/*
   bf98spc.c
   Dynamic Befunge-Space ANSI C Functions - source.
   v0.98 Oct 1 1998 Chris Pressey
   v0.98a Mar 26 2003 Chris Pressey

   Copyright (c)1998, 2001, 2003, Cat's Eye Technologies.
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

     Redistributions of source code must retain the above copyright
     notice, this list of conditions and the following disclaimer.

     Redistributions in binary form must reproduce the above copyright
     notice, this list of conditions and the following disclaimer in
     the documentation and/or other materials provided with the
     distribution.

     Neither the name of Cat's Eye Technologies nor the names of its
     contributors may be used to endorse or promote products derived
     from this software without specific prior written permission. 

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
   OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
   OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   POSSIBILITY OF SUCH DAMAGE. 

*/

/*
   Why use this package?
   - It's ANSI C
   - You need to store a large, dynamically allocated,
       Cartesian 2D space with 32-bit addressing and 32-bit cell data
   - You don't care about dynamic 1D, 3D etc spaces.
*/

#include <stdio.h>
#include <stdlib.h>

#include "bf98spc.h"

/* internal functions */

keytree * find_keytree(keytree * k, signed long int key_x, signed long int key_y, int * found)
{
  int compare = 0;
  keytree * l = k;

  *found = 0;

  if (l != NULL)
  {
    while (1)
    {
      compare = (l->key_x == key_x ? l->key_y - key_y : l->key_x - key_x);
      if (compare > 0)
      {
	if (l->right != NULL)
	{
	  l = l->right;
	} else
	{
	  return l;
	}
      } else
      if (compare < 0)
      {
	if (l->left != NULL)
	{
	  l = l->left;
	} else
	{
          /* This space intentionally left blank. */
	  return l;
	}
      } else
      {
	*found = 1;
	return l;
      }
    }
  } else
  {
    return NULL;
  }
  return l;
}

void destroy_keytree (keytree * k)
{
  if (k != NULL)
  {
    destroy_keytree (k->left);
    k->left = NULL;
    destroy_keytree (k->right);
    k->right = NULL;
    free(k->data);
    free(k);
  }
}

/* exported functions */

signed long int bfspace_fetch (bfspace * p, signed long int x, signed long int y)
{
  keytree * k;
  int found;

  k = find_keytree(p->root, (x >> SNIPPET_BITS), (y >> SNIPPET_BITS), &found);
  if (found)
  {
    if (k != NULL)
    {
      x = (x & SNIPPET_MASK);
      y = (y & SNIPPET_MASK);
      return k->data->space[(x << SNIPPET_BITS) + y];
    } else
    {
      return 32;
    }
  } else
  {
    /* Hello, sailor! */
    return 32;
  }
}

int bfspace_store (bfspace * p, signed long int x, signed long int y, signed long int data)
{
  keytree * n;
  keytree * k;
  int found, i;

  n = (keytree *)malloc(sizeof(keytree));
  n->left = NULL;
  n->right = NULL;
  n->key_x = x >> SNIPPET_BITS;
  n->key_y = y >> SNIPPET_BITS;

