/****************************************************************************
 *               express.cpp
 *
 * This module implements an expression parser for the floats, vectors and
 * colours in scene description files.
 *
 * from Persistence of Vision(tm) Ray Tracer version 3.6.
 * Copyright 1991-2003 Persistence of Vision Team
 * Copyright 2003-2004 Persistence of Vision Raytracer Pty. Ltd.
 *---------------------------------------------------------------------------
 * NOTICE: This source code file is provided so that users may experiment
 * with enhancements to POV-Ray and to port the software to platforms other
 * than those supported by the POV-Ray developers. There are strict rules
 * regarding how you are permitted to use this file. These rules are contained
 * in the distribution and derivative versions licenses which should have been
 * provided with this file.
 *
 * These licences may be found online, linked from the end-user license
 * agreement that is located at http://www.povray.org/povlegal.html
 *---------------------------------------------------------------------------
 * This program is based on the popular DKB raytracer version 2.12.
 * DKBTrace was originally written by David K. Buck.
 * DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
 *---------------------------------------------------------------------------
 * $File: //depot/povray/3.6-release/source/express.cpp $
 * $Revision: #3 $
 * $Change: 3032 $
 * $DateTime: 2004/08/02 18:43:41 $
 * $Author: chrisc $
 * $Log$
 *****************************************************************************/

#include <ctype.h>
#include "frame.h"
#include "vector.h"
#include "parse.h"
#include "parstxtr.h"
#include "parsestr.h"
#include "colour.h"
#include "splines.h"
#include "express.h"
#include "matrices.h"
#include "povray.h"
#include "tokenize.h"
#include "pattern.h"
#include "pigment.h"
#include "normal.h"
#include "texture.h"
#include "hfield.h"
#include "render.h"
#include "ray.h"
#include "objects.h"
#include "pov_util.h"
#include "fncode.h"
#include "fnpovfpu.h"
#include "function.h"
#include "mathutil.h"
#include "fileinputoutput.h"

#include <algorithm>

BEGIN_POV_NAMESPACE

USING_POV_BASE_NAMESPACE

/*****************************************************************************
* Local preprocessor defines
******************************************************************************/

#define ftrue(f) ((int)(fabs(f)>EPSILON))


/*****************************************************************************
* Local typedefs
******************************************************************************/


/*****************************************************************************
* Local variables
******************************************************************************/

unsigned int Number_Of_Random_Generators; // GLOBAL VARIABLE
unsigned int *next_rand; // GLOBAL VARIABLE

bool Allow_Identifier_In_Call, Identifier_In_Call; // GLOBAL VARIABLE

/*****************************************************************************
* Static functions
******************************************************************************/

static void Parse_Vector_Param (VECTOR Vector);
static void Parse_Vector_Param2 (VECTOR Vect1, VECTOR Vect2);
static void Parse_Trace(VECTOR Res);
static int Parse_Inside();
static bool Parse_Call();
static DBL Parse_Function_Call();
static void Parse_Vector_Function_Call(EXPRESS Express, int *Terms);
static void Parse_Spline_Call(EXPRESS Express, int *Terms);
static void Parse_Num_Factor (EXPRESS Express,int *Terms);
static void Parse_Num_Term (EXPRESS Express, int *Terms);
static void Parse_Rel_Factor (EXPRESS Express,int *Terms);
static void Parse_Rel_Term (EXPRESS Express, int *Terms);
static void Parse_Logical (EXPRESS Express, int *Terms);
static void Parse_Express (EXPRESS Express, int *Terms);
static void Promote_Express (EXPRESS Express,int *Old_Terms,int New_Terms);
static void POV_strupr (char *s);
static void POV_strlwr (char *s);

static DBL stream_rand (int stream);
static int stream_seed (int seed);



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

DBL Parse_Float_Param()
{
  DBL Local;
  EXPRESS Express;
  int Terms = 1;
  bool old_allow_id = Allow_Identifier_In_Call;
  Allow_Identifier_In_Call = false;

  GET(LEFT_PAREN_TOKEN);
  Parse_Express(Express,&Terms);

  if (Terms>1)
  {
    Error ("Float expected but vector or color expression found.");
  }

  Local = Express[0];

  GET(RIGHT_PAREN_TOKEN);

  Allow_Identifier_In_Call = old_allow_id;

  return (Local);
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_Float_Param2(DBL *Val1,DBL *Val2)
{
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   GET (LEFT_PAREN_TOKEN);
   *Val1 = Parse_Float();
   Parse_Comma();
   *Val2 = Parse_Float();
   GET (RIGHT_PAREN_TOKEN);

   Allow_Identifier_In_Call = old_allow_id;
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void Parse_Vector_Param(VECTOR Vector)
{
  GET(LEFT_PAREN_TOKEN);
  Parse_Vector(Vector);
  GET(RIGHT_PAREN_TOKEN);
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void Parse_Vector_Param2(VECTOR Val1,VECTOR Val2)
{
   GET (LEFT_PAREN_TOKEN);
   Parse_Vector(Val1);
   Parse_Comma();
   Parse_Vector(Val2);
   GET (RIGHT_PAREN_TOKEN);
  }

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void Parse_Trace(VECTOR Res)
  {
   OBJECT *Object;  
   INTERSECTION Intersect;
   RAY    Ray;
   VECTOR Local_Normal;

   GET (LEFT_PAREN_TOKEN);
   
   EXPECT
     CASE (OBJECT_ID_TOKEN)
       Object = (OBJECT *)Token.Data;
       EXIT
     END_CASE
                
     OTHERWISE
       Object = NULL;
       UNGET
       EXIT
     END_CASE
   END_EXPECT

   if (Object == NULL) 
     Error ("Object identifier expected.");

   Parse_Comma();

   Initialize_Ray_Containers( &Ray );
   Parse_Vector(Ray.Initial);
   Parse_Comma();
   Parse_Vector(Ray.Direction);
   VNormalizeEq( Ray.Direction );

   Parse_Comma();

   if ( Intersection( &Intersect, Object, &Ray ) ) 
   {
     Assign_Vector( Res, Intersect.IPoint );
     Normal( Local_Normal, Intersect.Object, &Intersect );

     if (Test_Flag(Intersect.Object,INVERTED_FLAG))
     {
       Local_Normal[X] = -Local_Normal[X];
       Local_Normal[Y] = -Local_Normal[Y];
       Local_Normal[Z] = -Local_Normal[Z];
     }
   }
   else 
   {
     Res[X]=Res[Y]=Res[Z]=0;
     Local_Normal[X] = Local_Normal[Y] = Local_Normal[Z] = 0;
   }

   Destroy_IStacks();

   EXPECT
     CASE (VECTOR_FUNCT_TOKEN)
       /* All of these functions return a VECTOR result */
       if(Token.Function_Id == VECTOR_ID_TOKEN) 
       {
         Assign_Vector((DBL *)Token.Data, Local_Normal);
       }
       else 
       {
         UNGET
       }
       EXIT
     END_CASE
                
     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

   GET (RIGHT_PAREN_TOKEN);

  }

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static int Parse_Inside()
{
   OBJECT *Object;  
   VECTOR Local_Vector;
   int Result = 0;

   GET (LEFT_PAREN_TOKEN);
   
   EXPECT
     CASE (OBJECT_ID_TOKEN)
       Object = (OBJECT *)Token.Data;
       EXIT
     END_CASE
                
     OTHERWISE
       Object = NULL;
       UNGET
       EXIT
     END_CASE
   END_EXPECT

   if (Object == NULL) 
     Error ("Object identifier expected.");
   if((Object->Type & PATCH_OBJECT) == PATCH_OBJECT)
     Error ("Solid object identifier expected.");

   Parse_Comma();

   Parse_Vector(Local_Vector);

   if (Inside_Object(Local_Vector, Object)) 
     Result = 1;
   else
     Result = 0;

   GET (RIGHT_PAREN_TOKEN);

   return Result;
}

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
*   Thorsten Froehlich
*
* DESCRIPTION
*
*   Utility function that determines if this is a call or access of an
*   identifier and stores the result in a global variable.  If an identifier
*   is allowed is determined by another global variable.
*
* CHANGES
*
******************************************************************************/

bool Parse_Call()
{
	if(Allow_Identifier_In_Call)
	{
		EXPECT_ONE
			CASE(LEFT_PAREN_TOKEN)
				Identifier_In_Call = false;
				return true;
			END_CASE
		END_EXPECT

		UNGET

		Identifier_In_Call = true;
		return false;
	}
	else
	{
		GET(LEFT_PAREN_TOKEN)
	}

	return true;
}

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
*   NOTE: Function Parse_RValue in parse.cpp depends on this function to be
*   able to only use Token.Data of the current token in order to have a kind
*   of two token look-ahead in Parse_RValue! [trf]
*
* CHANGES
*
******************************************************************************/

