/**
* This code is used to determine the alignment of NPCs in the hospital.
*/
/*
* These defines set the shape of the distribution of alignments handed out
* by pick_al. Using the standard normal distribution, split into ten steps
* on each side of the average, we can safely disregard the probability of
* values outside of the range of -3.0 to 3.0 (99.7% of values will fall
* within this range of three * standard deviation from the average).
* Range Prob.
* P( 0.0 < z < 0.3 ) = 0.1179
* P( 0.3 < z < 0.6 ) = 0.1078
* P( 0.6 < z < 0.9 ) = 0.0902
* P( 0.9 < z < 1.2 ) = 0.0690
* P( 1.2 < z < 1.5 ) = 0.0483
* P( 1.5 < z < 1.8 ) = 0.0309
* P( 1.8 < z < 2.1 ) = 0.0180
* P( 2.1 < z < 2.4 ) = 0.0097
* P( 2.4 < z < 2.7 ) = 0.0047
* P( 2.7 < z ) = 0.0035
*
* These probabilites are then converted into cumulative limits out of
* a total chance, as integers:
*/
#define TOTAL_CHANCE 150
#define CENTRE 0
#define LIMIT_ONE 35
#define LIMIT_TWO 68
#define LIMIT_THREE 95
#define LIMIT_FOUR 115
#define LIMIT_FIVE 130
#define LIMIT_SIX 139
#define LIMIT_SEVEN 145
#define LIMIT_EIGHT 147
#define LIMIT_NINE 149
/**
* This function produces a random alignment for an npc, based on a
* normal distribution around a supplied average, with a maximum and
* minimum limit provided by a requested range.
* <p>
* The alignment produced will be within the range[ average - range,
* average + range ]
* @param average The average alignment for this npc
* @param range The range request for alignment - the difference between
* average and maximum possible alignment
* <p>
*/
int pick_al( int average, int range ) {
int choice, section, section_width, result;
// Must be a positive range.
if( range < 0 ) {
range = -range;
}
// Must have a range of 10 at least.
if( range < 10 ) {
range = 10;
}
section_width = floor( range / 10 );
choice = random( TOTAL_CHANCE );
switch( choice ) {
case CENTRE..LIMIT_ONE:
section = 0;
break;
case ( LIMIT_ONE + 1 )..LIMIT_TWO:
section = 1;
break;
case ( LIMIT_TWO + 1 )..LIMIT_THREE:
section = 2;
break;
case ( LIMIT_THREE + 1 )..LIMIT_FOUR:
section = 3;
break;
case ( LIMIT_FOUR + 1 )..LIMIT_FIVE:
section = 4;
break;
case ( LIMIT_FIVE + 1 )..LIMIT_SIX:
section = 5;
break;
case ( LIMIT_SIX + 1 )..LIMIT_SEVEN:
section = 6;
break;
case ( LIMIT_SEVEN + 1 )..LIMIT_EIGHT:
section = 7;
break;
case ( LIMIT_EIGHT + 1 )..LIMIT_NINE:
section = 8;
break;
default:
section = 9;
break;
}
result = section * section_width;
result = result + random( section_width );
switch( random( 2 ) ) {
case( 0 ):
result = average + result;
break;
default:
result = average - result;
break;
}
result = result + average;
return result;
} /* pick_al */
