/* See {float_image_func.h}. */
/* Last edited on 2018-03-04 22:06:40 by stolfilocal */

#define _GNU_SOURCE
#include <math.h>
#include <limits.h>
#include <assert.h>
 
#include <bool.h>
#include <jsmath.h>
#include <affirm.h>
#include <gauss_table.h>
#include <float_image.h>
#include <float_image_func.h>

/* BASIC FUNCTIONAL IMAGES */

/* In the following procedures, if {RX} is nonzero, {x} will be reduced modulo {RX}.
  Ditto for {RY} and {y}. */

bool_t float_image_func_circle(double xctr, double yctr, double rad, double x, double y, int32_t RX, int32_t RY);
  /* Function that is true iff {(x,y)} is inside the disk with center
    {(xctr,yctr)} and radius {rad}. */

float float_image_func_bell(double xctr, double yctr, double xdev, double ydev, double x, double y, int32_t RX, int32_t RY);
  /* Function that is 1 at {(xctr,yctr)} and decays to 0 like a Gaussian bell with 
    deviations {xdev} and {ydev} along the two axes. */

bool_t float_image_func_circle(double xctr, double yctr, double rad, double x, double y, int32_t RX, int32_t RY)
  { double dx = x - xctr;
    double dy = y - yctr;
    double dr2 = dx*dx + dy*dy;
    return (dr2 <= rad);
  }
  
float float_image_func_bell(double xctr, double yctr, double xdev, double ydev, double x, double y, int32_t RX, int32_t RY)
  {
    double gx = gauss_table_folded_bell(x - xctr, xdev, RX);
    double gy = gauss_table_folded_bell(y - yctr, ydev, RY);
    return (float)(gx*gy);
  }