DBL Parse_Function_Call()
{
	FUNCTION_PTR funct = (FUNCTION_PTR )Token.Data;
	FunctionCode *f = POVFPU_GetFunction(*funct);
	unsigned int pmax = f->parameter_cnt - 1;
	unsigned int param = 0;
	DBL params[MAX_PARAMETER_LIST];

	if(Parse_Call() == false)
		return 0.0;

	// first store results in local array so recursive calls to
	// this function do not overwrite the global function stack
	// accessed by POVFPU_SetLocal [trf]
	for(param = 0; param < pmax; param++)
	{
		params[param] = Parse_Float();
		Parse_Comma();
	}
	params[param] = Parse_Float();

	GET (RIGHT_PAREN_TOKEN);

	for(param = 0; param < f->parameter_cnt; param++)
		POVFPU_SetLocal(param, params[param]);

	return POVFPU_Run(*funct);
}

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
*   NOTE: Function Parse_RValue in parse.cpp depends on this function to be
*   able to only use Token.Data of the current token in order to have a kind
*   of two token look-ahead in Parse_RValue! [trf]
*
* CHANGES
*
******************************************************************************/

void Parse_Vector_Function_Call(EXPRESS Express, int *Terms)
{
	FUNCTION_PTR funct = (FUNCTION_PTR )Token.Data;
	FunctionCode *f = POVFPU_GetFunction(*funct);
	unsigned int pmax = f->parameter_cnt - 1;
	unsigned int param = 0;
	DBL params[MAX_PARAMETER_LIST];

	if(Parse_Call() == false)
		return;

	// first store results in local array so recursive calls to
	// this function do not overwrite the global function stack
	// accessed by POVFPU_SetLocal [trf]
	for(param = 0; param < pmax; param++)
	{
		params[param] = Parse_Float();
		Parse_Comma();
	}
	params[param] = Parse_Float();

	GET (RIGHT_PAREN_TOKEN);

	for(param = 0; param < f->parameter_cnt; param++)
		POVFPU_SetLocal(param + f->return_size, params[param]);

	(void)POVFPU_Run(*funct);

	for(param = 0; param < f->return_size; param++)
		Express[param] = POVFPU_GetLocal(param);

	*Terms = f->return_size;
}

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
*   NOTE: Function Parse_RValue in parse.cpp depends on this function to be
*   able to only use Token.Data of the current token in order to have a kind
*   of two token look-ahead in Parse_RValue! [trf]
*
* CHANGES
*
******************************************************************************/

void Parse_Spline_Call(EXPRESS Express, int *Terms)
{
	SPLINE *spline = (SPLINE*)(Token.Data);
	DBL Val;

	if(Parse_Call() == false)
		return;

	Val=Parse_Float();
	Get_Token();

	if(Token.Token_Id == COMMA_TOKEN)
	{
		/*If there is a second parameter, make a copy of the spline
		with a new type and evaluate that.*/
		spline = Copy_Spline(spline);
		Get_Token();
		switch(Token.Token_Id)
		{
			case LINEAR_SPLINE_TOKEN:
				spline->Type = LINEAR_SPLINE;
				break;
			case QUADRATIC_SPLINE_TOKEN:
				spline->Type = QUADRATIC_SPLINE;
				break;
			case CUBIC_SPLINE_TOKEN:
				spline->Type = CATMULL_ROM_SPLINE;
				break;
			case NATURAL_SPLINE_TOKEN:
				spline->Type = NATURAL_SPLINE;
				break;
			default:
				Error("linear_spline, quadratic_spline, natural_spline, or cubic_spline expected.");
				break;
		}

		GET(RIGHT_PAREN_TOKEN);
		Get_Spline_Val(spline, Val, Express, Terms);
		Destroy_Spline(spline);
		spline = NULL;
	}
	else
	{
		UNGET
		GET(RIGHT_PAREN_TOKEN);
		Get_Spline_Val(spline, Val, Express, Terms);
	}
}

/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_Num_Factor (EXPRESS Express,int *Terms)
{
  int i = 0;
  DBL Val,Val2;
  VECTOR Vect,Vect2,Vect3;
  OBJECT *Object;  
  TRANSFORM Trans;
  TURB Turb;
  UCS2 *Local_String, *Local_String2;
  char *Local_C_String;
  IStream *f;
  POV_ARRAY *a;
  int Old_Ok=Ok_To_Declare;
  DBL greater_val, less_val, equal_val ;

  Ok_To_Declare=true;

  EXPECT
    CASE (FLOAT_FUNCT_TOKEN)
       /* All of these functions return a DBL result */
       switch(Token.Function_Id)
         {
          case ABS_TOKEN:
            Val = Parse_Float_Param();
            Val = fabs(Val);
            break;

          case ACOS_TOKEN:
            Val = Parse_Float_Param();
            if ( Val > 1.0 )
            {
              Warning(0,"Domain error in acos.");
              Val = 1.0;
            }
            else if (Val < -1.0)
            {
              Warning(0,"Domain error in acos.");
              Val = -1.0;
            }
            Val = acos(Val);
            break;

          case VAL_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Local_C_String=Parse_C_String();
            Val = atof(Local_C_String);
            POV_FREE(Local_C_String);
            GET (RIGHT_PAREN_TOKEN);
            break;

          case ASC_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Local_String=Parse_String();
            Val = (DBL)Local_String[0];
            POV_FREE(Local_String);
            GET (RIGHT_PAREN_TOKEN);
            break;

          case ASIN_TOKEN:
            Val = Parse_Float_Param();
            if ( Val > 1.0 )
            {
              Warning(0,"Domain error in asin.");
              Val = 1.0;
            }
            else if (Val < -1.0)
            {
              Warning(0,"Domain error in asin.");
              Val = -1.0;
            }
            Val = asin(Val);
            break;

          case ATAN_TOKEN:
            Val = atan(Parse_Float_Param());
            break;

          case ATAN2_TOKEN:
            Parse_Float_Param2(&Val,&Val2);
            if (ftrue(Val) || ftrue(Val2))
               Val = atan2(Val,Val2);
            else
               Error("Domain error in atan2!");
            break;

          case COSH_TOKEN:
               Val = cosh(Parse_Float_Param());
               break;
          case SINH_TOKEN:
               Val = sinh(Parse_Float_Param());
               break;
          case TANH_TOKEN:
               Val = tanh(Parse_Float_Param());
               break;
          case ACOSH_TOKEN:
               Val = acosh(Parse_Float_Param());
               break;
          case ASINH_TOKEN:
               Val = asinh(Parse_Float_Param());
               break;
          case ATANH_TOKEN:
               Val = atanh(Parse_Float_Param());
               break;
          case CEIL_TOKEN:
            Val = ceil(Parse_Float_Param());
            break;

          case CLOCK_TOKEN:
            Val = opts.FrameSeq.Clock_Value;
            break;

           case CLOCK_ON_TOKEN:
             Val=(DBL) ( opts.FrameSeq.FrameType == FT_MULTIPLE_FRAME );
           break;

          case COS_TOKEN:
            Val = cos(Parse_Float_Param());
            break;

          case DEFINED_TOKEN:
            Val = Parse_Ifdef_Param();
            break;

          case DEGREES_TOKEN:
            Val = Parse_Float_Param()/M_PI_180;
            break;

          case DIV_TOKEN:
            Parse_Float_Param2(&Val,&Val2);
            Val=(DBL) ( (int)(Val/Val2) );
            break;

          case EXP_TOKEN:
            Val = exp(Parse_Float_Param());
            break;

          case FILE_EXISTS_TOKEN:
            GET (LEFT_PAREN_TOKEN);

            Local_C_String=Parse_C_String();
 
            Val = ((f=Locate_File(Local_C_String,POV_File_Text_User,NULL,false))==NULL) ? 0.0 : 1.0;
            if (f != NULL)
               delete f;

            POV_FREE(Local_C_String);

