我尝试为大纲提供者创建凸路径。我需要一个带有圆角左上角和右上角的矩形。有一种方法可以做到这一点,但有一个问题:我的凸路径有什么问题?它像凸面一样在油漆上绘画,并且在几何上应该没问题。
(是的,我知道public void addRoundRect(左浮动,顶部浮动,右浮动,底部浮动,@ NonNull float []半径,@ NonNull方向目录))
有我的ConvexView的实现
val Int.toPx: Int
get() = (this * Resources.getSystem().displayMetrics.density).toInt()
class ConvexView @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {
private val paint = Paint().apply {
isAntiAlias = true
color = Color.RED
strokeWidth = 5f
style = Paint.Style.STROKE
}
private val convexPath = Path()
val r = 24.toPx.toFloat()
val d = r * 2
override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
with (convexPath) {
reset()
arcTo(0f, 0f, d, d, -90f, -90f, true)
lineTo(0f, measuredHeight.toFloat())
lineTo(measuredWidth.toFloat(), measuredHeight.toFloat())
lineTo(measuredWidth.toFloat(), r)
arcTo(measuredWidth.toFloat() - d, 0f,
measuredWidth.toFloat(), d,
0f, -90f, true)
lineTo(r, 0f)
}
Log.d("CONVEX", "Path is convex = ${convexPath.isConvex}")
}
override fun onDraw(canvas: Canvas?) {
canvas?.save()
canvas?.drawPath(convexPath, paint)
canvas?.restore()
}
}
但是路径仍然不凸
在第二个arcTo()调用中,您需要指定最后一个参数forceMoveTo = false。 arcTo(....,true)终止路径一次。因此,它绘制了两个永远不会凸的独立路径。