planets.c

/*
 * planets.c
 * 
 * Kevin P. Smith  2/21/89
 * 
 * This file contains the galaxy definition as well as some support for
 * determining when parts of the galactic map need to be redrawn.
 */
#include "copyright2.h"

#include <stdio.h>
#include <math.h>
#include "netrek.h"

/* Note:  DETAIL * MUST * be a factor of GWIDTH. */
#define DETAIL 40		/* Size of redraw array */
#define PDIST 4500		/* Distance to turn on redraw flag */
#define SIZE (GWIDTH/DETAIL)

int             redraws[DETAIL][DETAIL];
static int      plinitialized = 0;

void
initPlanets()
{
   int             i, j, k;
   int             endi, endj;
   struct planet  *pl;
   int             offset = PDIST / SIZE + 1;
   float           dist;

   for (i = 0; i < DETAIL; i++) {
      for (j = 0; j < DETAIL; j++) {
	 redraws[i][j] = -1;
      }
   }

   for (k = 0, pl = planets; k < MAXPLANETS; k++, pl++) {
      endi = pl->pl_x / SIZE + offset + 1;
      for (i = (pl->pl_x / SIZE) - offset; i < endi && i < DETAIL; i++) {
	 if (i < 0)
	    i = 0;
	 endj = pl->pl_y / SIZE + offset + 1;
	 for (j = (pl->pl_y / SIZE) - offset; j < endj && j < DETAIL; j++) {
	    dist = hypot((float) (pl->pl_x - (i * SIZE + SIZE / 2)),
			 (float) (pl->pl_y - (j * SIZE + SIZE / 2)));
	    if (dist <= PDIST) {
	       redraws[i][j] = k;
	    }
	 }
      }
   }
   plinitialized = 1;
}

void
checkRedraw(x, y)
    int             x, y;
{
   int             i;

   if (!plinitialized || x < 0 || y < 0 || x >= GWIDTH || y >= GWIDTH)
      return;
   i = redraws[x / SIZE][y / SIZE];
   if (i == -1)
      return;
   planets[i].pl_flags |= PLREDRAW;
}