commonMain.ru.casperix.math.curve.float32.UniformCurve2f.kt Maven / Gradle / Ivy

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package ru.casperix.math.curve.float32

import ru.casperix.math.vector.float32.Vector2f
import kotlinx.serialization.Serializable

@Serializable
class UniformCurve2f(val curve: ParametricCurve2f, val parts: Int = 10) : ParametricCurve2f {

    val positionList = (0..parts).map {
        curve.getPosition(it.toFloat() / parts)
    }

    val destList = (0 until parts).map {
        positionList[it].distTo(positionList[it + 1])
    }


    val dest = destList.reduce { a, b -> a + b }
    override fun divide(t: Float): Pair {
        return curve.divide(t)
    }

    override fun getTangent(t: Float): Vector2f {
        return curve.getTangent(getCurveT(t))
    }

    override fun getNormal(t: Float): Vector2f {
        return curve.getNormal(getCurveT(t))
    }

    override fun getPosition(t: Float): Vector2f {
        return curve.getPosition(getCurveT(t))
    }

    private fun getCurveT(t: Float): Float {
        val (index, position) = getSegmentPosition(t)


        val tStart = index / parts.toFloat()
        val tOffset = position / parts.toFloat()

        return tStart + tOffset
    }

    override fun length(): Float {
        return dest
    }

    data class SegmentPosition(val index: Int, val position: Float)

    private fun getSegmentPosition(t: Float): SegmentPosition {
        val offset = t * dest

        var summaryDest = 0f
        destList.forEachIndexed { index, dest ->
            if (offset < summaryDest + dest) {
                val position = (offset - summaryDest) / dest
                return SegmentPosition(index, position)
            }
            summaryDest += dest
        }
        return SegmentPosition(destList.size - 1, 1f)
    }
}