))
}
pub fn scene(
    job: &RenderJob,
    clip: &str,
    time: f32,
    pitch: f32,
    yaw: f32,
    cache: &mut equipment::TextureCache,
) -> Result<Scene, String> {
    let body = &job.character;
    let mut draws = Vec::new();
    if let Some(preset) = &job.preset {
        let controls = PreviewControls {
            clip_name: clip.into(),
            time,
            ..Default::default()
        };
        for layer in equipment::layers_cached(
            preset,
            usize::from(job.sex == "female"),
            body,
            &controls,
            cache,
        )? {
            let m = layer.model;
            draws.push(Draw {
                positions: Arc::new(layer.mesh.positions.iter().map(|p| point(&m, *p)).collect()),
                normals: Arc::new(layer.mesh.normals.iter().map(|n| normal(&m, *n)).collect()),
                uvs: Arc::new(
                    layer
                        .mesh
                        .uvs
                        .into_iter()
                        .map(|[u, v]| [u, 1. - v])
                        .collect(),
                ),
                vertex_colors: Arc::new(Vec::new()),
                indices: layer.mesh.indices,
                color: layer.mesh.color,
                albedo: layer.albedo,
                shiny: layer.shiny,
                specular: layer.specular,
                cutoff: 0.5,
                flat_normals: false,
            });
        }
    } else {
        let bones = preview::sample_skin_matrices(body, clip, time);
        let mut positions = Vec::with_capacity(body.positions.len());
        let mut normals = Vec::with_capacity(body.positions.len());
        for (i, p) in body.positions.iter().enumerate() {
            let mut m = preview::identity();
            if !bones.is_empty() && body.weights.len() == body.positions.len() {
                m = [0.; 16];
                let joints = body.joints.get(i).copied().unwrap_or([0; 4]);
                for (j, w) in joints.into_iter().zip(body.weights[i]) {
                    let b = bones.get(j as usize).ok_or("ongeldige skinjoint")?;
                    for k in 0..16 {
                        m[k] += b[k] * w;
                    }
                }
            }
            positions.push(point(&m, *p));
            normals.push(normal(
                &m,
                body.normals.get(i).copied().unwrap_or([0., 1., 0.]),
            ));
        }
        let positions = Arc::new(positions);
        let normals = Arc::new(normals);
        let uvs = Arc::new(body.uvs.clone());
        let colors = Arc::new(body.colors.clone());
        if body.surfaces.is_empty() {
            draws.push(Draw {
                positions,
                normals,
                uvs,
                vertex_colors: colors,
                indices: body.indices.clone(),
                color: body.base_color,
                albedo: None,
                shiny: None,
                specular: 0.,
                cutoff: 0.001,
                flat_normals: !body.source_normals_complete,
            });
        } else {
            for surface in &body.surfaces {
                draws.push(Draw {
                    positions: positions.clone(),
                    normals: normals.clone(),
                    uvs: uvs.clone(),
                    vertex_colors: colors.clone(),
                    indices: body.indices[surface.first..surface.first + surface.count].to_vec(),
                    color: surface.color,
                    albedo: surface.albedo.clone(),
                    shiny: None,
                    specular: 0.,
                    cutoff: surface.cutoff,
                    flat_normals: surface.flat_normals,
                });
            }
        }
    }
    let (view, projection) = camera(
        job.framing,
        yaw,
        pitch,
        job.target_width as f32 / job.target_height as f32,
    );
    Ok(Scene {
        draws,
        view,
        projection,
        width: job.target_width * SCALE,
        height: job.target_height * SCALE,
    })
}

impl Scene {
    pub fn validate(&self) -> Result<(), String> {
        if self.width == 0
            || self.height == 0
            || self.width > MAX_HIGHRES
            || self.height > MAX_HIGHRES
            || self.draws.len() > 4096
            || self
                .view
                .iter()
                .chain(&self.projection)
                .any(|v| !v.is_finite())
        {
            return Err("ongeldige GPU-scène/afmetingen".into());
        }
        for d in &self.draws {
            if d.positions.len() > 1_000_000
                || d.positions.len() != d.normals.len()
                || d.indices.len() > 3_000_000
                || !d.indices.len().is_multiple_of(3)
                || d.indices.iter().any(|i| *i as usize >= d.positions.len())
                || d.positions
                    .iter()
                    .chain(d.normals.iter())
                    .flatten()
                    .chain(d.uvs.iter().flatten())
                    .chain(d.vertex_colors.iter().flatten())
                    .chain(d.color.iter())
                    .any(|v| !v.is_finite())
                || !d.specular.is_finite()
                || !d.cutoff.is_finite()
            {
                return Err("ongeldige of te grote GPU-geometrie".into());
            }
            for t in [d.albedo.as_ref(), d.shiny.as_ref()].into_iter().flatten() {
                if t.width == 0
                    || t.height == 0
                    || t.width > 2048
                    || t.height > 2048
                    || t.rgba.len() != t.width as usize * t.height as usize * 4
                {
                    return Err("ongeldige GPU-texture".into());
                }
            }
        }
        Ok(())
    }
}

#[derive(Default)]
pub struct GpuRenderer {
    program: Option<glow::Program>,
    vao: Option<glow::VertexArray>,
    vbo: Option<glow::Buffer>,
    ebo: Option<glow::Buffer>,
    fbo: Option<glow::Framebuffer>,
    colors: Vec<glow::Texture>,
    depth: Option<glow::Renderbuffer>,
    extent: [u32; 2],
}
impl GpuRenderer {
    /// # Safety
    /// A native OpenGL 3.3 context must be current on this thread.
    pub unsafe fn destroy(&mut self, gl: &glow::Context) {
        self.destroy_target(gl);
        if let Some(x) = self.program.take() {
            gl.delete_program(x);
        }
        if let Some(x) = self.vao.take() {
            gl.delete_vertex_array(x);
        }
        if let Some(x) = self.vbo.take() {
            gl.delete_buffer(x);
        }
        if let Some(x) = self.ebo.take() {
            gl.delete_buffer(x);
        }
    }
    unsafe fn destroy_target(&mut self, gl: &glow::Context) {
        for x in self.colors.drain(..) {
            gl.delete_texture(x);
        }
        if let Some(x) = self.depth.take() {
            gl.delete_renderbuffer(x);
        }
        if let Some(x) = self.fbo.take() {
            gl.delete_framebuffer(x);
        }
        self.extent = [0, 0];
    }
    unsafe fn init(&mut self, gl: &glow::Context) -> Result<(), String> {
        if self.program.is_some() {
            return Ok(());
        }
        let p = gl.create_program()?;
        let mut shaders = Vec::new();
        for (kind, source) in [
            (glow::VERTEX_SHADER, VERTEX),
            (glow::FRAGMENT_SHADER, FRAGMENT),
        ] {
            let shader = gl.create_shader(kind)?;
            gl.shader_source(shader, source);
            gl.compile_shader(shader);
            if !gl.get_shader_compile_status(shader) {
                let error = gl.get_shader_info_log(shader);
                gl.delete_shader(shader);
                for s in shaders {
                    gl.delete_shader(s);
                }
                gl.delete_program(p);
                return Err(error);
            }
            gl.attach_shader(p, shader);
            shaders.push(shader);
        }
        gl.link_program(p);
        let result = if gl.get_program_link_status(p) {
            Ok(())
        } else {
            Err(gl.get_program_info_log(p))
        };
        for s in shaders {
            gl.detach_shader(p, s);
            gl.delete_shader(s);
        }
        if let Err(e) = result {
            gl.delete_program(p);
            return Err(e);
        }
        self.program = Some(p);
        self.vao = Some(gl.create_vertex_array()?);
        self.vbo = Some(gl.create_buffer()?);
        self.ebo = Some(gl.create_buffer()?);
        Ok(())
    }
    unsafe fn target(&mut self, gl: &glow::Context, w: u32, h: u32) -> Result<(), String> {
        if self.extent == [w, h] {
            return Ok(());
        }
        self.destroy_target(gl);
        self.fbo = Some(gl.create_framebuffer()?);
        gl.bind_framebuffer(glow::FRAMEBUFFER, self.fbo);
        for slot in 0..3 {
            let t = gl.create_texture()?;
            self.colors.push(t);
            gl.bind_texture(glow::TEXTURE_2D, Some(t));
            gl.tex_parameter_i32(
                glow::TEXTURE_2D,
                glow::TEXTURE_MIN_FILTER,
                glow::NEAREST as i32,
            );
            gl.tex_parameter_i32(
                glow::TEXTURE_2D,
                glow::TEXTURE_MAG_FILTER,
                glow::NEAREST as i32,
            );
            gl.tex_image_2d(
                glow::TEXTURE_2D,
                0,
                glow::RGBA8 as i32,
                w as i32,
                h as i32,
                0,
                glow::RGBA,
                glow::UNSIGNED_BYTE,
                None,
            );
            gl.framebuffer_texture_2d(
                glow::FRAMEBUFFER,
                glow::COLOR_ATTACHMENT0 + slot,
                glow::TEXTURE_2D,
                Some(t),
                0,
            );
        }
        let d = gl.create_renderbuffer()?;
        self.depth = Some(d);
        gl.bind_renderbuffer(glow::RENDERBUFFER, Some(d));
        gl.renderbuffer_storage(
            glow::RENDERBUFFER,
            glow::DEPTH_COMPONENT24,
            w as i32,
            h as i32,
        );
        gl.framebuffer_renderbuffer(
            glow::FRAMEBUFFER,
            glow::DEPTH_ATTACHMENT,
            glow::RENDERBUFFER,
            Some(d),
        );
        gl.draw_buffers(&[
            glow::COLOR_ATTACHMENT0,
            glow::COLOR_ATTACHMENT1,
            glow::COLOR_ATTACHMENT2,
        ]);
        if gl.check_framebuffer_status(glow::FRAMEBUFFER) != glow::FRAMEBUFFER_COMPLETE {
            return Err("productie-FBO onvolledig".into());
        }
        self.extent = [w, h];
        Ok(())
    }
    /// Render and read back unlit color, view-space normals, scalar specular and
    /// the actual depth attachment. All four use the same winning surface.
