COMPOSITE_PATTERN patch instructions.
-------------------------------------

Simply introduce the code between the comments, labled with MCA,
into the indicated file positions.


1) frame.h: TPATTERN_FIELDS definition

  union {                     \
   DENSITY_FILE *Density_File; \
/*-added-MCA-990525-*/        \
   PIGMENT *Density;          \
/*-------MCA--------*/        \
   IMAGE *Image;              \


2) parstxtr.c: Parse_Pattern(), in the EXPECT with all other patterns

/*-added-MCA-990525-*/
     CASE (COMPOSITE_TOKEN)
       New->Type = COMPOSITE_PATTERN;
       New->Vals.Density = Create_Pigment();
       Parse_Begin();
       Parse_Pigment ( &(New->Vals.Density) );
       Parse_End();
       Post_Pigment(New->Vals.Density);
       EXIT
     END_CASE
/*-------MCA--------*/


3) pattern.c: at top with the other #includes

/*-added-MCA-990525-*/
#include "pigment.h"
/*-------MCA--------*/


4) pattern.c: at top of Evaluate_TPat ()

  VECTOR TPoint;
/*-added-MCA-990525-*/
  COLOUR TCol;
/*-------MCA--------*/


5) pattern.c: at end of 'switch (TPat->Type)' body in Evaluate_TPat ()

/*-added-MCA-990525-*/
    case COMPOSITE_PATTERN: 
    	Compute_Pigment(TCol, TPat->Vals.Density, TPoint, Intersection);
    	value = (TCol[0]+TCol[1]+TCol[2])/3;
    	break;
/*-------MCA--------*/

	 default: Error("Problem in Evaluate_TPat.");


6) pattern.c: at end of Copy_TPat_Fields ()

  if (Old->Type == DENSITY_FILE_PATTERN)
  {
     New->Vals.Density_File = Copy_Density_File(Old->Vals.Density_File);
  }
/*-added-MCA-990525-*/
  if (Old->Type == COMPOSITE_PATTERN)
  {
     New->Vals.Density = Copy_Pigment(Old->Vals.Density);
  }
/*-------MCA--------*/
}


7) pattern.c: at end of Destroy_TPat_Fields()

  if (Tpat->Type == DENSITY_FILE_PATTERN)
  {
     Destroy_Density_File(Tpat->Vals.Density_File);
  }
/*-added-MCA-990525-*/
  if (Tpat->Type == COMPOSITE_PATTERN)
  {
     Destroy_Pigment(Tpat->Vals.Density);
  }
/*-------MCA--------*/
}


8) pattern.h: in pattern id definitions 

	- may be #defined

#define FUNCTION_PATTERN        33
#define SLOPE_PATTERN           34
#define IMAGE_PATTERN           35
/*-added-MCA-990525-*/
#define COMPOSITE_PATTERN       36
/*-------MCA--------*/

	- or as an enum

  FUNCTION_PATTERN,
  SLOPE_PATTERN,
/* NK 1998 */
  IMAGE_PATTERN,
/* NK ---- */
/*-added-MCA-990525-*/
  COMPOSITE_PATTERN     
/*-------MCA--------*/
};

	- or something else similar, depending on which
	  source you have. Put it in as the last pattern 
	  identifier.