io.data2viz.shape.curve.CardinalClosed.kt Maven / Gradle / Ivy
package io.data2viz.shape.curve
import io.data2viz.path.PathAdapter
import io.data2viz.shape.Curve
class CardinalClosed(override val context: PathAdapter, tension: Double = 0.0) : Curve {
private var x0 = -1.0
private var y0 = -1.0
private var x1 = -1.0
private var y1 = -1.0
private var x2 = -1.0
private var y2 = -1.0
private var x3 = -1.0
private var y3 = -1.0
private var x4 = -1.0
private var y4 = -1.0
private var x5 = -1.0
private var y5 = -1.0
private var lineStatus = -1
private var pointStatus = -1
private val k = (1.0 - tension) / 6.0
override fun areaStart() {}
override fun areaEnd() {}
override fun lineStart() {
x0 = -1.0
y0 = -1.0
x1 = -1.0
y1 = -1.0
x2 = -1.0
y2 = -1.0
x3 = -1.0
y3 = -1.0
x4 = -1.0
y4 = -1.0
x5 = -1.0
y5 = -1.0
pointStatus = 0
}
override fun lineEnd() {
when (pointStatus) {
1 -> {
context.moveTo(x3, y3)
context.closePath()
}
2 -> {
context.lineTo(x3, y3)
context.closePath()
}
3 -> {
point(x3, y3)
point(x4, y4)
point(x5, y5)
}
}
if (lineStatus > 0) context.closePath()
lineStatus = 1 - lineStatus
}
// TODO : non specific, inherit from Cardinal
private fun curve(x: Double, y: Double) {
context.bezierCurveTo(
x1 + k * (x2 - x0),
y1 + k * (y2 - y0),
x2 + k * (x1 - x),
y2 + k * (y1 - y),
x2,
y2
)
}
override fun point(x: Double, y: Double) {
when (pointStatus) {
0 -> {
pointStatus = 1
x3 = x
y3 = y
}
1 -> {
pointStatus = 2
x4 = x
y4 = y
context.moveTo(x4, y4)
}
2 -> {
pointStatus = 3
x5 = x
y5 = y
}
else -> curve(x, y)
}
x0 = x1
x1 = x2
x2 = x
y0 = y1
y1 = y2
y2 = y
}
}