io.data2viz.shape.curve.Cardinal.kt Maven / Gradle / Ivy
package io.data2viz.shape.curve
import io.data2viz.path.PathAdapter
import io.data2viz.shape.Curve
class Cardinal(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 lineStatus = -1
private var pointStatus = -1
private val k = (1.0 - tension) / 6.0
override fun areaStart() {
lineStatus = 0
}
override fun areaEnd() {
lineStatus = -1
}
override fun lineStart() {
x0 = -1.0
y0 = -1.0
x1 = -1.0
y1 = -1.0
x2 = -1.0
y2 = -1.0
pointStatus = 0
}
override fun lineEnd() {
when (pointStatus) {
2 -> context.lineTo(x2, y2)
3 -> curve(x1, y1)
}
if (lineStatus > -1) {
if (lineStatus > 0) {
context.closePath()
}
lineStatus = 1 - lineStatus
}
}
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
if (lineStatus > 0) context.lineTo(x, y) else context.moveTo(x, y)
}
1 -> {
pointStatus = 2
x1 = x
y1 = y
}
2 -> {
pointStatus = 3
curve(x, y)
}
else -> curve(x, y)
}
x0 = x1
x1 = x2
x2 = x
y0 = y1
y1 = y2
y2 = y
}
}