    /// # Safety
    /// `gl` is current on the UI thread. GL state is reset for egui painting.
    pub unsafe fn render(&mut self, gl: &glow::Context, scene: &Scene) -> Result<Buffers, String> {
        if scene.width == 0
            || scene.height == 0
            || scene.width > MAX_HIGHRES
            || scene.height > MAX_HIGHRES
        {
            return Err("highres moet 1–2048 pixels zijn (8× target)".into());
        }
        scene.validate()?;
        let previous = gl.get_parameter_i32(glow::FRAMEBUFFER_BINDING);
        let mut vp = [0; 4];
        gl.get_parameter_i32_slice(glow::VIEWPORT, &mut vp);
        let result = (|| {
            self.init(gl)?;
            self.target(gl, scene.width, scene.height)?;
            gl.bind_framebuffer(glow::FRAMEBUFFER, self.fbo);
            gl.draw_buffers(&[
                glow::COLOR_ATTACHMENT0,
                glow::COLOR_ATTACHMENT1,
                glow::COLOR_ATTACHMENT2,
            ]);
            gl.viewport(0, 0, scene.width as i32, scene.height as i32);
            gl.disable(glow::SCISSOR_TEST);
            gl.disable(glow::CULL_FACE);
            gl.disable(glow::BLEND);
            gl.enable(glow::DEPTH_TEST);
            gl.depth_mask(true);
            gl.depth_func(glow::LESS);
            gl.clear_depth_f32(1.);
            gl.clear_color(0., 0., 0., 0.);
            gl.clear(glow::COLOR_BUFFER_BIT | glow::DEPTH_BUFFER_BIT);
            let p = self.program.ok_or("shader ontbreekt")?;
            gl.use_program(Some(p));
            gl.uniform_matrix_4_f32_slice(
                gl.get_uniform_location(p, "u_view").as_ref(),
                false,
                &scene.view,
            );
            gl.uniform_matrix_4_f32_slice(
                gl.get_uniform_location(p, "u_projection").as_ref(),
                false,
                &scene.projection,
            );
            gl.bind_vertex_array(self.vao);
            gl.bind_buffer(glow::ARRAY_BUFFER, self.vbo);
            gl.bind_buffer(glow::ELEMENT_ARRAY_BUFFER, self.ebo);
            for (slot, size, offset) in [(0, 3, 0), (1, 3, 3), (2, 2, 6), (3, 4, 8)] {
                gl.enable_vertex_attrib_array(slot);
                gl.vertex_attrib_pointer_f32(slot, size, glow::FLOAT, false, 12 * 4, offset * 4);
            }
            for draw in &scene.draws {
                if draw.positions.len() != draw.normals.len()
                    || draw
                        .indices
                        .iter()
                        .any(|i| *i as usize >= draw.positions.len())
                    || draw.indices.len() > i32::MAX as usize
                {
                    return Err("ongeldige GPU-geometrie".into());
                }
                let mut data = Vec::with_capacity(draw.positions.len() * 12);
                for (i, pos) in draw.positions.iter().enumerate() {
                    data.extend_from_slice(pos);
                    data.extend_from_slice(&draw.normals[i]);
                    data.extend_from_slice(&draw.uvs.get(i).copied().unwrap_or([0.; 2]));
                    data.extend_from_slice(&draw.vertex_colors.get(i).copied().unwrap_or([1.; 4]));
                }
                gl.buffer_data_u8_slice(
                    glow::ARRAY_BUFFER,
                    std::slice::from_raw_parts(data.as_ptr().cast(), data.len() * 4),
                    glow::STREAM_DRAW,
                );
                gl.buffer_data_u8_slice(
                    glow::ELEMENT_ARRAY_BUFFER,
                    std::slice::from_raw_parts(
                        draw.indices.as_ptr().cast(),
                        draw.indices.len() * 4,
                    ),
                    glow::STREAM_DRAW,
                );
                gl.uniform_4_f32(
                    gl.get_uniform_location(p, "u_color").as_ref(),
                    draw.color[0],
                    draw.color[1],
                    draw.color[2],
                    draw.color[3],
                );
                gl.uniform_1_f32(
                    gl.get_uniform_location(p, "u_specular").as_ref(),
                    draw.specular,
                );
                gl.uniform_1_f32(gl.get_uniform_location(p, "u_cutoff").as_ref(), draw.cutoff);
                gl.uniform_1_i32(
                    gl.get_uniform_location(p, "u_flat").as_ref(),
                    i32::from(draw.flat_normals),
                );
                let mut temp = Vec::new();
                for (unit, name, texture) in [
                    (0, "u_albedo", draw.albedo.as_ref()),
                    (1, "u_shiny", draw.shiny.as_ref()),
                ] {
                    gl.active_texture(glow::TEXTURE0 + unit);
                    gl.uniform_1_i32(gl.get_uniform_location(p, name).as_ref(), unit as i32);
                    gl.uniform_1_i32(
                        gl.get_uniform_location(p, &format!("{name}_enabled"))
                            .as_ref(),
                        i32::from(texture.is_some()),
                    );
                    if let Some(image) = texture {
                        let t = gl.create_texture()?;
                        temp.push(t);
                        gl.bind_texture(glow::TEXTURE_2D, Some(t));
                        gl.tex_parameter_i32(
                            glow::TEXTURE_2D,
                            glow::TEXTURE_MIN_FILTER,
                            glow::NEAREST as i32,
                        );
                        gl.tex_parameter_i32(
                            glow::TEXTURE_2D,
                            glow::TEXTURE_MAG_FILTER,
                            glow::NEAREST as i32,
                        );
                        gl.tex_parameter_i32(
                            glow::TEXTURE_2D,
                            glow::TEXTURE_WRAP_S,
                            glow::REPEAT as i32,
                        );
                        gl.tex_parameter_i32(
                            glow::TEXTURE_2D,
                            glow::TEXTURE_WRAP_T,
                            glow::REPEAT as i32,
                        );
                        gl.tex_image_2d(
                            glow::TEXTURE_2D,
                            0,
                            if unit == 0 {
                                glow::SRGB8_ALPHA8 as i32
                            } else {
                                glow::RGBA8 as i32
                            },
                            image.width as i32,
                            image.height as i32,
                            0,
                            glow::RGBA,
                            glow::UNSIGNED_BYTE,
                            Some(&image.rgba),
                        );
                    } else {
                        gl.bind_texture(glow::TEXTURE_2D, None);
                    }
                }
                gl.draw_elements(
                    glow::TRIANGLES,
                    draw.indices.len() as i32,
                    glow::UNSIGNED_INT,
                    0,
                );
                for t in temp {
                    gl.delete_texture(t);
                }
            }
            let pixels = scene.width as usize * scene.height as usize;
            let mut maps = Vec::new();
            gl.pixel_store_i32(glow::PACK_ALIGNMENT, 1);
            for slot in 0..3 {
                let mut data = vec![0; pixels * 4];
                gl.read_buffer(glow::COLOR_ATTACHMENT0 + slot);
                gl.read_pixels(
                    0,
                    0,
                    scene.width as i32,
                    scene.height as i32,
                    glow::RGBA,
                    glow::UNSIGNED_BYTE,
                    glow::PixelPackData::Slice(&mut data),
                );
                flip_rows(&mut data, scene.width as usize * 4, scene.height as usize);
