#import "@preview/polylux:0.4.0": *
#import "@preview/cetz:0.5.0"
#import "@preview/cetz-plot:0.1.3": plot
#import "@preview/cetz:0.5.0": canvas

#set math.mat(delim: "[")

// Infos
#let auteur = "Anthony PERRONI"
#let numero = "49871"
#let titre = "Codes LDPC"
#let annee = "2025 - 2026"

// Template
#let myslide(partie, contenu) = slide[
  // Header
  #block(width: 100%, fill: black, inset: (top: 0.6cm, bottom: 0.6cm, left: 1.5cm, right: 1.5cm))[
    #set text(fill: white, size: 28pt, weight: "bold")
    #partie
  ]
  // Contenu
  #pad(x: 1.5cm, top: 0.2cm)[
    #set text(size: 20pt)
    #contenu
  ]

  // Footer
  #v(1fr)
  #context {
    let cur = counter("logical-slide").get().first()
    let fins = query(<fin>)
    let tot = if fins.len() > 0 {
      counter("logical-slide").at(fins.first().location()).first()
    } else {
      counter("logical-slide").final().first()
    }

    if cur > 1 {
      block(width: 100%, fill: black, inset: (top: 0.2cm, bottom: 0.2cm, left: 1.5cm, right: 1.5cm))[
        #set text(fill: white, size: 12pt, weight: "bold")
        #grid(
          columns: (1.5fr, 2fr, 1fr, auto),
          align: (left, center, center, right),
          [#auteur n°#numero], [#titre], [#annee], if cur <= tot [#(cur - 1) / #(tot - 1)] else [Annexe],
        )
      ]
    }
  }
]

// Plan
#let design_plan(items) = {
  let r = 6pt
  let epaisseur = 2pt
  let hauteur_ligne = 2.5em
  let espace_vertical = 20pt

  pad(left: 1cm, top: 1cm)[
    #block[
      #place(dx: r, dy: hauteur_ligne / 2)[
        #line(
          length: (items.len() - 1) * (hauteur_ligne + espace_vertical),
          angle: 90deg,
          stroke: epaisseur + black,
        )
      ]

      #grid(
        columns: (2 * r, auto),
        column-gutter: 20pt,
        row-gutter: espace_vertical,
        ..items
          .map(item => (
            box(height: hauteur_ligne, align(center + horizon)[
              #circle(radius: r, fill: white, stroke: epaisseur + black)
            ]),
            box(height: hauteur_ligne, align(left + horizon)[
              #text(weight: "bold", size: 1.1em)[#item]
            ]),
          ))
          .flatten()
      )
    ]
  ]
}

// Graphe de Tanner en filigrane
#let graphe_tanner_fond(taille, spread) = {
  cetz.canvas(length: taille, {
    import cetz.draw: *

    let n_var = 18
    let n_chk = 9
    let var_y = 11
    let chk_y = -8

    // Calcul automatique pour que le graphe soit centré sur X=0
    let dist_v = (n_var - 1) * spread
    let v_start = -dist_v / 2
    let vpos = range(n_var).map(i => (v_start + i * spread, var_y))

    let spread_c = dist_v / (n_chk - 1)
    let c_start = -dist_v / 2
    let cpos = range(n_chk).map(i => (c_start + i * spread_c, chk_y))

    let edges = (
      (0, 0),
      (0, 4),
      (0, 8),
      (1, 1),
      (1, 5),
      (1, 0),
      (2, 2),
      (2, 6),
      (2, 1),
      (3, 3),
      (3, 7),
      (3, 2),
      (4, 4),
      (4, 8),
      (4, 3),
      (5, 5),
      (5, 0),
      (5, 4),
      (6, 6),
      (6, 1),
      (6, 5),
      (7, 7),
      (7, 2),
      (7, 6),
      (8, 8),
      (8, 3),
      (8, 7),
      (9, 0),
      (9, 3),
      (9, 6),
      (10, 1),
      (10, 4),
      (10, 7),
      (11, 2),
      (11, 5),
      (11, 8),
      (12, 0),
      (12, 5),
      (12, 7),
      (13, 1),
      (13, 3),
      (13, 8),
      (14, 2),
      (14, 4),
      (14, 6),
      (15, 0),
      (15, 4),
      (15, 7),
      (16, 1),
      (16, 5),
      (16, 8),
      (17, 2),
      (17, 3),
      (17, 6),
    )

    for e in edges {
      let vp = vpos.at(e.at(0))
      let cp = cpos.at(e.at(1))
      line((vp.at(0), vp.at(1)), (cp.at(0), cp.at(1)), stroke: 0.45pt + rgb("#e0e0e0"))
    }

    for p in vpos {
      circle((p.at(0), p.at(1)), radius: 0.25, fill: white, stroke: 0.8pt + rgb("#cccccc"))
    }

    for p in cpos {
      let (x, y) = p
      rect((x - 0.25, y - 0.25), (x + 0.25, y + 0.25), fill: white, stroke: 0.8pt + rgb("#cccccc"))
    }
  })
}

// Schema Shannon
// #let canal_shannon_intro() = {
//   cetz.canvas({
//     import cetz.draw: *
//
//     // Styles
//     let s = (stroke: 2pt + black)
//     let s_fleche = (stroke: 2pt + black)
//     let pointe_pleine = (end: "stealth", fill: black)
//
//     let espacement = 5.5
//
//     // Blocs
//     content((0, 0), [Source], name: "src", frame: "rect", ..s, padding: .3)
//     content((espacement, 0), [Emetteur], name: "em", frame: "rect", ..s, padding: .3)
//     content((espacement * 2, 0), [Canal], name: "chan", frame: "rect", ..s, padding: .3)
//     content((espacement * 3, 0), [Récepteur], name: "rec", frame: "rect", ..s, padding: .3)
//     content((espacement * 4, 0), [Destinataire], name: "dest", frame: "rect", ..s, padding: .3)
//
//     // Bruit
//     content((rel: (0, 1.8), to: "chan"), [Bruit], name: "bruit", frame: "rect", ..s, padding: .3)
//
//     // Codage / Décodage
//     content((rel: (0, 1), to: "em"), [*Codage*])
//     content((rel: (0, 1), to: "rec"), [*Décodage*])
//
//     // Flèches (On utilise s_fleche et pointe_pleine)
//     line("src.east", "em.west", mark: pointe_pleine, ..s_fleche)
//     line("em.east", "chan.west", mark: pointe_pleine, ..s_fleche)
//     line("chan.east", "rec.west", mark: pointe_pleine, ..s_fleche)
//     line("rec.east", "dest.west", mark: pointe_pleine, ..s_fleche)
//     line("bruit.south", "chan.north", mark: pointe_pleine, ..s_fleche)
//
//     // Annotation
//     let note-style = (size: 0.75em, style: "italic")
//     content((espacement * 0.5, -0.5), text(..note-style)[Message])
//     content((espacement * 1.5, -0.5), text(..note-style)[Signal])
//     content((espacement * 2.5, -0.5), text(..note-style)[Signal])
//     content((espacement * 3.5, -0.5), text(..note-style)[Message])
//   })
// }

#let canal_shannon_intro() = {
  // Couleurs
  let col-u = blue // Signal propre
  let col-p = orange // Signal bruité
  let C_MAIN = black
  let C_BG = rgb("#f8f9fa") // Le gris très clair demandé
  let C_LABEL = black

  cetz.canvas(length: 1cm, {
    import cetz.draw: *

    let x_left = 4.0
    let x_right = 16.0
    let x_noise = 22.5
    let y_top = 14.5
    let y_mid = 9.0
    let y_bot = 3.5

    // Style des lignes avec flèches
    let s_ligne = (stroke: 1.5pt + C_MAIN, mark: (end: "stealth", fill: C_MAIN, size: 0.25))
    let s_bruit_fleche = (
      stroke: (paint: black, thickness: 1.5pt, dash: "dashed"),
      mark: (end: "stealth", fill: black, size: 0.25),
    )

    // Fonction de bloc avec le nouveau fond
    let bloc(pos, txt, stxt, n) = {
      content(
        pos,
        [#set align(center); #text(C_MAIN, weight: "bold", size: 1.2em)[#txt] \ #text(
            C_MAIN,
            size: 0.85em,
            style: "italic",
          )[#stxt]],
        frame: "rect",
        fill: C_BG,
        stroke: C_MAIN + 1.5pt,
        padding: 0.7,
        radius: 0.3,
        name: n,
      )
    }

    // --- ONDES (Bruit dosé : "tremblement" au lieu de "chaos") ---
    let wave_vert(x, y_start, y_end, is_noisy) = {
      let n_points = 200
      let color = if is_noisy { col-p } else { col-u }

      line(
        ..range(n_points + 1).map(i => {
          let t = i / n_points
          let y = y_start + t * (y_end - y_start)

          // Enveloppe pour raccord propre
          let env = if t < 0.05 { t / 0.05 } else if t > 0.95 { (1 - t) / 0.05 } else { 1.0 }

          let signal = 0.35 * calc.sin(t * 6 * calc.pi)

          // Bruit dosé : on a baissé les fréquences et l'amplitude
          let bruit = if is_noisy {
            (0.08 * calc.sin(t * 45 * calc.pi) + 0.05 * calc.cos(t * 97 * calc.pi))
          } else { 0 }

          (x + (signal + bruit) * env, y)
        }),
        stroke: color + 1.6pt,
      )
    }

    wave_vert(x_right, y_top - 1.5, y_mid + 1, false) // Bleu
    wave_vert(x_right, y_mid - 1, y_bot + 1.5, true) // Orange

    // --- BLOCS ---
    bloc((x_left, y_top), "Source", "Information", "src")
    bloc((x_right, y_top), "Émetteur", "Codage", "em")
    bloc((x_right, y_mid), "Canal", "", "canal")
    bloc((x_noise, y_mid), "Bruit", "", "bruit")
    bloc((x_right, y_bot), "Récepteur", "Décodage", "rec")
    bloc((x_left, y_bot), "Destinataire", "Information", "dest")

    // --- CONNEXIONS ---
    line("src.east", "em.west", ..s_ligne)
    line("bruit.west", "canal.east", ..s_bruit_fleche)
    line("rec.west", "dest.east", ..s_ligne)

    // --- ANNOTATIONS ---
    let lab(pos, body, color: C_LABEL, anchor: "center") = content(
      pos,
      text(size: 0.95em, fill: color, style: "italic", weight: "medium")[#body],
      anchor: anchor,
    )

    lab(((x_left + x_right) / 2 - 0.3, y_top + 0.7), "Message")
    lab((x_right + 1.2, (y_top + y_mid) / 2), "Signal", color: col-u, anchor: "west")
    lab((x_right + 1.2, (y_mid + y_bot) / 2), "Signal + Bruit", color: col-p, anchor: "west")
    lab(((x_left + x_right) / 2 + 0.3, y_bot - 0.7), "Message reçu")
  })
}

#let plongement_schema() = {
  cetz.canvas(length: 1.5cm, {
    import cetz.draw: *

    // Styles
    let style-pointille = (stroke: (paint: black, thickness: 1.2pt, dash: "dashed"))
    let style-point = (fill: black, stroke: none)
    let rayon-point = 0.08
    let pointe-fleche = (end: "stealth", fill: black)

    let m = (
      p00: (-4, 0),
      p01: (-2, 0),
      p11: (-2, -2),
      p10: (-4, -2),
    )

    // Arêtes pointillés
    line(m.p00, m.p01, m.p11, m.p10, close: true, ..style-pointille)

    // Points sur les sommets
    circle(m.p00, radius: rayon-point, ..style-point)
    circle(m.p01, radius: rayon-point, ..style-point)
    circle(m.p11, radius: rayon-point, ..style-point)
    circle(m.p10, radius: rayon-point, ..style-point)

    // Étiquettes
    content(m.p00, [00], anchor: "south-east", padding: .2)
    content(m.p01, [01], anchor: "south-west", padding: .2)
    content(m.p11, [11], anchor: "north-west", padding: .2)
    content(m.p10, [10], anchor: "north-east", padding: .2)

    content((-3, -2.6), [$FF_2^2$])

    line((-1.2, -1), (1.2, -1), mark: pointe-fleche, stroke: 1.5pt + black)
    content((0, -0.6), [*Plongement*])

    // Sommets face arrière
    let cb = (p000: (2.5, 0), p001: (4.5, 0), p011: (4.5, -2), p010: (2.5, -2))
    // Sommets face avant (décalés)
    let cf = (p100: (3.5, 1), p101: (5.5, 1), p111: (5.5, -1), p110: (3.5, -1))

    // Arêtes pointillés du cube
    line(cb.p000, cb.p001, cb.p011, cb.p010, close: true, ..style-pointille) // Face arrière
    line(cf.p100, cf.p101, cf.p111, cf.p110, close: true, ..style-pointille) // Face avant
    line(cb.p000, cf.p100, ..style-pointille) // Liaisons
    line(cb.p001, cf.p101, ..style-pointille)
    line(cb.p011, cf.p111, ..style-pointille)
    line(cb.p010, cf.p110, ..style-pointille)

    // Points sur les sommets du cube
    circle(cb.p000, radius: rayon-point, ..style-point)
    circle(cb.p001, radius: rayon-point, ..style-point)
    circle(cb.p011, radius: rayon-point, ..style-point)
    circle(cb.p010, radius: rayon-point, ..style-point)
    circle(cf.p100, radius: rayon-point, ..style-point)
    circle(cf.p101, radius: rayon-point, ..style-point)
    circle(cf.p111, radius: rayon-point, ..style-point)
    circle(cf.p110, radius: rayon-point, ..style-point)

