summaryrefslogtreecommitdiff
path: root/src/map/path.c
blob: 52dcd0ac8d10a0bb71bc1dbd1c796368c26a5f0b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
// Copyright (c) Athena Dev Teams - Licensed under GNU GPL
// For more information, see LICENCE in the main folder

#include "../common/cbasetypes.h"
#include "../common/nullpo.h"
#include "../common/showmsg.h"
#include "../common/malloc.h"
#include "map.h"
#include "battle.h"
#include "path.h"

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


#define MAX_HEAP 150

struct tmp_path { short x,y,dist,before,cost,flag;};
#define calc_index(x,y) (((x)+(y)*MAX_WALKPATH) & (MAX_WALKPATH*MAX_WALKPATH-1))

const char walk_choices [3][3] =
{
	{1,0,7},
	{2,-1,6},
	{3,4,5},
};

/*==========================================
 * heap push (helper function)
 *------------------------------------------*/
static void push_heap_path(int *heap,struct tmp_path *tp,int index)
{
	int i,h;

	h = heap[0];
	heap[0]++;

	for( i = (h-1)/2; h > 0 && tp[index].cost < tp[heap[i+1]].cost; i = (h-1)/2 )
		heap[h+1] = heap[i+1], h = i;

	heap[h+1] = index;
}

/*==========================================
 * heap update (helper function)
 * cost���������̂ō��̕��ֈړ�
 *------------------------------------------*/
static void update_heap_path(int *heap,struct tmp_path *tp,int index)
{
	int i,h;

	ARR_FIND( 0, heap[0], h, heap[h+1] == index );
	if( h == heap[0] )
	{
		ShowError("update_heap_path bug\n");
		exit(EXIT_FAILURE);
	}

	for( i = (h-1)/2; h > 0 && tp[index].cost < tp[heap[i+1]].cost; i = (h-1)/2 )
		heap[h+1] = heap[i+1], h = i;

	heap[h+1] = index;
}

/*==========================================
 * heap pop (helper function)
 *------------------------------------------*/
static int pop_heap_path(int *heap,struct tmp_path *tp)
{
	int i,h,k;
	int ret,last;

	if( heap[0] <= 0 )
		return -1;
	ret = heap[1];
	last = heap[heap[0]];
	heap[0]--;

	for( h = 0, k = 2; k < heap[0]; k = k*2+2 )
	{
		if( tp[heap[k+1]].cost > tp[heap[k]].cost )
			k--;
		heap[h+1] = heap[k+1], h = k;
	}

	if( k == heap[0] )
		heap[h+1] = heap[k], h = k-1;

	for( i = (h-1)/2; h > 0 && tp[heap[i+1]].cost > tp[last].cost; i = (h-1)/2 )
		heap[h+1] = heap[i+1], h = i;

	heap[h+1]=last;

	return ret;
}

/*==========================================
 * calculate cost for the specified position
 *------------------------------------------*/
static int calc_cost(struct tmp_path *p,int x1,int y1)
{
	int xd = abs(x1 - p->x);
	int yd = abs(y1 - p->y);
	return (xd + yd)*10 + p->dist;
}

/*==========================================
 * attach/adjust path if neccessary
 *------------------------------------------*/
static int add_path(int *heap,struct tmp_path *tp,int x,int y,int dist,int before,int cost)
{
	int i;

	i = calc_index(x,y);

	if( tp[i].x == x && tp[i].y == y )
	{
		if( tp[i].dist > dist )
		{
			tp[i].dist = dist;
			tp[i].before = before;
			tp[i].cost = cost;
			if( tp[i].flag )
				push_heap_path(heap,tp,i);
			else
				update_heap_path(heap,tp,i);
			tp[i].flag = 0;
		}
		return 0;
	}

	if( tp[i].x || tp[i].y )
		return 1;

	tp[i].x = x;
	tp[i].y = y;
	tp[i].dist = dist;
	tp[i].before = before;
	tp[i].cost = cost;
	tp[i].flag = 0;
	push_heap_path(heap,tp,i);

	return 0;
}


/*==========================================
 * is (x,y) passable?
 * flag: 0x10000 = ranged attack check
 *       0x30000 = stacking check
 *------------------------------------------*/
static int can_place(struct map_data *m,int x,int y,int flag)
{
	if( map_getcellp(m,x,y,CELL_CHKPASS) )
		return 1;
	if( (flag&0x10000)&&map_getcellp(m,x,y,CELL_CHKGROUND) )
		return 1;
#ifdef CELL_NOSTACK
	//Special flag for CELL_NOSTACK systems. Returns true when the given cell is stacked. [Skotlex]
	if( (flag&0x30000)&&map_getcellp(m,x,y,CELL_CHKSTACK) )
		return 1;
#endif
	return 0;
}

