| 1 |
+ |
#ifndef lint |
| 2 |
+ |
static const char RCSid[] = "$Id$"; |
| 3 |
+ |
#endif |
| 4 |
|
/* |
| 5 |
|
* Disk2Square.c |
| 6 |
|
* |
| 11 |
|
* Modified interface slightly (G. Ward) |
| 12 |
|
*/ |
| 13 |
|
|
| 14 |
+ |
#define _USE_MATH_DEFINES |
| 15 |
|
#include <math.h> |
| 16 |
+ |
#include "fvect.h" |
| 17 |
|
|
| 18 |
|
/* |
| 19 |
|
This transforms points on [0,1]^2 to points on unit disk centered at |
| 41 |
|
|
| 42 |
|
/* Map a [0,1]^2 square to a unit radius disk */ |
| 43 |
|
void |
| 44 |
< |
SDsquare2disk(double ds[2], double seedx, double seedy) |
| 44 |
> |
square2disk(RREAL ds[2], double seedx, double seedy) |
| 45 |
|
{ |
| 46 |
|
|
| 47 |
|
double phi, r; |
| 71 |
|
phi = 0.; |
| 72 |
|
} |
| 73 |
|
} |
| 74 |
< |
|
| 74 |
> |
r *= 0.9999999999999; /* prophylactic against MS sin()/cos() impl. */ |
| 75 |
|
ds[0] = r * cos(phi); |
| 76 |
|
ds[1] = r * sin(phi); |
| 77 |
|
|
| 79 |
|
|
| 80 |
|
/* Map point on unit disk to a unit square in [0,1]^2 range */ |
| 81 |
|
void |
| 82 |
< |
SDdisk2square(double sq[2], double diskx, double disky) |
| 82 |
> |
disk2square(RREAL sq[2], double diskx, double disky) |
| 83 |
|
{ |
| 84 |
|
double r = sqrt( diskx*diskx + disky*disky ); |
| 85 |
|
double phi = atan2( disky, diskx ); |
| 103 |
|
a = -(phi - 3*M_PI/2) * b / (M_PI/4); |
| 104 |
|
} |
| 105 |
|
|
| 106 |
< |
sq[0] = (a + 1) * 0.5; |
| 107 |
< |
sq[1] = (b + 1) * 0.5; |
| 106 |
> |
sq[0] = a*(0.5/0.9999999999999) + 0.5; |
| 107 |
> |
sq[1] = b*(0.5/0.9999999999999) + 0.5; |
| 108 |
|
} |