    // Étiquettes du cube
    content(cb.p000, [000], anchor: "south-east", padding: .2)
    // content(cb.p001, [001], anchor: "south-west", padding: .2)
    content((rel: (-0.85, 0.1), to: cb.p001), [001], anchor: "south-west", padding: .2)
    content(cb.p011, [011], anchor: "north-west", padding: .2)
    content(cb.p010, [010], anchor: "north-east", padding: .2)
    content(cf.p100, [100], anchor: "south-east", padding: .2)
    content(cf.p101, [101], anchor: "south-west", padding: .2)
    content(cf.p111, [111], anchor: "north-west", padding: .2)
    // content(cf.p110, [110], anchor: "north-east", padding: .2)
    content((rel: (0.85, -0.1), to: cf.p110), [110], anchor: "north-east", padding: .2)

    content((4, -2.6), [$FF_2^3$])
  })
}

#let definition(
  titre: "Définition",
  accent: black,
  titre_taille: 1.13em,
  corps_taille: 1.2em,
  contenu,
) = {
  block(
    width: 100%,
    fill: rgb("#f8f9fa"),
    stroke: 0.5pt + gray.lighten(60%),
    radius: 8pt,
    clip: true,

    grid(
      columns: (5pt, 1fr),
      rows: auto,
      fill: (col, row) => if col == 0 { accent },
      [],
      block(
        width: 100%,
        inset: (x: 16pt, y: 15pt),
        {
          {
            set text(fill: accent, weight: 800, size: titre_taille, tracking: 0.5pt)
            show math.equation: set text(weight: 700, size: 1.05em)
            titre
          }
          v(18pt, weak: true)
          {
            set text(size: corps_taille)
            set par(leading: 0.7em, justify: false)
            contenu
          }
        },
      ),
    ),
  )
}

#let limite_shannon_graphique() = {
  let col-shannon = red.darken(10%)
  let col-code-long = blue.darken(20%)
  let col-code-short = gray.lighten(10%)
  set text(size: 11pt)

  move(dx: -5pt, dy: 0pt)[
    #cetz.canvas({
      import cetz.draw: *

      plot.plot(
        size: (23, 15),

        // 1. On grossit les labels d'axes (15pt)
        x-label: pad(bottom: 30pt)[#move(dy: 80pt)[#text(size: 18pt)[$E_b/N_0$ (dB)]]],
        y-label: move(dx: -20pt, dy: -10pt)[#text(size: 18pt)[Bit Error Rate (BER)]],

        x-min: 0,
        x-max: 10,
        y-min: -8.5,
        y-max: 0.2,
        x-tick-step: 1,
        y-tick-step: 2,

        // Axis
        x-format: x => move(dy: 14pt)[#text(size: 16pt)[#x]],
        y-format: y => move(dx: -5pt)[#text(size: 16pt)[$10^(#y)$]],

        x-grid: true,
        y-grid: true,

        // Légende positionnée en bas.
        legend: "north-east",
        legend-style: (
          stroke: 0.5pt + gray,
          fill: white,
          padding: 0.2,
          offset: (-161.4pt, -45.1pt),
        ),
        {
          // 1. Limite de Shannon (Asymptote)
          plot.add(
            ((1.5, -8.5), (1.5, 0.2)),
            style: (stroke: (paint: col-shannon, thickness: 2pt, dash: "dashed")),
            label: [Limite de Shannon],
          )

          // 2. Petit bloc linéaire (n ≈ 100) - Ultra-densifié (smooth)
          plot.add(
            (
              (0.0, 0.00),
              (0.2, -0.01),
              (0.4, -0.03),
              (0.6, -0.05),
              (0.8, -0.07),
              (1.0, -0.10),
              (1.2, -0.13),
              (1.4, -0.17),
              (1.6, -0.21),
              (1.8, -0.25),
              (2.0, -0.30),
              (2.2, -0.36),
              (2.4, -0.43),
              (2.6, -0.51),
              (2.8, -0.60),
              (3.0, -0.70),
              (3.2, -0.80),
              (3.4, -0.91),
              (3.6, -1.03),
              (3.8, -1.16),
              (4.0, -1.30),
              (4.2, -1.44),
              (4.4, -1.59),
              (4.6, -1.75),
              (4.8, -1.92),
              (5.0, -2.10),
              (5.2, -2.28),
              (5.4, -2.47),
              (5.6, -2.67),
              (5.8, -2.88),
              (6.0, -3.10),
              (6.2, -3.32),
              (6.4, -3.55),
              (6.6, -3.79),
              (6.8, -4.04),
              (7.0, -4.30),
              (7.2, -4.56),
              (7.4, -4.83),
              (7.6, -5.11),
              (7.8, -5.40),
              (8.0, -5.70),
              (8.2, -6.00),
              (8.4, -6.31),
              (8.6, -6.63),
              (8.8, -6.96),
              (9.0, -7.30),
              (9.2, -7.62),
              (9.4, -7.95),
              (9.6, -8.29),
              (9.8, -8.64),
              (10.0, -9.00),
            ),
            style: (stroke: (paint: col-code-short, thickness: 1.5pt)),
            label: [Code court ($n approx 100$)],
          )

          // 3. Grand bloc linéaire (n = 64 800) - Ultra-densifié (smooth & waterfall net)
          plot.add(
            (
              (0.0, 0.0),
              (0.2, -0.005),
              (0.4, -0.01),
              (0.6, -0.02),
              (0.8, -0.035),
              (1.0, -0.05),
              (1.1, -0.07),
              (1.2, -0.10),
              (1.3, -0.14),
              (1.4, -0.20),
              (1.45, -0.28),
              (1.50, -0.40),
              (1.52, -0.45),
              (1.54, -0.52),
              (1.56, -0.60),
              (1.58, -0.69),
              (1.60, -0.80),
              (1.62, -0.92),
              (1.64, -1.05),
              (1.66, -1.19),
              (1.68, -1.34),
              (1.70, -1.50),
              (1.72, -1.69),
              (1.74, -1.89),
              (1.76, -2.11),
              (1.78, -2.35),
              (1.80, -2.60),
              (1.82, -2.88),
              (1.84, -3.18),
              (1.86, -3.50),
              (1.88, -3.84),
              (1.90, -4.20),
              (1.92, -4.52),
              (1.94, -4.86),
              (1.96, -5.22),
              (1.98, -5.60),
              (2.00, -6.00),
              (2.02, -6.32),
              (2.04, -6.64),
              (2.06, -6.94),
              (2.08, -7.23),
              (2.10, -7.50),
              (2.12, -7.66),
              (2.14, -7.81),
              (2.16, -7.95),
              (2.18, -8.08),
              (2.20, -8.20),
              (2.22, -8.32),
              (2.24, -8.44),
              (2.25, -8.50),
            ),
            style: (stroke: (paint: col-code-long, thickness: 3.5pt)),
            label: [Code long ($n = 64\,800$)],
          )
        },
      )
    })
  ]
}

#let decor_matrice_etoilee() = {
  // Ajuste length (ex: 0.6mm ou 0.7mm) selon ta diapo
  cetz.canvas(length: 0.7mm, {
    import cetz.draw: *

    // --- 1. Paramètres de la Matrice ---
    let nx = 430
    let ny = 265

    // --- 2. Paramètres de la Loupe ---
    let loupe_x = nx * 0.70
    let loupe_y = -ny / 2.0
    let R = 50.0
    let zoom = 3.0

    // --- 3. Paramètre d'Estompage (Gauche uniquement) ---
    let fade_left = 220.0

    // Palette de couleurs
    let col_focus = rgb("#0284c7")
    let col_fade = rgb("#64748b")
    let col_grid = rgb("#e2e8f0")

    // --- Fonction pseudo-aléatoire ---
    let pseudo_rand(x, y) = {
      let v = x * 7919 + y * 104729 + (x * x) * 313 + (y * y) * 991 + (x * y) * 101
      calc.rem(calc.abs(v), 100)
    }

    // --- ÉTAPE A : Dessin de la matrice (Fade à gauche uniquement) ---
    for x in range(nx) {
      for y in range(ny) {
        let hash = pseudo_rand(x, y)
        let is_active = hash < 12

        if is_active {
          // L'intensité ne dépend plus que de la position X
          let intensity = calc.min(1.0, x / fade_left)

          if intensity > 0.05 {
            let radius = 0.20 + 0.15 * intensity
            let c = col_fade.lighten((1.0 - intensity) * 80%)
            circle((x, -y), radius: radius, fill: c, stroke: none)
          }
        }
      }
    }

    // --- ÉTAPE B : Dessin de la Loupe ---
    circle((loupe_x, loupe_y), radius: R, fill: white, stroke: none)

    // Grille zoomée
    let limit = 20
    for k in range(-limit, limit + 1) {
      let offset = k * zoom
      if calc.abs(offset) < R {
        let half_chord = calc.sqrt(R * R - offset * offset)
        line(
          (loupe_x + offset, loupe_y + half_chord),
          (loupe_x + offset, loupe_y - half_chord),
          stroke: 0.5pt + col_grid,
        )
        line(
          (loupe_x - half_chord, loupe_y + offset),
          (loupe_x + half_chord, loupe_y + offset),
          stroke: 0.5pt + col_grid,
        )
      }
    }

    // Points zoomés
    let search_r = int(R / zoom) + 2
    let lx_int = int(loupe_x)
    let ly_idx = int(-loupe_y)

    for x in range(lx_int - search_r, lx_int + search_r + 1) {
      for y in range(ly_idx - search_r, ly_idx + search_r + 1) {
        let hash = pseudo_rand(x, y)
        if hash < 12 {
          let dx = x - loupe_x
          let dy = -y - loupe_y
          let d_orig = calc.sqrt(dx * dx + dy * dy)
          let d_zoom = d_orig * zoom

          if d_zoom <= R - 1.2 {
            circle((loupe_x + dx * zoom, loupe_y + dy * zoom), radius: 1.1, fill: col_focus, stroke: none)
          }
        }
      }
    }

    // Bordures de la Loupe
    circle((loupe_x, loupe_y), radius: R, stroke: 1.8pt + col_focus.lighten(20%))
    circle((loupe_x, loupe_y), radius: R + 1.5, stroke: 1.0pt + col_focus.lighten(50%))
    circle((loupe_x, loupe_y), radius: R + 3.5, stroke: 0.5pt + col_focus.lighten(80%))
  })
}

#let hldpc() = {
  import cetz.draw: *

  let points = (
    (7, 0),
    (10, 0),
    (15, 0),
    (22, 0),
    (24, 0),
    (29, 0),
    (3, 1),
    (6, 1),
    (18, 1),
    (19, 1),
    (25, 1),
    (27, 1),
    (5, 2),
    (9, 2),
    (13, 2),
    (14, 2),
    (17, 2),
    (28, 2),
    (0, 3),
    (8, 3),
    (11, 3),
    (16, 3),
    (20, 3),
    (26, 3),
    (1, 4),
    (2, 4),
    (4, 4),
    (12, 4),
    (21, 4),
    (23, 4),
    (5, 5),
    (6, 5),
    (8, 5),
    (10, 5),
    (21, 5),
    (29, 5),
    (14, 6),
    (15, 6),
    (16, 6),
    (18, 6),
    (22, 6),
    (28, 6),
    (0, 7),
    (1, 7),
    (4, 7),
    (9, 7),
    (20, 7),
    (26, 7),
    (2, 8),
    (3, 8),
    (11, 8),
    (12, 8),
    (17, 8),
    (19, 8),
    (7, 9),
    (13, 9),
    (23, 9),
    (24, 9),
    (25, 9),
    (27, 9),
    (0, 10),
    (6, 10),
    (15, 10),
    (18, 10),
    (21, 10),
    (26, 10),
    (2, 11),
    (7, 11),
    (10, 11),
    (17, 11),
    (22, 11),
    (27, 11),
    (8, 12),
    (11, 12),
    (14, 12),
    (20, 12),
    (23, 12),
    (29, 12),
    (4, 13),
    (5, 13),
    (9, 13),
    (13, 13),
    (16, 13),
    (19, 13),
    (1, 14),
    (3, 14),
    (12, 14),
    (24, 14),
    (25, 14),
    (28, 14),
  )

  cetz.canvas(length: 0.45cm, {
    let nx = 30
    let ny = 15
    let cell_size = 1.0
    let h_width = nx * cell_size
    let h_height = ny * cell_size

    // Palette unifiée
    let color_blue = orange
    let color_orange = blue
    let col_dot_base = gray.darken(30%)

    // Définition des couleurs de fond (lighten)
    let col_row_bg = color_blue.lighten(90%)
    let col_col_bg = color_orange.lighten(90%)
    // Calcul du mélange pour l'intersection
    let col_mix_bg = col_row_bg.mix(col_col_bg)

    // Label "H ="
    content((-3.4, -h_height / 2), text(size: 1.6em, weight: "bold")[$bold(H) =$])

    // Sélection visuelle (Focus)
    let sel_row = 7
    let sel_col = 10

    // Rectangles de fond
    rect((0, -sel_row), (h_width, -sel_row - 1), fill: col_row_bg, stroke: none)
    rect((sel_col, 0), (sel_col + 1, -h_height), fill: col_col_bg, stroke: none)
    rect((sel_col, -sel_row), (sel_col + 1, -sel_row - 1), fill: col_mix_bg, stroke: none)

    // Grands crochets matriciels
    let b_w = 0.6
    set-style(stroke: (thickness: 1.5pt, cap: "round"))
    line((b_w, 0.3), (0, 0.3), (0, -h_height - 0.3), (b_w, -h_height - 0.3))
    line((h_width - b_w, 0.3), (h_width, 0.3), (h_width, -h_height - 0.3), (h_width - b_w, -h_height - 0.3))

    // Dessin des points
    for (x, y) in points {
      let px = x + 0.5
      let py = -y - 0.5

      let is_row = (y == sel_row)
      let is_col = (x == sel_col)

      let d_col = col_dot_base
      let r = 0.16

      if is_row {
        d_col = color_blue
        r = 0.24
      } else if is_col {
        d_col = color_orange
        r = 0.24
      }

      circle((px, py), radius: r, fill: d_col, stroke: none)
    }

    // 5. Légendes w_r et w_c
    content((h_width + 0.5, -sel_row - 0.5), anchor: "west", text(
      fill: color_blue,
      weight: "bold",
      size: 1.1em,
    )[$w_r = 6$])
    content((sel_col + 0.5, 0.8), anchor: "south", text(fill: color_orange, weight: "bold", size: 1.1em)[$w_c = 3$])
  })
}