            GET (RIGHT_PAREN_TOKEN);
            break;

          case FLOAT_ID_TOKEN:
            Val = *((DBL *) Token.Data);
            break;

          case FLOAT_TOKEN:
            Val = Token.Token_Float;
            break;

          case FLOOR_TOKEN:
            Val = floor(Parse_Float_Param());
            break;

          case FINALCLOCK_TOKEN:
            Val = opts.FrameSeq.FinalClock;
            break;

          case FINALFRAME_TOKEN:
            Val = opts.FrameSeq.FinalFrame;
            break;
   
          case FRAMENUMBER_TOKEN:
            Val = opts.FrameSeq.FrameNumber;
            break;

          case IMAGE_WIDTH_TOKEN:
            Val = Frame.Screen_Width;
            break;

          case IMAGE_HEIGHT_TOKEN:
            Val = Frame.Screen_Height;
            break;

          case INITIALFRAME_TOKEN:
            Val = opts.FrameSeq.InitialFrame;
            break;

          case INITIALCLOCK_TOKEN:
            Val = opts.FrameSeq.InitialClock;
            break;

          case INT_TOKEN:
            Val = (DBL) ((int) Parse_Float_Param());
            break;

          case INSIDE_TOKEN:
            Val = (DBL) Parse_Inside();
            break;

          case LN_TOKEN:
            Val = Parse_Float_Param();
            if (Val<=0.0)
              Error("ln of negative number %lf",Val);
            else
              Val = log(Val);
            break;

          case LOG_TOKEN:
            Val = Parse_Float_Param();
            if (Val<=0.0)
              Error("log of negative number %lf",Val);
            else
              Val = log10(Val);
            break;

          case MAX_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Val = Parse_Float();
            EXPECT
              CASE(COMMA_TOKEN)
                Val2 = Parse_Float();
                Val = max(Val,Val2);
              END_CASE

              OTHERWISE
                UNGET
                GET (RIGHT_PAREN_TOKEN);
                EXIT
              END_CASE
            END_EXPECT
            break;

          case MIN_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Val = Parse_Float();
            EXPECT
              CASE(COMMA_TOKEN)
                Val2 = Parse_Float();
                Val = min(Val,Val2);
              END_CASE

              OTHERWISE
                UNGET
                GET (RIGHT_PAREN_TOKEN);
                EXIT
              END_CASE
            END_EXPECT
            break;

          case SELECT_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Val = Parse_Float();
            Parse_Comma();
            less_val = Parse_Float();
            Parse_Comma();
            equal_val = Parse_Float();
            EXPECT
              CASE(COMMA_TOKEN)
                greater_val = Parse_Float();
                GET (RIGHT_PAREN_TOKEN);
                if(Val < 0.0)
                  Val = less_val;
                else if(Val == 0.0)
                  Val = equal_val;
                else
                  Val = greater_val;
               EXIT
              END_CASE

              OTHERWISE
                UNGET
                GET (RIGHT_PAREN_TOKEN);
                if(Val < 0.0)
                  Val = less_val;
                else
                  Val = equal_val;
                EXIT
              END_CASE
            END_EXPECT
            break;

          case MOD_TOKEN:
            Parse_Float_Param2(&Val,&Val2);
            Val = fmod(Val,Val2);
            break;

          case PI_TOKEN:
            Val = M_PI;
            break;

          case SQR_TOKEN:
            Val = Parse_Float_Param();
            Val = (Val*Val);
            break;

          case POW_TOKEN:
            Parse_Float_Param2(&Val,&Val2);
            if((Val == 0.0) && (Val2 == 0.0))
               Error("Domain error.");
            Val=pow(Val,Val2);
            break;

          case RADIANS_TOKEN:
            Val = Parse_Float_Param()*M_PI_180;
            break;

          case SIN_TOKEN:
            Val = sin(Parse_Float_Param());
            break;

          case SQRT_TOKEN:
            Val = Parse_Float_Param();
            if (Val<0.0)
              Error("sqrt of negative number %lf",Val);
            else
              Val = sqrt(Val);
            break;

          case STRCMP_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Local_String=Parse_String();
            Parse_Comma();
            Local_String2=Parse_String();
            Val = (DBL)UCS2_strcmp(Local_String, Local_String2);
            POV_FREE(Local_String);
            POV_FREE(Local_String2);
            GET (RIGHT_PAREN_TOKEN);
            break;

          case STRLEN_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Local_String=Parse_String();
            Val = (DBL)UCS2_strlen(Local_String);
            POV_FREE(Local_String);
            GET (RIGHT_PAREN_TOKEN);
            break;

          case TAN_TOKEN:
            Val = tan(Parse_Float_Param());
            break;

          case VDOT_TOKEN:
            Parse_Vector_Param2(Vect,Vect2);
            VDot(Val,Vect,Vect2);
            break;

          case VLENGTH_TOKEN:
            Parse_Vector_Param(Vect);
            VLength(Val,Vect);
            break;

          case VERSION_TOKEN:
            Val = opts.Language_Version / 100.0;
            break;

          case TRUE_TOKEN:
          case YES_TOKEN:
          case ON_TOKEN:
            Val = 1.0;
            break;

          case FALSE_TOKEN:
          case NO_TOKEN:
          case OFF_TOKEN:
            Val = 0.0;
            break;

          case SEED_TOKEN:
            Val = stream_seed((int)Parse_Float_Param());
            break;

          case RAND_TOKEN:
            i = (int)Parse_Float_Param();
            if ((i < 0) || (i >= Number_Of_Random_Generators))
              Error("Illegal random number generator.");
            Val = stream_rand(i);
            break;

          case CLOCK_DELTA_TOKEN:
            Val = Clock_Delta;
            break;

          case DIMENSIONS_TOKEN:
            GET(LEFT_PAREN_TOKEN)
            GET(ARRAY_ID_TOKEN)
            a = (POV_ARRAY *)(*(Token.DataPtr));
            Val = a->Dims+1;
            GET(RIGHT_PAREN_TOKEN)
            break;

          case DIMENSION_SIZE_TOKEN:
            GET(LEFT_PAREN_TOKEN)
            GET(ARRAY_ID_TOKEN)
            Parse_Comma();
            a = (POV_ARRAY *)(*(Token.DataPtr));
            i = (int)Parse_Float()-1.0;
            if ((i < 0) || (i > a->Dims))
              Val = 0.0;
            else
              Val = a->Sizes[i];
            GET(RIGHT_PAREN_TOKEN)
            break;
         }
       for (i=0; i < *Terms; i++)
         Express[i]=Val;
       EXIT
     END_CASE

     CASE (VECTOR_FUNCT_TOKEN)
       /* All of these functions return a VECTOR result */
       switch(Token.Function_Id)
         {
          case VAXIS_ROTATE_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Parse_Vector(Vect2);
            Parse_Comma();
            Parse_Vector(Vect3);
            Parse_Comma();
            Val=Parse_Float()*M_PI_180;
            GET (RIGHT_PAREN_TOKEN);
            Compute_Axis_Rotation_Transform(&Trans,Vect3,Val);
            MTransPoint(Vect, Vect2, &Trans);
            break;

          case VCROSS_TOKEN:
            Parse_Vector_Param2(Vect2,Vect3);
            VCross(Vect,Vect2,Vect3);
            break;

          case VECTOR_ID_TOKEN:
            Assign_Vector(Vect, (DBL *)Token.Data);
            break;

          case VNORMALIZE_TOKEN:
            Parse_Vector_Param(Vect2);
            if((Vect2[X] == 0.0) && (Vect2[Y] == 0.0) && (Vect2[Z] == 0.0))
            {
              if (opts.Language_Version >= 350)
                PossibleError("Normalizing zero-length vector.");
              Vect[X] = Vect[Y] = Vect[Z] = 0.0 ;
            }
            else
              VNormalize(Vect,Vect2);
            break;

          case VROTATE_TOKEN:
            Parse_Vector_Param2(Vect2,Vect3);
            Compute_Rotation_Transform (&Trans, Vect3);
            MTransPoint(Vect, Vect2, &Trans);
            break;

          case VTURBULENCE_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            Turb.Lambda = Parse_Float();
            Parse_Comma();
            Turb.Omega = Parse_Float();
            Parse_Comma();
            Turb.Octaves = (int)Parse_Float();
            if(Turb.Octaves < 1)
               Turb.Octaves = 1;
            if(Turb.Octaves > 10) // avoid domain errors
               Turb.Octaves = 10;
            Parse_Comma();
            Parse_Vector(Vect2); // input vector
            Parse_Comma();
            GET (RIGHT_PAREN_TOKEN);
            DTurbulence(Vect, Vect2, &Turb);
            break;

          case X_TOKEN:
            Make_Vector(Vect,1.0,0.0,0.0);
            break;

          case Y_TOKEN:
            Make_Vector(Vect,0.0,1.0,0.0);
            break;

          case Z_TOKEN:
            Make_Vector(Vect,0.0,0.0,1.0);
            break;
            
          case TRACE_TOKEN:
            Parse_Trace( Vect );
            break;

          case MIN_EXTENT_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            EXPECT
              CASE (OBJECT_ID_TOKEN)
                Object = (OBJECT *)Token.Data;
                if ( Object ) 
                {
                  Vect[X]=Object->BBox.Lower_Left[X];
                  Vect[Y]=Object->BBox.Lower_Left[Y];
                  Vect[Z]=Object->BBox.Lower_Left[Z];
                }
                EXIT
              END_CASE

              OTHERWISE
                Object = NULL;
                Make_Vector(Vect,0.0,0.0,0.0);
                UNGET
                EXIT
              END_CASE
            END_EXPECT