/*==========================================
 * can you move from (x0,y0) to (x1,y1) in one step?
 * (helper function for path_blownpos())
 *------------------------------------------*/
static int can_move(struct map_data *m,int x0,int y0,int x1,int y1,int flag)
{
	if( x1 < 0 || y1 < 0 || x1 >= m->xs || y1 >= m->ys)
		return 0; // out-of-bounds coordinates
	if( flag&0x20000 ) //Flag to ignore everything, for use with Taekwon's Jump skill currently. [Skotlex] 
		return 1;
#ifndef CELL_NOSTACK
	//In no-stack mode, do not check current cell.
	if( !can_place(m,x0,y0,flag) )
		return 0;
#endif
	if( !can_place(m,x1,y1,flag) )
		return 0;
	if( x0 == x1 || y0 == y1 )
		return 1;
	if( !can_place(m,x0,y1,flag) || !can_place(m,x1,y0,flag) )
		return 0;
	return 1;
}

/*==========================================
 * (x0,y0)����(dx,dy)������count�Z����
 * ������΂������Ƃ̍��W������
 *------------------------------------------*/
int path_blownpos(int m,int x0,int y0,int dx,int dy,int count)
{
	struct map_data *md;

	if( !map[m].gat )
		return -1;
	md = &map[m];

	if( count>25 ){ //Cap to prevent too much processing...?
		ShowWarning("path_blownpos: count too many %d !\n",count);
		count=25;
	}
	if( dx > 1 || dx < -1 || dy > 1 || dy < -1 ){
		ShowError("path_blownpos: illegal dx=%d or dy=%d !\n",dx,dy);
		dx=(dx>0)?1:((dx<0)?-1:0);
		dy=(dy>0)?1:((dy<0)?-1:0);
	}
	
	while( (count--)>0 && (dx || dy) )
	{
		if( !can_move(md,x0,y0,x0+dx,y0+dy,0) ){
			int fx=(dx!=0 && can_move(md,x0,y0,x0+dx,y0,0));
			int fy=(dy!=0 && can_move(md,x0,y0,x0,y0+dy,0));
			if( fx && fy ){
				if(rand()&1) dx=0;
				else		 dy=0;
			}
			if( !fx )		dx=0;
			if( !fy )		dy=0;
		}
		x0+=dx;
		y0+=dy;
	}
	return (x0<<16)|y0; //TODO: use 'struct point' here instead?
}

/*==========================================
 * is ranged attack from (x0,y0) to (x1,y1) possible?
 *------------------------------------------*/
bool path_search_long(struct shootpath_data *spd,int m,int x0,int y0,int x1,int y1,cell_t cell)
{
	int dx, dy;
	int wx = 0, wy = 0;
	int weight;
	struct map_data *md;
	struct shootpath_data s_spd;

	if( spd == NULL )
		spd = &s_spd; // use dummy output variable

	if (!map[m].gat)
		return false;
	md = &map[m];

	dx = (x1 - x0);
	if (dx < 0) {
		swap(x0, x1);
		swap(y0, y1);
		dx = -dx;
	}
	dy = (y1 - y0);

	spd->rx = spd->ry = 0;
	spd->len = 1;
	spd->x[0] = x0;
	spd->y[0] = y0;

	if (map_getcellp(md,x1,y1,cell))
		return false;

	if (dx > abs(dy)) {
		weight = dx;
		spd->ry = 1;
	} else {
		weight = abs(y1 - y0);
		spd->rx = 1;
	}

	while (x0 != x1 || y0 != y1)
	{
		if (map_getcellp(md,x0,y0,cell))
			return false;
		wx += dx;
		wy += dy;
		if (wx >= weight) {
			wx -= weight;
			x0++;
		}
		if (wy >= weight) {
			wy -= weight;
			y0++;
		} else if (wy < 0) {
			wy += weight;
			y0--;
		}
		if( spd->len<MAX_WALKPATH )
		{
			spd->x[spd->len] = x0;
			spd->y[spd->len] = y0;
			spd->len++;
		}
	}

	return true;
}

/*==========================================
 * path search (x0,y0)->(x1,y1)
 * wpd: path info will be written here
 * flag: &1 = easy path search only
 * cell: type of obstruction to check for
 *------------------------------------------*/
bool path_search(struct walkpath_data *wpd,int m,int x0,int y0,int x1,int y1,int flag,cell_t cell)
{
	int heap[MAX_HEAP+1];
	struct tmp_path tp[MAX_WALKPATH*MAX_WALKPATH];
	register int i,j,len,x,y,dx,dy;
	int rp,xs,ys;
	struct map_data *md;
	struct walkpath_data s_wpd;

	if( wpd == NULL )
		wpd = &s_wpd; // use dummy output variable

	if( !map[m].gat )
		return false;
	md = &map[m];