#let hldpc_dual(row1: 0, row2: 14) = {
  import cetz.draw: *
  let points = (
    (7, 0),
    (10, 0),
    (15, 0),
    (22, 0),
    (24, 0),
    (29, 0),
    (3, 1),
    (6, 1),
    (18, 1),
    (19, 1),
    (25, 1),
    (27, 1),
    (5, 2),
    (9, 2),
    (13, 2),
    (14, 2),
    (17, 2),
    (28, 2),
    (0, 3),
    (8, 3),
    (11, 3),
    (16, 3),
    (20, 3),
    (26, 3),
    (1, 4),
    (2, 4),
    (4, 4),
    (12, 4),
    (21, 4),
    (23, 4),
    (5, 5),
    (6, 5),
    (8, 5),
    (10, 5),
    (21, 5),
    (29, 5),
    (14, 6),
    (15, 6),
    (16, 6),
    (18, 6),
    (22, 6),
    (28, 6),
    (0, 7),
    (1, 7),
    (4, 7),
    (9, 7),
    (20, 7),
    (26, 7),
    (2, 8),
    (3, 8),
    (11, 8),
    (12, 8),
    (17, 8),
    (19, 8),
    (7, 9),
    (13, 9),
    (23, 9),
    (24, 9),
    (25, 9),
    (27, 9),
    (0, 10),
    (6, 10),
    (15, 10),
    (18, 10),
    (21, 10),
    (26, 10),
    (2, 11),
    (7, 11),
    (10, 11),
    (17, 11),
    (22, 11),
    (27, 11),
    (8, 12),
    (11, 12),
    (14, 12),
    (20, 12),
    (23, 12),
    (29, 12),
    (4, 13),
    (5, 13),
    (9, 13),
    (13, 13),
    (16, 13),
    (19, 13),
    (1, 14),
    (3, 14),
    (12, 14),
    (24, 14),
    (25, 14),
    (28, 14),
  )

  cetz.canvas(length: 0.35cm, {
    let nx = 30
    let ny = 15
    let col_1 = orange
    let col_2 = blue

    content((-3.4, -7.5), text(size: 1.6em)[$H =$])

    // Fonds de lignes
    rect((0, -row1), (nx, -row1 - 1), fill: col_1.lighten(90%), stroke: none)
    if row2 != none { rect((0, -row2), (nx, -row2 - 1), fill: col_2.lighten(90%), stroke: none) }

    // Crochets
    set-style(stroke: (thickness: 1.2pt))
    line((0.5, 0.3), (0, 0.3), (0, -ny - 0.3), (0.5, -ny - 0.3))
    line((nx - 0.5, 0.3), (nx, 0.3), (nx, -ny - 0.3), (nx - 0.5, -ny - 0.3))

    for (x, y) in points {
      let d_col = gray.darken(30%)
      let r = 0.15
      if y == row1 {
        d_col = col_1
        r = 0.22
      } else if y == row2 {
        d_col = col_2
        r = 0.22
      }
      circle((x + 0.5, -y - 0.5), radius: r, fill: d_col, stroke: none)
    }
  })
}

// Données de H partagées (mêmes points que hldpc / hldpc_dual)
#let _h_pts = (
  (7, 0),
  (10, 0),
  (15, 0),
  (22, 0),
  (24, 0),
  (29, 0),
  (3, 1),
  (6, 1),
  (18, 1),
  (19, 1),
  (25, 1),
  (27, 1),
  (5, 2),
  (9, 2),
  (13, 2),
  (14, 2),
  (17, 2),
  (28, 2),
  (0, 3),
  (8, 3),
  (11, 3),
  (16, 3),
  (20, 3),
  (26, 3),
  (1, 4),
  (2, 4),
  (4, 4),
  (12, 4),
  (21, 4),
  (23, 4),
  (5, 5),
  (6, 5),
  (8, 5),
  (10, 5),
  (21, 5),
  (29, 5),
  (14, 6),
  (15, 6),
  (16, 6),
  (18, 6),
  (22, 6),
  (28, 6),
  (0, 7),
  (1, 7),
  (4, 7),
  (9, 7),
  (20, 7),
  (26, 7),
  (2, 8),
  (3, 8),
  (11, 8),
  (12, 8),
  (17, 8),
  (19, 8),
  (7, 9),
  (13, 9),
  (23, 9),
  (24, 9),
  (25, 9),
  (27, 9),
  (0, 10),
  (6, 10),
  (15, 10),
  (18, 10),
  (21, 10),
  (26, 10),
  (2, 11),
  (7, 11),
  (10, 11),
  (17, 11),
  (22, 11),
  (27, 11),
  (8, 12),
  (11, 12),
  (14, 12),
  (20, 12),
  (23, 12),
  (29, 12),
  (4, 13),
  (5, 13),
  (9, 13),
  (13, 13),
  (16, 13),
  (19, 13),
  (1, 14),
  (3, 14),
  (12, 14),
  (24, 14),
  (25, 14),
  (28, 14),
)

#let tanner_illustration() = {
  cetz.canvas(length: 1.1cm, {
    import cetz.draw: *

    let vy = 2.6
    let cy = 0.0
    let vxs = (0.0, 1.2, 2.4, 3.6)
    let cxs = (0.9, 2.7)

    let edges = ((0, 0), (1, 0), (2, 0), (1, 1), (2, 1), (3, 1))

    // Dessin des arêtes
    for (vi, ci) in edges {
      line(
        (vxs.at(vi), vy - 0.28),
        (cxs.at(ci), cy + 0.32),
        stroke: 0.9pt + gray.darken(10%),
      )
    }

    // Nœuds de contrôle (carrés, orange)
    let cnames = ([$c_0$], [$c_1$])
    for j in range(2) {
      let cx = cxs.at(j)
      let s = 0.30
      rect(
        (cx - s, cy - s),
        (cx + s, cy + s),
        fill: orange.lighten(75%),
        stroke: 1.8pt + orange,
        name: "c" + str(j),
      )
      content(
        (cx, cy - s - 0.3),
        anchor: "north",
        text(size: 0.8em, fill: orange, weight: "bold")[#cnames.at(j)],
      )
    }

    // Nœuds de variable (cercles, bleu)
    let vnames = ([$v_0$], [$v_1$], [$v_2$], [$v_3$])
    for i in range(4) {
      let vx = vxs.at(i)
      let r = 0.28
      circle(
        (vx, vy),
        radius: r,
        fill: blue.lighten(75%),
        stroke: 1.8pt + blue,
        name: "v" + str(i),
      )
      content(
        (vx, vy + r + 0.25),
        anchor: "south",
        text(size: 0.8em, fill: blue, weight: "bold")[#vnames.at(i)],
      )
    }
  })
}

// Mini matrice H avec surbrillance d'une ligne et/ou colonne
#let h_mini_tanner(hl_row: none, hl_col: none) = {
  let pts = _h_pts
  cetz.canvas(length: 0.215cm, {
    import cetz.draw: *
    let nx = 30
    let ny = 15
    content((-7, -7.5), text(size: 1.5em, weight: "bold")[$H =$])
    if hl_row != none {
      rect((0, -hl_row), (nx, -hl_row - 1), fill: orange.lighten(85%), stroke: none)
    }
    if hl_col != none {
      rect((hl_col, 0), (hl_col + 1, -ny), fill: blue.lighten(85%), stroke: none)
    }
    set-style(stroke: (thickness: 0.9pt, cap: "round"))
    line((0.4, 0.25), (0, 0.25), (0, -ny - 0.25), (0.4, -ny - 0.25))
    line((nx - 0.4, 0.25), (nx, 0.25), (nx, -ny - 0.25), (nx - 0.4, -ny - 0.25))
    for (x, y) in pts {
      let r = 0.13
      let col = gray.darken(25%)
      if hl_row != none and y == hl_row {
        col = orange
        r = 0.22
      } else if hl_col != none and x == hl_col {
        col = blue
        r = 0.22
      }
      circle((x + 0.5, -y - 0.5), radius: r, fill: col, stroke: none)
    }
    if hl_row != none {
      content((nx + 0.5, -hl_row - 0.5), anchor: "west", text(fill: orange, size: 1.0em, weight: "bold")[$c_#hl_row$])
    }
    if hl_col != none {
      content((hl_col + 0.5, 0.70), anchor: "south", text(fill: blue, size: 1.0em, weight: "bold")[$v_#hl_col$])
    }
  })
}

#let hldpc_dynamic(hl_rows: (), hl_cols: (), show_labels: true, h_show: true) = {
  import cetz.draw: *

  let points = (
    (7, 0),
    (10, 0),
    (15, 0),
    (22, 0),
    (24, 0),
    (29, 0),
    (3, 1),
    (6, 1),
    (18, 1),
    (19, 1),
    (25, 1),
    (27, 1),
    (5, 2),
    (9, 2),
    (13, 2),
    (14, 2),
    (17, 2),
    (28, 2),
    (0, 3),
    (8, 3),
    (11, 3),
    (16, 3),
    (20, 3),
    (26, 3),
    (1, 4),
    (2, 4),
    (4, 4),
    (12, 4),
    (21, 4),
    (23, 4),
    (5, 5),
    (6, 5),
    (8, 5),
    (10, 5),
    (21, 5),
    (29, 5),
    (14, 6),
    (15, 6),
    (16, 6),
    (18, 6),
    (22, 6),
    (28, 6),
    (0, 7),
    (1, 7),
    (4, 7),
    (9, 7),
    (20, 7),
    (26, 7),
    (2, 8),
    (3, 8),
    (11, 8),
    (12, 8),
    (17, 8),
    (19, 8),
    (7, 9),
    (13, 9),
    (23, 9),
    (24, 9),
    (25, 9),
    (27, 9),
    (0, 10),
    (6, 10),
    (15, 10),
    (18, 10),
    (21, 10),
    (26, 10),
    (2, 11),
    (7, 11),
    (10, 11),
    (17, 11),
    (22, 11),
    (27, 11),
    (8, 12),
    (11, 12),
    (14, 12),
    (20, 12),
    (23, 12),
    (29, 12),
    (4, 13),
    (5, 13),
    (9, 13),
    (13, 13),
    (16, 13),
    (19, 13),
    (1, 14),
    (3, 14),
    (12, 14),
    (24, 14),
    (25, 14),
    (28, 14),
  )

  cetz.canvas(length: 0.4cm, {
    let nx = 30
    let ny = 15

    let col_row = orange
    let col_col = blue
    let col_dot_base = gray.darken(30%)

    // Marge pour réduire l'épaisseur des bandes (crée le gap visuel)
    let gap = 0.1

    if h_show {
      content((-3.4, -ny / 2), text(size: 1.6em, weight: "bold")[$H =$])
    } else {
      content((-3.4, -ny / 2), text(size: 1.6em, weight: "bold")[$space space space$])
    }

    // 1. Dessiner les fonds des lignes (avec gap)
    for r in hl_rows {
      rect((0, -r - gap), (nx, -r - 1 + gap), fill: col_row.lighten(85%), stroke: none)
    }

    // 2. Dessiner les fonds des colonnes (avec gap)
    for c in hl_cols {
      rect((c + gap, 0), (c + 1 - gap, -ny), fill: col_col.lighten(85%), stroke: none)
    }

    // 3. Dessiner les intersections
    for r in hl_rows {
      for c in hl_cols {
        rect(
          (c + gap, -r - gap),
          (c + 1 - gap, -r - 1 + gap),
          fill: col_row.lighten(85%).mix(col_col.lighten(85%)),
          stroke: none,
        )
      }
    }

    // 4. Les grands crochets matriciels
    let b_w = 0.6
    set-style(stroke: (thickness: 1.5pt, cap: "round"))
    line((b_w, 0.3), (0, 0.3), (0, -ny - 0.3), (b_w, -ny - 0.3))
    line((nx - b_w, 0.3), (nx, 0.3), (nx, -ny - 0.3), (nx - b_w, -ny - 0.3))

    // 5. Dessin des points
    for (x, y) in points {
      let px = x + 0.5
      let py = -y - 0.5

      let is_row = y in hl_rows
      let is_col = x in hl_cols

      let d_col = col_dot_base
      let r = 0.15

      // Détermine la couleur et la taille si le point est dans une zone surlignée
      if is_row and is_col {
        d_col = col_row.mix(col_col) // Point à l'intersection
        r = 0.24
      } else if is_row {
        d_col = col_row
        r = 0.24
      } else if is_col {
        d_col = col_col
        r = 0.24
      }

      circle((px, py), radius: r, fill: d_col, stroke: none)
    }

    // 6. Affichage optionnel des labels
    if show_labels {
      for r in hl_rows {
        content((nx + 0.5, -r - 0.5), anchor: "west", text(fill: col_row, weight: "bold", size: 1.1em)[$c_#r$])
      }
      for c in hl_cols {
        content((c + 0.5, -ny - 0.8), anchor: "north", text(fill: col_col, weight: "bold", size: 1.1em)[$v_#c$])
      }
    }
  })
}

// Graphe de Tanner paramétrable
//   scale    : taille d'une unité cetz
//   hl_row   : index du check node à mettre en évidence (none = aucun)
//   hl_col   : index du variable node à mettre en évidence (none = aucun)
//   show_all : afficher toutes les arêtes
//   colored  : colorier tous les nœuds (bleu/orange) même sans highlight
#let tanner_canvas(
  scale: 0.43cm,
  hl_row: none,
  hl_col: none,
  show_all: false,
  colored: false,
  v_c_show: true,
) = {
  let pts = _h_pts
  cetz.canvas(length: scale, {
    import cetz.draw: *
    let n_var = 30
    let n_chk = 15
    let vy = 5.5
    let cy = 0.0

    // --- Logique de centrage ---
    let gap_v = 1.0 // Espacement des cercles
    let gap_c = 1.8 // Espacement des carrés (un peu plus large pour l'équilibre visuel)

    let width_v = (n_var - 1) * gap_v
    let width_c = (n_chk - 1) * gap_c
    let offset_c = (width_v - width_c) / 2 // Calcul du décalage pour centrer C sous V

