Two Pears, One Bruised

// composition: two pears sit on the lower-right thirds crossing, the near one bruised on its lit shoulder; the upper-left two-thirds is left as bare paper
// light comes from the upper right, so both bodies dissolve leftward into a cool shadow that pools along the table
// layering: pale table and air washes, cast shadow, each pear built from facets of colour back-to-front, then bruise, hatched shadow flanks, contact darks and broken contour last
const PALETTE = [
  "#eae4d6", // ground — warm paper
  "#e0c88f", // light — the sunlit turn of the fruit
  "#c8a044", // mass — the ochre body
  "#87904f", // mid — unripe green facets
  "#5b6872", // shadow — cool blue-grey
  "#8a4536", // accent — the bruise, rationed
  "#332f29", // ink — the last darks
];

// The half-width of the fruit at sixteen stations, t = 0 at the stem to 1 at the
// base: a knob at the stem, a near-straight neck, a fast swell, a belly that
// holds, then a base that flattens where the fruit takes the table. Sampled
// rather than solved — a closed form gave a cone, and past t = 1 a negative sine
// under a fractional power gave NaN, which silently emptied every fill polygon
// downstream and left p5.brush reading x off an absent vertex.
const PEAR_PROFILE = [0.16, 0.2, 0.24, 0.27, 0.3, 0.34, 0.42, 0.56, 0.72, 0.86, 0.95, 1.0, 1.0, 0.95, 0.82, 0.44];

function pearRadius(t) {
  const u = constrain(t, 0, 1) * (PEAR_PROFILE.length - 1);
  const i = Math.min(PEAR_PROFILE.length - 2, Math.floor(u));
  return lerp(PEAR_PROFILE[i], PEAR_PROFILE[i + 1], u - i);
}

function pearPoint(p, t, u) {
  const tc = constrain(t, 0, 1);
  const r = pearRadius(tc) * p.w;
  const ax = p.bx + p.lean * (1 - tc) * p.h;
  return [ax + constrain(u, -1.3, 1.3) * r, p.by - (1 - tc) * p.h];
}

// positive shade is turned toward the light, negative is turned away
function pearShade(t, u) {
  return constrain(0.74 * u - 0.9 * (t - 0.38), -1, 1);
}

// Cool grey is held back for the flank that is genuinely turned away; letting it
// into the mid tones punched grey windows through the lit side of the fruit.
function facetColour(shade) {
  const r = random();
  if (shade > 0.5) return r < 0.7 ? "#e0c88f" : "#c8a044";
  if (shade > 0.06) return r < 0.58 ? "#c8a044" : r < 0.84 ? "#e0c88f" : "#87904f";
  if (shade > -0.3) return r < 0.46 ? "#87904f" : r < 0.8 ? "#c8a044" : "#e0c88f";
  return r < 0.52 ? "#5b6872" : r < 0.82 ? "#87904f" : "#332f29";
}

// A closed band of the body's surface, for hatching one flank without touching
// the lit side. Built by pushing so the point list can never carry a hole.
function bandShape(p, tA, tB, uOut, uIn) {
  const pts = [];
  const steps = 7;
  for (let k = 0; k <= steps; k++) pts.push(pearPoint(p, lerp(tA, tB, k / steps), uOut));
  for (let k = steps; k >= 0; k--) pts.push(pearPoint(p, lerp(tA, tB, k / steps), uIn));
  return pts;
}

// The body laid in whole first, so the facets have a mass to sit on rather than
// paper to float over.
function pearSilhouette(p, col, op, bleed, swell) {
  brush.noStroke();
  brush.fillBleed(bleed, "out");
  brush.fillTexture(0.46, 0.44);
  brush.fill(col, op);
  brush.beginShape(0.34);
  for (let k = 0; k <= 18; k++) {
    const t = k / 18;
    const q = pearPoint(p, t, -swell + random(-0.04, 0.03));
    brush.vertex(q[0], q[1]);
  }
  for (let k = 18; k >= 0; k--) {
    const t = k / 18;
    const q = pearPoint(p, t, swell + random(-0.03, 0.04));
    brush.vertex(q[0], q[1]);
  }
  brush.endShape(true);
}