            GET (RIGHT_PAREN_TOKEN);
            break;
 
          case MAX_EXTENT_TOKEN:
            GET (LEFT_PAREN_TOKEN);
            EXPECT
              CASE (OBJECT_ID_TOKEN)
                Object = (OBJECT *)Token.Data;
                if ( Object ) 
                {
                   Vect[X]=Object->BBox.Lower_Left[X]+Object->BBox.Lengths[X];
                   Vect[Y]=Object->BBox.Lower_Left[Y]+Object->BBox.Lengths[Y];
                   Vect[Z]=Object->BBox.Lower_Left[Z]+Object->BBox.Lengths[Z];
                }
                EXIT
              END_CASE
                 
              OTHERWISE
                Object = NULL;
                Make_Vector(Vect,0.0,0.0,0.0);
                UNGET
                EXIT
              END_CASE
            END_EXPECT
            GET (RIGHT_PAREN_TOKEN);
            break;
        }
 

      /* If it was expecting a DBL, promote it to a VECTOR.
          I haven't yet figured out what to do if it was expecting
          a COLOUR value with Terms>3
       */
       if(*Terms < 3)
         *Terms = 3;

       for(i = 0; i < 3; i++)
         Express[i] = Vect[i];
       EXIT
     END_CASE

     CASE (FUNCT_ID_TOKEN)
       Val = Parse_Function_Call();
       for(i = 0; i < *Terms; i++)
         Express[i] = Val;
       EXIT
     END_CASE

     CASE (VECTFUNCT_ID_TOKEN)
       *Terms = 5; // will be adjusted by Parse_Vector_Function_Call
       for(i = 0; i < *Terms; i++)
         Express[i] = 0.0;
       Parse_Vector_Function_Call(Express, Terms);
       EXIT
     END_CASE

     CASE (SPLINE_ID_TOKEN)
       *Terms = 5; // will be adjusted by Parse_Spline_Call
       for(i = 0; i < *Terms; i++)
         Express[i] = 0.0;
       Parse_Spline_Call(Express, Terms);
       EXIT
     END_CASE

     CASE (COLOUR_ID_TOKEN)
       *Terms=5;
       for (i=0; i<5; i++)
         Express[i]=(DBL)(  ((COLC *)(Token.Data))[i]  );
       EXIT
     END_CASE

     CASE (UV_ID_TOKEN)
       *Terms=2;
       for (i=0; i<2; i++)
         Express[i]=(DBL)(  ((DBL *)(Token.Data))[i]  );
       EXIT
     END_CASE

     CASE (VECTOR_4D_ID_TOKEN)
       *Terms=4;
       for (i=0; i<4; i++)
         Express[i]=(DBL)(  ((DBL *)(Token.Data))[i]  );
       EXIT
     END_CASE

     CASE (T_TOKEN)
       *Terms=4;
       Express[0]=0.0;
       Express[1]=0.0;
       Express[2]=0.0;
       Express[3]=1.0;
       EXIT
     END_CASE

     CASE (U_TOKEN)
       *Terms=2;
       Express[0]=1.0;
       Express[1]=0.0;
       EXIT
     END_CASE

     CASE (V_TOKEN)
       *Terms=2;
       Express[0]=0.0;
       Express[1]=1.0;
       EXIT
     END_CASE

     CASE (PLUS_TOKEN)
     END_CASE

     CASE (DASH_TOKEN)
       Ok_To_Declare=Old_Ok;
       Parse_Num_Factor(Express,Terms);
       Old_Ok=Ok_To_Declare;
       Ok_To_Declare=true;
       for (i=0; i<*Terms; i++)
         Express[i]=-Express[i];
       EXIT
     END_CASE

     CASE (EXCLAMATION_TOKEN)
       Ok_To_Declare=Old_Ok;
       Parse_Num_Factor(Express,Terms);
       Old_Ok=Ok_To_Declare;
       Ok_To_Declare=true;
       for (i=0; i<*Terms; i++)
         Express[i] = ftrue(Express[i])?0.0:1.0;
       EXIT
     END_CASE

     CASE (LEFT_PAREN_TOKEN)
       Parse_Express(Express,Terms);
       GET(RIGHT_PAREN_TOKEN);
       EXIT
     END_CASE

/* This case parses a 2, 3, 4, or 5 term vector.  First parse 2 terms.
   Note Parse_Comma won't crash if it doesn't find one.
 */

     CASE (LEFT_ANGLE_TOKEN)
       Express[X] = Parse_Float();   Parse_Comma();
       Express[Y] = Parse_Float();   Parse_Comma();
       *Terms=2;

       EXPECT
         CASE_EXPRESS
           /* If a 3th float is found, parse it. */
           Express[2] = Parse_Float(); Parse_Comma();
           *Terms=3;
           EXPECT
             CASE_EXPRESS
               /* If a 4th float is found, parse it. */
               Express[3] = Parse_Float(); Parse_Comma();
               *Terms=4;
               EXPECT
                 CASE_EXPRESS
                   /* If a 5th float is found, parse it. */
                   Express[4] = Parse_Float();
                   *Terms=5;
                 END_CASE

                 OTHERWISE
                   /* Only 4 found. */
                   UNGET
                   GET (RIGHT_ANGLE_TOKEN)
                   EXIT
                 END_CASE
               END_EXPECT
               EXIT
             END_CASE

             OTHERWISE
               /* Only 3 found. */
               UNGET
               GET (RIGHT_ANGLE_TOKEN)
               EXIT
             END_CASE
           END_EXPECT
           EXIT
         END_CASE

         OTHERWISE
           /* Only 2 found. */
           UNGET
           GET (RIGHT_ANGLE_TOKEN)
           EXIT
         END_CASE
       END_EXPECT
       EXIT
     END_CASE

     OTHERWISE
       Expectation_Error ("numeric expression");
     END_CASE
   END_EXPECT
   
   Ok_To_Declare=Old_Ok;

   /* Parse VECTOR.x or COLOR.red type things */
   EXPECT
     CASE(PERIOD_TOKEN)
       EXPECT
         CASE (VECTOR_FUNCT_TOKEN)
           switch(Token.Function_Id)
           {
             case X_TOKEN:
               i=X;
               break;

             case Y_TOKEN:
               i=Y;
               break;

             case Z_TOKEN:
               i=Z;
               break;
               
             default:
               Expectation_Error ("x, y, or z");
           }
           EXIT
         END_CASE

         CASE (COLOUR_KEY_TOKEN)
           switch(Token.Function_Id)
           {
             case RED_TOKEN:
               i=pRED;
               break;
               
             case GREEN_TOKEN:
               i=pGREEN;
               break;

             case BLUE_TOKEN:
               i=pBLUE;
               break;

             case FILTER_TOKEN:
               i=pFILTER;
               break;
               
             case TRANSMIT_TOKEN:
               i=pTRANSM;
               break;
               
             case GRAY_TOKEN:
               *Terms=1;
               Express[0]=GREY_SCALE(Express);
               return;
               
             default:
               Expectation_Error ("red, green, blue, filter, or transmit");
           }
           EXIT
         END_CASE

         CASE(U_TOKEN)
           i=U;
           EXIT
         END_CASE

         CASE(V_TOKEN)
           i=V;
           EXIT
         END_CASE

         CASE(T_TOKEN)
           i=T;
           EXIT
         END_CASE

         OTHERWISE
           Expectation_Error ("x, y, z or color component");
         END_CASE
       END_EXPECT

       if (i>=*Terms)
          Error("Bad operands for period operator.");
       *Terms=1;
       Express[0]=Express[i];
       EXIT
     END_CASE
     
     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT
  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

/* If first operand of a 2-operand function had more terms than the second,
   then the parsing of the 2nd operand would have automatically promoted it.
   But if 2nd operand has more terms then we must go back promote the 1st
   operand before combining them  Promote_Express does it.  If Old_Terms=1
   then set all terms to Express[0].  Otherwise pad extra terms with 0.0.
*/

static void Promote_Express(EXPRESS Express,int *Old_Terms,int New_Terms)
{
   register int i;

   if (*Old_Terms >= New_Terms)
     return;

   if (*Old_Terms==1)
   {
     for(i=1;i<New_Terms;i++)
     {
        Express[i]=Express[0];
     }
   }
   else
   {
     for(i=(*Old_Terms);i<New_Terms;i++)
     {
        Express[i]=0.0;
     }
   }

   *Old_Terms=New_Terms;
  }




/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
*    2000 : NK promotion bugfix
*
******************************************************************************/

static void Parse_Num_Term (EXPRESS Express,int *Terms)
{
   register int i;
   EXPRESS Local_Express;
   int Local_Terms;

   Parse_Num_Factor(Express,Terms);

