-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=60870


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-- Indicator profile initialization routine
-- Defines indicator profile properties and indicator parameters
-- TODO: Add minimal and maximal value of numeric parameters and default color of the streams
function Init()
    indicator:name("Slope in Degrees");
    indicator:description("Slope in Degrees");
    indicator:requiredSource(core.Tick);
    indicator:type(core.Indicator);
    indicator.parameters:addGroup("Calculation");
    indicator.parameters:addInteger("Period", "Period", "Period", 1, 1, 1000);
	
	indicator.parameters:addGroup("Style");
     
	indicator.parameters:addInteger("height", "Height (% of chart height)", "", 20);
    indicator.parameters:addColor("up", "Up Color", "", core.rgb(0, 255, 0));
	indicator.parameters:addColor("down", "Down Color", "", core.rgb(255, 0, 0));
	indicator.parameters:addColor("color", "Label Color", "", core.rgb(0, 0, 0));
    indicator.parameters:addInteger("transparency", "Fill Transparency", "0 - opaque, 100 - transparent", 75, 0, 100);
	
	
	 indicator.parameters:addGroup("OB/OS Levels");	
    indicator.parameters:addDouble("overbought", "Overbought Level","", 45);
    indicator.parameters:addDouble("oversold","Oversold Level","", -45);
	indicator.parameters:addColor("level_overboughtsold_color", "Line Color","", core.rgb(128, 128, 128));
    indicator.parameters:addInteger("level_overboughtsold_width","Line width","", 1, 1, 5);
    indicator.parameters:addInteger("level_overboughtsold_style", "Line Style","", core.LINE_SOLID);
    indicator.parameters:setFlag("level_overboughtsold_style", core.FLAG_LEVEL_STYLE);
	indicator.parameters:addBoolean("Alternate", "Alternate OB/OS Colors", "", false);
end

-- Indicator instance initialization routine
-- Processes indicator parameters and creates output streams
-- TODO: Refine the first period calculation for each of the output streams.
-- TODO: Calculate all constants, create instances all subsequent indicators and load all required libraries
-- Parameters block
local Period;
local height,up, down,transparency;
local first;
local source = nil;
local color;
-- Streams block
local Slope = nil;
local Alternate;
local Label={0,10, 20,30, 40, 50, 60, 70, 80, 90, -10, -20, -30, -40, -50, -60,-70, -80, -90};
-- Routine
function Prepare(nameOnly)
    Period = instance.parameters.Period;
	Alternate = instance.parameters.Alternate;
	height = instance.parameters.height/100;
	up = instance.parameters.up;
	down = instance.parameters.down;
	color = instance.parameters.color;
	transparency = instance.parameters.transparency;
    source = instance.source;
    first = source:first()+Period+1;

    local name = profile:id() .. "(" .. source:name() .. ", " .. tostring(Period) .. ")";
    instance:name(name);
	
	if   (nameOnly) then
        return;
    end
	 
	  Slope = instance:addInternalStream(0, 0);
	  
	  
	instance:ownerDrawn(true);
 
end


local init = false;
 
function Draw(stage, context)
    if stage~= 2 then
	return;
	end
	
	   if not init then
	   context:createSolidBrush(2, up);
       context:createPen(1, context.SOLID, 1, up);
	   
	   context:createSolidBrush(4, down);
       context:createPen(3, context.SOLID, 1, down);
	   
	   context:createFont (5, "Arial", 10, 10, 0)
	   
	    context:createPen(6, context:convertPenStyle (instance.parameters.level_overboughtsold_style), instance.parameters.level_overboughtsold_width, instance.parameters.level_overboughtsold_color);
		context:createSolidBrush(7, instance.parameters.level_overboughtsold_color);
	   
	   
	   transparency = context:convertTransparency(instance.parameters.transparency);
	   init= true;
	   end
	   
	context:setClipRectangle (  context:left (), context:top(), context:right (), context:bottom());
	
	    local firstBar, lastBar = context:firstBar(), context:lastBar();
        firstBar=math.max(firstBar, first);
        lastBar=math.min(lastBar, source:size()-1);
	
		if firstBar<= first then
		return;
		end	

	local i;
	local x11,y11, x12,y12;
	local top, bottom; 
	local HeightCoeff;
	local min, max, Max;
	
	
	
	for i= firstBar,  	lastBar, 1 do	
		x1, x , x  = context:positionOfBar (i-Period); 
		visible, y1 = context:pointOfPrice (source[i-Period])
		x2, c1 , c2  = context:positionOfBar (i);	 
		visible, y2 = context:pointOfPrice (source[i])
		Slope[i] = AngleCalculation(x1,y1, x2,y2);
	end			 
	
	
          min,max=mathex.minmax(Slope, firstBar, lastBar);	 
			Max=math.max(math.abs(min), math.abs(max));
									
			top, bottom = context:top(), context:bottom();
			HeightCoeff=(bottom-top)*(height )/Max;
	
	for i= firstBar,  	lastBar, 1 do	
	
				x1, x , x  = context:positionOfBar (i-Period);
				y1=(source[i-Period]);	
				x2, c1 , c2  = context:positionOfBar (i);	
				y2= (source[i]);
	
			     BarHeight=HeightCoeff*Slope[i];
				 
					 if Slope[i] < 0 then
					y2=bottom-HeightCoeff* Max + BarHeight;
				     y1=bottom-HeightCoeff* Max ;
						 if Alternate and Slope[i] <= instance.parameters.oversold then
						 context:drawRectangle(6, 7, c1, y1, c2, y2, transparency);
						 else
						context:drawRectangle(1, 2, c1, y1, c2, y2, transparency);
						end
					else
					 y1=bottom-HeightCoeff* Max  +BarHeight;
				     y2=bottom-HeightCoeff* Max ;
							 if Alternate and Slope[i] >= instance.parameters.overbought then
							 context:drawRectangle(6, 7, c1, y1, c2, y2, transparency);
							else
							context:drawRectangle(3, 4, c1, y1, c2, y2, transparency);
							end
					end
			  
			 
				 
	end
	
	
  
	
	
	          for j= 1, 19, 1 do
					 	 
					   if math.abs(Label[j])<= Max then
					   iwidth, iheight = context:measureText (5, tostring(Label[j]), context.LEFT)	
					   y=bottom-HeightCoeff* Max - HeightCoeff* Label[j];					  
					   context:drawText (5,tostring( Label[j]), color, -1,  context:right ()-iwidth, y-iheight,  context:right  () , y, context.LEFT  )
                       end				 
			 	end
				
				     y=bottom-HeightCoeff* Max - HeightCoeff* (instance.parameters.overbought);			
					context:drawLine (6,  context:left (), y,  context:right (), y);
					  y=bottom-HeightCoeff* Max - HeightCoeff* (instance.parameters.oversold);			
	                context:drawLine (6,  context:left (), y,  context:right (), y);
					
					  y=bottom-HeightCoeff* Max - HeightCoeff* (0);			
	                context:drawLine (6,  context:left (), y,  context:right (), y);
end	

function  AngleCalculation(x1,y1, x2,y2)
	   -- x1=1;
	--	x2=2;
		--y1=0;
		--y2=1;
		 return (math.atan2((y2-y1), (x2-x1)) * 180 / math.pi);
end


-- Indicator calculation routine
-- TODO: Add your code for calculation output values
function Update(period)


if period < source:size()-1 then
return;
end
  
  
  core.host:execute("setStatus", string.format("%." .. 2 .. "f", -Slope[period])); 
  
  
end