    // Noeuds connectés au check ou variable mis en évidence
    let hl_var_set = if hl_row != none {
      pts.filter(p => p.at(1) == hl_row).map(p => p.at(0))
    } else { () }
    let hl_chk_set = if hl_col != none {
      pts.filter(p => p.at(0) == hl_col).map(p => p.at(1))
    } else { () }

    // — ARÊTES —
    for (vj, ci) in pts {
      let vx = vj * gap_v
      let ccx = offset_c + (ci * gap_c)
      let is_row = hl_row != none and ci == hl_row
      let is_col = hl_col != none and vj == hl_col
      let do_draw = is_row or is_col or show_all
      if do_draw {
        let s = if is_row { 1.5pt + orange } else if is_col { 2.0pt + blue } else { 0.50pt + gray.lighten(20%) }
        line((vx, vy), (ccx, cy), stroke: s)
      }
    }

    // — NŒUDS DE CONTRÔLE (carrés) —
    for j in range(n_chk) {
      let ccx = offset_c + (j * gap_c)
      let sz = 0.40
      let is_main = hl_row != none and j == hl_row
      let is_conn = hl_chk_set.contains(j)
      let fc = if is_main { orange.lighten(48%) } else if is_conn { blue.lighten(60%) } else if colored {
        orange.lighten(76%)
      } else { white }
      let sc = if is_main { 1.8pt + orange } else if is_conn { 1.8pt + blue } else if colored { 1.2pt + orange } else {
        1.0pt + black
      }
      rect((ccx - sz, cy - sz), (ccx + sz, cy + sz), fill: fc, stroke: sc)
      if is_main {
        content((ccx, cy - sz - 0.33), anchor: "north", text(size: 0.52em, fill: orange, weight: "bold")[$c_#j$])
      } else if is_conn {
        content((ccx, cy - sz - 0.33), anchor: "north", text(size: 0.52em, fill: blue, weight: "bold")[$c_#j$])
      }
    }

    // — NŒUDS DE VARIABLE (cercles) —
    for i in range(n_var) {
      let vx = i * gap_v
      let r = 0.33
      let is_main = hl_col != none and i == hl_col
      let is_conn = hl_var_set.contains(i)
      let fc = if is_main { blue.lighten(48%) } else if is_conn { orange.lighten(60%) } else if colored {
        blue.lighten(76%)
      } else { white }
      let sc = if is_main { 1.5pt + blue } else if is_conn { 1.5pt + orange } else if colored { 1.2pt + blue } else {
        1.0pt + black
      }
      circle((vx, vy), radius: r, fill: fc, stroke: sc)
      if is_main {
        content((vx, vy + r + 0.30), anchor: "south", text(size: 0.52em, fill: blue, weight: "bold")[$v_#i$])
      } else if is_conn {
        content((vx, vy + r + 0.30), anchor: "south", text(size: 0.52em, fill: orange, weight: "bold")[$v_#i$])
      }
    }

    // Légendes des couches
    if v_c_show {
      content((-2.0, vy), anchor: "east", text(size: 0.65em, weight: "bold")[$V$])
      content((-2.0, cy), anchor: "east", text(size: 0.65em, weight: "bold")[$C$])
    }
  })
}

// Diagramme passage de messages (Belief Propagation)
#let bp_diagram() = {
  cetz.canvas(length: 1.05cm, {
    import cetz.draw: *
    let vy = 3.0
    let cy = 0.0
    let vxs = (0.0, 1.3, 2.6, 3.9)
    let cxs = (0.65, 2.6)
    let edges = ((0, 0), (1, 0), (2, 0), (1, 1), (2, 1), (3, 1))
    let mk_bl = (end: "stealth", fill: blue, size: 0.17)
    let mk_or = (end: "stealth", fill: orange, size: 0.17)

    // Flèches bidirectionnelles décalées
    for (vi, ci) in edges {
      let vx = vxs.at(vi)
      let cx = cxs.at(ci)
      // V → C (bleu, décalé à gauche)
      line((vx - 0.06, vy - 0.32), (cx - 0.06, cy + 0.38), mark: mk_bl, stroke: 1.4pt + blue.lighten(15%))
      // C → V (orange, décalé à droite)
      line((cx + 0.06, cy + 0.38), (vx + 0.06, vy - 0.32), mark: mk_or, stroke: 1.4pt + orange.lighten(10%))
    }

    // Nœuds de variable
    let vnames = ([$v_0$], [$v_1$], [$v_2$], [$v_3$])
    for i in range(4) {
      let vx = vxs.at(i)
      let r = 0.30
      circle((vx, vy), radius: r, fill: blue.lighten(72%), stroke: 1.6pt + blue)
      content((vx, vy + r + 0.20), anchor: "south", text(size: 0.70em, fill: blue, weight: "bold")[#vnames.at(i)])
    }

    // Nœuds de contrôle
    let cnames = ([$c_0$], [$c_1$])
    for j in range(2) {
      let cx = cxs.at(j)
      let s = 0.33
      rect((cx - s, cy - s), (cx + s, cy + s), fill: orange.lighten(72%), stroke: 1.6pt + orange)
      content((cx, cy - s - 0.22), anchor: "north", text(size: 0.70em, fill: orange, weight: "bold")[#cnames.at(j)])
    }

    // Légendes des flèches
    content((4.45, vy - 0.5), anchor: "west", text(size: 0.65em, fill: blue, weight: "bold")[$mu_(j arrow i)$])
    content((4.45, cy + 0.4), anchor: "west", text(size: 0.65em, fill: orange, weight: "bold")[$nu_(i arrow j)$])
  })
}

#let icon_var = box(baseline: 20%)[
  #cetz.canvas({
    import cetz.draw: *
    circle((0, 0), radius: 0.35em, fill: blue.lighten(88%), stroke: 1.5pt + blue)
  })
]

#let icon_chk = box(baseline: 20%)[
  #cetz.canvas({
    import cetz.draw: *
    rect((-0.35em, -0.35em), (0.35em, 0.35em), fill: orange.lighten(88%), stroke: 1.5pt + orange)
  })
]

// Calcule la parité d'un Check Node i en fonction des Variable Nodes connectés
#let calcule_parite(v_values, index_chk) = {
  let neighbors = _h_pts.filter(p => p.at(1) == index_chk).map(p => p.at(0))
  let somme = 0
  for n in neighbors {
    somme = somme + v_values.at(n)
  }
  calc.rem(somme, 2)
}

#let tanner_status(
  scale: 0.43cm,
  v_values: none,
  hl_v: (),
  highlight_edges: false,
) = {
  let pts = _h_pts
  cetz.canvas(length: scale, {
    import cetz.draw: *
    let n_var = 30
    let n_chk = 15
    let vy = 5.5
    let cy = 0.0
    let gap_v = 1.0
    let gap_c = 1.8
    let width_v = (n_var - 1) * gap_v
    let width_c = (n_chk - 1) * gap_c
    let offset_c = (width_v - width_c) / 2

    let col_ok = green
    let col_err = red

    for (vj, ci) in pts {
      let vx = vj * gap_v
      let ccx = offset_c + (ci * gap_c)
      let p_ci = calcule_parite(v_values, ci)
      let is_err_edge = highlight_edges and hl_v.contains(vj) and p_ci == 1

      if not is_err_edge {
        line((vx, vy), (ccx, cy), stroke: 0.4pt + gray.lighten(60%))
      }
    }

    for (vj, ci) in pts {
      let vx = vj * gap_v
      let ccx = offset_c + (ci * gap_c)
      let p_ci = calcule_parite(v_values, ci)
      let is_err_edge = highlight_edges and hl_v.contains(vj) and p_ci == 1

      if is_err_edge {
        line((vx, vy), (ccx, cy), stroke: 1.5pt + col_err)
      }
    }

    for j in range(n_chk) {
      let ccx = offset_c + (j * gap_c)
      let sz = 0.40
      let p = calcule_parite(v_values, j)
      let is_ok = (p == 0)

      rect(
        (ccx - sz, cy - sz),
        (ccx + sz, cy + sz),
        fill: if is_ok { col_ok.lighten(92%) } else { col_err.lighten(92%) },
        stroke: if is_ok { 1.2pt + col_ok } else { 1.5pt + col_err },
      )
      content((ccx, cy), text(size: 0.65em, weight: "bold", fill: if is_ok { col_ok } else { col_err })[#p])
    }

    for i in range(n_var) {
      let vx = i * gap_v
      let r = 0.33
      let val = v_values.at(i)
      let is_err = hl_v.contains(i)

      circle(
        (vx, vy),
        radius: r,
        fill: if is_err { col_err.lighten(92%) } else { blue.lighten(92%) },
        stroke: if is_err { 1.5pt + col_err } else { 1.2pt + blue },
      )
      content((vx, vy), text(size: 0.55em, weight: "bold", fill: if is_err { col_err } else { blue })[#val])
    }
  })
}

// Composant de zoom d'une seule contrainte (CN) et ses VN voisins
#let zoom_contrainte(is_ok: true) = {
  cetz.canvas(length: 1cm, {
    import cetz.draw: *
    let col = if is_ok { green } else { red }

    rect((-2.2, -1.2), (2.2, 2.0), stroke: none, fill: none)

    let blue_fill = blue.lighten(90%)
    let blue_stroke = 1.2pt + blue
    let red_fill = red.lighten(90%)
    let red_stroke = 2pt + red
    let gray_stroke = 0.8pt + gray

    for i in (0, 1, 2) {
      let x = i * 1.5 - 1.5
      let is_failed_vn = not is_ok and i == 1
      line((x, 1.5), (0, 0), stroke: if is_failed_vn { red_stroke } else { gray_stroke })
    }

    for i in (0, 1, 2) {
      let x = i * 1.5 - 1.5
      let is_failed_vn = not is_ok and i == 1
      circle(
        (x, 1.5),
        radius: 0.3,
        stroke: if is_failed_vn { red_stroke } else { blue_stroke },
        fill: if is_failed_vn { red_fill } else { blue_fill },
      )

      let val = if is_failed_vn { "1" } else { "0" }
      content((x, 1.5), text(size: 12pt, fill: if is_failed_vn { col } else { blue }, weight: "bold")[#val])
    }

    rect(
      (-0.3, -0.3),
      (0.3, 0.3),
      stroke: if not is_ok { red_stroke } else { 2pt + col },
      fill: if not is_ok { red_fill } else { col.lighten(90%) },
    )
    content((0, 0), text(fill: col, weight: "bold", size: 15pt)[#(if is_ok { "0" } else { "1" })])

    let eq_size = 14pt
    if is_ok {
      content(
        (0, -0.7),
        text(fill: col, size: eq_size)[$0 plus.o 0 plus.o 0 = bold(0)$],
        anchor: "north",
      )
    } else {
      content(
        (0, -0.71),
        text(fill: col, size: eq_size)[$0 plus.o 1 plus.o 0 = bold(1)$],
        anchor: "north",
      )
    }
  })
}

// --- Schémas pour la Topologie et la Construction ---
// Visualisation du Girth et d'un cycle de longueur 4
#let schema_girth_4(highlight: false) = {
  cetz.canvas(length: 0.8cm, {
    import cetz.draw: *
    let s_dash = (paint: red, thickness: 2pt, dash: "dashed")

    // Positionnement
    let v0 = (-1.5, 2)
    let v1 = (1.5, 2)
    let c0 = (-1.5, 0)
    let c1 = (1.5, 0)

    // Arêtes
    line(v0, c0, v1, c1, v0, stroke: if highlight { s_dash } else { 1pt + gray })
    // line(v0, c1, stroke: 1pt + gray.lighten(60%))

    // Noeuds
    circle(v0, radius: 0.3, fill: blue.lighten(90%), stroke: 1.2pt + blue)
    circle(v1, radius: 0.3, fill: blue.lighten(90%), stroke: 1.2pt + blue)
    rect(
      (c0.at(0) - 0.3, c0.at(1) - 0.3),
      (c0.at(0) + 0.3, c0.at(1) + 0.3),
      fill: orange.lighten(90%),
      stroke: 1.2pt + orange,
    )
    rect(
      (c1.at(0) - 0.3, c1.at(1) - 0.3),
      (c1.at(0) + 0.3, c1.at(1) + 0.3),
      fill: orange.lighten(90%),
      stroke: 1.2pt + orange,
    )

    // if highlight {
    //   content(
    //     (0, 1),
    //     text(fill: red, weight: "bold", size: 0.8em)[Cycle $L=4$],
    //     frame: "rect",
    //     stroke: none,
    //     fill: rgb("ffffffcc"),
    //   )
    // }
  })
}

#let echo_chamber() = {
  cetz.canvas(length: 1cm, {
    import cetz.draw: *
    let v0 = (0, 2)
    let c0 = (0, 0)

    line(v0, c0, mark: (end: "stealth", fill: red), stroke: 2pt + red)
    arc((0, 0), start: -45deg, stop: 225deg, radius: 0.5, mark: (end: "stealth", fill: red), stroke: 1.5pt + red)

    circle(v0, radius: 0.3, fill: blue.lighten(90%), stroke: 1.5pt + blue)
    rect((-0.3, -0.3), (0.3, 0.3), fill: orange.lighten(90%), stroke: 1.5pt + orange)

    content((1, 1), text(fill: red, size: 0.8em, style: "italic")[Auto-renforcement \ d'une erreur], anchor: "west")
  })
}

#let peg_concept() = {
  cetz.canvas(length: 0.6cm, {
    import cetz.draw: *
    circle((0, 4), radius: 0.4, fill: blue.lighten(80%), stroke: 1.5pt + blue)
    let targets = ((-3, 0), (0, 0), (3, 0))
    for t in targets {
      line((0, 4), t, stroke: 1.5pt + green)
      rect(
        (t.at(0) - 0.3, t.at(1) - 0.3),
        (t.at(0) + 0.3, t.at(1) + 0.3),
        fill: orange.lighten(90%),
        stroke: 1.2pt + orange,
      )
    }
    content((0, -1.2), text(size: 0.8em, fill: green, weight: "bold")[Distance maximale], anchor: "north")
  })
}