   Local_Terms=*Terms;

   EXPECT
     CASE (STAR_TOKEN)
       Parse_Num_Factor(Local_Express,&Local_Terms);
       if (Local_Terms>*Terms)
         Promote_Express(Express,Terms,Local_Terms);
       else
         Promote_Express(Local_Express,&Local_Terms,*Terms);

       for(i=0;i<*Terms;i++)
         Express[i] *= Local_Express[i];
     END_CASE

     CASE (SLASH_TOKEN)
       Parse_Num_Factor(Local_Express,&Local_Terms);
       if (Local_Terms>*Terms)
         Promote_Express(Express,Terms,Local_Terms);
       else
         Promote_Express(Local_Express,&Local_Terms,*Terms);

       for(i=0;i<*Terms;i++)
       {
         if (Local_Express[i]==0.0) /* must be 0.0, not EPSILON */
         {
           Express[i]=HUGE_VAL;
           Warning(0,"Divide by zero.");
         }
         else
         {
           Express[i] /= Local_Express[i];
         }
       }
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
*    2000 :  NK promotion bugfix
*
******************************************************************************/

void Parse_Rel_Factor (EXPRESS Express,int *Terms)
{
   register int i;
   EXPRESS Local_Express;
   int Local_Terms;

   Parse_Num_Term(Express,Terms);

   Local_Terms=*Terms;

   EXPECT
     CASE (PLUS_TOKEN)
       Parse_Num_Term(Local_Express,&Local_Terms);
       if (Local_Terms>*Terms)
       {
         Promote_Express(Express,Terms,Local_Terms);
       }
       else
       {
         Promote_Express(Local_Express,&Local_Terms,*Terms);
       }

       for(i=0;i<*Terms;i++)
         Express[i] += Local_Express[i];
     END_CASE

     CASE (DASH_TOKEN)
       Parse_Num_Term(Local_Express,&Local_Terms);
       if (Local_Terms>*Terms)
       {
         Promote_Express(Express,Terms,Local_Terms);
       }
       else
       {
         Promote_Express(Local_Express,&Local_Terms,*Terms);
       }

       for(i=0;i<*Terms;i++)
         Express[i] -= Local_Express[i];
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void Parse_Rel_Term (EXPRESS Express,int *Terms)
{
   register int i;
   EXPRESS Local_Express;
   int Local_Terms;

   Parse_Rel_Factor(Express,Terms);

   Local_Terms=*Terms;

   EXPECT
     CASE (LEFT_ANGLE_TOKEN)
       Parse_Rel_Factor(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)(Express[i] < Local_Express[i]);
     END_CASE

     CASE (REL_LE_TOKEN)
       Parse_Rel_Factor(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)((Express[i] <= Local_Express[i]) || (!ftrue(Express[i]-Local_Express[i])));
     END_CASE

     CASE (EQUALS_TOKEN)
       Parse_Rel_Factor(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)(!ftrue(Express[i]-Local_Express[i]));
     END_CASE

     CASE (REL_NE_TOKEN)
       Parse_Rel_Factor(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)ftrue(Express[i]-Local_Express[i]);
     END_CASE

     CASE (REL_GE_TOKEN)
       Parse_Rel_Factor(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)((Express[i] >= Local_Express[i]) || (!ftrue(Express[i]-Local_Express[i])));
     END_CASE

     CASE (RIGHT_ANGLE_TOKEN)
       Parse_Rel_Factor(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)(Express[i] > Local_Express[i]);
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void Parse_Logical (EXPRESS Express,int *Terms)
{
   register int i;
   EXPRESS Local_Express;
   int Local_Terms;

   Parse_Rel_Term(Express,Terms);

   Local_Terms=*Terms;

   EXPECT
     CASE (AMPERSAND_TOKEN)
       Parse_Rel_Term(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)(ftrue(Express[i]) && ftrue(Local_Express[i]));
     END_CASE

     CASE (BAR_TOKEN)
       Parse_Rel_Term(Local_Express,&Local_Terms);
       Promote_Express(Express,Terms,Local_Terms);

       for(i=0;i<*Terms;i++)
         Express[i] = (DBL)(ftrue(Express[i]) || ftrue(Local_Express[i]));
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void Parse_Express (EXPRESS Express,int *Terms)
{
   EXPRESS Local_Express1, Local_Express2;
   EXPRESS *Chosen;
   int Local_Terms1, Local_Terms2;

   Local_Terms1 = 1;

   Parse_Logical(Express,&Local_Terms1);

   EXPECT
     CASE (QUESTION_TOKEN)
       if (Local_Terms1 != 1)
         Error("Conditional must evaluate to a float.");
       Local_Terms1 = Local_Terms2 = *Terms;
       Parse_Express(Local_Express1,&Local_Terms1);
       GET(COLON_TOKEN);
       Parse_Express(Local_Express2,&Local_Terms2);
       if (ftrue(Express[0]))
         {
          Chosen = (EXPRESS *)&Local_Express1;
          *Terms = Local_Terms1;
         }
       else
         {
          Chosen = (EXPRESS *)&Local_Express2;
          *Terms = Local_Terms2;
         }
       POV_MEMCPY(Express,Chosen,sizeof(EXPRESS));
       EXIT
     END_CASE

     OTHERWISE
       /* Not a (c)?a:b expression.  Since Express was parsed with
          Local_Terms1=1 then we may have to promote this.  Suppose
          Terms=3 but Local_Terms1=1.  If this had been a (c)?a:b
          then a float is ok but since it is not a condition then
          it must be promoted to Terms=3.  Note that the parameters
          below look wrong but they are not.
        */
       Promote_Express (Express,&Local_Terms1,*Terms);
       /* On the other hand, Local_Terms1 may be bigger than Terms.
          If so, Express already is promoted and Terms must reflect that.
        */
       *Terms=Local_Terms1;
       UNGET
       EXIT
     END_CASE
   END_EXPECT

  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

DBL Parse_Float ()
{
   EXPRESS Express;
   int Terms;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   Terms=1;

   if (opts.Language_Version < 150)
      Parse_Num_Factor(Express,&Terms);
   else
      Parse_Rel_Factor(Express,&Terms);
   
   if (Terms>1)
      Error ("Float expected but vector or color expression found.");

   Allow_Identifier_In_Call = old_allow_id;

   return (Express[0]);
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

DBL Allow_Float (DBL defval)
{
  DBL retval;

  EXPECT
    CASE_EXPRESS
      retval = Parse_Float();
      EXIT
    END_CASE

    OTHERWISE
      UNGET
      retval = defval;
      EXIT
    END_CASE
  END_EXPECT

  return (retval);
  }


/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

int Allow_Vector (VECTOR Vect)
{
  int retval;

  EXPECT
    CASE_EXPRESS
      Parse_Vector(Vect);
      retval = true;
      EXIT
    END_CASE

    OTHERWISE
      UNGET
      retval = false;
      EXIT
    END_CASE
  END_EXPECT

  return (retval);
  }

  
  
/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_Vector (VECTOR Vector)
{
   EXPRESS Express;
   int Terms;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   /* Initialize expression. [DB 12/94] */

   for (Terms = 0; Terms < 5; Terms++)
   {
     Express[Terms] = 0.0;
   }

   Terms=3;

   if (opts.Language_Version < 150)
      Parse_Num_Factor(Express,&Terms);
   else
      Parse_Rel_Factor(Express,&Terms);

   if (Terms>3)
      Error ("Vector expected but color expression found.");

   for(Terms=0;Terms<3;Terms++)
      Vector[Terms]=Express[Terms];

   Allow_Identifier_In_Call = old_allow_id;
}


/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_Vector4D (VECTOR Vector)
{
   EXPRESS Express;
   int Terms;
   int Dim = 4;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   /* Initialize expression. [DB 12/94] */

   for (Terms = 0; Terms < 5; Terms++)
   {
     Express[Terms] = 0.0;
   }

   Terms=Dim;

   if (opts.Language_Version < 150)
      Parse_Num_Factor(Express,&Terms);
   else
      Parse_Rel_Factor(Express,&Terms);

   if (Terms>Dim)
      Error ("Vector expected but color expression found.");

   for(Terms=0;Terms<Dim;Terms++)
      Vector[Terms]=Express[Terms];

   Allow_Identifier_In_Call = old_allow_id;
}




/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_UV_Vect (UV_VECT UV_Vect)
{
   EXPRESS Express;
   int Terms;
    bool old_allow_id = Allow_Identifier_In_Call;
    Allow_Identifier_In_Call = false;

   /* Initialize expression. [DB 12/94] */

   for (Terms = 0; Terms < 5; Terms++)
   {
     Express[Terms] = 0.0;
   }

   Terms=2;

   if (opts.Language_Version < 150)
      Parse_Num_Factor(Express,&Terms);
   else
      Parse_Rel_Factor(Express,&Terms);

   if (Terms>2)
      Error ("UV_Vector expected but vector or color expression found.");

   for(Terms=0;Terms<2;Terms++)
      UV_Vect[Terms]=Express[Terms];

