76 lines
1.8 KiB
Kotlin
76 lines
1.8 KiB
Kotlin
package org.openrndr.extra.noise
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import org.openrndr.math.Vector2
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private const val SQRT3 = 1.7320508075688772935274463415059
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private const val F2 = 0.5 * (SQRT3 - 1.0)
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private const val G2 = (3.0 - SQRT3) / 6.0
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fun simplex(seed: Int, position: Vector2): Double = simplex(seed, position.x, position.y)
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//fun simplex2D(seed:Int, x:Double, y:Double) = simplex(seed, x, y)
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fun simplex(seed: Int, x: Double, y: Double): Double {
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var t = (x + y) * F2
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val i = (x + t).fastFloor()
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val j = (y + t).fastFloor()
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t = ((i + j) * G2)
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val x0 = x - (i - t)
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val y0 = y - (j - t)
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val i1: Int
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val j1: Int
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if (x0 > y0) {
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i1 = 1
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j1 = 0
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} else {
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i1 = 0
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j1 = 1
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}
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val x1 = (x0 - i1 + G2)
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val y1 = (y0 - j1 + G2)
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val x2 = (x0 - 1 + 2 * G2)
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val y2 = (y0 - 1 + 2 * G2)
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val n0: Double
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val n1: Double
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val n2: Double
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t = 0.5 - x0 * x0 - y0 * y0
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if (t < 0)
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n0 = 0.0
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else {
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t *= t
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n0 = t * t * gradCoord2D(seed, i, j, x0, y0)
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}
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t = 0.5 - x1 * x1 - y1 * y1
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if (t < 0)
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n1 = 0.0
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else {
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t *= t
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n1 = t * t * gradCoord2D(seed, i + i1, j + j1, x1, y1)
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}
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t = 0.5 - x2 * x2 - y2 * y2
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if (t < 0)
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n2 = 0.0
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else {
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t *= t
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n2 = t * t * gradCoord2D(seed, i + 1, j + 1, x2, y2)
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}
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return 50.0 * (n0 + n1 + n2)
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}
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val simplex1D: (Int, Double) -> Double = ::simplex
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val simplex2D: (Int, Double, Double) -> Double = ::simplex
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val simplex3D: (Int, Double, Double, Double) -> Double = ::simplex
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val simplex4D: (Int, Double, Double, Double) -> Double = ::simplex
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fun Vector2.Companion.simplex(seed: Int, x: Double): Vector2 = Vector2(
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simplex(seed, x, 0.0, 0.0, 0.0),
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simplex(seed, 0.0, x + 31.3383, 0.0, 0.0)
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) |