// --- VRAIES MATRICES GÉNÉRÉES ---

#let _h_pts = (
  (10, 0),
  (14, 0),
  (15, 0),
  (16, 0),
  (17, 0),
  (2, 1),
  (5, 1),
  (7, 1),
  (13, 1),
  (16, 1),
  (18, 1),
  (21, 1),
  (28, 1),
  (4, 2),
  (9, 2),
  (15, 2),
  (17, 2),
  (18, 2),
  (3, 3),
  (13, 3),
  (17, 3),
  (25, 3),
  (29, 3),
  (1, 4),
  (2, 4),
  (9, 4),
  (29, 4),
  (5, 5),
  (7, 5),
  (11, 5),
  (14, 5),
  (16, 5),
  (22, 5),
  (27, 5),
  (6, 6),
  (14, 6),
  (22, 6),
  (28, 6),
  (1, 7),
  (11, 7),
  (12, 7),
  (21, 7),
  (23, 7),
  (0, 8),
  (5, 8),
  (23, 8),
  (26, 8),
  (27, 8),
  (1, 9),
  (3, 9),
  (4, 9),
  (6, 9),
  (7, 9),
  (8, 9),
  (11, 9),
  (19, 9),
  (21, 9),
  (26, 9),
  (12, 10),
  (15, 10),
  (20, 10),
  (29, 10),
  (2, 11),
  (12, 11),
  (20, 11),
  (24, 11),
  (28, 11),
  (0, 12),
  (3, 12),
  (8, 12),
  (10, 12),
  (18, 12),
  (19, 12),
  (24, 12),
  (25, 12),
  (4, 13),
  (8, 13),
  (20, 13),
  (22, 13),
  (23, 13),
  (26, 13),
  (0, 14),
  (6, 14),
  (9, 14),
  (10, 14),
  (13, 14),
  (19, 14),
  (24, 14),
  (25, 14),
  (27, 14),
)

#let _p_pts = (
  (0, 0),
  (1, 0),
  (3, 0),
  (4, 0),
  (7, 0),
  (8, 0),
  (10, 0),
  (13, 0),
  (14, 0),
  (2, 1),
  (3, 1),
  (9, 1),
  (10, 1),
  (11, 1),
  (12, 1),
  (13, 1),
  (0, 2),
  (1, 2),
  (2, 2),
  (4, 2),
  (7, 2),
  (8, 2),
  (9, 2),
  (10, 2),
  (11, 2),
  (12, 2),
  (2, 3),
  (3, 3),
  (4, 3),
  (11, 3),
  (12, 3),
  (13, 3),
  (14, 3),
  (0, 4),
  (2, 4),
  (3, 4),
  (5, 4),
  (7, 4),
  (9, 4),
  (11, 4),
  (14, 4),
  (0, 5),
  (2, 5),
  (3, 5),
  (4, 5),
  (7, 5),
  (8, 5),
  (9, 5),
  (10, 5),
  (12, 5),
  (13, 5),
  (14, 5),
  (2, 6),
  (3, 6),
  (8, 6),
  (9, 6),
  (11, 6),
  (3, 7),
  (4, 7),
  (5, 7),
  (6, 7),
  (7, 7),
  (8, 7),
  (10, 7),
  (11, 7),
  (13, 7),
  (1, 8),
  (2, 8),
  (3, 8),
  (8, 8),
  (9, 8),
  (12, 8),
  (0, 9),
  (5, 9),
  (9, 9),
  (11, 9),
  (0, 10),
  (3, 10),
  (4, 10),
  (7, 10),
  (8, 10),
  (10, 10),
  (11, 10),
  (12, 10),
  (13, 10),
  (0, 11),
  (1, 11),
  (3, 11),
  (4, 11),
  (5, 11),
  (6, 11),
  (11, 11),
  (14, 11),
  (2, 12),
  (4, 12),
  (6, 12),
  (8, 12),
  (9, 12),
  (11, 12),
  (12, 12),
  (14, 12),
  (3, 13),
  (4, 13),
  (5, 13),
  (7, 13),
  (8, 13),
  (10, 13),
  (11, 13),
  (13, 13),
  (14, 13),
  (1, 14),
  (2, 14),
  (9, 14),
)

// --- Composant d'illustration des vraies densités ---

#let paradoxe_densite_reel() = {
  cetz.canvas(length: 0.18cm, {
    // Réglage de l'échelle pour que ça tienne
    import cetz.draw: *

    // Fonction pour dessiner une matrice à partir de ses points
    let draw_real_matrix(offset_x, cols, rows, pts, title, col, dens_text) = {
      // Cadre
      rect((offset_x, 0), (offset_x + cols, -rows), stroke: 1.5pt + black)

      // Titre au dessus
      content((offset_x + cols / 2, 2.5), text(weight: "bold", size: 0.8em)[#title])
      // Densité en dessous
      content((offset_x + cols / 2, -rows - 2.2), text(
        fill: gray,
        weight: "bold",
        size: 0.65em,
      )[_Densité_ : #dens_text])

      // Dessin des vrais points (les '1')
      for (x, y) in pts {
        circle((offset_x + x + 0.5, -y - 0.5), radius: 0.35, fill: col, stroke: none)
      }
    }

    // --- 1. Dessin de la matrice H (0 à 30) ---
    // draw_real_matrix(0, 30, 15, _h_pts, "H (Clairsemée)", orange, "20%")

    draw_real_matrix(0, 30, 15, _h_pts, "H", orange, "20%")

    // --- 2. Zone centrale élargie pour le Pivot de Gauss ---
    let arrow_start = 32
    let arrow_end = 50
    let center_x = (arrow_start + arrow_end) / 2

    line((arrow_start, -7.5), (arrow_end, -7.5), mark: (end: "stealth", fill: black), stroke: 1.5pt + black)
    content((center_x, -5), text(size: 0.70em, style: "italic", weight: "bold")[Pivot de Gauss])

    // --- 3. Dessin de la matrice P décalée ---
    // On commence P à 52 (au lieu de 41)
    // draw_real_matrix(52, 15, 15, _p_pts, "Bloc P (Dense)", blue, "50%")
    draw_real_matrix(52, 15, 15, _p_pts, "Bloc P", blue, "50%")
  })
}

#let schema_systematique() = {
  cetz.canvas(length: 1cm, {
    import cetz.draw: *
    let w_p = 2.2
    let w_i = 2.4
    let h = 1.5

    // --- MATRICE H = [P^T | I] ---
    group({
      translate((-w_p - w_i - 1.5, 0))
      content((-0.2, h / 2), $bold(H) =$, anchor: "east")

      // 1. Les fonds colorés (sans bordure)
      rect((0, 0), (w_p, h), fill: blue.lighten(80%), stroke: none)
      rect((w_p, 0), (w_p + w_i, h), fill: gray.lighten(90%), stroke: none)

      // 2. Les lignes (une seule par intersection)
      rect((0, 0), (w_p + w_i, h), stroke: 1.5pt + black) // Contour global
      line((w_p, 0), (w_p, h), stroke: 1pt + black) // Séparation propre

      content((w_p / 2, h / 2), $bold(P)^top$, text: (fill: blue.darken(20%), weight: "bold"))
      content((w_p + w_i / 2, h / 2), $bold(I)_(n-k)$)
    })

    // Flèche centrale
    line((-1.0, h / 2), (0.7, h / 2), mark: (end: "stealth", fill: black), stroke: 1.5pt + black)

    // --- MATRICE G = [I | P] ---
    group({
      translate((2.5, 0))
      content((-0.2, h / 2), $bold(G) =$, anchor: "east")

      // 1. Les fonds colorés (sans bordure)
      rect((0, 0), (w_i, h), fill: gray.lighten(90%), stroke: none)
      rect((w_i, 0), (w_i + w_p, h), fill: blue.lighten(80%), stroke: none)

      // 2. Les lignes
      rect((0, 0), (w_i + w_p, h), stroke: 1.5pt + black) // Contour global
      line((w_i, 0), (w_i, h), stroke: 1pt + black) // Séparation propre

      content((w_i / 2, h / 2), $bold(I)_k$)
      content((w_i + w_p / 2, h / 2), $bold(P)$, text: (fill: blue.darken(20%), weight: "bold"))
    })
  })
}

#let dessiner_matrice(nom, blocs, hauteur: 1.5) = {
  cetz.canvas(length: 1cm, {
    import cetz.draw: *

    group({
      // 1. Nom de la matrice à gauche (ex: "H =")
      if nom != none {
        content((-0.2, hauteur / 2), nom, anchor: "east")
      }

      let x = 0 // Curseur pour avancer de gauche à droite

      // 2. Étape des fonds et du texte (sans aucune bordure)
      for bloc in blocs {
        let w = bloc.at("largeur", default: 2)
        let bg = bloc.at("fond", default: none)
        let txt = bloc.at("texte", default: none)

        // Dessine le fond coloré
        rect((x, 0), (x + w, hauteur), fill: bg, stroke: none)

        // Place le texte exactement au milieu du bloc
        content((x + w / 2, hauteur / 2), txt)

        x += w // On décale le curseur pour le prochain bloc
      }

      let largeur_totale = x

      // 3. Étape des lignes (pour des intersections parfaites)
      x = 0
      for i in range(blocs.len() - 1) {
        x += blocs.at(i).at("largeur", default: 2)
        // Lignes de séparation internes (plus fines)
        line((x, 0), (x, hauteur), stroke: 1pt + black)
      }

      // 4. Contour global par-dessus tout (plus épais)
      rect((0, 0), (largeur_totale, hauteur), stroke: 1.5pt + black, fill: none)
    })
  })
}


//Comp 1

#let vvals = (1, 0, 1, 0)
#let edges = ((0, 0), (1, 0), (3, 0), (0, 1), (2, 1), (3, 1), (1, 2), (2, 2))

#let graph_layout(step: 1) = {
  cetz.canvas(length: 0.85cm, {
    import cetz.draw: *
    let (vy, cy) = (4.5, 0.0) // vy = Top (Variable Nodes), cy = Bottom (Check Nodes)
    let vxs = (0.0, 2.5, 5.0, 7.5)
    let cxs = (1.25, 3.75, 6.25)

    let r_v = 0.45
    let s_c = 0.4

    // --- 1. LES ARÊTES AVEC DIRECTIONALITÉ ---
    for (k, (vi, ci)) in edges.enumerate() {
      let v_pos = (vxs.at(vi), vy)
      let c_pos = (cxs.at(ci), cy)

      if step == 1 {
        // VN -> CN : On part du haut vers le bas
        line(
          v_pos,
          c_pos,
          shorten-start: r_v,
          shorten-end: s_c,
          mark: (end: ">", fill: blue, size: 0.3),
          stroke: 2pt + blue,
        )
      } else if step == 2 {
        // CN -> VN : On part du bas vers le haut
        let is_err = (ci == 0 or ci == 2)
        let col = if is_err { red } else { green.darken(20%) }
        line(
          c_pos,
          v_pos,
          shorten-start: s_c,
          shorten-end: r_v,
          mark: (end: ">", fill: col, size: 0.3),
          stroke: 2pt + col,
        )
      } else {
        // Étape 3 : Passif
        line(v_pos, c_pos, shorten-start: r_v, shorten-end: s_c, stroke: 1pt + gray.lighten(70%))
      }
    }

    // --- 2. LES VARIABLE NODES (VN) ---
    for i in range(4) {
      let pos = (vxs.at(i), vy)
      let is_flip = (step == 3 and i == 1)
      let col = if is_flip { red } else { blue }
      let bg = if is_flip { red.lighten(92%) } else { blue.lighten(90%) }
      let val = if is_flip { "1" } else { str(vvals.at(i)) }

      circle(pos, radius: r_v, fill: bg, stroke: (if is_flip { 2.5pt } else { 1.5pt }) + col)
      content(pos, text(weight: "bold", fill: col, size: 1.1em)[#val])
      content((pos.at(0), pos.at(1) + 0.8), text(size: 0.8em, fill: col.darken(0%))[$v_#i$])

      if is_flip {
        content((pos.at(0) + 0.1, pos.at(1) + 1.3), text(fill: red, weight: "bold", size: 0.7em)[FLIP !])
      }
    }

    // --- 3. LES CHECK NODES (CN) ---
    for j in range(3) {
      let pos = (cxs.at(j), cy)
      let val = if j == 1 { 0 } else { 1 }
      let col = orange
      let bg = orange.lighten(90%)

      if step >= 2 {
        let is_ok = (val == 0)
        col = if is_ok { green.darken(20%) } else { red }
        bg = col.lighten(92%)
      }

      rect((pos.at(0) - s_c, pos.at(1) - s_c), (pos.at(0) + s_c, pos.at(1) + s_c), fill: bg, stroke: 1.8pt + col)
      content(pos, text(weight: "bold", fill: col, size: 1.1em)[#str(val)])
      content((pos.at(0), pos.at(1) - 0.8), text(size: 0.8em, fill: col.darken(0%))[$c_#j$])
    }
  })
}

#let bf_step1_sending() = graph_layout(step: 1)
#let bf_step2_verdict() = graph_layout(step: 2)
#let bf_step3_flip() = graph_layout(step: 3)

#let schema_vote_majoritaire(n_erreurs: 3, flipped: true) = {
  cetz.canvas(length: 1.0cm, {
    import cetz.draw: *

    // Positions des CN autour du VN central
    let v_pos = (0.0, 0.0)
    let c_positions = (
      (-2.2, 1.8),
      (0.0, 2.2),
      (2.2, 1.8),
      (-2.2, -1.8),
    )
    // Statuts des CN (1=Erreur)
    let states = (1, 1, 1, 0)

    let col_err = red
    let col_ok = green.darken(10%)