                maps.push(data);
            }
            let mut depth = vec![1f32; pixels];
            let bytes = std::slice::from_raw_parts_mut(depth.as_mut_ptr().cast(), pixels * 4);
            gl.read_pixels(
                0,
                0,
                scene.width as i32,
                scene.height as i32,
                glow::DEPTH_COMPONENT,
                glow::FLOAT,
                glow::PixelPackData::Slice(bytes),
            );
            flip_rows(&mut depth, scene.width as usize, scene.height as usize);
            let error = gl.get_error();
            if error != glow::NO_ERROR {
                return Err(format!("productie-GL fout 0x{error:x}"));
            }
            let specular = maps.pop().unwrap();
            let normal = maps.pop().unwrap();
            let diffuse = maps.pop().unwrap();
            Ok(Buffers {
                width: scene.width,
                height: scene.height,
                diffuse,
                normal,
                specular,
                depth,
            })
        })();
        gl.bind_framebuffer(
            glow::FRAMEBUFFER,
            std::num::NonZeroU32::new(previous as u32).map(glow::NativeFramebuffer),
        );
        gl.viewport(vp[0], vp[1], vp[2], vp[3]);
        gl.bind_vertex_array(None);
        gl.use_program(None);
        gl.active_texture(glow::TEXTURE0);
        gl.disable(glow::DEPTH_TEST);
        gl.disable(glow::SCISSOR_TEST);
        gl.enable(glow::BLEND);
        gl.pixel_store_i32(glow::PACK_ALIGNMENT, 4);
        result
    }
}
fn flip_rows<T>(data: &mut [T], stride: usize, height: usize) {
    for y in 0..height / 2 {
        let split = (height - 1 - y) * stride;
        let (a, b) = data.split_at_mut(split);
        a[y * stride..(y + 1) * stride].swap_with_slice(&mut b[..stride]);
    }
}
const VERTEX: &str = r#"#version 330
layout(location=0)in vec3 a_position;layout(location=1)in vec3 a_normal;layout(location=2)in vec2 a_uv;layout(location=3)in vec4 a_color;
uniform mat4 u_view;uniform mat4 u_projection;out vec3 v_normal;out vec3 v_view_position;out vec2 v_uv;out vec4 v_color;
void main(){v_color=a_color;v_normal=mat3(u_view)*a_normal;v_uv=a_uv;vec4 position=u_view*vec4(a_position,1.0);v_view_position=position.xyz;gl_Position=u_projection*position;}
"#;
const FRAGMENT: &str = r#"#version 330
in vec3 v_normal;in vec3 v_view_position;uniform bool u_flat;in vec2 v_uv;in vec4 v_color;uniform vec4 u_color;uniform float u_cutoff;uniform vec3 u_light_direction; // deliberately unused: production maps are unlit
uniform float u_specular;
uniform sampler2D u_albedo;uniform sampler2D u_shiny;uniform bool u_albedo_enabled;uniform bool u_shiny_enabled;
layout(location=0)out vec4 diffuse;layout(location=1)out vec4 normal;layout(location=2)out vec4 specular;
vec3 encode_srgb(vec3 x){return mix(x*12.92,1.055*pow(max(x,vec3(0.0)),vec3(1.0/2.4))-0.055,step(vec3(0.0031308),x));}
void main(){vec3 n=normalize(v_normal);if(u_flat){n=normalize(cross(dFdx(v_view_position),dFdy(v_view_position)));if(!gl_FrontFacing)n=-n;}vec4 c=u_color*v_color;if(u_albedo_enabled)c*=texture(u_albedo,v_uv);if(c.a<u_cutoff)discard;float s=u_specular;if(u_shiny_enabled)s*=dot(texture(u_shiny,v_uv).rgb,vec3(0.2126,0.7152,0.0722));diffuse=vec4(encode_srgb(clamp(c.rgb,0.0,1.0)),c.a);normal=vec4(n*0.5+0.5,c.a);specular=vec4(vec3(clamp(s,0.0,1.0)),c.a);}
"#;

fn image(w: u32, h: u32, rgba: Vec<u8>) -> ImageBuf {
    ImageBuf {
        width: w,
        height: h,
        rgba,
    }
}
fn linear(x: u8) -> f32 {
    static LUT: std::sync::OnceLock<[f32; 256]> = std::sync::OnceLock::new();
    LUT.get_or_init(|| {
        std::array::from_fn(|i| {
            let v = i as f32 / 255.;
            if v <= 0.04045 {
                v / 12.92
            } else {
                ((v + 0.055) / 1.055).powf(2.4)
            }
        })
    })[x as usize]
}

fn srgb(x: f32) -> u8 {
    let v = if x <= 0.0031308 {
        x * 12.92
    } else {
        1.055 * x.powf(1. / 2.4) - 0.055
    };
    (v * 255.).round().clamp(0., 255.) as u8
}
impl Buffers {
    pub fn validate(&self) -> Result<(), String> {
        let pixels = (self.width as usize)
            .checked_mul(self.height as usize)
            .ok_or("te veel pixels")?;
        if self.width == 0
            || self.height == 0
            || self.width > MAX_HIGHRES
            || self.height > MAX_HIGHRES
            || self.diffuse.len() != pixels * 4
            || self.normal.len() != pixels * 4
            || self.specular.len() != pixels * 4
            || self.depth.len() != pixels
            || self
                .depth
                .iter()
                .any(|d| !d.is_finite() || !(0.0..=1.0).contains(d))
        {
            return Err("ongeldige GPU-mapafmetingen/data".into());
        }
        Ok(())
    }
}
pub fn detail_map(raw: &Buffers) -> Result<Vec<u8>, String> {
    raw.validate()?;
    let w = raw.width as usize;
    let h = raw.height as usize;
    let mut out = vec![0; w * h];
    for y in 0..h {
        for x in 0..w {
            let i = y * w + x;
            let mut edge = 0f32;
            for (nx, ny) in [
                (x.saturating_sub(1), y),
                ((x + 1).min(w - 1), y),
                (x, y.saturating_sub(1)),
                (x, (y + 1).min(h - 1)),
            ] {
                let j = ny * w + nx;
                let a = raw.diffuse[i * 4 + 3] as f32 / 255.;
                let b = raw.diffuse[j * 4 + 3] as f32 / 255.;
                edge = edge.max((a - b).abs());
                if a > 0. && b > 0. {
                    for c in 0..3 {
                        edge = edge.max(
                            (linear(raw.diffuse[i * 4 + c]) - linear(raw.diffuse[j * 4 + c])).abs(),
                        );
                        edge = edge.max(
                            (raw.normal[i * 4 + c] as f32 - raw.normal[j * 4 + c] as f32).abs()
                                / 255.,
                        );
                    }
                    edge = edge.max(((raw.depth[i] - raw.depth[j]).abs() * 200.).min(1.));
                }
            }
            out[i] = (edge * 255.).round().clamp(0., 255.) as u8;
        }
    }
    Ok(out)
}
pub fn detail_image(raw: &Buffers, detail: &[u8]) -> ImageBuf {
    let mut rgba = Vec::with_capacity(detail.len() * 4);
    for (i, v) in detail.iter().enumerate() {
        rgba.extend_from_slice(&[*v, *v, *v, raw.diffuse[i * 4 + 3]]);
    }
    image(raw.width, raw.height, rgba)
}
pub fn resolve(raw: &Buffers, detail: &[u8], w: u32, h: u32) -> Result<Target, String> {
    raw.validate()?;
    if w == 0 || h == 0 || w > MAX_HIGHRES / SCALE || h > MAX_HIGHRES / SCALE {
        return Err("ongeldige target-afmetingen".into());
    }
    if raw.width != w * SCALE
        || raw.height != h * SCALE
        || detail.len() != raw.width as usize * raw.height as usize
    {
        return Err("ongeldige 8× resolve-afmetingen".into());
    }
    let count = w as usize * h as usize;
    let mut diffuse = vec![0; count * 4];
    let mut normals = diffuse.clone();
    let mut specular = diffuse.clone();
    let mut depth = vec![0u16; count * 2];
    let mut depth_preview = diffuse.clone();
    for y in 0..h {
        for x in 0..w {
            let i = (y * w + x) as usize;
            let mut closest = 1f32;
            let mut coverage = 0f32;
            for dy in 0..SCALE {
                for dx in 0..SCALE {
                    let j = ((y * SCALE + dy) * raw.width + x * SCALE + dx) as usize;
                    let a = raw.diffuse[j * 4 + 3] as f32 / 255.;
                    coverage += a;
                    if a > 0. && raw.depth[j].is_finite() {
                        closest = closest.min(raw.depth[j]);
                    }
                }
            }
            let alpha = (coverage / (SCALE * SCALE) as f32 * 255.)