   Allow_Identifier_In_Call = old_allow_id;
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

int Parse_Unknown_Vector(EXPRESS Express, bool allow_identifier, bool *had_identifier)
{
   int Terms;
   bool old_allow_id = Allow_Identifier_In_Call;

   Allow_Identifier_In_Call = allow_identifier;
   Identifier_In_Call = false;

   /* Initialize expression. [DB 12/94] */

   for (Terms = 0; Terms < 5; Terms++)
   {
     Express[Terms] = 0.0;
   }

   Terms=1;

   if (opts.Language_Version < 150)
      Parse_Num_Factor(Express,&Terms);
   else
      Parse_Rel_Factor(Express,&Terms);

   if(had_identifier != NULL)
      *had_identifier = Identifier_In_Call;

   Allow_Identifier_In_Call = old_allow_id;

   return(Terms);
}


/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_Scale_Vector (VECTOR Vector)
{
   Parse_Vector(Vector);

   if (Vector[X] == 0.0)
    {
     Vector[X] = 1.0;
     Warning(0, "Illegal Value: Scale X by 0.0. Changed to 1.0.");
    }
   if (Vector[Y] == 0.0)
    {
     Vector[Y] = 1.0;
     Warning(0, "Illegal Value: Scale Y by 0.0. Changed to 1.0.");
    }
   if (Vector[Z] == 0.0)
    {
     Vector[Z] = 1.0;
     Warning(0, "Illegal Value: Scale Z by 0.0. Changed to 1.0.");
    }
  }



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

void Parse_Colour (COLOUR Colour)
{
  EXPRESS Express;
  int Terms;
  register int i;
  bool old_allow_id = Allow_Identifier_In_Call;
  Allow_Identifier_In_Call = false;

  /* Initialize expression. [DB 12/94] */

  for (Terms = 0; Terms < 5; Terms++)
  {
    Express[Terms] = 0.0;
  }

  Make_ColourA (Colour, 0.0, 0.0, 0.0, 0.0, 0.0);

  bool startedParsing = false;

  ALLOW(COLOUR_TOKEN)

  EXPECT
    CASE (COLOUR_KEY_TOKEN)
      switch(Token.Function_Id)
        {
         case ALPHA_TOKEN:
           Warning(155, "Keyword ALPHA discontinued. Use FILTER instead.");
           /* missing break deliberate */

         case FILTER_TOKEN:
                   Colour[pFILTER] = (COLC)Parse_Float();
                   break;

         case BLUE_TOKEN:
                   Colour[pBLUE] = (COLC)Parse_Float();
                   break;

         case GREEN_TOKEN:
                   Colour[pGREEN] = (COLC)Parse_Float();
                   break;

         case RED_TOKEN:
                   Colour[pRED] = (COLC)Parse_Float();
                   break;

         case TRANSMIT_TOKEN:
                   Colour[pTRANSM] = (COLC)Parse_Float();
                   break;

         case RGB_TOKEN:
           if(startedParsing)
           {
             UNGET
             EXIT
           }
           else
           {
             Terms=3;
             Parse_Express(Express,&Terms);
             if (Terms != 3)
               Warning(0, "Suspicious expression after rgb.");
             for (i=0;i<Terms;i++)
               Colour[i]=(COLC)Express[i];
           }
           break;

         case RGBF_TOKEN:
           if(startedParsing)
           {
             UNGET
             EXIT
           }
           else
           {
             Terms=4;
             Parse_Express(Express,&Terms);
             if (Terms != 4)
               Warning(0, "Suspicious expression after rgbf.");
             for (i=0;i<Terms;i++)
               Colour[i]=(COLC)Express[i];
           }
           break;

         case RGBT_TOKEN:
           if(startedParsing)
           {
             UNGET
             EXIT
           }
           else
           {
             Terms=4;
             Parse_Express(Express,&Terms);
             if (Terms != 4)
               Warning(0, "Suspicious expression after rgbt.");
             for (i=0;i<Terms;i++)
               Colour[i]=(COLC)Express[i];
             Colour[pTRANSM]=Colour[pFILTER];
             Colour[pFILTER]=0.0;
           }
           break;

         case RGBFT_TOKEN:
           if(startedParsing)
           {
             UNGET
             EXIT
           }
           else
           {
             Terms=5;
             Parse_Express(Express,&Terms);
             if (Terms != 5)
               Warning(0, "Suspicious expression after rgbft.");
             for (i=0;i<Terms;i++)
               Colour[i]=(COLC)Express[i];
           }
           break;
        }
      startedParsing = true;
    END_CASE

    CASE (COLOUR_ID_TOKEN)
      UNGET
      if (startedParsing)
      { 
        EXIT
      }
      else
      {
        Terms=5;
        Parse_Express(Express,&Terms);
        for (i=0;i<Terms;i++)
          Colour[i]=(COLC)Express[i];
        startedParsing = true;
      }
    END_CASE

    CASE_VECTOR
      UNGET
      if (startedParsing) 
      {
        EXIT
      }
      else
      {
        Terms=5;
        Parse_Express(Express,&Terms);
        if (Terms != 5)
          Error("Color expression expected but float or vector expression found.");
        for (i=0;i<Terms;i++)
          Colour[i]=(COLC)Express[i];
        startedParsing = true;
      }
    END_CASE

    OTHERWISE
      UNGET
      EXIT
    END_CASE
  END_EXPECT

  Allow_Identifier_In_Call = old_allow_id;
}

/*****************************************************************************
*
* FUNCTION
*
*   Parse_Blend_Map
*
* INPUT
*
*   Type of map to parse: pigment_map, normal_map etc
*   
* OUTPUT
*   
* RETURNS
*
*   Pointer to created blend map
*   
* AUTHOR
*
*   Chris Young 11/94
*   
* DESCRIPTION   :
*
* CHANGES
*
******************************************************************************/

BLEND_MAP *Parse_Blend_Map (int Blend_Type,int Pat_Type)
{
   BLEND_MAP *New = NULL;
   BLEND_MAP_ENTRY *Temp_Ent;
   int i;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   Parse_Begin ();

   EXPECT
     CASE2 (COLOUR_MAP_ID_TOKEN, PIGMENT_MAP_ID_TOKEN)
     CASE3 (NORMAL_MAP_ID_TOKEN, TEXTURE_MAP_ID_TOKEN, SLOPE_MAP_ID_TOKEN)
       New = Copy_Blend_Map ((BLEND_MAP *) Token.Data);
       if (Blend_Type != New->Type)
       {
         Error("Wrong identifier type");
       }
       EXIT
     END_CASE

     OTHERWISE
       UNGET
       Temp_Ent = Create_BMap_Entries(MAX_BLEND_MAP_ENTRIES);
       i = 0;

       EXPECT
         CASE (LEFT_SQUARE_TOKEN)
           if (i >= MAX_BLEND_MAP_ENTRIES)
             Error ("Too many entries in map. The maximum is %d entries per map.", MAX_BLEND_MAP_ENTRIES);

           switch (Pat_Type)
           {
             case AVERAGE_PATTERN:
               Temp_Ent[i].value = Allow_Float(1.0);
               Parse_Comma();
               break;
              
             default:
               Temp_Ent[i].value = Parse_Float();
               Parse_Comma();
               break;
           }

           switch (Blend_Type)
           {
             case PIGMENT_TYPE:
               Temp_Ent[i].Vals.Pigment=Copy_Pigment(Default_Texture->Pigment);
               Parse_Pigment(&(Temp_Ent[i].Vals.Pigment));
               break;

             case NORMAL_TYPE:
               Temp_Ent[i].Vals.Tnormal=Copy_Tnormal(Default_Texture->Tnormal);
               Parse_Tnormal(&(Temp_Ent[i].Vals.Tnormal));
               break;

             case SLOPE_TYPE:
               Parse_UV_Vect(Temp_Ent[i].Vals.Point_Slope);
               break;

             case TEXTURE_TYPE:
               Temp_Ent[i].Vals.Texture=Parse_Texture();
               break;

             case DENSITY_TYPE:
               Temp_Ent[i].Vals.Pigment=NULL;
               Parse_Media_Density_Pattern (&(Temp_Ent[i].Vals.Pigment));
               break;

             default:
               Error("Type not implemented yet.");
           }
           i++;

