#ifndef lint
static char *rcsid = "$Header: /tmp_mnt/vida/disks/disk5/Users/terry/r/gassy/RCS/crossover.c,v 1.3 1992/10/09 06:43:50 terry Exp terry $";
#endif

#include "types.h"
#include "utility.h"

/*
 * Now cross them over, choosing from context->population and 
 * moving into new_population. There are nselected to choose from (in 
 * selections), and nreproducers must be produced (into new_population).
 */

VOID *
no_crossover_random_copy(selections, nselected, nreproducers, new_population, context)
INT *selections;
INT nselected;
INT nreproducers;
POPULATION new_population;
CONTEXT *context;
{
    /*
     * Just choose them randomly & copy them complete.
     */
    register INT i;
    
    for (i = 0; i < nreproducers; i++){
	copy_individual(&new_population[i], &context->population[selections[uniform(nselected)]], context);
    }

    return;
}

VOID *
no_crossover(selections, nselected, nreproducers, new_population, context)
INT *selections;
INT nselected;
INT nreproducers;
POPULATION new_population;
CONTEXT *context;
{
    /*
     * Just copy them as you see 'em in selections.
     */
    register INT i;
    
    for (i = 0; i < nreproducers; i++){
	copy_individual(&new_population[i], &context->population[selections[i]], context);
    }

    return;
}

#if defined(APP_INDIVIDUALS_HAVE_CONSTANT_SIZE) && defined(APP_INDIVIDUALS_ARE_STRINGS)

VOID uniform_crossover_function();
VOID two_pt_crossover_function();
VOID one_pt_crossover_function();

VOID *
one_pt_crossover(selections, nselected, nreproducers, new_population, context)
INT *selections;
INT nselected;
INT nreproducers;
POPULATION new_population;
CONTEXT *context;
{
    general_crossover(one_pt_crossover_function, selections, nselected, nreproducers, new_population, context);
}

VOID
one_pt_crossover_function(parent_1, parent_2, child_1, child_2, context)
INDIVIDUAL_TYPE parent_1;
INDIVIDUAL_TYPE parent_2;
INDIVIDUAL_TYPE child_1;
INDIVIDUAL_TYPE child_2;
CONTEXT *context;
{
    register INT crossover_point = uniform(context->genome_size - 1) + 1; /* produces 1..context->genome_size-1 */
    register INT pos;
    
    for (pos = 0; pos < crossover_point; pos++){
	child_1[pos] = parent_1[pos];
	child_2[pos] = parent_2[pos];
    }
    for (; pos < context->genome_size; pos++){
	child_1[pos] = parent_2[pos];
	child_2[pos] = parent_1[pos];
    }
    
    return;
}

VOID *
two_pt_crossover(selections, nselected, nreproducers, new_population, context)
INT *selections;
INT nselected;
INT nreproducers;
POPULATION new_population;
CONTEXT *context;
{
    general_crossover(two_pt_crossover_function, selections, nselected, nreproducers, new_population, context);
}

VOID
two_pt_crossover_function(parent_1, parent_2, child_1, child_2, context)
INDIVIDUAL_TYPE parent_1;
INDIVIDUAL_TYPE parent_2;
INDIVIDUAL_TYPE child_1;
INDIVIDUAL_TYPE child_2;
CONTEXT *context;
{
    register INT crossover_point_1 = uniform(context->genome_size - 1) + 1; /* produces 1..context->genome_size-1 */
    register INT crossover_point_2 = uniform(context->genome_size - 1) + 1; /* produces 1..context->genome_size-1 */
    register INT pos;
	
    /* If the two crossover points are the same, this becomes one point crossover. */
	    
    if (crossover_point_1 > crossover_point_2){
	register INT tmp;
	tmp = crossover_point_1;
	crossover_point_1 = crossover_point_2;
	crossover_point_2 = tmp;
    }
    
    for (pos = 0; pos < crossover_point_1; pos++){
	child_1[pos] = parent_1[pos];
	child_2[pos] = parent_2[pos];
    }
    for (; pos < crossover_point_2; pos++){
	child_1[pos] = parent_2[pos];
	child_2[pos] = parent_1[pos];
    }
    for (; pos < context->genome_size; pos++){
	child_1[pos] = parent_1[pos];
	child_2[pos] = parent_2[pos];
    }
    
    return;
}

VOID *
uniform_crossover(selections, nselected, nreproducers, new_population, context)
INT *selections;
INT nselected;
INT nreproducers;
POPULATION new_population;
CONTEXT *context;
{
    general_crossover(uniform_crossover_function, selections, nselected, nreproducers, new_population, context);
}

VOID
uniform_crossover_function(parent_1, parent_2, child_1, child_2, context)
INDIVIDUAL_TYPE parent_1;
INDIVIDUAL_TYPE parent_2;
INDIVIDUAL_TYPE child_1;
INDIVIDUAL_TYPE child_2;
CONTEXT *context;
{
    register INT pos;
    
    for (pos = 0; pos < context->genome_size; pos++){
	if (DO_UNIFORM){
	    child_1[pos] = parent_1[pos];
	    child_2[pos] = parent_2[pos];
	}
	else {
	    child_1[pos] = parent_2[pos];
	    child_2[pos] = parent_1[pos];
	}
    }
    
    return;
}

#endif