%% 
%% $Revision: 1.1.6.2 $
%% 
%%
%% Copyright 1994-2003 The MathWorks, Inc.
%%
%% Abstract: Discrete Filter block target file

%implements "DiscreteFilter" "C"

%% Function: BlockInstanceSetup ==============================================
%% Abstract:
%%   Set expression folding compliance
%%
%function BlockInstanceSetup(block, system) void
  %<LibBlockSetIsExpressionCompliant(block)>
  %% cache whether or not state initialization is required
  %<SLibSetSkipInitializationFlag(system,block,[])>
%endfunction


%% InitializeConditions =========================================================
%%
%function InitializeConditions(block, system) Output
  %if NumDWork > 0 && !block.SkipInitialization
    /* %<Type> Block: %<Name> */
    %if ParamSettings.Realization == "General"
      %assign rollVars = ["<dwork>/DSTATE"]
      %assign rollRegions = [0:%<LibBlockDWorkWidth(DSTATE)-1>]
      %roll sigIdx = rollRegions, lcv = RollThreshold, block, "Roller", rollVars
	%<LibBlockDWork(DSTATE, "", lcv, sigIdx)> = 0.0;
      %endroll
    %else
      %<LinLibInitializeConditions(block,system)>
    %endif
    
  %endif
%endfunction


%% FcnNumElem ================================================================
%% Abstract: return an element of the numerator
%function FcnNumElem(rollR,numR,lcvR,idxR,rollC,lcvC,idxC) Output
  %if rollR && rollC
    %assign idxStr = "%<lcvR> + %<numR>*%<lcvC>"
  %elseif rollR
    %assign idxStr = "%<lcvR> + %<numR*idxC>"
  %elseif rollC
    %assign idxStr = "%<numR>*%<lcvC> + %<idxR>"
  %else
    %assign idxStr = idxR + numR*idxC
  %endif
  %if rollR || rollC
    %<LibBlockParameter(Numerator, idxStr, "", 0)>
  %else
    %<LibBlockParameter(Numerator, "", "", idxStr)>
  %endif
%endfunction

%% FcnTransFcnOutput
%% Abstract: output code for a discrete filter
%function FcnTransFcnOutput(block, system) Output
    %assign nNumRows    = Numerator.Dimensions[0]
    %assign nNumCols    = Numerator.Dimensions[1]
    %assign nDenCols    = Denominator.Dimensions[1]
    %assign rowRollVars = ["y0"]
    %assign rowRollReg  = [0:%<nNumRows-1>]
    %assign U           = LibBlockInputSignal(0, "", "", 0)
    %assign D0          = LibBlockParameter(Denominator, "", "", 0)
    %roll rowIdx = rowRollReg, lcvR = RollThreshold, block, "Roller", rowRollVars
      %assign rowRoll     = (lcvR != "")
      %assign Yi = LibBlockOutputSignal(0, "", lcvR, rowIdx)
      %assign colRollVars = ["<dwork>/DSTATE"]
      %<Yi> = %<LibBlockParameter(Numerator, lcvR, "", rowIdx)> / %<D0>*%<U>;
      %if nDenCols > 1
        %assign colRollReg  = [0:%<nDenCols-2>]
	%roll colIdx = colRollReg, lcvC = RollThreshold, block, "Roller", colRollVars
 	  %assign colRoll = (lcvC != "")
          %assign x = LibBlockDWork(DSTATE, "", lcvC, colIdx)
	  %if colRoll 
	    %assign colIdxPlus1 = 0
	  %else
	  %endif
          %if colRoll
	    %assign lcvCPlus1 = "(%<lcvC>+1)"
            if (%<lcvCPlus1> <= %<(nNumCols - 1)>) {
 	      %<Yi> = %<Yi> +\ 
	        (%<FcnNumElem(rowRoll,nNumRows,lcvR,rowIdx,colRoll,lcvCPlus1,0)>\
  	        - %<LibBlockParameter(Numerator, lcvR, "", rowIdx)>*\
  	        %<LibBlockParameter(Denominator, lcvCPlus1, "", 0)> / %<D0>) / %<D0>*%<x>;
	    } else {
   	      %<Yi> = %<Yi> -\
	        (%<LibBlockParameter(Numerator, lcvR, "", rowIdx)>*\
  	        %<LibBlockParameter(Denominator, lcvCPlus1, "", 0)> / %<D0>) / %<D0>*%<x>;
            }
	  %else
	    %assign colIdxPlus1 = %<colIdx + 1>
            %if colIdxPlus1 <= (nNumCols - 1)
   	      %<Yi> = %<Yi> +\
	        (%<FcnNumElem(rowRoll,nNumRows,lcvR,rowIdx,colRoll,"",colIdxPlus1)>\
  	        - %<LibBlockParameter(Numerator, lcvR, "", rowIdx)>*\
  	        %<LibBlockParameter(Denominator, "", "", colIdxPlus1)> / %<D0>) / %<D0>*%<x>;
	    %else
   	      %<Yi> = %<Yi> -\
	        %<LibBlockParameter(Numerator, lcvR, "", rowIdx)>*\
  	        %<LibBlockParameter(Denominator, "", "", colIdxPlus1)> / %<D0> / %<D0>*%<x>;
            %endif
	  %endif
        %endroll 
      %endif
    %endroll 
%endfunction