           GET (RIGHT_SQUARE_TOKEN);
         END_CASE

         OTHERWISE
           UNGET
           if (i < 1)
             Error ("Must have at least one entry in map.");
           New = Create_Blend_Map ();
           New->Number_Of_Entries = i;
           New->Type=Blend_Type;
           New->Transparency_Flag=true; /*Temp fix.  Really set in Post_???*/
           New->Blend_Map_Entries = (BLEND_MAP_ENTRY *)POV_REALLOC(Temp_Ent,sizeof(BLEND_MAP_ENTRY)*i,"blend map entries");
           EXIT
         END_CASE
       END_EXPECT
       EXIT
     END_CASE
   END_EXPECT

   Parse_End ();

   Allow_Identifier_In_Call = old_allow_id;

   return (New);
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

BLEND_MAP *Parse_Blend_List (int Count,BLEND_MAP *Def_Map,int Blend_Type)
{
   BLEND_MAP *New;
   BLEND_MAP_ENTRY *Temp_Ent;
   int Type, i;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   i = 0;

   if(Blend_Type == PIGMENT_TYPE)
   {
     EXPECT
       CASE(PIGMENT_TOKEN)
         UNGET
         Type=PIGMENT_TYPE;
         EXIT
       END_CASE

       OTHERWISE
         UNGET
         Type=COLOUR_TYPE;
         EXIT
       END_CASE
     END_EXPECT
   }
   else
   {
     Type=Blend_Type;
   }

   Temp_Ent = Create_BMap_Entries(Count);

   switch(Type)
   {
     case COLOUR_TYPE:
       EXPECT
         CASE_EXPRESS
           Parse_Colour (Temp_Ent[i].Vals.Colour);
           Parse_Comma ();
           Temp_Ent[i].value = (SNGL)i;
           if (++i >= Count)
             EXIT
         END_CASE

         OTHERWISE
           UNGET
           EXIT
         END_CASE
       END_EXPECT
       break;

     case PIGMENT_TYPE:
       EXPECT
         CASE(PIGMENT_TOKEN)
           Parse_Begin ();
           Temp_Ent[i].Vals.Pigment=Copy_Pigment(Default_Texture->Pigment);
           Parse_Pigment(&(Temp_Ent[i].Vals.Pigment));
           Parse_End ();
           Parse_Comma ();
           Temp_Ent[i].value = (SNGL)i;
           if (++i >= Count)
             EXIT
         END_CASE

         OTHERWISE
           UNGET
           EXIT
         END_CASE
       END_EXPECT
       break;

     case NORMAL_TYPE:
       EXPECT
         CASE(TNORMAL_TOKEN)
           Parse_Begin ();
           Temp_Ent[i].Vals.Tnormal=Copy_Tnormal(Default_Texture->Tnormal);
           Parse_Tnormal(&(Temp_Ent[i].Vals.Tnormal));
           Parse_End ();
           Parse_Comma ();
           Temp_Ent[i].value = (SNGL)i;
           if (++i >= Count)
             EXIT
         END_CASE

         OTHERWISE
           UNGET
           EXIT
         END_CASE
       END_EXPECT
       break;

     case TEXTURE_TYPE:
       EXPECT
         CASE(TEXTURE_TOKEN)
           Parse_Begin ();
           Temp_Ent[i].Vals.Texture=Parse_Texture();
           Parse_End ();
           Parse_Comma ();
           Temp_Ent[i].value = (SNGL)i;
           if (++i >= Count)
             EXIT
         END_CASE

         OTHERWISE
           UNGET
           EXIT
         END_CASE
       END_EXPECT
       break;

     case DENSITY_TYPE:
       EXPECT
         CASE(DENSITY_TOKEN)
           Parse_Begin ();
           Temp_Ent[i].Vals.Pigment=NULL;
           Parse_Media_Density_Pattern (&(Temp_Ent[i].Vals.Pigment));
           Parse_End ();
           Parse_Comma ();
           Temp_Ent[i].value = (SNGL)i;
           if (++i >= Count)
             EXIT
         END_CASE

         OTHERWISE
           UNGET
           EXIT
         END_CASE
       END_EXPECT
       break;

   }
   
   if ((Type==NORMAL_TYPE) && (i==0))
   {
     POV_FREE(Temp_Ent);
     return (NULL);
   }

   while (i < Count)
   {
     switch (Type)
     {
        case COLOUR_TYPE:
          Assign_Colour(Temp_Ent[i].Vals.Colour,Def_Map->Blend_Map_Entries[i].Vals.Colour);
          break;

        case PIGMENT_TYPE:
          Temp_Ent[i].Vals.Pigment=Copy_Pigment(Default_Texture->Pigment);
          break;

        case NORMAL_TYPE:
          Temp_Ent[i].Vals.Tnormal=Copy_Tnormal(Default_Texture->Tnormal);
          break;

        case TEXTURE_TYPE:
          Temp_Ent[i].Vals.Texture=Copy_Textures(Default_Texture);
          break;

        case DENSITY_TYPE:
          Temp_Ent[i].Vals.Pigment=NULL;
          break;

     }
     Temp_Ent[i].value = (SNGL)i;
     i++;
   }

   New = Create_Blend_Map ();
   New->Number_Of_Entries = Count;
   New->Type=Type;
   New->Transparency_Flag=true; /*Temp fix.  Really set in Post_???*/
   New->Blend_Map_Entries = Temp_Ent;

   Allow_Identifier_In_Call = old_allow_id;

   return (New);
}

/*****************************************************************************
*
* FUNCTION    Parse_Item_Into_Blend_List
*
* INPUT       Blend_Type
*
* OUTPUT
*
* RETURNS     BLEND_MAP
*
* AUTHOR      Nathan Kopp and others - copied & modified from Parse_Blend_List
*
* DESCRIPTION
*
*   This performs a similar funciton to Parse_Blend_List.  It was created
*   specifically for uv mapping.  It is different from Parse_Blend_List in
*   the following ways:
*     It will parse exactly one item (normal,pigment, or texture).
*     It will NOT parse any wrapping tokens, such as "texture{...}"
*       (It is looking only for the body of the item, not the entire item.)
*     Because it always parses exactly one item, no default blend list is
*       needed.
*
* CHANGES
*
******************************************************************************/

BLEND_MAP *Parse_Item_Into_Blend_List (int Blend_Type)
{
   BLEND_MAP *New;
   BLEND_MAP_ENTRY *Temp_Ent;
   int Type;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   Type=Blend_Type;

   Temp_Ent = Create_BMap_Entries(1);
   Temp_Ent[0].value = 0.0f;

   switch(Type)
   {
     case COLOUR_TYPE:
           Parse_Colour (Temp_Ent[0].Vals.Colour);
       break;

     case PIGMENT_TYPE:
           Temp_Ent[0].Vals.Pigment=Copy_Pigment(Default_Texture->Pigment);
           Parse_Pigment(&(Temp_Ent[0].Vals.Pigment));
       break;

     case NORMAL_TYPE:
           Temp_Ent[0].Vals.Tnormal=Copy_Tnormal(Default_Texture->Tnormal);
           Parse_Tnormal(&(Temp_Ent[0].Vals.Tnormal));
       break;

     case TEXTURE_TYPE:
           Temp_Ent[0].Vals.Texture=Parse_Texture();
       break;

     case DENSITY_TYPE:
           Temp_Ent[0].Vals.Pigment=NULL;
           Parse_Media_Density_Pattern (&(Temp_Ent[0].Vals.Pigment));
       break;

   }
   
   New = Create_Blend_Map ();
   New->Number_Of_Entries = 1;
   New->Type=Type;
   New->Transparency_Flag=true; /*Temp fix.  Really set in Post_???*/
   New->Blend_Map_Entries = Temp_Ent;

   Allow_Identifier_In_Call = old_allow_id;

   return (New);
}

/*****************************************************************************
*
* FUNCTION
*
*   Parse_Colour_Map
*
* INPUT
*   
* OUTPUT
*
* RETURNS
*
*   Pointer to newly created BLEND_MAP that has colors as all
*   its entries.
*   
* AUTHOR
*
*   POV-Ray Team
*   
* DESCRIPTION   : This seperate routine parses color_maps only.  It
*                 cannot be used for pigment_maps because it accomidates
*                 the old double entry color maps from vers 1.0
*
* CHANGES
*
******************************************************************************/

BLEND_MAP *Parse_Colour_Map ()
{
   BLEND_MAP *New = NULL;
   int i,j,c,p,ii;
   EXPRESS Express;
   int Terms;
   BLEND_MAP_ENTRY *Temp_Ent;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   Parse_Begin ();

   EXPECT
     CASE (COLOUR_MAP_ID_TOKEN)
       New = Copy_Blend_Map ((BLEND_MAP *) Token.Data);
       EXIT
     END_CASE

     OTHERWISE
       UNGET
       Temp_Ent = Create_BMap_Entries(MAX_BLEND_MAP_ENTRIES);
       i = 0;
       j = 1;