    // Arêtes avec flèche CN→VN
    for (i, p) in c_positions.enumerate() {
      let col = if states.at(i) == 1 { col_err } else { col_ok }
      // VN→CN (bleu)
      line(
        v_pos,
        p,
        mark: (end: "stealth", fill: blue.lighten(20%), size: 0.16),
        stroke: 1.2pt + blue.lighten(30%),
      )
      // CN→VN (coloré)
      line(
        p,
        (v_pos.at(0) + 0.06, v_pos.at(1) + 0.06),
        mark: (end: "stealth", fill: col, size: 0.18),
        stroke: 1.8pt + col,
      )
      // Badge message
      let mx = (v_pos.at(0) + p.at(0)) / 2
      let my = (v_pos.at(1) + p.at(1)) / 2
      content(
        (mx, my),
        box(
          fill: if states.at(i) == 1 { red.lighten(88%) } else { green.lighten(88%) },
          stroke: 0.5pt + col,
          radius: 2pt,
          inset: (x: 3pt, y: 1.5pt),
        )[#text(size: 0.52em, fill: col, weight: "bold")[#if states.at(i) == 1 { [✗] } else { [✓] }]],
      )
    }

    // CN (carrés)
    for (i, p) in c_positions.enumerate() {
      let col = if states.at(i) == 1 { col_err } else { col_ok }
      let sz = 0.35
      rect(
        (p.at(0) - sz, p.at(1) - sz),
        (p.at(0) + sz, p.at(1) + sz),
        fill: col.lighten(90%),
        stroke: 1.8pt + col,
      )
      content(p, text(size: 0.72em, fill: col, weight: "bold")[#states.at(i)])
    }

    // VN central
    let r_vn = 0.52
    let col_vn = if flipped { red } else { blue }
    circle(
      v_pos,
      radius: r_vn,
      fill: col_vn.lighten(82%),
      stroke: 2.5pt + col_vn,
    )
    let val_txt = if flipped { [0] } else { [1] }
    content(v_pos, text(size: 0.95em, fill: col_vn, weight: "bold")[#val_txt])

    // Décision sous le nœud
    if flipped {
      content(
        (0, -1.0),
        box(
          fill: red.lighten(88%),
          stroke: 1.2pt + red,
          radius: 4pt,
          inset: (x: 7pt, y: 4pt),
        )[#text(fill: red, weight: "bold", size: 0.78em)[FLIP : 1 → 0]],
      )
    } else {
      content(
        (0, -1.0),
        box(
          fill: rgb("#f8f9fa"),
          stroke: 0.8pt + gray,
          radius: 4pt,
          inset: (x: 7pt, y: 4pt),
        )[#text(fill: gray.darken(40%), size: 0.72em, style: "italic")[Majorité = 3/4 ✗]],
      )
    }
  })
}

// --- Définitions de style globales ---
#let iterative_decoder_colors = (
  top: rgb("000000"), // Noir
  cn_update: rgb("ff9933"), // Orange
  vn_update: rgb("3366cc"), // Bleu
  success: rgb("339900"), // Vert
  failure: rgb("cc3333"), // Rouge
  edge: black,
)

// Définir des styles de nœuds avec de grands insets pour un espacement généreux
#let node_style = (
  cn_update: (
    stroke: iterative_decoder_colors.cn_update,
    fill: iterative_decoder_colors.cn_update.lighten(90%),
    radius: 4pt,
    inset: (x: 20pt, y: 15pt), // Grand inset horizontal et vertical
    label: (align: center, gutter: 8pt, size: 1em),
  ),
  vn_update: (
    stroke: iterative_decoder_colors.vn_update,
    fill: iterative_decoder_colors.vn_update.lighten(90%),
    radius: 4pt,
    inset: (x: 20pt, y: 15pt),
    label: (align: center, gutter: 8pt, size: 1em),
  ),
  diamond_node: (
    radius: 1pt, // Coins légèrement arrondis pour le diamant
    label: (align: center, size: 1em, gutter: 0pt), // Font légèrement plus petit pour la lisibilité
  ),
  output_node: (
    radius: 4pt,
    inset: (x: 10pt, y: 8pt), // Espacement légèrement plus compact pour les sorties
    label: (align: center, size: 1em, gutter: 4pt),
  ),
)

// Style d'arête
#let edge_style = (
  stroke: iterative_decoder_colors.edge,
  mark: (end: ">"),
)

#let schema_boucle_bf() = {
  cetz.canvas(length: 0.9cm, {
    import cetz.draw: *

    let s_fleche = (stroke: 1.5pt + black, mark: (end: "stealth", fill: black, size: 0.22))
    let col_1 = orange
    let col_2 = blue
    let col_3 = green.darken(10%)
    let col_stop = red

    // --- 1. PARAMÈTRES ---
    let w_boite = 9.2
    let h_boite = 3.2
    let espacement_titre = 8pt // Un peu réduit pour l'équilibre

    let y_init = 12.0
    let y_cn = 8.0
    let y_vn = 3.5
    let y_check = -1.0
    let y_fail = -5.5

    let w_l = 2.4
    let h_l = 1.3

    // --- 2. ANCRES (Rectangles invisibles) ---
    rect((-2.5, y_init - 0.6), (2.5, y_init + 0.6), stroke: none, name: "init")
    rect((-w_boite / 2, y_cn - h_boite / 2), (w_boite / 2, y_cn + h_boite / 2), stroke: none, name: "cn")
    rect((-w_boite / 2, y_vn - h_boite / 2), (w_boite / 2, y_vn + h_boite / 2), stroke: none, name: "vn")
    rect((-w_l, y_check - h_l), (w_l, y_check + h_l), stroke: none, name: "check")
    // Bloc succès bien large
    rect((5.8, y_check - 1.0), (12.5, y_check + 1.0), stroke: none, name: "ok")
    rect((-w_boite / 2, y_fail - 0.7), (w_boite / 2, y_fail + 0.7), stroke: none, name: "fail")

    // --- 3. DESSIN DES FLÈCHES ---
    line("init.south", "cn.north", ..s_fleche)
    line("cn.south", "vn.north", ..s_fleche)
    line("vn.south", "check.north", ..s_fleche)
    line("check.south", "fail.north", ..s_fleche)
    line("check.east", "ok.west", ..s_fleche)
    line("check.west", (-6.5, y_check), (-6.5, y_cn), "cn.west", ..s_fleche)

    // --- 4. DESSIN VISUEL ---

    // Mot reçu
    rect("init.north-west", "init.south-east", fill: black, radius: 25pt)
    content("init", text(white, weight: "bold", size: 1.1em)[Mot reçu $bold(r)$])

    // ① CN Update - Correction de l'équilibre
    rect("cn.north-west", "cn.south-east", fill: col_1.lighten(97%), stroke: 2.2pt + col_1, radius: 5pt)
    content("cn")[
      #set align(center + horizon)
      #block(breakable: false)[
        #set align(left)
        #stack(dir: ttb, spacing: espacement_titre, text(1.1em, fill: col_1, weight: "bold")[① CN Update], text(
          0.85em,
        )[Calcul du syndrome $bold(s) = bold(H)bold(r)^T$ \ Chaque $c_i$ évalue sa parité])
      ]
    ]

    // ② VN Update - Correction de l'équilibre
    rect("vn.north-west", "vn.south-east", fill: col_2.lighten(97%), stroke: 2.2pt + col_2, radius: 5pt)
    content("vn")[
      #set align(center + horizon)
      #block(breakable: false)[
        #set align(left)
        #stack(dir: ttb, spacing: espacement_titre, text(1.1em, fill: col_2, weight: "bold")[② VN Update], text(
          0.85em,
        )[Chaque $v_j$ compte ses erreurs\ Si majorité → FLIP])
      ]
    ]

    // Losange
    line(
      "check.north",
      "check.east",
      "check.south",
      "check.west",
      close: true,
      fill: green.lighten(97%),
      stroke: 2.2pt + col_3,
    )
    content("check", text(1.1em, weight: "bold")[$bold(s) = bold(0)$])

    // Succès : Largeur corrigée et texte sur une ligne
    rect("ok.north-west", "ok.south-east", fill: col_3.lighten(97%), stroke: 2.2pt + col_3, radius: 5pt)
    content("ok", text(col_3, weight: "bold", size: 1.1em)[Succès : $hat(bold(c))=bold(r)$])

    // Échec - Correction de l'équilibre
    rect("fail.north-west", "fail.south-east", fill: col_stop.lighten(97%), stroke: 2.2pt + col_stop, radius: 5pt)
    content("fail")[
      #set align(center + horizon)
      #text(col_stop, weight: "bold", size: 1.1em)[iter $>$ M $arrow.r$ Échec]
    ]

    // --- 5. ÉTIQUETTES ---
    // Oui centré sur sa flèche
    content((4.1, y_check + 0.6), text(col_3, weight: "bold", size: 1.1em)[Oui])

    content((1.2, (y_check + y_fail) / 2), text(col_stop, weight: "bold", size: 1.1em)[Non])
    content((-7.3, (y_cn + y_check) / 2), angle: 90deg, text(size: 1.1em, style: "italic", weight: "bold")[iter $+1$])
  })
}

/////
//
//
//

#let schema_llr_droite() = {
  cetz.canvas(length: 1cm, {
    import cetz.draw: *

    let col_left = blue.darken(10%) // Bit 0 (Inversé)
    let col_right = red.darken(10%) // Bit 1 (Inversé)
    let col_ax = black
    let col_mid = gray.darken(30%)

    let L = 7.0 // demi-longueur de l'axe
    let y0 = 0.0
    let y_top = 1.8

    // ── 1. Zones colorées (Dessinées en PREMIER, en HAUT) ──
    // Zone gauche (négative) -> Bit 0
    rect((-L, y0 + 0.02), (-0.05, y0 + 0.32), fill: col_left.lighten(92%), stroke: none)
    content((-L / 2, y0 + 0.65), text(fill: col_left, weight: "bold", size: 0.9em)[Bit = 0])

    // Zone droite (positive) -> Bit 1
    rect((0.05, y0 + 0.02), (L, y0 + 0.32), fill: col_right.lighten(92%), stroke: none)
    content((L / 2, y0 + 0.65), text(fill: col_right, weight: "bold", size: 0.9em)[Bit = 1])

    // ── 2. Axe horizontal (Dessiné APRÈS pour passer AU-DESSUS) ──
    line((-L, y0), (L, y0), stroke: 1.8pt + col_ax, mark: (end: "stealth", fill: col_ax, size: 0.22))
    content((L + 0.5, y0), text(size: 0.85em)[$L(v_i)$], anchor: "west")

    // ── 3. Zéro ──
    line((0, -0.2), (0, 0.2), stroke: 1.5pt + col_mid)
    content((0, -0.5), text(size: 0.8em, fill: col_mid)[0])

    // ── 4. Points exemples (Sans les Volts) ──

    // -6 (Bit 0 à gauche)
    let px_left = -5.0
    circle((px_left, y0), radius: 0.15, fill: col_left, stroke: none)
    // La ligne pointillée part de l'axe vers le haut
    line((px_left, y0), (px_left, y_top), stroke: (paint: col_left, thickness: 1pt, dash: "dashed"))
    content(
      (px_left, y_top + 0.1),
      box(fill: col_left.lighten(92%), stroke: 0.5pt + col_left, radius: 3pt, inset: 4pt)[
        #text(fill: col_left, weight: "bold", size: 0.75em)[$-6$]
      ],
      anchor: "south",
    )

    // +0.3 (Proche de zéro, Bit 1)
    let px_near = 0.6
    circle((px_near, y0), radius: 0.15, fill: col_right.lighten(40%), stroke: none)
    line((px_near, y0), (px_near, y_top - 0.7), stroke: (paint: col_right.lighten(20%), thickness: 1pt, dash: "dashed"))
    content(
      (px_near, y_top - 0.65),
      box(fill: white, stroke: 0.5pt + col_right.lighten(30%), radius: 3pt, inset: 3pt)[
        #text(fill: col_right.darken(20%), size: 0.7em)[$+0.3$]
      ],
      anchor: "south-west",
    )

    // +10 (Bit 1 à droite)
    let px_right = 5.8
    circle((px_right, y0), radius: 0.15, fill: col_right, stroke: none)
    line((px_right, y0), (px_right, y_top), stroke: (paint: col_right, thickness: 1pt, dash: "dashed"))
    content(
      (px_right, y_top + 0.1),
      box(fill: col_right.lighten(92%), stroke: 0.5pt + col_right, radius: 3pt, inset: 4pt)[
        #text(fill: col_right, weight: "bold", size: 0.75em)[$+10$]
      ],
      anchor: "south",
    )
  })
}

///2
#let schema_sum_product_dual() = {
  cetz.canvas(length: 1cm, {
    import cetz.draw: *

    let col_cn = orange.darken(0%)
    let col_vn = blue.darken(0%)
    let col_msg = gray.darken(35%)

    // --- PARTIE HAUTE : MISE À JOUR CN (PRODUIT DES TANH) ---
    group({
      let base_y = 4.0
      let cn_pos = (0.0, base_y)
      let vn_in_pos = ((-3.2, base_y + 1.3), (-3.2, base_y - 1.3))
      let vn_out_pos = (3.2, base_y)

      // 1. Check Node Central (cj)
      rect(
        (cn_pos.at(0) - 0.45, cn_pos.at(1) - 0.45),
        (cn_pos.at(0) + 0.45, cn_pos.at(1) + 0.45),
        fill: col_cn.lighten(90%),
        stroke: 2pt + col_cn,
        name: "cj_top",
      )
      content("cj_top", text(size: 0.75em, fill: col_cn, weight: "bold")[$c_j$])

      // 2. Variable Node de sortie (v0)
      circle(vn_out_pos, radius: 0.5, fill: white, stroke: 2pt + col_vn, name: "v0_top")
      content("v0_top", text(size: 0.7em, fill: col_vn, weight: "bold")[$v_0$])

      // 3. Arête de sortie : cj -> v0
      line("cj_top", "v0_top", stroke: 2.2pt + orange, mark: (end: "stealth", fill: orange, size: 0.25))
      content((1.8, base_y + 0.6), text(size: 0.8em, fill: orange.darken(0%), weight: "bold")[$m_(c_j arrow v_0)$])