                .round()
                .clamp(0., 255.) as u8;
            if alpha == 0 {
                continue;
            }
            let mut color = [0.; 3];
            let mut n = [0.; 3];
            let mut shiny = 0.;
            let mut sum = 0.;
            // One coherent front-surface cluster; never average foreground with a rear
            // surface. Edges get extra weight, and any thin covered feature survives.
            for dy in 0..SCALE {
                for dx in 0..SCALE {
                    let j = ((y * SCALE + dy) * raw.width + x * SCALE + dx) as usize;
                    let a = raw.diffuse[j * 4 + 3] as f32 / 255.;
                    if a == 0. || raw.depth[j] > closest + 0.0025 {
                        continue;
                    }
                    let weight = a * (1. + 4. * detail[j] as f32 / 255.);
                    sum += weight;
                    for c in 0..3 {
                        color[c] += linear(raw.diffuse[j * 4 + c]) * weight;
                        n[c] += (raw.normal[j * 4 + c] as f32 / 255. * 2. - 1.) * weight;
                    }
                    shiny += raw.specular[j * 4] as f32 * weight;
                }
            }
            if sum <= 0. {
                return Err("ongeldige depth/coverage in GPU-resultaat".into());
            }
            n = normalize(n);
            let d = (closest.clamp(0., 1.) * 65535.).round() as u16;
            for c in 0..3 {
                diffuse[i * 4 + c] = srgb(color[c] / sum);
                normals[i * 4 + c] = ((n[c] * 0.5 + 0.5) * 255.).round().clamp(0., 255.) as u8;
                specular[i * 4 + c] = (shiny / sum).round().clamp(0., 255.) as u8;
                depth_preview[i * 4 + c] = (d >> 8) as u8;
            }
            for map in [
                &mut diffuse,
                &mut normals,
                &mut specular,
                &mut depth_preview,
            ] {
                map[i * 4 + 3] = alpha;
            }
            depth[i * 2] = d;
            depth[i * 2 + 1] = u16::from(alpha) * 257;
        }
    }
    Ok(Target {
        diffuse: image(w, h, diffuse),
        normal: image(w, h, normals),
        specular: image(w, h, specular),
        depth,
        depth_preview: image(w, h, depth_preview),
    })
}

fn safe_parent(root: &Path, relative: &Path) -> Result<PathBuf, String> {
    let relative = relative
        .to_str()
        .ok_or("ongeldig uitvoerpad")?
        .replace('\\', "/");
    let relative = crate::project::portable_relative(&relative)?;
    let relative = relative.as_str();
    let canonical = root.canonicalize().map_err(|e| e.to_string())?;
    let path = root.join(relative);
    let parent = path.parent().ok_or("uitvoermap ontbreekt")?;
    let mut prefix = root.to_path_buf();
    for part in Path::new(relative)
        .parent()
        .unwrap_or(Path::new(""))
        .components()
    {
        prefix.push(part);
        if !prefix.exists() {
            std::fs::create_dir(&prefix).map_err(|e| e.to_string())?;
        }
        let real = prefix.canonicalize().map_err(|e| e.to_string())?;
        if !real.starts_with(&canonical) {
            return Err("uitvoer verlaat projectmap".into());
        }
    }
    if !parent
        .canonicalize()
        .map_err(|e| e.to_string())?
        .starts_with(canonical)
    {
        return Err("onveilig uitvoerpad".into());
    }
    Ok(path)
}
fn atomic_file(
    root: &Path,
    relative: &Path,
    write: impl FnOnce(&mut std::fs::File) -> Result<(), String>,
) -> Result<(), String> {
    let path = safe_parent(root, relative)?;
    let temp = path.with_extension(format!("part-{}", std::process::id()));
    let mut owned = false;
    let result = (|| {
        let mut file = std::fs::OpenOptions::new()
            .write(true)
            .create_new(true)
            .open(&temp)
            .map_err(|e| e.to_string())?;
        owned = true;
        write(&mut file)?;
        file.sync_all().map_err(|e| e.to_string())?;
        std::fs::hard_link(&temp, &path).map_err(|e| e.to_string())?;
        Ok(())
    })();
    if owned {
        let _ = std::fs::remove_file(temp);
    }
    result
}
pub fn write_rgba(root: &Path, relative: &Path, img: &ImageBuf) -> Result<(), String> {
    if img.width == 0
        || img.height == 0
        || img.width > MAX_HIGHRES / SCALE
        || img.height > MAX_HIGHRES / SCALE
        || img.rgba.len() != img.width as usize * img.height as usize * 4
    {
        return Err("ongeldige PNG-afmetingen".into());
    }
    atomic_file(root, relative, |file| {
        let mut encoder = png::Encoder::new(file, img.width, img.height);
        encoder.set_color(png::ColorType::Rgba);
        encoder.set_depth(png::BitDepth::Eight);
        if relative
            .file_name()
            .and_then(|p| p.to_str())
            .map(|p| p.ends_with("_diffuse.png"))
            .unwrap_or(false)
        {
            encoder.set_source_srgb(png::SrgbRenderingIntent::Perceptual);
        }
        let mut writer = encoder.write_header().map_err(|e| e.to_string())?;
        writer
            .write_image_data(&img.rgba)
            .map_err(|e| e.to_string())?;
        writer.finish().map_err(|e| e.to_string())
    })
}
pub fn write_depth(
    root: &Path,
    relative: &Path,
    w: u32,
    h: u32,
    depth: &[u16],
) -> Result<(), String> {
    if w == 0
        || h == 0
        || w > MAX_HIGHRES / SCALE
        || h > MAX_HIGHRES / SCALE
        || depth.len() != w as usize * h as usize * 2
    {
        return Err("ongeldige 16-bit depthafmetingen".into());
    }
    let bytes: Vec<u8> = depth.iter().flat_map(|x| x.to_be_bytes()).collect();
    atomic_file(root, relative, |file| {
        let mut encoder = png::Encoder::new(file, w, h);
        encoder.set_color(png::ColorType::GrayscaleAlpha);
        encoder.set_depth(png::BitDepth::Sixteen);
        let mut writer = encoder.write_header().map_err(|e| e.to_string())?;
        writer.write_image_data(&bytes).map_err(|e| e.to_string())?;
        writer.finish().map_err(|e| e.to_string())
    })
}
fn write_json(root: &Path, name: &str, value: serde_json::Value) -> Result<(), String> {
    use std::io::Write;
    let data = serde_json::to_vec_pretty(&value).map_err(|e| e.to_string())?;
    atomic_file(root, Path::new(name), |f| {
        f.write_all(&data).map_err(|e| e.to_string())
    })
}

pub struct GpuRequest {
    pub scene: Scene,
    reply: mpsc::SyncSender<Result<Buffers, String>>,
}
impl GpuRequest {
    pub fn fail(self, error: String) {
        let _ = self.reply.send(Err(error));
    }
    /// # Safety
    /// `gl` must be current on this UI thread.
