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Gold Medal Software 1
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Gold Medal Software Volume 1 (Gold Medal) (1994).iso
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povsrc20.arj
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COLOUR.C
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1993-07-28
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/****************************************************************************
* colour.c
*
* This module implements routines to manipulate colours.
*
* from Persistence of Vision Raytracer
* Copyright 1993 Persistence of Vision Team
*---------------------------------------------------------------------------
* 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 Team. There are strict rules under
* which you are permitted to use this file. The rules are in the file
* named POVLEGAL.DOC which should be distributed with this file. If
* POVLEGAL.DOC is not available or for more info please contact the POV-Ray
* Team Coordinator by leaving a message in CompuServe's Graphics Developer's
* Forum. The latest version of POV-Ray may be found there as well.
*
* 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.
*
*****************************************************************************/
#include "frame.h"
#include "vector.h"
#include "povproto.h"
#define FABS(x) ((x) < 0.0 ? (0.0 - (x)) : (x))
COLOUR_MAP_ENTRY *Build_Entries;
COLOUR *Create_Colour ()
{
COLOUR *New;
if ((New = (COLOUR *) malloc (sizeof (COLOUR))) == NULL)
MAError ("color");
Make_Colour (New, 0.0, 0.0, 0.0);
return (New);
}
COLOUR *Copy_Colour (Old)
COLOUR *Old;
{
COLOUR *New;
if (Old != NULL)
{
New = Create_Colour ();
*New = *Old;
}
else New = NULL;
return (New);
}
COLOUR_MAP_ENTRY *Create_CMap_Entries (Map_Size)
int Map_Size;
{
COLOUR_MAP_ENTRY *New;
if ((New = (COLOUR_MAP_ENTRY *)
malloc(Map_Size * sizeof (COLOUR_MAP_ENTRY))) == NULL)
MAError ("colour map entry");
return (New);
}
COLOUR_MAP_ENTRY *Copy_CMap_Entries (Old,Map_Size)
COLOUR_MAP_ENTRY *Old;
int Map_Size;
{
COLOUR_MAP_ENTRY *New;
register int i;
if (Old != NULL)
{
New = Create_CMap_Entries (Map_Size);
for (i = 0; i < Map_Size; i++)
New[i] = Old[i];
}
else
New = NULL;
return (New);
}
COLOUR_MAP *Create_Colour_Map ()
{
COLOUR_MAP *New;
if ((New = (COLOUR_MAP *) malloc (sizeof (COLOUR_MAP))) == NULL)
MAError ("colour map");
New->Users = 0;
New->Number_Of_Entries = 0;
New->Colour_Map_Entries = NULL;
New->Transparency_Flag = FALSE;
return (New);
}
COLOUR_MAP *Copy_Colour_Map (Old)
COLOUR_MAP *Old;
{
COLOUR_MAP *New;
New = Old;
if (New != NULL)
New->Users++;
return (New);
}
DBL Colour_Distance (colour1, colour2)
COLOUR *colour1, *colour2;
{
return (FABS (colour1->Red - colour2->Red)
+ FABS (colour1->Green - colour2->Green)
+ FABS (colour1->Blue - colour2->Blue));
}
void Add_Colour (result, colour1, colour2)
COLOUR *result, *colour1, *colour2;
{
result->Red = colour1->Red + colour2->Red;
result->Green = colour1->Green + colour2->Green;
result->Blue = colour1->Blue + colour2->Blue;
result->Filter = colour1->Filter + colour2->Filter;
}
void Scale_Colour (result, colour, factor)
COLOUR *result, *colour;
DBL factor;
{
result->Red = colour->Red * factor;
result->Green = colour->Green * factor;
result->Blue = colour->Blue * factor;
result->Filter = colour->Filter * factor;
}
void Clip_Colour (result, colour)
COLOUR *result, *colour;
{
if (colour -> Red > 1.0)
result -> Red = 1.0;
else if (colour -> Red < 0.0)
result -> Red = 0.0;
else result -> Red = colour -> Red;
if (colour -> Green > 1.0)
result -> Green = 1.0;
else if (colour -> Green < 0.0)
result -> Green = 0.0;
else result -> Green = colour -> Green;
if (colour -> Blue > 1.0)
result -> Blue = 1.0;
else if (colour -> Blue < 0.0)
result -> Blue = 0.0;
else result -> Blue = colour -> Blue;
if (colour -> Filter > 1.0)
result -> Filter = 1.0;
else if (colour -> Filter < 0.0)
result -> Filter = 0.0;
else result -> Filter = colour -> Filter;
}
void Destroy_Colour_Map (CMap)
COLOUR_MAP *CMap;
{
if (CMap == NULL)
return;
if (CMap->Users < 0)
return;
CMap->Users--;
if (CMap->Users >= 0)
return;
free (CMap->Colour_Map_Entries);
free (CMap);
}