%% Function: Outputs ===========================================================
%% Abstract:
%%   Using the state and potentially the inputs, compute the output.
%%
%function Outputs(block, system) Output
  %if ParamSettings.Realization == "General"
    %<FcnTransFcnOutput(block, system)>\
  %else
    %<LinLibOutputs(block, system)>\
  %endif
%endfunction



%% Function: Update ============================================================
%% Abstract:
%%   Update the states.
%%   
%function Update(block, system) Output
  %if NumDWork > 0
    /* %<Type> Block: %<Name> */
    {
    %if ParamSettings.Realization == "General"
      %assign nx = LibBlockDWorkWidth(DSTATE)
      %assign U = LibBlockInputSignal(0, "", "", 0)
      %assign D0 = LibBlockParameter(Denominator, "", "", 0)
      %% static only because DOS doesn't work with arrays on stack
      static real_T xnew[%<nx>];
      %assign xnew0 = "xnew[0]"
      %<xnew0> = %<U>;
      %assign region = [0:%<nx-1>]
      %assign rollVars = ["<dwork>/DSTATE"]
      %roll sigIdx = region, lcv = RollThreshold, block, "Roller", rollVars
        %assign lcvPlus1 = (lcv != "") ? "%<lcv>+1" : ""
        %assign sigIdxPlus1 = (lcv != "") ? "" : %<sigIdx + 1>
        %<xnew0> = %<xnew0> -\
	 %<LibBlockParameter(Denominator, lcvPlus1, "", sigIdxPlus1)>*\
         %<LibBlockDWork(DSTATE, "", lcv, sigIdx)> / %<D0>;
      %endroll

      %if nx > 1
        %assign region = [0:%<nx-2>]
        %roll sigIdx = region, lcv = RollThreshold, block, "Roller", rollVars
          %assign lcvPlus1 = (lcv != "") ? "%<lcv>+1" : ""
          %assign sigIdxPlus1 = (lcv != "") ? "" : %<sigIdx + 1>
          xnew%<SLibGet1DArrayIndexer(nx, "", lcvPlus1, sigIdxPlus1)> =\
    	%<LibBlockDWork(DSTATE, "", lcv, sigIdx)>;
        %endroll
      %endif
      %assign xd = "&%<LibBlockDWork(DSTATE, "", "", 0)>"
      (void)memcpy(%<xd>, xnew, sizeof(real_T)*%<nx>);
    %else
      %<LinLibUpdate(block, system)>\
    %endif
    }
  %endif
%endfunction

%% [EOF] dfilter.tlc