    pub unsafe fn service(self, renderer: &mut GpuRenderer, gl: &glow::Context) {
        let result = renderer.render(gl, &self.scene);
        let _ = self.reply.send(result);
    }
}
#[derive(Default)]
struct Pending {
    pass: Option<RenderEvent>,
    progress: Option<RenderEvent>,
    terminal: Option<RenderEvent>,
}
#[derive(Clone, Default)]
pub struct Mailbox(Arc<Mutex<Pending>>);
impl Mailbox {
    pub fn publish(&self, event: RenderEvent) {
        if let Ok(mut state) = self.0.lock() {
            match event {
                RenderEvent::Pass { .. } => {
                    state.pass = Some(event);
                    state.progress = None;
                }
                RenderEvent::Step { .. } => state.progress = Some(event),
                _ => state.terminal = Some(event),
            }
        }
    }
    pub fn drain(&self) -> Vec<RenderEvent> {
        let mut events = Vec::new();
        if let Ok(mut s) = self.0.lock() {
            events.extend(s.pass.take());
            events.extend(s.progress.take());
            events.extend(s.terminal.take());
        }
        events
    }
}
pub struct RenderThread {
    pub mailbox: Mailbox,
    pub gpu: mpsc::Receiver<GpuRequest>,
    pub cancel: Arc<AtomicBool>,
    pub handle: Option<thread::JoinHandle<()>>,
}
impl Drop for RenderThread {
    fn drop(&mut self) {
        self.cancel.store(true, Ordering::Relaxed);
    }
}
pub fn spawn(job: RenderJob, ctx: Option<eframe::egui::Context>) -> RenderThread {
    let mailbox = Mailbox::default();
    let output = mailbox.clone();
    let cancel = Arc::new(AtomicBool::new(false));
    let flag = cancel.clone();
    let (tx, gpu) = mpsc::channel();
    let handle = thread::spawn(move || {
        let mut emit = |event| {
            output.publish(event);
            if let Some(ctx) = &ctx {
                ctx.request_repaint();
            }
        };
        let result = execute(job, &tx, &flag, ctx.as_ref(), &mut emit);
        if let Err(error) = result {
            if flag.load(Ordering::Relaxed) {
                emit(RenderEvent::Cancelled);
            } else {
                emit(RenderEvent::Failed(error));
            }
        }
    });
    RenderThread {
        mailbox,
        gpu,
        cancel,
        handle: Some(handle),
    }
}
fn execute(
    mut job: RenderJob,
    gpu: &mpsc::Sender<GpuRequest>,
    cancel: &AtomicBool,
    ctx: Option<&eframe::egui::Context>,
    emit: &mut dyn FnMut(RenderEvent),
) -> Result<(), String> {
    job.framing.validate()?;
    if job.target_width == 0
        || job.target_height == 0
        || job.target_width > MAX_HIGHRES / SCALE
        || job.target_height > MAX_HIGHRES / SCALE
    {
        return Err("8× highres vereist targetafmetingen 1–256".into());
    }
    if !["male", "female"].contains(&job.sex.as_str()) {
        return Err("ongeldig geslacht".into());
    }
    if let Some(p) = &job.preset {
        p.validate()?;
        if !p.applies[usize::from(job.sex == "female")] {
            return Err("equipment niet geldig voor dit geslacht".into());
        }
        if p.attachments.is_empty() {
            return Err("equipment heeft geen onderdelen".into());
        }
    }
    let plan = plan(&job.character, job.fps)?;
    let output_bytes =
        u64::from(plan.images) * u64::from(job.target_width) * u64::from(job.target_height) * 16;
    if output_bytes > 16 * 1024 * 1024 * 1024 {
        return Err("batch groter dan 16 GiB ongecomprimeerde targetmaps".into());
    }
    std::fs::create_dir_all(&job.output).map_err(|e| e.to_string())?;
    let stamp = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .map_err(|e| e.to_string())?
        .as_nanos();
    let root = job
        .output
        .join(format!("run-{stamp}-{}", std::process::id()));
    std::fs::create_dir(&root).map_err(|e| e.to_string())?;
    let set = job
        .preset
        .as_ref()
        .map(|p| p.name.as_str())
        .unwrap_or("body")
        .to_string();
    write_json(
        &root,
        "render.json",
        serde_json::json!({"format_version":1,"status":"incomplete","sex":job.sex,"set":set,"target":[job.target_width,job.target_height],"fps":job.fps,"highres_scale":SCALE,"framing":job.framing,"near":NEAR,"far":FAR,"normal_space":"view (+Y up), PNG rows top-down","camera_distance":10,"yaw_zero":"camera on -Z","pitches":[-30,0,30],"yaw_step":30,"sampling":"clip -> frame (t=frame/fps) -> pitch -> yaw -> pass; ceil(duration*fps) snapped within 4*f32_epsilon*max(1,samples) of an integer to omit floating terminal duplicates; root motion retained","alpha":"straight, opaque/cutout, coverage resolve","diffuse":"unlit sRGB albedo × vertex color, linear-light detail resolve","depth":"16-bit gray+alpha; distance=near+(sample/65535)*(far-near)","specular":"linear scalar; body defaults zero","pass_order":PASSES,"saved_maps":["diffuse","depth","normal","specular"],"clips":plan.clips.iter().enumerate().map(|(i,c)|serde_json::json!({"name":c.source_name,"token":c.token,"frames":c.frames,"duration":job.character.clips.get(i).map(|c|c.duration).unwrap_or(0.)})).collect::<Vec<_>>(),"images":plan.images,"passes":plan.passes,"png_files":plan.files}),
    )?;
    // Internal unique names select every source clip, even duplicate display names.
    for (i, c) in job.character.clips.iter_mut().enumerate() {
        c.name = format!("render-clip-{i}");
    }
    let mut completed = 0u32;
    let mut cache = equipment::TextureCache::default();
    let result = (|| {
        for sample in samples(&plan) {
            let clip = &plan.clips[sample.clip];
            let frame = sample.frame;
            let pitch = sample.pitch;
            let yaw = sample.yaw;
            let key = if job.character.clips.is_empty() {
                String::new()
            } else {
                format!("render-clip-{}", sample.clip)
            };
            if cancel.load(Ordering::Relaxed) {
                return Err("geannuleerd".into());
            }
            let pose = format!(
                "{} {set} · {} f{frame}/{} · p{pitch} y{yaw}",
                job.sex, clip.source_name, clip.frames
            );
            emit(RenderEvent::Step {
                index: completed,
                total: plan.passes,
                label: format!("{pose} · highres"),
            });
            let scene = scene(
                &job,
                &key,
                frame as f32 / job.fps as f32,
                pitch as f32,
                yaw as f32,
                &mut cache,
            )?;
            let (tx, rx) = mpsc::sync_channel(1);
            gpu.send(GpuRequest { scene, reply: tx })
                .map_err(|_| "GPU-service gesloten")?;
            if let Some(ctx) = ctx {
                ctx.request_repaint();
            }
            let raw = loop {
                match rx.recv_timeout(std::time::Duration::from_millis(100)) {
                    Ok(result) => break result?,
                    Err(mpsc::RecvTimeoutError::Timeout) => {
                        if cancel.load(Ordering::Relaxed) {
                            return Err("geannuleerd".into());
                        }
                    }
                    Err(_) => return Err("GPU-service gestopt".into()),
                }
            };
            completed += 1;
            emit(RenderEvent::Pass {
                index: completed - 1,
                total: plan.passes,
                label: format!("{pose} · highres"),
                image: Some(image(raw.width, raw.height, raw.diffuse.clone())),
            });
            if cancel.load(Ordering::Relaxed) {
                return Err("geannuleerd".into());
            }
            emit(RenderEvent::Step {
                index: completed,
                total: plan.passes,
                label: format!("{pose} · detail"),
            });
            let detail = detail_map(&raw)?;
            completed += 1;
            emit(RenderEvent::Pass {
                index: completed - 1,
                total: plan.passes,
                label: format!("{pose} · detail"),
                image: Some(detail_image(&raw, &detail)),
            });
            if cancel.load(Ordering::Relaxed) {
                return Err("geannuleerd".into());
            }
            emit(RenderEvent::Step {
                index: completed,
                total: plan.passes,
                label: format!("{pose} · target-res / diffuse"),
            });
            let target = resolve(&raw, &detail, job.target_width, job.target_height)?;
            for (map, preview) in [
                ("diffuse", target.diffuse),
                ("depth", target.depth_preview),
                ("normal", target.normal),
                ("specular", target.specular),
            ] {
                if cancel.load(Ordering::Relaxed) {
                    return Err("geannuleerd".into());
                }
                emit(RenderEvent::Step {
                    index: completed,
                    total: plan.passes,
                    label: format!("{pose} · {map}"),
                });
                let path = output_path(&job.sex, &set, &clip.token, frame, pitch, yaw, map)?;
                if map == "depth" {
                    write_depth(
                        &root,
                        &path,
                        job.target_width,
                        job.target_height,
                        &target.depth,
                    )?;
                } else {
                    write_rgba(&root, &path, &preview)?;
                }
                completed += 1;
                emit(RenderEvent::Pass {
                    index: completed - 1,
                    total: plan.passes,
                    label: format!(
                        "{pose} · {}",
                        if map == "diffuse" {
                            "target-res / diffuse"
                        } else {
                            map
                        }
                    ),
                    image: Some(preview),
                });
            }
        }
        Ok(())
    })();
    match result {
        Ok(()) => {
            write_json(
                &root,
                "complete.json",
                serde_json::json!({"status":"complete","passes":completed,"png_files":plan.files}),
            )?;
            emit(RenderEvent::Finished {
                saved: Some(root.display().to_string()),
            });
            Ok(())
        }
        Err(error) => {
            let name = if cancel.load(Ordering::Relaxed) {
                "cancelled.json"
            } else {
                "failed.json"
            };
            let _ = write_json(
                &root,
                name,
                serde_json::json!({"error":error,"completed_passes":completed,"total_passes":plan.passes}),
            );
            Err(error)
        }
    }
}

/// Real readback regression: nearest-surface depth/normal/specular, preserved
/// texture × vertex albedo/alpha and independence from opposed light directions.