// Cezanne's method as code: no outline, only planes of colour set edge to edge,
// each one a little larger or smaller than its neighbour so the form turns. The
// column count shifts row to row so the planes never stack into a plaid.
function facetPass(p, rows, cols, tLo, tHi, uLo, uHi, spill, opBase) {
  brush.noStroke();
  brush.fillBleed(0.15, "out");
  brush.fillTexture(0.33, 0.34);
  for (let i = 0; i < rows; i++) {
    const t0 = lerp(tLo, tHi, i / rows);
    const t1 = lerp(tLo, tHi, (i + 1) / rows);
    const cn = Math.max(2, cols - (i % 3 === 1 ? 1 : 0));
    for (let j = 0; j < cn; j++) {
      const u0 = lerp(uLo, uHi, j / cn);
      const u1 = lerp(uLo, uHi, (j + 1) / cn);
      const tm = (t0 + t1) / 2;
      const um = (u0 + u1) / 2;
      const shade = pearShade(tm, um);
      const edge = j === 0 || j === cn - 1 ? spill : 0;
      const jit = 0.07;
      const a = pearPoint(p, t0 + random(-0.012, 0.012), u0 - edge + random(-jit, jit));
      const b = pearPoint(p, t0 + random(-0.012, 0.012), u1 + edge + random(-jit, jit));
      const c = pearPoint(p, t1 + random(-0.012, 0.012), u1 + edge + random(-jit, jit));
      const d = pearPoint(p, t1 + random(-0.012, 0.012), u0 - edge + random(-jit, jit));
      // a plane thinner than the brush is a smudge, not a facet
      if (Math.abs(b[0] - a[0]) + Math.abs(c[0] - d[0]) < 5) continue;
      const op = constrain(randomGaussian(opBase + 34 * Math.abs(shade), 18), 74, 214);
      brush.fill(facetColour(shade), op);
      brush.polygon([a, b, c, d]);
    }
  }
}

function flankHatch(p, tA, tB, uOut, uIn, tool, col, weight, gap, ang) {
  brush.hatchStyle(tool, col, weight);
  brush.hatch(gap, ang, { rand: 0.2, continuous: false });
  brush.noStroke();
  brush.noFill();
  brush.polygon(bandShape(p, tA, tB, uOut, uIn));
  brush.noHatch();
}

function contourFragment(p, tA, tB, side, col, w, curl) {
  brush.noFill();
  brush.set(curl, col, w);
  brush.beginShape(0.35);
  for (let k = 0; k <= 5; k++) {
    const t = lerp(tA, tB, k / 5);
    const q = pearPoint(p, t, side * (1 + random(-0.02, 0.05)));
    brush.vertex(q[0], q[1]);
  }
  brush.endShape(false);
}

const NEAR = { bx: 508, by: 610, h: 256, w: 80, lean: -0.045 };
const FAR = { bx: 622, by: 586, h: 160, w: 62, lean: 0.09 };

function setup() {
  createCanvas(800, 800, WEBGL);
  brush.scaleBrushes(2.4);
  noLoop();
}

function draw() {
  translate(-width / 2, -height / 2);
  background("#eae4d6");

  // --- the table: pale cool air laid in first, running off the right edge
  brush.noStroke();
  brush.fillBleed(0.62, "out");
  brush.fillTexture(0.3, 0.4);
  brush.fill("#5b6872", 34);
  brush.circle(586, 660, 112, true);
  brush.fill("#5b6872", 26);
  brush.circle(740, 640, 88, true);
  brush.fill("#5b6872", 16);
  brush.circle(440, 688, 60, true);
  brush.fill("#e0c88f", 36);
  brush.circle(612, 500, 96, true);
  brush.fill("#e0c88f", 22);
  brush.circle(726, 446, 66, true);
  brush.fill("#e0c88f", 14);
  brush.circle(492, 436, 50, true);

  // --- cast shadow: low, long and pressed close, so it lies on the cloth
  brush.fillBleed(0.3, "out");
  brush.fillTexture(0.5, 0.52);
  brush.fill("#5b6872", 170);
  brush.circle(474, 618, 28, true);
  brush.fill("#5b6872", 146);
  brush.circle(438, 624, 23, true);
  brush.fill("#5b6872", 112);
  brush.circle(404, 630, 18, true);
  brush.fill("#5b6872", 78);
  brush.circle(374, 635, 13, true);
  brush.fill("#5b6872", 46);
  brush.circle(348, 640, 10, true);
  brush.fill("#5b6872", 150);
  brush.circle(584, 592, 22, true);
  brush.fill("#5b6872", 104);
  brush.circle(552, 602, 17, true);
  brush.fill("#87904f", 66);
  brush.circle(500, 626, 22, true);

  // a fine tooth inside the shadow only — enough to read as dark cloth, not cloth
  brush.hatchStyle("2H", "#5b6872", 0.7);
  brush.hatch(5, 168, { rand: 0.16, continuous: false });
  brush.noStroke();
  brush.noFill();
  brush.polygon([
    [386, 632],
    [482, 615],
    [488, 638],
    [380, 651],
  ]);
  brush.noHatch();

  // --- far pear, painted back-to-front and kept a shade cooler than the near one
  pearSilhouette(FAR, "#c8a044", 132, 0.3, 0.98);
  pearSilhouette(FAR, "#87904f", 82, 0.18, 0.86);
  facetPass(FAR, 8, 3, 0.02, 0.99, -1, 1, 0.08, 110);
  facetPass(FAR, 4, 2, 0.34, 0.94, -1, -0.1, 0.05, 124);
  facetPass(FAR, 3, 2, 0.5, 0.94, 0.1, 1, 0.03, 96);
  flankHatch(FAR, 0.24, 0.94, -1.02, -0.34, "2H", "#5b6872", 0.85, 6, 84);

