--[[

SCRIPT: DBLIM
AUTHOR: L Shems
URL: http://repository.justfly.solutions
DATE: 28 Apr 2019
VERSION: 1.0
LICENSE: https://www.gnu.org/licenses/gpl-3.0.en.html
DESCRIPTION:

DeadBand and Rate Limiter:

Implementation of a linear mapping of an input x to an output y
with the input x between xmin and xmax and output y between 0 and 100%
on both sides of the center position of the input
xmin and xmax adjustable in-flight by any control source

so:

y = sign(x)* minimum(xmax, maximum(xmin, ( (abs(x)-xmin) * 100%/(xmax-xmin) )  )

To be used to create a dead band (zero output y) for any input abs(x) smaller than xmin
and limit the output y to 100% for any input abs(x) greater then xmax
and have a linear interpolation between these two endpoints (xmin,0) and (xmax,100)


            y
            ^       
           100%     ----
            |      /
            |     / ^
            |    /  |
 -----------0----------> x
       /    |   ^   |
      /     |   |   |
     /      |   |   |
 ----     -100% |   |
                |   |
              xmin xmax
   
  
  
Source x to be provided in the script setup:        i.e. snapflap -> choose stick ele (raw) or input ele
Source to be provided to supply xmin:               to allow in flight adaptation through i.e. slider S1.
Source to be provided to supply xmax:               to allow in flight adaptation through i.e. slider S2.
Value xminv will override the xmin source value:    set to -1 to disable value override.
Value xmaxv will override the xmax source value:    set to -1 to disable value override.

Output y is provided as output
To check the correct function and settings:
Source x is provided as output 
xmin is provided as output
xmax is provided as output
--]]


local P={}

P.input =
	{
		{ "x", SOURCE,},              -- x input value
		{ "xmin", SOURCE},            -- xmin value via specified control, sign is ignored
		{ "xmax", SOURCE},            -- xmax value via specified control, sign is ignored
		{ "xminv", VALUE,-1,100,5},   -- xmin value forced setting, -1 is use xmin source
		{ "xmaxv", VALUE,-1,100,95},  -- xmax value forced setting, -1 is use xmax source
	} 

P.output = 
  {"y",
   "x",
   "xmin",
   "xmax",
  }

-- periodically called function
P.run=function(x, xmin, xmax, xminv, xmaxv)
  
	--set xmin, xmax if no input sources are given
  xmin = (xminv<0) and math.abs(xmin) or xminv*10.24
  xmax = (xmaxv<0) and math.abs(xmax) or xmaxv*10.24
  
  --limit xmin and xmax
  xmin = math.max(0,xmin)
  xmax = math.min(xmax,1024)
  
  --make sure xmax is greater than xmin
  xmax = math.max(xmin+1,xmax)
  
	return x/math.abs(x) * math.min(1024, math.max(0,  (math.abs(x)-xmin) * 1024/(xmax-xmin) )), x, xmin, xmax
end

return P