/// # Safety
/// Run on a current disposable native context.
pub unsafe fn map_regression_probe(gl: &glow::Context) -> Result<(), String> {
    let triangle = |z, normal, color, specular| Draw {
        positions: Arc::new(vec![[-0.9, -0.9, z], [0.9, -0.9, z], [0., 0.9, z]]),
        normals: Arc::new(vec![normal; 3]),
        uvs: Arc::new(vec![[0.; 2]; 3]),
        vertex_colors: Arc::new(Vec::new()),
        indices: vec![0, 1, 2],
        color,
        albedo: None,
        shiny: None,
        specular,
        cutoff: 0.001,
        flat_normals: false,
    };
    let mut renderer = GpuRenderer::default();
    let mut scene = Scene {
        draws: vec![
            triangle(-0.5, [0., 0., 1.], [1., 0., 0., 1.], 0.75),
            triangle(0.5, [1., 0., 0.], [0., 1., 0., 1.], 0.),
        ],
        view: preview::identity(),
        projection: preview::identity(),
        width: 32,
        height: 32,
    };
    let result = (|| {
        let raw = renderer.render(gl, &scene)?;
        let i = 16 * 32 + 16;
        if raw.diffuse[i * 4..i * 4 + 4] != [255, 0, 0, 255]
            || (raw.depth[i] - 0.25).abs() > 1e-5
            || raw.normal[i * 4..i * 4 + 3] != [128, 128, 255]
            || raw.specular[i * 4].abs_diff(191) > 1
        {
            return Err(format!(
                "GPU map winner mismatch: color {:?} depth {} normal {:?} spec {}",
                &raw.diffuse[i * 4..i * 4 + 4],
                raw.depth[i],
                &raw.normal[i * 4..i * 4 + 4],
                raw.specular[i * 4]
            ));
        }
        scene.draws.reverse();
        let reverse = renderer.render(gl, &scene)?;
        if reverse.diffuse != raw.diffuse
            || reverse.normal != raw.normal
            || reverse.depth != raw.depth
        {
            return Err("GPU map winner depends on submission order".into());
        }
        scene.draws = vec![triangle(-0.5, [0., 0., 1.], [0.5, 0.75, 1., 1.], 0.)];
        scene.draws[0].vertex_colors = Arc::new(vec![[0.5, 1., 0.5, 1.]; 3]);
        scene.draws[0].albedo = Some(Arc::new(equipment::Texture {
            content_hash: 99,
            width: 1,
            height: 1,
            rgba: vec![128, 255, 64, 192],
        }));
        let expected = [
            srgb(linear(128) * 0.25),
            srgb(0.75),
            srgb(linear(64) * 0.5),
            192,
        ];
        // Production intentionally has no lighting input. This optional conventional
        // uniform is optimized out now; a future accidental lighting term using it
        // must fail these actual GPU readbacks under opposed light directions.
        for light in [[0., 0., 1.], [0., 0., -1.], [1., 0., 0.]] {
            let p = renderer.program.ok_or("missing probe program")?;
            gl.use_program(Some(p));
            gl.uniform_3_f32(
                gl.get_uniform_location(p, "u_light_direction").as_ref(),
                light[0],
                light[1],
                light[2],
            );
            let output = renderer.render(gl, &scene)?;
            let pixel = &output.diffuse[i * 4..i * 4 + 4];
            if pixel.iter().zip(expected).any(|(a, b)| a.abs_diff(b) > 1) {
                return Err(format!("diffuse is lit or alpha/vertex/texture lost under {light:?}: {pixel:?} vs {expected:?}"));
            }
        }
        let detail = detail_map(&raw)?;
        let target = resolve(&raw, &detail, 4, 4)?;
        if target.diffuse.width != 4
            || target.depth.len() != 32
            || target
                .normal
                .rgba
                .chunks_exact(4)
                .filter(|p| p[3] > 0)
                .any(|p| {
                    let n = p[..3]
                        .iter()
                        .map(|x| (*x as f32 / 255. * 2. - 1.).powi(2))
                        .sum::<f32>()
                        .sqrt();
                    (n - 1.).abs() > 0.03
                })
        {
            return Err("target map dimensions/normals invalid".into());
        }
        let mut flat = Scene {
            draws: vec![triangle(-0.5, [1., 0., 0.], [1., 0., 0., 1.], 0.)],
            view: preview::identity(),
            projection: preview::identity(),
            width: 32,
            height: 32,
        };
        flat.draws[0].flat_normals = true;
        let derived = renderer.render(gl, &flat)?;
        if derived.normal[i * 4..i * 4 + 3] != [128, 128, 255] {
            return Err(format!(
                "flat normals are not geometry-derived: {:?}",
                &derived.normal[i * 4..i * 4 + 4]
            ));
        }
        println!("Production GPU maps PASS: nearest depth=0.25, normal=[128,128,255], specular=191, albedo texture×vertex={expected:?}, alpha preserved, diffuse identical under 3 opposed lights; target maps valid; missing source normals use actual GPU triangle derivatives");
        Ok(())
    })();
    renderer.destroy(gl);
    result
}

#[cfg(test)]
mod tests {
    use super::*;
    struct Temp(PathBuf);
    impl Temp {
        fn new() -> Self {
            let p = std::env::temp_dir().join(format!(
                "paperdoll-production-{}-{}",
                std::process::id(),
                std::time::SystemTime::now()
                    .duration_since(std::time::UNIX_EPOCH)
                    .unwrap()
                    .as_nanos()
            ));
            std::fs::create_dir(&p).unwrap();
            Self(p)
        }
    }
    impl Drop for Temp {
        fn drop(&mut self) {
            let _ = std::fs::remove_dir_all(&self.0);
        }
    }
    fn body() -> PreviewCharacter {
        preview::load_gltf_file(
            &Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/bodies/test-body-male.glb"),
        )
        .unwrap()
    }
    fn raw(w: u32, h: u32) -> Buffers {
        let n = (w * h) as usize;
        Buffers {
            width: w,
            height: h,
            diffuse: [255, 0, 0, 255].repeat(n),
            normal: [128, 128, 255, 255].repeat(n),
            specular: [191, 191, 191, 255].repeat(n),
            depth: vec![0.25; n],
        }
    }
    #[test]
    fn job_counts_every_clip_frame_angle_and_exact_order() {
        let mut b = body();
        let mut c = b.clips[0].clone();
        c.name = "../A \u{2603}".into();
        c.duration = 0.5;
        b.clips = vec![c.clone(), c];
        let p = plan(&b, 3).unwrap();
        assert_eq!((p.images, p.passes, p.files), (144, 864, 576));
        let s = samples(&p).collect::<Vec<_>>();
        assert_eq!(s.len(), 144);
        assert_eq!(
            s[0],
            Sample {
                clip: 0,
                frame: 0,
                pitch: -30,
                yaw: 0
            }
        );
        assert_eq!(s[11].yaw, 330);
        assert_eq!(s[12].pitch, 0);
        assert_eq!(s[35].pitch, 30);
        assert_eq!(s[36].frame, 1);
        assert_eq!(s[72].clip, 1);
        assert_ne!(p.clips[0].token, p.clips[1].token);
        assert!(p.clips.iter().all(|c| equipment::valid_name(&c.token)));
        assert_eq!(
            PASSES,
            [
                "highres",
                "detail",
                "target-res / diffuse",
                "depth",
                "normal",
                "specular"
            ]
        );
        b.clips.clear();
        let p = plan(&b, 12).unwrap();
        assert_eq!((p.images, p.files), (36, 144));
    }
    #[test]
    fn floating_terminal_timestamp_does_not_duplicate_the_loop_endpoint() {
        let mut b = body();
        b.clips.truncate(1);