  // --- near pear, the larger and warmer mass, overlapping its neighbour
  pearSilhouette(NEAR, "#c8a044", 152, 0.3, 0.99);
  pearSilhouette(NEAR, "#e0c88f", 96, 0.2, 0.88);
  facetPass(NEAR, 11, 4, 0.01, 0.995, -1, 1, 0.12, 120);
  facetPass(NEAR, 5, 2, 0.28, 0.96, -1, -0.14, 0.06, 134);
  facetPass(NEAR, 4, 2, 0.44, 0.97, 0.12, 1, 0.03, 104);
  facetPass(NEAR, 3, 2, 0.1, 0.46, -0.5, 0.7, 0.02, 98);

  // the shadow side, hatched twice: cool grey over the whole flank, ink in the well
  flankHatch(NEAR, 0.2, 0.95, -1.02, -0.3, "2H", "#5b6872", 0.9, 5, 76);
  flankHatch(NEAR, 0.62, 0.96, -1.0, -0.46, "2H", "#332f29", 0.75, 8, 116);

  // --- the bruise: a soft russet stain on the lit shoulder, then its darker core
  brush.noStroke();
  brush.fillBleed(0.5, "out");
  brush.fillTexture(0.52, 0.48);
  const b1 = pearPoint(NEAR, 0.35, 0.4);
  brush.fill("#8a4536", 120);
  brush.circle(b1[0], b1[1], 21, true);
  const b2 = pearPoint(NEAR, 0.44, 0.58);
  brush.fill("#8a4536", 150);
  brush.circle(b2[0], b2[1], 14, true);
  const b3 = pearPoint(NEAR, 0.26, 0.22);
  brush.fill("#8a4536", 84);
  brush.circle(b3[0], b3[1], 11, true);
  brush.fillBleed(0.14, "out");
  const b4 = pearPoint(NEAR, 0.39, 0.5);
  brush.fill("#8a4536", 208);
  brush.circle(b4[0], b4[1], 8.5, true);
  brush.fill("#8a4536", 176);
  brush.circle(b4[0] - 7, b4[1] + 6, 6, true);
  brush.fill("#8a4536", 158);
  brush.circle(b2[0] + 4, b2[1] + 8, 5, true);
  brush.fill("#332f29", 150);
  brush.circle(b4[0] + 2, b4[1] + 1.5, 3.4, true);

  // --- darks last: where the fruit meets the cloth, and where the two bodies touch
  brush.noFill();
  brush.set("2B", "#332f29", 2.1);
  brush.line(480, 608, 522, 611);
  brush.set("2B", "#332f29", 1.5);
  brush.line(524, 611, 546, 608);
  brush.set("2B", "#332f29", 1.7);
  brush.line(602, 585, 640, 587);
  brush.set("2B", "#5b6872", 1.4);
  brush.beginShape(0.4);
  brush.vertex(568, 584);
  brush.vertex(574, 552);
  brush.vertex(578, 524);
  brush.endShape(false);
  brush.set("2H", "#5b6872", 1.0);
  brush.line(580, 512, 578, 486);

  // --- broken contour: only the shadow side gets a line, and never a whole one
  contourFragment(NEAR, 0.52, 0.8, -1, "#332f29", 1.4, "2B");
  contourFragment(NEAR, 0.84, 0.96, -1, "#332f29", 1.0, "2B");
  contourFragment(NEAR, 0.16, 0.34, -1, "#5b6872", 0.9, "2B");
  contourFragment(FAR, 0.46, 0.72, -1, "#332f29", 1.1, "2B");
  contourFragment(FAR, 0.84, 0.96, 1, "#5b6872", 0.95, "2B");
  contourFragment(NEAR, 0.88, 0.97, 1, "#332f29", 1.0, "2B");

  // --- stems, short and seated right on the shoulder of the fruit
  brush.noFill();
  brush.set("2B", "#332f29", 1.7);
  const s1 = pearPoint(NEAR, 0.01, -0.3);
  brush.beginShape(0.4);
  brush.vertex(s1[0], s1[1] + 6);
  brush.vertex(s1[0] - 4, s1[1] - 5);
  brush.vertex(s1[0] - 1, s1[1] - 16);
  brush.endShape(false);
  brush.set("2B", "#332f29", 1.3);
  const s2 = pearPoint(FAR, 0.01, 0.3);
  brush.beginShape(0);
  brush.vertex(s2[0], s2[1] + 5);
  brush.vertex(s2[0] + 4, s2[1] - 9);
  brush.endShape(false);

  // two slow strokes for the cloth, out at the edges of the shadow, nothing above
  brush.set("cpencil", "#5b6872", 1.2);
  brush.field("hand");
  brush.flowLine(326, 654, 62, 8);
  brush.flowLine(704, 646, 66, 178);
  brush.noField();

  // one seed of the accent adrift on the cloth, well away from the fruit
  brush.noStroke();
  brush.fillBleed(0.3, "out");
  brush.fill("#8a4536", 176);
  brush.circle(400, 694, 4.4, true);
}