Jerry
64 lines
2.3 KiB
JavaScript
64 lines
2.3 KiB
JavaScript
const GLSL = `
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const float IMPLICIT_TREFOIL_TAU = 6.283185307179586;
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float sdf(vec3 p) {
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p.z /= verticalScale;
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float phi = atan(p.y, p.x);
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vec2 torusSection = vec2(length(p.xy) - majorRadius, p.z);
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float best = 1.0e6;
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for (int branchIndex = 0; branchIndex < 3; branchIndex += 1) {
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float t = (phi + IMPLICIT_TREFOIL_TAU * float(branchIndex)) / 3.0;
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vec2 knotCenter = knotRadius * vec2(cos(2.0 * t), sin(2.0 * t));
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best = min(best, length(torusSection - knotCenter));
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}
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return best - tubeRadius;
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}
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vec3 color(vec3 p, vec3 normal) {
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float sweep = atan(p.y, p.x) / IMPLICIT_TREFOIL_TAU + p.z * 0.018;
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return mix(baseColor, accentColor, 0.5 + 0.5 * sin(6.283185307179586 * sweep));
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}
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`;
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export default {
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schema: "implicit.js/0.1.0",
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name: "trefoil torus-knot tube",
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description: "A constant-radius solid tube following a closed trefoil torus knot path.",
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units: "mm",
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params: {
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majorRadius: { type: "number", label: "Major radius", min: 10, max: 24, step: 0.25, default: 16.5, unit: "mm" },
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knotRadius: { type: "number", label: "Lobe radius", min: 3.5, max: 10, step: 0.1, default: 6.9, unit: "mm" },
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tubeRadius: { type: "number", label: "Tube radius", min: 0.8, max: 4.5, step: 0.05, default: 2.05, unit: "mm" },
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verticalScale: { type: "number", label: "Vertical scale", min: 0.65, max: 1.6, step: 0.05, default: 1 },
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baseColor: { type: "color", label: "Copper color", default: "#ff7a33" },
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accentColor: { type: "color", label: "Cyan color", default: "#2ee8ff" }
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},
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animations: {
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knotBreath: {
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label: "Knot breath",
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duration: 5.2,
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loop: true,
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update({ progress, set }) {
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const wave = Math.sin(progress * Math.PI * 2);
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set("tubeRadius", 2.05 + wave * 0.95);
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set("knotRadius", 6.9 + wave * 1.7);
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set("verticalScale", 1 + wave * 0.3);
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}
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}
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},
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bounds: ({ params }) => {
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const xy = params.majorRadius + params.knotRadius + params.tubeRadius + 5;
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const z = params.knotRadius * params.verticalScale + params.tubeRadius + 5;
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return [[-xy, -xy, -z], [xy, xy, z]];
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},
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render: ({ params }) => ({
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steps: 220,
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epsilon: Math.max(0.006, params.tubeRadius * 0.004),
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normalEpsilon: Math.max(0.04, params.tubeRadius * 0.028),
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stepScale: 0.72,
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maxStep: Math.max(params.tubeRadius * 0.68, 0.7)
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}),
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glsl: GLSL
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};
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