        b.clips[0].duration = f32::from_bits(1f32.to_bits() + 1);
        assert_eq!(plan(&b, 2).unwrap().clips[0].frames, 2);
        b.clips[0].duration = 1.00001;
        assert_eq!(plan(&b, 2).unwrap().clips[0].frames, 3);
    }
    #[test]
    fn planner_rejects_invalid_or_unbounded_inputs() {
        let mut b = body();
        assert!(plan(&b, 0).is_err());
        assert!(plan(&b, 241).is_err());
        for duration in [f32::NAN, f32::INFINITY, -1., 10000.] {
            b.clips[0].duration = duration;
            assert!(plan(&b, 12).is_err());
        }
    }
    #[test]
    fn output_tokens_only_four_target_maps() {
        let expected = PathBuf::from("male/body/clip000-walk/f000012/p-30_y330_diffuse.png");
        assert_eq!(
            output_path("male", "body", "clip000-walk", 12, -30, 330, "diffuse").unwrap(),
            expected
        );
        for map in ["diffuse", "normal", "depth", "specular"] {
            assert!(output_path("female", "sword", "clip000-bind", 0, 30, 0, map).is_ok());
        }
        for map in ["highres", "detail", "shiny", "../x"] {
            assert!(output_path("male", "body", "clip000-bind", 0, 0, 0, map).is_err());
        }
        for token in ["../escape", "A", "a/b", "a\\b", ".", "a b"] {
            assert!(output_path("male", token, "clip000-bind", 0, 0, 0, "diffuse").is_err());
        }
        assert!(output_path("male", "body", "walk", 0, 1, 0, "depth").is_err());
        assert!(output_path("male", "body", "walk", 0, 0, 360, "depth").is_err());
    }
    #[test]
    fn resolve_preserves_thin_foreground_and_matching_maps() {
        let mut r = raw(8, 8);
        r.diffuse = [0, 255, 0, 255].repeat(64);
        r.depth.fill(0.75);
        r.diffuse[..4].copy_from_slice(&[255, 0, 0, 255]);
        r.depth[0] = 0.25;
        let d = detail_map(&r).unwrap();
        assert!(d.iter().any(|x| *x > 0));
        let t = resolve(&r, &d, 1, 1).unwrap();
        assert_eq!(t.diffuse.rgba, [255, 0, 0, 255]);
        assert_eq!(t.specular.rgba, [191, 191, 191, 255]);
        assert!((t.depth[0] as i32 - 16384).abs() <= 1);
        let n = &t.normal.rgba;
        let len = (0..3)
            .map(|c| (n[c] as f32 / 255. * 2. - 1.).powi(2))
            .sum::<f32>()
            .sqrt();
        assert!((len - 1.).abs() < 0.01);
        r.diffuse.fill(0);
        r.diffuse[..4].copy_from_slice(&[255, 0, 0, 255]);
        let t = resolve(&r, &detail_map(&r).unwrap(), 1, 1).unwrap();
        assert_eq!(t.diffuse.rgba[3], 4);
        assert_eq!(t.depth[1], 1028);
        assert_eq!(t.normal.rgba[3], 4);
        assert_eq!(t.specular.rgba[3], 4);
    }
    #[test]
    fn invalid_map_dimensions_and_depth_fail_without_panics() {
        let mut r = raw(8, 8);
        r.normal.pop();
        assert!(detail_map(&r).is_err());
        assert!(resolve(&r, &[0; 64], 1, 1).is_err());
        let mut r = raw(8, 8);
        r.depth[0] = f32::NAN;
        assert!(resolve(&r, &[0; 64], 1, 1).is_err());
        let r = raw(8, 8);
        assert!(resolve(&r, &[0; 63], 1, 1).is_err());
        assert!(resolve(&r, &[0; 64], 0, 1).is_err());
        assert!(resolve(&r, &[0; 64], 257, 1).is_err());
    }
    #[test]
    fn atomic_pngs_roundtrip_no_overwrite_or_temp_deletion() {
        let t = Temp::new();
        let p = Path::new("map_diffuse.png");
        write_rgba(&t.0, p, &image(1, 1, vec![128, 64, 32, 192])).unwrap();
        let original = std::fs::read(t.0.join(p)).unwrap();
        assert!(write_rgba(&t.0, p, &image(1, 1, vec![0; 4])).is_err());
        assert_eq!(std::fs::read(t.0.join(p)).unwrap(), original);
        let mut reader = png::Decoder::new(std::io::Cursor::new(original))
            .read_info()
            .unwrap();
        assert!(reader.info().srgb.is_some());
        let mut out = vec![0; reader.output_buffer_size().unwrap()];
        reader.next_frame(&mut out).unwrap();
        assert_eq!(out, [128, 64, 32, 192]);
        write_depth(&t.0, Path::new("depth.png"), 1, 1, &[16384, 32896]).unwrap();
        let mut reader = png::Decoder::new(std::io::BufReader::new(
            std::fs::File::open(t.0.join("depth.png")).unwrap(),
        ))
        .read_info()
        .unwrap();
        assert_eq!(reader.info().bit_depth, png::BitDepth::Sixteen);
        assert_eq!(reader.info().color_type, png::ColorType::GrayscaleAlpha);
        assert!(reader.info().srgb.is_none());
        let mut out = vec![0; reader.output_buffer_size().unwrap()];
        reader.next_frame(&mut out).unwrap();
        assert_eq!(out, [64, 0, 128, 128]);
        let tmp =
            t.0.join("blocked.png")
                .with_extension(format!("part-{}", std::process::id()));
        std::fs::write(&tmp, b"keep").unwrap();
        assert!(write_rgba(&t.0, Path::new("blocked.png"), &image(1, 1, vec![0; 4])).is_err());
        assert_eq!(std::fs::read(tmp).unwrap(), b"keep");
        assert!(write_depth(&t.0, Path::new("bad.png"), 1, 1, &[0]).is_err());
        assert!(write_rgba(&t.0, Path::new("bad.png"), &image(257, 1, vec![0; 1028])).is_err());
        assert!(write_rgba(&t.0, Path::new("../escape.png"), &image(1, 1, vec![0; 4])).is_err());
    }
    #[cfg(unix)]
    #[test]
    fn output_rejects_escaping_symlinks() {
        let root = Temp::new();
        let outside = Temp::new();
        std::os::unix::fs::symlink(&outside.0, root.0.join("link")).unwrap();
        assert!(write_rgba(
            &root.0,
            Path::new("link/sub/x.png"),
            &image(1, 1, vec![0; 4])
        )
        .is_err());
        assert!(!outside.0.join("sub").exists());
    }
    #[test]
    fn latest_mailbox_is_bounded_and_retains_terminal() {
        let m = Mailbox::default();
        for i in 0..1000 {
            m.publish(RenderEvent::Pass {
                index: i,
                total: 1000,
                label: i.to_string(),
                image: Some(image(1, 1, vec![0; 4])),
            });
        }
        m.publish(RenderEvent::Step {
            index: 999,
            total: 1000,
            label: "working".into(),
        });
        m.publish(RenderEvent::Cancelled);
        let events = m.drain();
        assert_eq!(events.len(), 3);
        assert!(matches!(&events[0], RenderEvent::Pass { index: 999, .. }));
        assert!(matches!(&events[2], RenderEvent::Cancelled));
        assert!(m.drain().is_empty());
    }

    #[test]
    fn fixed_body_and_equipment_camera_agree_and_body_is_not_a_draw() {
        let temp = Temp::new();
        let mut job = RenderJob {
            character: body(),
            sex: "male".into(),
            preset: None,
            target_width: 64,
            target_height: 96,
            fps: 12,
            framing: CameraFraming {
                height_milli: 3100,
                center_y_milli: 1200,
            },
            output: temp.0.clone(),
        };
        let mut cache = equipment::TextureCache::default();
        let b = scene(&job, "walk", 0.5, 30., 90., &mut cache).unwrap();
        let mut preset = equipment::Preset::new("sword".into());
        let fixture =
            Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/equipment/sword.obj");
        equipment::import_obj(&mut preset, &fixture).unwrap();
        let joint = job
            .character
            .joint_names
            .iter()
            .position(|n| n == "RightHand")
            .unwrap();
        preset.bind(0, &job.character, 0, joint).unwrap();
        let count = preset
            .attachments
            .iter()
            .map(|a| a.meshes.len())