      // 4. Voisins entrants (vi)
      for (i, p) in vn_in_pos.enumerate() {
        let n_name = "vin_" + str(i)
        circle(p, radius: 0.45, fill: col_vn.lighten(92%), stroke: 1.2pt + col_vn, name: n_name)
        content(n_name, text(size: 0.65em, fill: col_vn, weight: "bold")[$v_#(i + 1)$])

        line(n_name, "cj_top", stroke: 1.1pt + col_msg, mark: (end: "stealth", fill: col_msg, size: 0.2))
        content((p.at(0) + 1.4, p.at(1)), text(size: 0.75em, fill: col_msg)[$m_(v_#(i + 1) arrow c_j)$])
      }
    })

    // Séparateur discret
    line((-4.5, 1.8), (4.5, 1.8), stroke: (paint: gray.lighten(85%), dash: "dashed"))

    // --- PARTIE BASSE : MISE À JOUR VN (SOMME DES LLR) ---
    group({
      let base_y = -1.5
      let vn_pos = (0.0, base_y)
      let cn_in_pos = ((-3.2, base_y + 1.2), (-3.2, base_y - 1.2))
      let cn_out_pos = (3.2, base_y)

      // 1. Variable Node Central (vj)
      circle(vn_pos, radius: 0.55, fill: col_vn.lighten(90%), stroke: 2pt + col_vn, name: "vj_bot")
      content("vj_bot", text(weight: "bold", fill: col_vn)[$v_j$])

      // 2. Check Node de sortie (c0) - Toujours ORANGE
      rect(
        (cn_out_pos.at(0) - 0.4, cn_out_pos.at(1) - 0.4),
        (cn_out_pos.at(0) + 0.4, cn_out_pos.at(1) + 0.4),
        fill: white,
        stroke: 1.8pt + orange,
        name: "c0_bot",
      )
      content("c0_bot", text(size: 0.65em, fill: orange.darken(0%), weight: "bold")[$c_0$])

      // 3. Arête de sortie : vj -> c0
      line("vj_bot", "c0_bot", stroke: 2.2pt + blue, mark: (end: "stealth", fill: blue, size: 0.25))
      content((1.8, base_y - 0.7), text(size: 0.8em, fill: blue.darken(0%), weight: "bold")[$m_(v_j arrow c_0)$])

      // 4. Entrée Canal LLR
      let canal_top = (0.0, base_y + 2.2)
      line(canal_top, "vj_bot", stroke: 1.8pt + blue, mark: (end: "stealth", fill: blue, size: 0.22))
      content((canal_top.at(0), canal_top.at(1) + 0.3), text(
        size: 0.85em,
        fill: blue,
        weight: "bold",
      )[$L_"canal" (y_j)$])

      // 5. Check Nodes entrants
      for (i, p) in cn_in_pos.enumerate() {
        let n_name = "cin_" + str(i)
        rect(
          (p.at(0) - 0.35, p.at(1) - 0.35),
          (p.at(0) + 0.35, p.at(1) + 0.35),
          fill: orange.lighten(95%),
          stroke: 1pt + orange,
          name: n_name,
        )
        content(n_name, text(size: 0.6em, fill: orange.darken(0%))[$c_#(i + 1)$])

        line(n_name, "vj_bot", stroke: 1.1pt + col_msg, mark: (end: "stealth", fill: col_msg, size: 0.2))
        content((p.at(0) + 1.4, p.at(1)), text(size: 0.75em, fill: col_msg)[$m_(c_#(i + 1) arrow v_j)$])
      }
    })
  })
}

#let col_cn = orange
#let col_vn = blue
#let col_msg = gray.darken(50%)
#let s_len = 1.1cm

// 1. INITIALISATION
#let schema_detailed_init() = cetz.canvas(length: s_len, {
  import cetz.draw: *

  // Couleurs pures
  let col_vn_pure = blue
  let col_cn_pure = orange
  let col_msg_dark = gray.darken(50%)

  // Noeud Variable
  circle((0, 0), radius: 0.6, fill: col_vn_pure.lighten(90%), stroke: 2pt + col_vn_pure, name: "vj")
  content("vj", text(weight: "bold")[$v_j$])

  // Entrée canal
  line((0, 1.8), (0, 0.6), stroke: 2pt + blue, mark: (end: "stealth", fill: blue, size: 0.2))
  content((0, 2.1), text(fill: blue, size: 0.9em, weight: "bold")[$L_("canal")$])

  // Targets plus éloignées sur la droite (x: 4.0)
  let targets = ((4.0, 1.2), (4.0, -1.2))
  for (i, p) in targets.enumerate() {
    let name = "c" + str(i + 1)

    // Check Nodes
    rect(
      (p.at(0) - 0.4, p.at(1) - 0.4),
      (p.at(0) + 0.4, p.at(1) + 0.4),
      fill: col_cn_pure.lighten(95%),
      stroke: 1.5pt + col_cn_pure,
      name: name,
    )
    content(name, text(size: 0.7em, fill: col_cn_pure, weight: "bold")[$c_#(i + 1)$])

    // Arête
    line("vj.east", name, stroke: 1.2pt + col_msg_dark, mark: (end: "stealth", fill: col_msg_dark))

    // Position du message calculée pour être "collée" à l'arête
    // On place le texte à mi-chemin (x=2.0) avec un léger offset y
    let y_offset = if p.at(1) > 0 { 0.4 } else { -0.25 }
    content((2.0, p.at(1) * 0.5 + y_offset), text(size: 0.75em, fill: col_msg_dark)[$m_(v_j arrow c_#(i + 1))$])
  }
})

// 2. CN UPDATE
#let schema_detailed_cn() = cetz.canvas(length: s_len, {
  import cetz.draw: *
  rect((-0.5, -0.5), (0.5, 0.5), fill: col_cn.lighten(90%), stroke: 2.2pt + col_cn, name: "cj")
  content("cj", text(weight: "bold", fill: col_cn)[$c_j$])

  let ins = ((-3.0, 1.3), (-3.0, -1.3))
  for (i, p) in ins.enumerate() {
    let v_name = "vi" + str(i + 1)
    circle(p, radius: 0.45, fill: col_vn.lighten(92%), stroke: 1.2pt + col_vn, name: v_name)
    line(v_name, "cj", stroke: 1.1pt + col_msg, mark: (end: "stealth", fill: col_msg))
    content(v_name, text(size: 0.65em, fill: col_vn, weight: "bold")[$v_#(i + 1)$])
    content((p.at(0) + 1.5, p.at(1)), text(size: 0.75em, fill: col_msg)[$m_(v_#(i + 1) arrow c_j)$])
  }

  circle((3.0, 0), radius: 0.6, fill: white, stroke: 2pt + col_vn, name: "v0")
  content("v0", text(size: 0.75em, fill: col_vn, weight: "bold")[$v_0$])
  line("cj", "v0", stroke: 2.3pt + orange, mark: (end: "stealth", fill: orange, size: 0.25))
  content((1.8, 0.6), text(size: 0.85em, fill: orange, weight: "bold")[$m_(c_j arrow v_0)$])
})

// 3. VN UPDATE
#let schema_detailed_vn() = cetz.canvas(length: s_len, {
  import cetz.draw: *
  circle((0, 0), radius: 0.7, fill: col_vn.lighten(90%), stroke: 2.5pt + col_vn, name: "vj")
  content("vj", text(weight: "bold", fill: col_vn)[$v_j$])

  line((0, 2.0), (0, 0.7), stroke: 2pt + blue, mark: (end: "stealth", fill: blue, size: 0.2))
  content((0, 2.3), text(size: 0.85em, fill: blue, weight: "bold")[$L_("canal")$])

  let ins = ((-3.0, 1.2), (-3.0, -1.2))
  for (i, p) in ins.enumerate() {
    let c_name = "ci" + str(i + 1)
    rect(
      (p.at(0) - 0.4, p.at(1) - 0.4),
      (p.at(0) + 0.4, p.at(1) + 0.4),
      fill: col_cn.lighten(95%),
      stroke: 1.2pt + col_cn,
      name: c_name,
    )
    line(c_name, "vj", stroke: 1.1pt + col_msg, mark: (end: "stealth", fill: col_msg))
    content(c_name, text(size: 0.65em, fill: col_cn, weight: "bold")[$c_#(i + 1)$])
    content((p.at(0) + 1.5, p.at(1)), text(size: 0.75em, fill: col_msg)[$m_(c_#(i + 1) arrow v_j)$])
  }

  rect((2.6, -0.45), (3.4, 0.45), fill: white, stroke: 2pt + orange, name: "c0")
  content("c0", text(size: 0.7em, fill: col_cn, weight: "bold")[$c_0$])
  line("vj", "c0", stroke: 2.3pt + blue, mark: (end: "stealth", fill: blue, size: 0.25))
  content((1.7, -0.8), text(size: 0.85em, fill: blue, weight: "bold")[$m_(v_j arrow c_0)$])
})

// 4. DÉCISION FINALE
#let schema_detailed_decision() = cetz.canvas(length: s_len, {
  import cetz.draw: *
  let col_vn_dec = green

  // 1. Variable Node Central (Le bit j)
  circle((0, 0), radius: 0.75, fill: green.lighten(92%), stroke: 2.5pt + col_vn_dec, name: "vn")
  content("vn", text(weight: "bold", size: 1.1em)[$Lambda_j$])

  // 2. Entrée LLR Canal
  line((0, 1.7), (0, 0.75), stroke: 1.8pt + blue, mark: (end: "stealth", fill: blue, size: 0.15))
  content((0, 2.0), text(fill: blue, size: 0.8em, weight: "bold")[$L_"canal"$])

  // 3. Arrivées des Check Nodes (i)
  let ins = ((-2.3, 1.0), (-2.3, -1.0), (2.3, 1.0), (2.3, -1.0))
  for (i, p) in ins.enumerate() {
    let name = "call" + str(i)
    rect(
      (p.at(0) - 0.3, p.at(1) - 0.3),
      (p.at(0) + 0.3, p.at(1) + 0.3),
      fill: orange.lighten(95%),
      stroke: 1.1pt + orange,
      name: name,
    )
    line(name, "vn", stroke: 1.1pt + orange, mark: (end: "stealth", fill: orange, size: 0.12))
    content(name, text(size: 0.5em, fill: orange, weight: "bold")[$c_#i$])
  }

  // 4. ÉQUATION LAMBDA : On somme sur les voisins du bit j -> N(v_j)
  content((0, -2), text(size: 0.8em, fill: col_vn_dec)[
    $display(Lambda_j = L_("canal") + sum_(i in cal(N)(v_j)) m_(c_i arrow v_j))$
  ])

  // 5. Bloc Hard Decision
  content((3.5, 0), name: "verdict", box(fill: white, stroke: 1.5pt + black, inset: 6pt, radius: 2pt)[
    #set text(size: 0.6em)
    #set math.cases(gap: 0.3em)
    $hat(v)_j = cases(0 "si" Lambda_j > 0, 1 "si" Lambda_j < 0)$
  ])

  // 6. Liaison pointillés
  line((0.8, 0), "verdict.west", stroke: (paint: black, thickness: 1.3pt, dash: "dotted"))
})

// ③ Schéma Min-Sum : comparaison SP vs MS + highlight du terme minimum
// #let schema_min_sum_vis() = {
//   cetz.canvas(length: 1cm, {
//     import cetz.draw: *
//
//     let col_ms   = blue.darken(15%)
//     let col_min  = red.darken(5%)
//     let col_sgn  = orange.darken(5%)
//
//     // Messages entrants (4 voisins u ≠ v)
//     let msgs = (2.1, 0.4, 3.7, 1.2)
//     let sgns = (1, -1, 1, 1)   // signes
//
//     let y_base = 0.0
//     let xs = (-4.5, -1.5, 1.5, 4.5)
//
//     // Titre colonnes
//     content((-3.0, 4.8), text(size: 0.82em, fill: col_sgn, weight: "bold")[Signes])
//     content((3.0, 4.8), text(size: 0.82em, fill: col_ms, weight: "bold")[|Amplitudes|])
//
//     for (i, x) in xs.enumerate() {
//       let m   = msgs.at(i)
//       let s   = sgns.at(i)
//       let is_min = (m == 0.4)
//       let col_box = if is_min { col_min } else { col_ms }
//
//       // Barre amplitude
//       let bar_h = m * 0.55
//       rect((x - 0.5, y_base), (x + 0.5, y_base + bar_h),
//            fill: col_box.lighten(if is_min { 70% } else { 85% }),
//            stroke: 1.5pt + col_box)
//
//       // Valeur amplitude
//       content((x, y_base + bar_h + 0.35),
//         text(size: 0.82em, fill: col_box, weight: "bold")[#m])
//
//       // Signe (XOR logic)
//       let s_txt = if s > 0 { [+] } else { [−] }
//       let s_col = col_sgn
//       content((x, -0.65),
//         box(fill: s_col.lighten(88%), stroke: 0.5pt + s_col,
//             radius: 2pt, inset: (x:6pt, y:3pt))[
//           #text(size: 0.88em, fill: s_col, weight: "bold")[#s_txt]
//         ])
//
//       // Label u_i
//       content((x, -1.3), text(size: 0.74em, fill: gray.darken(30%))[
//         $m_(#(i+1)→c)$
//       ])
//     }
//
//     // Flèche vers résultat
//     let y_res = -2.4
//     line((0, -1.6), (0, y_res + 0.3),
//          mark: (end: "stealth", fill: black, size: 0.2),
//          stroke: 1.4pt + black)
//
//     // Encadré résultat
//     content((0, y_res - 0.1),
//       box(fill: col_min.lighten(88%), stroke: 1.5pt + col_min,
//           radius: 5pt, inset: (x: 14pt, y: 8pt))[
//         #set text(size: 0.82em)
//         Signe produit : #text(fill: col_sgn, weight: "bold")[$(-1)^1 = -$]
//         #h(8pt)
//         Min : #text(fill: col_min, weight: "bold")[$0.4$]
//         #h(8pt)
//         $=>$ #text(fill: col_min, weight: "bold")[$m_(c→v) = -0.4$]
//       ])
//
//     // Étiquette "minimum"
//     content((-1.5, y_base + 0.4 * 0.55 + 0.95),
//       text(size: 0.72em, fill: col_min, style: "italic",
//            weight: "bold")[← minimum !])
//   })
// }

