63 lines
1.2 KiB
Kotlin
63 lines
1.2 KiB
Kotlin
package org.openrndr.extra.noise
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private val G2 = 1.0 / 4.0
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private val F2 = 1.0 / 2.0
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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 = i - t
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val Y0 = j - t
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val x0 = x - X0
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val y0 = y - Y0
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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 + F2
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val y2 = y0 - 1 + F2
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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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} |