            .sum::<usize>();
        job.preset = Some(preset);
        let e = scene(&job, "walk", 0.5, 30., 90., &mut cache).unwrap();
        assert_eq!(e.draws.len(), count);
        assert_eq!(b.view, e.view);
        assert_eq!(b.projection, e.projection);
        assert_eq!((e.width, e.height), (512, 768));
        assert_eq!(e.projection[5], 2. / 3.1);
        let center = point(&e.view, [0., 1.2, 0.]);
        assert!(center[0].abs() < 0.0001 && center[1].abs() < 0.0001);
        assert!((center[2] + 10.).abs() < 0.0001);
        let early = scene(&job, "attack", 0., 30., 90., &mut cache).unwrap();
        let late = scene(&job, "attack", 0.5, 30., 90., &mut cache).unwrap();
        assert_eq!(early.view, late.view);
        assert_eq!(early.projection, late.projection);
        assert_ne!(early.draws[0].positions, late.draws[0].positions);
        let mut invalid = e.clone();
        invalid.view[0] = f32::NAN;
        assert!(invalid.validate().is_err());
    }
    #[test]
    fn body_import_retains_texture_material_and_linear_vertex_color() {
        let temp = Temp::new();
        let source = std::fs::read(
            Path::new(env!("CARGO_MANIFEST_DIR")).join("tests/fixtures/bodies/test-body-male.glb"),
        )
        .unwrap();
        let glb = gltf::binary::Glb::from_slice(&source).unwrap();
        let mut json: serde_json::Value = serde_json::from_slice(&glb.json).unwrap();
        let mut bin = glb.bin.unwrap().into_owned();
        while !bin.len().is_multiple_of(4) {
            bin.push(0);
        }
        let position = json["meshes"][0]["primitives"][0]["attributes"]["POSITION"]
            .as_u64()
            .unwrap() as usize;
        let count = json["accessors"][position]["count"].as_u64().unwrap() as usize;
        let offset = bin.len();
        for _ in 0..count {
            for value in [0.25f32, 0.75, 0.5, 0.5] {
                bin.extend(value.to_le_bytes());
            }
        }
        let view = json["bufferViews"].as_array().unwrap().len();
        json["bufferViews"]
            .as_array_mut()
            .unwrap()
            .push(serde_json::json!({"buffer":0,"byteOffset":offset,"byteLength":count*16}));
        let accessor = json["accessors"].as_array().unwrap().len();
        json["accessors"].as_array_mut().unwrap().push(
            serde_json::json!({"bufferView":view,"componentType":5126,"count":count,"type":"VEC4"}),
        );
        json["meshes"][0]["primitives"][0]["attributes"]["COLOR_0"] = serde_json::json!(accessor);
        json["buffers"][0] = serde_json::json!({"uri":"geometry.bin","byteLength":bin.len()});
        json["images"] = serde_json::json!([{"uri":"albedo.png"}]);
        json["textures"] = serde_json::json!([{"source":0}]);
        let material = json["meshes"][0]["primitives"][0]["material"]
            .as_u64()
            .unwrap() as usize;
        json["materials"][material]["pbrMetallicRoughness"]["baseColorTexture"] =
            serde_json::json!({"index":0});
        json["materials"][material]["pbrMetallicRoughness"]["baseColorFactor"] =
            serde_json::json!([0.5, 0.75, 1., 1.]);
        std::fs::write(temp.0.join("geometry.bin"), bin).unwrap();
        std::fs::write(temp.0.join("body.gltf"), serde_json::to_vec(&json).unwrap()).unwrap();
        write_rgba(
            &temp.0,
            Path::new("albedo.png"),
            &image(1, 1, vec![128, 255, 64, 192]),
        )
        .unwrap();
        let body = preview::load_gltf_file(&temp.0.join("body.gltf")).unwrap();
        assert_eq!(body.colors[0], [0.25, 0.75, 0.5, 0.5]);
        assert_eq!(body.surfaces[0].color, [0.5, 0.75, 1., 1.]);
        assert_eq!(
            body.surfaces[0].albedo.as_ref().unwrap().rgba,
            [128, 255, 64, 192]
        );
        assert_eq!(body.colors.len(), body.positions.len());
        assert_eq!(body.uvs.len(), body.positions.len());
        assert!(body.surfaces[0].flat_normals);
        json["meshes"][0]["primitives"][0]["attributes"]
            .as_object_mut()
            .unwrap()
            .remove("NORMAL");
        std::fs::write(temp.0.join("body.gltf"), serde_json::to_vec(&json).unwrap()).unwrap();
        let missing = preview::load_gltf_file(&temp.0.join("body.gltf")).unwrap();
        assert!(!missing.source_normals_complete);
        let job = RenderJob {
            character: missing,
            sex: "male".into(),
            preset: None,
            target_width: 1,
            target_height: 1,
            fps: 12,
            framing: CameraFraming::default(),
            output: temp.0.clone(),
        };
        assert!(
            scene(
                &job,
                "",
                0.,
                0.,
                0.,
                &mut equipment::TextureCache::default()
            )
            .unwrap()
            .draws[0]
                .flat_normals
        );
    }
    #[test]
    fn complete_and_cancelled_batches_have_truthful_atomic_outputs() {
        for stop in [false, true] {
            let tmp = Temp::new();
            let mut b = body();
            b.clips.clear();
            let job = RenderJob {
                character: b,
                sex: "male".into(),
                preset: None,
                target_width: 1,
                target_height: 1,
                fps: 12,
                framing: CameraFraming::default(),
                output: tmp.0.clone(),
            };
            let flag = AtomicBool::new(false);
            let (tx, rx) = mpsc::channel::<GpuRequest>();
            let gpu = std::thread::spawn(move || {
                for request in rx {
                    let _ = request
                        .reply
                        .send(Ok(raw(request.scene.width, request.scene.height)));
                }
            });
            let mut labels = Vec::new();
            let result = execute(job, &tx, &flag, None, &mut |event| {
                if let RenderEvent::Pass { label, .. } = event {
                    labels.push(label);
                    if stop && labels.len() == 3 {
                        flag.store(true, Ordering::Relaxed);
                    }
                }
            });
            drop(tx);
            gpu.join().unwrap();
            let run = std::fs::read_dir(&tmp.0)
                .unwrap()
                .next()
                .unwrap()
                .unwrap()
                .path();
            assert!(run.join("render.json").exists());
            assert_eq!(run.join("complete.json").exists(), !stop);
            assert_eq!(run.join("cancelled.json").exists(), stop);
            assert_eq!(result.is_ok(), !stop);
            let frame = run.join("male/body/clip000-bind/f000000");
            assert!(frame.join("p-30_y000_diffuse.png").exists());
            assert_eq!(frame.join("p-30_y000_depth.png").exists(), !stop);
            assert!(!frame.join("p-30_y000_highres.png").exists());
            assert!(!frame.join("p-30_y000_detail.png").exists());
            if !stop {
                assert_eq!(labels.len(), 216);
                for labels in labels.chunks_exact(6) {
                    for (label, pass) in labels.iter().zip([
                        "highres",
                        "detail",
                        "target-res / diffuse",
                        "depth",
                        "normal",
                        "specular",
                    ]) {
                        assert!(label.ends_with(pass));
                    }
                }
            }
        }
    }
}