       EXPECT
         CASE (LEFT_SQUARE_TOKEN)
           Temp_Ent[i].value = Parse_Float();  Parse_Comma();

           EXPECT
             /* After [ must be a float. If 2nd thing found is another
                float then this is an old style color_map.
              */
             CASE_FLOAT
               Terms=1;
               Parse_Express(Express,&Terms);
               if (Terms==1)
                 {
                  Temp_Ent[j].value = Express[0];
                  Parse_Colour (Temp_Ent[i].Vals.Colour);

                  GET (COLOUR_TOKEN);
                  Parse_Colour (Temp_Ent[j].Vals.Colour);
                  i += 2;
                  j += 2;
                 }
               else
                 if (Terms==5)
                   {
                    for (ii=0;ii<5;ii++)
                      Temp_Ent[i].Vals.Colour[ii]=(COLC)Express[ii];
                    i++;
                    j++;
                   }
                 else
                   Error("Illegal expression syntax in color_map.");
               EXIT
             END_CASE

             CASE_COLOUR
               Parse_Colour (Temp_Ent[i].Vals.Colour);
               i++;
               j++;
               EXIT
             END_CASE

             OTHERWISE
               Expectation_Error("color");
               UNGET
               EXIT
             END_CASE

           END_EXPECT

           if (j > MAX_BLEND_MAP_ENTRIES)
             Error ("Blend_Map too long.");

           GET (RIGHT_SQUARE_TOKEN);
         END_CASE

         OTHERWISE
           UNGET
           if (i < 1)
             Error ("Must have at least one color in color map.");

           /* Eliminate duplicates */
           for (c = 1, p = 0; c<i; c++)
             {
              if (memcmp(&(Temp_Ent[p]),
                         &(Temp_Ent[c]),sizeof(BLEND_MAP_ENTRY)) == 0)
                p--;

              Temp_Ent[++p] = Temp_Ent[c];
             }
           p++;
           New = Create_Blend_Map ();
           New->Number_Of_Entries = p;
           New->Type=COLOUR_TYPE;
           New->Transparency_Flag=true; /*Temp fix.  Really set in Post_???*/
           New->Blend_Map_Entries = (BLEND_MAP_ENTRY *)POV_REALLOC(Temp_Ent,sizeof(BLEND_MAP_ENTRY)*p,"blend map entries");
           EXIT
         END_CASE
       END_EXPECT
       EXIT
     END_CASE
   END_EXPECT

   Parse_End ();

   Allow_Identifier_In_Call = old_allow_id;

   return (New);
}


/*****************************************************************************
*
* FUNCTION
*
*   Parse_Spline
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
*   Pointer to newly created SPLINE
*
* AUTHOR
*
*   Wolfgang Ortmann
*
* DESCRIPTION   : This seperate routine parses pure splines only. Splines in
*   lathe objects and SOR are similar but not identical
*
* CHANGES
*   Chris Huff Nov 2000 : Added the ability to use one spline as the basis for
*        another
*   Mark Wagner Nov 2000 : Modified to work with the dynamic-allocation version
*        of splines.c
*
******************************************************************************/

SPLINE * Parse_Spline()
{
   SPLINE * New = NULL;
   int i = 0;
   int Type = LINEAR_SPLINE;
   EXPRESS Express;
   int Terms, MaxTerms;
   DBL par;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   MaxTerms = 2;

   /*Check for spline identifier*/
   EXPECT
     CASE(SPLINE_ID_TOKEN)
       New = Copy_Spline((SPLINE *)Token.Data);
       i = New->Number_Of_Entries;
       MaxTerms = New->Terms;
       Type = New->Type;
       EXIT
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

   /* Determine kind of spline */
   EXPECT
     CASE(LINEAR_SPLINE_TOKEN)
       Type = LINEAR_SPLINE;
     END_CASE

     CASE(QUADRATIC_SPLINE_TOKEN)
       Type = QUADRATIC_SPLINE;
     END_CASE

     CASE(CUBIC_SPLINE_TOKEN)
       Type = CATMULL_ROM_SPLINE;
     END_CASE

     CASE(NATURAL_SPLINE_TOKEN)
       Type = NATURAL_SPLINE;
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

   if(New == NULL)
     New = Create_Spline(Type);
   else
     New->Type = Type;

   EXPECT
     CASE_FLOAT
       /* Entry has the form float,vector */
       par = Parse_Float();
       Parse_Comma();

       Terms = 2;
       Parse_Express(Express, &Terms);
       if(Terms > 5)
           Error("Too many components in vector!\n");
       MaxTerms = max(MaxTerms, Terms);
       Parse_Comma();
       /* MWW 2000 -- Changed call for dynamic allocation version */
       Insert_Spline_Entry(New, par, Express);
       i++;
     END_CASE

     OTHERWISE
       UNGET
       EXIT
     END_CASE
   END_EXPECT

   if(i < 1)
       Error("Spline must have at least one entry.");

   New->Terms = MaxTerms; // keep number of supplied terms

   Allow_Identifier_In_Call = old_allow_id;

   return New;
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void POV_strupr(char *s)
{
  int i,len;

  for (i = 0,len = strlen(s); i < len; i++)
  {
    s[i] = (char)toupper((int)s[i]);
  }
}



/*****************************************************************************
*
* FUNCTION
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
* DESCRIPTION
*
* CHANGES
*
******************************************************************************/

static void POV_strlwr(char *s)
{
  int i,len;

  for (i = 0,len = strlen(s); i < len; i++)
  {
    s[i] = (char)tolower((int)s[i]);
  }
}


/*****************************************************************************
*
* FUNCTION
*
*   stream_rand
*
* INPUT
*
*   stream - number of random stream
*
* OUTPUT
*
* RETURNS
*
*   DBL - random value
*
* AUTHOR
*
*   Dieter Bayer
*
* DESCRIPTION
*
*   Standard pseudo-random function.
*
* CHANGES
*
*   Feb 1996 : Creation.
*   Mar 1996 : Return 2^32 random values instead of 2^16 [AED]
*
******************************************************************************/

static DBL stream_rand(int stream)
{
  next_rand[stream] = next_rand[stream] * 1812433253L + 12345L;

  return((DBL)(next_rand[stream] & 0xFFFFFFFFUL) / 0xFFFFFFFFUL);
}



/*****************************************************************************
*
* FUNCTION
*
*   stream_seed
*
* INPUT
*
*   seed - Pseudo-random generator start value
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
*   Dieter Bayer
*
* DESCRIPTION
*
*   Set start value for pseudo-random generator.
*
* CHANGES
*
*   Feb 1996 : Creation.
*
******************************************************************************/

static int stream_seed(int seed)
{
  next_rand = (unsigned int *)POV_REALLOC(next_rand, (Number_Of_Random_Generators+1)*sizeof(unsigned int), "random number generator");

  next_rand[Number_Of_Random_Generators] = (unsigned int)seed;

  Number_Of_Random_Generators++;

  return (Number_Of_Random_Generators-1);
}



/*****************************************************************************
*
* FUNCTION
*
*   Init_Random_Generators
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
*   Dieter Bayer
*
* DESCRIPTION
*
* CHANGES
*
*   Feb 1996 : Creation.
*
******************************************************************************/

void Init_Random_Generators()
{
  Number_Of_Random_Generators = 0;

  next_rand = NULL;
}



/*****************************************************************************
*
* FUNCTION
*
*   Destroy_Random_Generators
*
* INPUT
*
* OUTPUT
*
* RETURNS
*
* AUTHOR
*
*   Dieter Bayer
*
* DESCRIPTION
*
* CHANGES
*
*   Feb 1996 : Creation.
*
******************************************************************************/

void Destroy_Random_Generators()
{
  if (next_rand != NULL)
  {
    POV_FREE(next_rand);
  }

  next_rand = NULL;

  Number_Of_Random_Generators = 0;
}

DBL Parse_Signed_Float(void)
{
   DBL Sign=1.0;
   DBL Val=0.0;
   bool old_allow_id = Allow_Identifier_In_Call;
   Allow_Identifier_In_Call = false;

   EXPECT
     CASE (PLUS_TOKEN)
     END_CASE
     
     CASE (DASH_TOKEN) 
        Sign=-1.0;
        Get_Token();  
        /* Deliberate fall through with no END_CASE */
     CASE (FLOAT_FUNCT_TOKEN)
       if (Token.Function_Id==FLOAT_TOKEN)
       {
          Val = Sign * Token.Token_Float;
          EXIT
       }
       else
       {
          Parse_Error(FLOAT_TOKEN);
       }
     END_CASE
     
     OTHERWISE
       Parse_Error(FLOAT_TOKEN);
     END_CASE
   END_EXPECT
 
   Allow_Identifier_In_Call = old_allow_id;

   return(Val);
}

END_POV_NAMESPACE
