/*
 * Copyright (c) 2000, Not a Number b.v.
 * This code is based at Ken Perlin's famous works...
 *
 */

#include <math.h>
#include "plugin.h"

/* ******************** GLOBAL VARIABLES ***************** */

/* Texture name */

char name[24]= "CHIP";

/* Subtype names must be less than 15 characters */

#define NR_TYPES   3
char stnames[NR_TYPES][16]= {"Intens", "Col", "Bump" };

/* Structure for buttons,
 *  butcode      name           default  min  max  0
 */

VarStruct varstr[]= {
   {   NUM|FLO,   "Offset",      -0.5,     -20.0, 20.0, 
   "From -20 to 20"},
   {   NUM|INT,   "Depth",      8.0,    1.0, 20.0, 
   "From 1 to 20"},
   {   NUM|FLO,   "Scale",      2.2,    -20.0, 80.0, 
   "From -20 to 80"},
   {   NUM|FLO,   "Falloff",      0.0,    -5.0, 5.0, 
   "From -5 to 5"},
   {    LABEL,      "Clouds2 form NaN",   0,    0,   0,   ""},
   {    LABEL,      "Adapted by:",   0,    0,   0,   ""},
   {    LABEL,      "Predrag Kurtovic",   0,    0,   0,   ""},
   {    LABEL,      "2.5.2000",   0,    0,   0,   ""},
};

/* The cast struct is for input in the main doit function
   Varstr and Cast must have the same variables in the same order,
   INCLUDING dummy variables for label fields. */

typedef struct Cast {
   float offset;
   int depth;
   float txtscale;
   float falloff;
} Cast;

/* result:
   Intensity, R, G, B, Alpha, nor.x, nor.y, nor.z
 */

float result[8];

/* cfra: the current frame */

float cfra;

int plugin_tex_doit(int, Cast*, float*, float*, float*);

/* ******************** Fixed functions ***************** */

int plugin_tex_getversion(void)
{
   return B_PLUGIN_VERSION;
}

void plugin_but_changed(int but)
{
}

void plugin_init(void)
{

}

/* this function should not be changed: */

void plugin_getinfo(PluginInfo *info)
{
   info->name= name;
   info->stypes= NR_TYPES;
   info->nvars= sizeof(varstr)/sizeof(VarStruct);

   info->snames= stnames[0];
   info->result= result;
   info->cfra= &cfra;
   info->varstr= varstr;

   info->init= plugin_init;
   info->tex_doit=  (TexDoit) plugin_tex_doit;
   info->callback= plugin_but_changed;
}

/* ********************* the texture ******************** */


/* return 0: One channel texture
   return 1: RGB texture
   return 2: Normals texture */

int plugin_tex_doit(int stype, Cast *cast, float *texvec, float *dxt, float *dyt)
{
   float val = 0.0;
   float a = 1.0;
   float p[3];
   float tv[3];
   int i;

   tv[0]=(texvec[0]+1.0)/2.0;
   tv[1]=(texvec[1]+1.0)/2.0;
   tv[2]=(texvec[2]+1.0)/2.0;

   p[0] = cast->txtscale * tv[0];
   p[1] = cast->txtscale * tv[1];
   p[2] = cast->txtscale * tv[2];

   for (i=0; i<cast->depth; i++) {
      val += a * hnoise(1.0, p[0], p[1], p[2]);

      p[0] *= 2.0;
      p[1] *= 2.0;
      p[2] *= 2.0;
      a *= 0.5;
   }

   /* always return this value */
   result[0] = CLAMP (val+cast->offset, 0.0, 1.0) * pow (fabs(sqrt(tv[0]*tv[0]+tv[1]*tv[1]+tv[2]*tv[2])), cast->falloff);

   if(stype==1) {
      /* color? then return 1;
       *
       * this is r, g, b, a:
       */
      result[1]= 0.5*result[0];
      result[2]= 1.0-val;
      result[3]= fsqrt(fabs(result[0]));
      result[4]= 1.0;

      return 1;
   }
   if(stype==2) {
      /* normal? then return 2
       *
       * This value is the displacement of the actual normal in
       * the Material calculation.
       */
      result[5]+= val;
      result[6]+= 1.0-val;
      result[7]= 0.0;

      return 2;
   }

   return 0;
}