  k = p->root;
  if (k == NULL)
  {
    /* add as root. */
    p->root = n;
    n->data = (snippet *)malloc(sizeof(snippet));
    for (i = 0; i < (SNIPPET_SIZE*SNIPPET_SIZE); i++)
    {
      n->data->space[i] = 32;
    }
    if (x > p->max_x) p->max_x = x;
    if (x < p->min_x) p->min_x = x;
    if (y > p->max_y) p->max_y = y;
    if (y < p->min_y) p->min_y = y;
    x = (x & SNIPPET_MASK);
    y = (y & SNIPPET_MASK);
    n->data->space[(short)(x << SNIPPET_BITS) + (short)(y)] = data;
    return 1;
  } else
  {
    k = find_keytree(k, n->key_x, n->key_y, &found);
    if (found)
    {
      if (k != NULL)
      {
	if (x > p->max_x) p->max_x = x;
	if (x < p->min_x) p->min_x = x;
	if (y > p->max_y) p->max_y = y;
	if (y < p->min_y) p->min_y = y;
	x = (x & SNIPPET_MASK);
	y = (y & SNIPPET_MASK);
	k->data->space[(short)(x << SNIPPET_BITS) + (short)(y)] = data;
	free (n);
	return 1;
      } else
      {
	return 0;
      }
    } else
    {
      if (((k->key_x == n->key_x ? k->key_y - n->key_y : k->key_x - n->key_x) < 0) && (k->left == NULL))
      {
	k->left = n;
      } else
      if (((k->key_x == n->key_x ? k->key_y - n->key_y : k->key_x - n->key_x) > 0) && (k->right == NULL))
      {
	k->right = n;
      } else
      {
	/* we'd be really, really screwed, but luckily this never seems to happen */
	return 0;
      }
      n->data = (snippet *)malloc(sizeof(snippet));
      for (i = 0; i < (SNIPPET_SIZE*SNIPPET_SIZE); i++)
      {
	n->data->space[i] = 32;
      }
      if (x > p->max_x) p->max_x = x;
      if (x < p->min_x) p->min_x = x;
      if (y > p->max_y) p->max_y = y;
      if (y < p->min_y) p->min_y = y;
      x = (x & SNIPPET_MASK);
      y = (y & SNIPPET_MASK);
      n->data->space[(short)(x << SNIPPET_BITS) + (short)(y)] = data;
      return 1;
    }
  }
}

int bfspace_inbounds (bfspace * p, signed long int x, signed long int y)
{
  /* "You can't tell a squid." -- Old Canadian saying */
  return ((x <= p->max_x) && (x >= p->min_x) &&
	  (y <= p->max_y) && (y >= p->min_y));
}

/* might as well pass a NULL for p, nothing is done with it */
bfspace * bfspace_alloc (bfspace * p)
{
  bfspace * n;
  n = (bfspace *)malloc(sizeof(bfspace));
  n->root = NULL;
  n->max_x = -MAXLONG;
  n->min_x = MAXLONG;
  n->max_y = -MAXLONG;
  n->min_y = MAXLONG;
  p = p;
  return n;
}

void bfspace_free (bfspace * p)
{
  destroy_keytree(p->root);
  free(p);
}

int bfspace_fread (bfspace * p, FILE * f,
                   signed long int x, signed long int y,
                   signed long int * w, signed long int * h,
                   unsigned long int flags)
{
  signed long int col = x;
  signed long int row = y;
  signed long int a = 0;

  /* Efficiency at any cost! */

  *w = 0;  *h = 0;

  while (!feof (f))
  {
    a = (long) 0 | fgetc(f);
    if ( ((a == (long)0x0a) || (a == (long)0x0d)) &&
         ((flags & (long)0x01) != (long)0x01) )
    {
      if (a == (long)'\x0d')
      {
        /* next char might be \x0a, and if so, suck it up too. */
        a = (long) 0 | fgetc(f);
        if (a != (long)'\x0a') ungetc(a, f);
      }
      col = x;
      row++;  if ((row-y) > *h) *h = (row-y);
    } else
    {
      if (!feof(f))
      {
        if (a != ' ')
        {
	  if (!(bfspace_store(p, col++, row, a))) return 0;
          if ((col-x) > *w) *w = (col-x);
        } else
        {
          col++;
        }
      }
    }
  }
  return 1;
}

int bfspace_fwrite (bfspace * p, FILE * f, signed long int x, signed long int y,
			signed long int w, signed long int h, unsigned long int flags)
{
  signed long int col = x;
  signed long int row = y;
  signed long int a = 0;

  signed long spccnt = 0;
  signed long i = 0;

  while ((row-y) < h)
  {
    a = bfspace_fetch(p, col++, row);
    spccnt=0;
    while (a == ((long)0|' ') && (col-x) < w)
    {
      spccnt++;
      a = bfspace_fetch(p, col++, row);
    }
    if (((flags & (long)0x1) != (long)0x1) && ((col-x) < w))
    {
      for(i=0;i<spccnt;i++) fputc(' ', f);
    }
    fputc((char)a, f);
    if (col-x >= w)
    {
      col = x;
      row++;
      fputc('\n', f);
    }
  }
  return 1;
}