19 lines
543 B
Kotlin
19 lines
543 B
Kotlin
package com.icegps.triangulation
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fun orient2d(bx: Double, by: Double, ax: Double, ay: Double, cx: Double, cy: Double): Double {
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// (ax,ay) (bx,by) are swapped such that the sign of the determinant is flipped. which is what Delaunator.kt expects.
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/*
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| a b | = | ax - cx ay - cy |
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| c d | | bx - cx by - cy |
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*/
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val a = twoDiff(ax, cx)
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val b = twoDiff(ay, cy)
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val c = twoDiff(bx, cx)
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val d = twoDiff(by, cy)
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val determinant = ddDiffDd(ddMultDd(a, d), ddMultDd(b, c))
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return determinant[1]
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} |