#let schema_min_sum_complet() = cetz.canvas(length: 1cm, {
  import cetz.draw: *

  let msgs = (2.8, 0.7, 4.2, 1.8)
  let sgns = (1, -1, 1, 1)
  let vals = ("+2.8", "-0.7", "+4.2", "+1.8")

  let col_ms = blue.darken(15%)
  let col_min = red.darken(10%)
  let col_vn_bg = blue.lighten(94%)

  // --- 1. GRAPHE DE TANNER ---
  group(name: "tanner", {
    for i in (0, 1, 2, 3) {
      let y_pos = 2.25 - i * 1.5
      line((-6.5, y_pos), (-2.0, 0), stroke: 1.2pt + gray.lighten(30%))
    }

    rect((-2.5, -0.5), (-1.5, 0.5), name: "cn", stroke: 2pt + orange, fill: orange.lighten(92%))
    content((-2.0, 0), text(size: 1.2em, fill: orange, weight: "bold")[$c$])

    for i in (0, 1, 2, 3) {
      let y_pos = 2.25 - i * 1.5
      circle((-6.5, y_pos), radius: 0.4, name: "v" + str(i), fill: col_vn_bg, stroke: 1.5pt + blue)
      content("v" + str(i), text(size: 0.75em, fill: blue.darken(20%), weight: "bold")[$v_#i$])

      let val = vals.at(i)
      content(((-6.5, y_pos), 42%, (-2.0, 0)), box(
        fill: col_vn_bg,
        stroke: 0.5pt + blue.lighten(60%),
        radius: 2pt,
        inset: 4pt,
      )[
        #text(size: 0.65em, fill: black.lighten(10%), weight: "bold")[#val]
      ])
    }
  })

  // --- 2. FLÈCHE GRISE ---
  line((-1.0, 0), (0.5, 0), mark: (end: "stealth", fill: gray), stroke: 1.5pt + gray)

  // --- 3. GRAPHIQUE DES BARRES ---
  group(name: "bars", {
    let base_x = 1.4
    for (i, m) in msgs.enumerate() {
      let x = base_x + i * 1.4
      let is_min = (m == 0.7)
      let col = if is_min { col_min } else { col_ms }

      rect((x - 0.4, 0), (x + 0.4, m * 0.45), fill: col.lighten(if is_min { 75% } else { 88% }), stroke: 1.5pt + col)
      content((x, m * 0.45 + 0.35), text(size: 0.7em, fill: col, weight: "bold")[#m])
      content((x, -0.7), box(fill: orange.lighten(92%), stroke: 0.5pt + orange, inset: 5pt, radius: 2pt)[
        #text(size: 0.8em, fill: orange, weight: "bold")[#(if sgns.at(i) > 0 [+] else [−])]
      ])
      if is_min { content((x, m * 0.45 + 0.8), text(size: 0.55em, fill: col, weight: "bold")[MIN]) }
    }
  })

  // --- 4. FLÈCHE ROUGE ---
  line((6.5, 0), (8.0, 0), mark: (end: "stealth", fill: col_min), stroke: 2pt + col_min)

  // --- 5. RÉSULTAT FINAL (Décalé plus à droite à x = 11.5) ---
  content((10.5, 0), box(stroke: 1.5pt + col_min, fill: col_min.lighten(96%), radius: 5pt, inset: 10pt)[
    #text(size: 0.8em, weight: "bold")[$m_(c arrow v_"cible") = -0.7$]
  ])
})


#let waterfall_plot(pts_uncoded, pts_bf) = {
  cetz.canvas({
    import cetz.draw
    plot.plot(
      size: (23, 14.5),
      x-label: pad(top: 5cm)[],
      y-label: [BER],
      x-min: 0,
      x-max: 8,
      y-min: -9,
      y-max: 0.2,
      x-tick-step: 1,
      y-tick-step: 1,
      x-grid: true,
      y-grid: true,
      y-format: y => $10^(#int(y))$,
      x-format: x => pad(top: 1cm)[#x],
      legend: (2, 6),
      legend-style: (
        padding: 0.3,
        stroke: gray.lighten(50%),
        fill: white,
      ),
      {
        plot.annotate({
          // for decade in range(-9, 0) {
          //   for minor in (2, 3, 4, 5, 6, 7, 8, 9) {
          //     let y_pos = decade + (calc.log(minor) / calc.log(10))
          //     if y_pos >= -9 and y_pos <= 0 {
          //       draw.line(
          //         (0, y_pos),
          //         (8, y_pos),
          //         stroke: (paint: gray.lighten(70%), thickness: 0.3pt),
          //       )
          //     }
          //   }
          // }
          draw.content((4, -10), text(size: 1.2em)[$E_b/N_0$ (dB)])
        })
        plot.add(
          pts_uncoded,
          label: [Signal non codé],
          style: (stroke: (paint: orange, thickness: 2pt, dash: "dashed")),
          mark: "+",
          mark-style: (stroke: orange, size: 0.5),
        )

        plot.add(
          pts_bf,
          label: [Bit-Flipping],
          style: (stroke: (paint: blue, thickness: 2.5pt)),
          mark: "square",
          mark-style: (stroke: blue, fill: white, size: 0.25),
        )
      },
    )
  })
}

#let convergence_plot(iters, syndrms) = {
  let n = iters.len()
  let max_s = 160.0
  let W = 20.0
  let H = 15.0
  let bw = W / n

  cetz.canvas({
    import cetz.draw

    for tick in (0, 50, 100, 150) {
      let y = (tick / max_s) * H
      draw.line((0, y), (W, y), stroke: 0.5pt + gray.lighten(60%))
      draw.content((-0.8, y), text(size: 13pt)[#tick])
    }

    for i in range(n) {
      let s = syndrms.at(i)
      let bh = (s / max_s) * H
      let x0 = i * bw
      let col = if s == 0 { green.darken(20%) } else { blue }

      draw.rect(
        (x0, 0),
        (x0 + bw * 0.8, bh),
        fill: col.lighten(70%),
        stroke: 1.2pt + col,
      )

      if calc.rem(i, 2) == 0 or i == n - 1 {
        draw.content((x0 + bw * 0.4, -0.4), text(size: 13pt)[#i])
      }
    }

    draw.line((0, 0), (W + 0.8, 0), stroke: 2pt, mark: (end: "stealth"))
    draw.line((0, 0), (0, H + 0.8), stroke: 2pt, mark: (end: "stealth"))

    draw.content((W / 2, -1), text(size: 19pt, weight: "bold")[Itérations])
    draw.content((-2.2, H / 2), angle: 90deg, text(size: 19pt, weight: "bold")[Syndromes])
  })
}

#let waterfall_plot(pts_uncoded, pts_bf) = {
  cetz.canvas({
    import cetz.draw: *
    plot.plot(
      size: (22, 15),
      x-label: none,
      y-label: none,
      x-min: 0,
      x-max: 10,
      y-min: -9,
      y-max: 0.2,
      x-tick-step: 1,
      y-tick-step: 1,
      x-grid: true,
      y-grid: true,
      style: (
        axes: (
          bottom: (tick: (label: (offset: 0.2))), // Chiffres plus proches de l'axe
          left: (tick: (label: (offset: 0.2))),
        ),
      ),
      y-format: y => $10^(#int(y))$,
      x-format: x => [#x],
      legend: (14.4, 12.9),
      legend-style: (padding: 0.3, stroke: gray.lighten(50%), fill: white),
      {
        plot.annotate({
          // for decade in range(-9, 0) {
          //   for minor in (2, 3, 4, 5, 6, 7, 8, 9) {
          //     let y_pos = decade + (calc.log(minor) / calc.log(10))
          //     if y_pos >= -9 and y_pos <= 0 {
          //       line((0, y_pos), (8, y_pos), stroke: (paint: gray.lighten(60%), thickness: 0.3pt))
          //     }
          //   }
          // }
          content((4, -9.9), text(size: 1.3em)[$E_b/N_0$ (dB)])
          content((-1, -4.5), angle: 90deg, text(size: 1.3em)[BER])
        })
        plot.add(
          pts_uncoded,
          label: [Signal non codé],
          style: (stroke: (paint: orange, thickness: 2pt, dash: "dashed")),
          mark: "+",
          mark-style: (stroke: orange, size: 0.5),
        )
        plot.add(
          pts_bf,
          label: [Bit-Flipping LDPC],
          style: (stroke: (paint: blue, thickness: 2.5pt)),
          mark: "square",
          mark-style: (stroke: blue, fill: white, size: 0.25),
        )
      },
    )
  })
}

#let simulation_image_flow(img_orig, img_noisy, img_r05, img_r66, img_r75, img_w: 150pt, gap_top: 3.0, gap_bot: 4.0) = {
  cetz.canvas({
    import cetz.draw: *

    let w_unit = img_w / 1cm
    let y_top = 5.0
    let y_bot = -6.0

    let x_side = (w_unit + gap_top) / 2
    let x_res = w_unit + gap_bot

    // --- LIGNE 1 : ÉMISSION ET BRUIT (Texte collé en haut) ---
    content(
      (-x_side, y_top),
      [
        #set align(center)
        #set par(leading: 0pt)
        #set text(bottom-edge: "baseline") // Supprime l'espace sous les lettres
        #text(weight: "bold", size: 1.3em)[Originale]
        #v(-0.6cm)
        #box(width: img_w, stroke: 2pt + black, radius: 4pt, inset: 0pt, img_orig)
      ],
      name: "orig",
    )

    content(
      (x_side, y_top),
      [
        #set align(center)
        #set par(leading: 0pt)
        #set text(bottom-edge: "baseline")
        #text(weight: "bold", size: 1.3em, fill: red)[Reçue (Bruité)]
        #v(-0.6cm)
        #box(width: img_w, stroke: 2pt + red, radius: 4pt, inset: 0pt, img_noisy)
      ],
      name: "noisy",
    )

    // --- FLÈCHE CANAL (Ajustée pour le nouveau centre de gravité) ---
    let y_img_center = y_top - 1.4

    line(
      (-x_side + w_unit / 2, y_img_center),
      (x_side - w_unit / 2, y_img_center),
      stroke: 4pt + gray,
      mark: (end: "stealth", fill: gray, size: 0.5),
    )

    content((0, y_img_center + 0.8), text(size: 1.1em, fill: gray.darken(40%), style: "italic")[AWGN (2.3 dB)])

    // --- LIGNE 2 : COMPARAISON DES RENDEMENTS (Texte collé en bas) ---
    let targets = (
      (pos: (-x_res, y_bot), img: img_r05, rate: [$R = 1/2$], col: green.darken(20%), name: "r1"),
      (pos: (0, y_bot), img: img_r66, rate: [$R = 2/3$], col: orange, name: "r2"),
      (pos: (x_res, y_bot), img: img_r75, rate: [$R = 3/4$], col: red, name: "r3"),
    )

    for t in targets {
      content(
        t.pos,
        [
          #set align(center)
          #set par(leading: 0pt)
          #set text(top-edge: "baseline") // Supprime l'espace au-dessus des lettres
          #box(width: img_w, stroke: 2.5pt + t.col, radius: 4pt, inset: 0pt, t.img)
          #v(-0.6cm)
          #text(weight: "bold", size: 1.5em, fill: t.col)[#t.rate]
        ],
        name: t.name,
      )
    }
  })
}

#let comparison_waterfall_plot(pts_unc, pts_bf, pts_sp, pts_ms) = {
  cetz.canvas({
    import cetz.draw: *
    plot.plot(
      size: (21, 15),
      x-label: none,
      y-label: none,
      x-min: 0,
      x-max: 11,
      y-min: -8,
      y-max: 0.2,
      x-tick-step: 1,
      y-tick-step: 1,
      x-grid: true,
      y-grid: true,
      style: (
        axes: (
          bottom: (tick: (label: (offset: 0.2))),
          left: (tick: (label: (offset: 0.2))),
        ),
      ),
      y-format: y => $10^(#int(y))$,
      x-format: x => [#x],
      legend: (13.2, 11.4),
      legend-style: (padding: 0.3, stroke: gray.lighten(50%), fill: white),
      {
        plot.annotate({
          // Grille logarithmique étendue jusqu'à x=11
          // for decade in range(-8, 0) {
          //   for minor in (2, 3, 4, 5, 6, 7, 8, 9) {
          //     let y_pos = decade + (calc.log(minor) / calc.log(10))
          //     if y_pos >= -8 and y_pos <= 0 {
          //       line((0, y_pos), (11, y_pos), stroke: (paint: gray.lighten(75%), thickness: 0.3pt))
          //     }
          //   }
          // }
          // Label X centré sur 11 unités (environ 5.5)
          content((5.5, -8.7), text(size: 1.3em)[$E_b/N_0$ (dB)])
          // Label Y
          content((-1.2, -4.0), angle: 90deg, text(size: 1.3em)[BER])
        })

        plot.add(
          pts_unc,
          label: [Signal non codé],
          style: (stroke: (paint: orange, thickness: 2pt, dash: "dashed")),
          mark: "+",
          mark-style: (stroke: orange, size: 1),
        )

        plot.add(
          pts_bf,
          label: [Bit-Flipping (Hard)],
          style: (stroke: (paint: red, thickness: 2pt)),
          mark: "x",
          mark-style: (stroke: red, size: 1),
        )

        plot.add(
          pts_ms,
          label: [Min-Sum (Soft)],
          style: (stroke: (paint: green.darken(20%), thickness: 2pt)),
          mark: "triangle",
          mark-style: (stroke: green.darken(20%), fill: white, size: 0.3),
        )

        plot.add(
          pts_sp,
          label: [Sum-Product (Soft)],
          style: (stroke: (paint: blue, thickness: 2pt)),
          mark: "square",
          mark-style: (stroke: blue, fill: white, size: 1),
        )
      },
    )
  })
}