Android draw fixed paths on ImageView with support multiple screens

Question

I have continents image and i need when user clicks on image detect which continent he is clicked.

I have tried collecting x y coordinates for every continent and when user clicks on image I check if user finger x y exists in my Paths like this:

val path = Path()
path.moveTo(409f, 1986f)
path.lineTo(414f, 1986f)
path.lineTo(418f, 1986f)
...
path.close()

val rectF = RectF()
path.computeBounds(rectF, true)
val r = Region()
r.setPath(path, Region(rectF.left.toInt(), rectF.top.toInt(), rectF.right.toInt(), rectF.bottom.toInt()))

ivMainMap?.setOnTouchListener { v, event ->
    val point = Point()
    point.x = event.x.toInt()
    point.y = event.y.toInt()
    if (r.contains(point.x, point.y)) {
        Toast.makeText(this, "South America", Toast.LENGTH_LONG).show()
    }
    return@setOnTouchListener true
}

but i faced issue with multiple screen sizes, after that i have tried collecting x y coordinates on 560 dpi screen and convert x y to new x y with current screen size density, like this:

private fun getExactX(x: Float): Float {
    val screenAdjust = Resources.getSystem().displayMetrics.densityDpi.toFloat() / 560f
    return ((x) * screenAdjust)
}

private fun getExactY(y: Float): Float {
    val screenAdjust = Resources.getSystem().displayMetrics.densityDpi.toFloat() / 560f
    return ((y) * screenAdjust)
}

but the issue still exist

Answer 1

Create a ratio multiplier:

DisplayMetrics displayMetrics = new DisplayMetrics();
    getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
    screen_width = displayMetrics.widthPixels;
    ratio_multiplier = screen_width/720; // Or whatever your base screen size is.

Then that ratio_multiplier can be used for anything that needs resizing.
I use this in all my programs for resizing button, images, etc.