adsoheightmap.h

Go to the documentation of this file.

/*****************************************************************************
 * $Id: adsoheightmap.h,v 1.6 2003/06/27 08:36:41 schou Exp $
 * Author: Jakob Schou Jensen <schou@sourceforge.net>
 * Licence: GPL
 *
 * Description: Adso height map
 *
 ****************************************************************************/

#ifndef ADSOHEIGHTMAP_H
#define ADSOHEIGHTMAP_H
#include <stdio.h>
#include <adsobase.h>
#include <adsomath.h>

class AdsoHeightMap {
  float *array;
  int w,h;
  float dp,dt;

public:
  float height(v3f pos){
    s2f p = s2f(pos);
    return height(p.t,p.p);
  }

  float height(float t, float p){
    float t0,p0,q,r;
    float v0,v1,v2,v3;
    int ti0,pi0;
    
    if(t<0) t = 0;
    if(t>=M_PI) t = (float)(M_PI-1e-10);
    
    t0 = floor(t/dt);
    p0 = floor((p+(float)M_PI)/dp);
    q = (p+(float)M_PI)/dp-p0;
    r = t/dt-t0;

    ti0 = (int)t0;
    pi0 = (int)p0;

    if(ti0>=h-1) return array[w*(h-1)];

    v0 = array[pi0%w+w*ti0];
    v1 = array[(pi0+1)%w+w*ti0];
    v2 = array[pi0%w+w*(ti0+1)];
    v3 = array[(pi0+1)%w+w*(ti0+1)];

    return v0*(1.0f-q)*(1.0f-r) + v1*q*(1.0f-r) + v2*(1.0f-q)*r + v3*q*r;
  }

  v3f slope(v3f pos){
    s2f p = s2f(pos);
    return slope(p.t,p.p);
  }

  v3f slope(float t, float p);

  int width(){ return w; }
  int height(){ return h; }

  int save(FILE *file);
  int load(FILE *file);

  AdsoHeightMap(float *a, int sw, int sh){
    array=a;
    w=sw;
    h=sh;
    dp=2.0f*(float)M_PI/w;
    dt=(float)M_PI/h;
  }

  AdsoHeightMap(){
    array=0;
  }
};

#endif

---