#ifdef CELL_NOSTACK
	//Do not check starting cell as that would get you stuck.
	if( x0 < 0 || x0 >= md->xs || y0 < 0 || y0 >= md->ys )
#else
	if( x0 < 0 || x0 >= md->xs || y0 < 0 || y0 >= md->ys /*|| map_getcellp(md,x0,y0,cell)*/ )
#endif
		return false;
	if( x1 < 0 || x1 >= md->xs || y1 < 0 || y1 >= md->ys || map_getcellp(md,x1,y1,cell) )
		return false;

	// calculate (sgn(x1-x0), sgn(y1-y0))
	dx = ((dx = x1-x0)) ? ((dx<0) ? -1 : 1) : 0;
	dy = ((dy = y1-y0)) ? ((dy<0) ? -1 : 1) : 0;

	// try finding direct path to target
	x = x0;
	y = y0;
	i = 0;
	while( i < ARRAYLENGTH(wpd->path) )
	{
		wpd->path[i] = walk_choices[-dy + 1][dx + 1];
		i++;

		x += dx;
		y += dy;

		if( x == x1 ) dx = 0;
		if( y == y1 ) dy = 0;

		if( dx == 0 && dy == 0 )
			break; // success
		if( map_getcellp(md,x,y,cell) )
			break; // obstacle = failure
	}

	if( x == x1 && y == y1 )
	{ //easy path successful.
		wpd->path_len = i;
		wpd->path_pos = 0;
		return true;
	}
	
	if( flag&1 )
		return false;

	memset(tp,0,sizeof(tp));

	i=calc_index(x0,y0);
	tp[i].x=x0;
	tp[i].y=y0;
	tp[i].dist=0;
	tp[i].before=0;
	tp[i].cost=calc_cost(&tp[i],x1,y1);
	tp[i].flag=0;
	heap[0]=0;
	push_heap_path(heap,tp,calc_index(x0,y0));
	xs = md->xs-1; // ���炩���߂P���Z���Ă���
	ys = md->ys-1;

	while(1)
	{
		int e=0,f=0,dist,cost,dc[4]={0,0,0,0};

		if(heap[0]==0)
			return false;
		rp   = pop_heap_path(heap,tp);
		x    = tp[rp].x;
		y    = tp[rp].y;
		dist = tp[rp].dist + 10;
		cost = tp[rp].cost;

		if(x==x1 && y==y1)
			break;

		// dc[0] : y++ �̎��̃R�X�g����
		// dc[1] : x-- �̎��̃R�X�g����
		// dc[2] : y-- �̎��̃R�X�g����
		// dc[3] : x++ �̎��̃R�X�g����

		if(y < ys && !map_getcellp(md,x  ,y+1,cell)) {
			f |= 1; dc[0] = (y >= y1 ? 20 : 0);
			e+=add_path(heap,tp,x  ,y+1,dist,rp,cost+dc[0]); // (x,   y+1)
		}
		if(x > 0  && !map_getcellp(md,x-1,y  ,cell)) {
			f |= 2; dc[1] = (x <= x1 ? 20 : 0);
			e+=add_path(heap,tp,x-1,y  ,dist,rp,cost+dc[1]); // (x-1, y  )
		}
		if(y > 0  && !map_getcellp(md,x  ,y-1,cell)) {
			f |= 4; dc[2] = (y <= y1 ? 20 : 0);
			e+=add_path(heap,tp,x  ,y-1,dist,rp,cost+dc[2]); // (x  , y-1)
		}
		if(x < xs && !map_getcellp(md,x+1,y  ,cell)) {
			f |= 8; dc[3] = (x >= x1 ? 20 : 0);
			e+=add_path(heap,tp,x+1,y  ,dist,rp,cost+dc[3]); // (x+1, y  )
		}
		if( (f & (2+1)) == (2+1) && !map_getcellp(md,x-1,y+1,cell))
			e+=add_path(heap,tp,x-1,y+1,dist+4,rp,cost+dc[1]+dc[0]-6);		// (x-1, y+1)
		if( (f & (2+4)) == (2+4) && !map_getcellp(md,x-1,y-1,cell))
			e+=add_path(heap,tp,x-1,y-1,dist+4,rp,cost+dc[1]+dc[2]-6);		// (x-1, y-1)
		if( (f & (8+4)) == (8+4) && !map_getcellp(md,x+1,y-1,cell))
			e+=add_path(heap,tp,x+1,y-1,dist+4,rp,cost+dc[3]+dc[2]-6);		// (x+1, y-1)
		if( (f & (8+1)) == (8+1) && !map_getcellp(md,x+1,y+1,cell))
			e+=add_path(heap,tp,x+1,y+1,dist+4,rp,cost+dc[3]+dc[0]-6);		// (x+1, y+1)
		tp[rp].flag=1;
		if(e || heap[0]>=MAX_HEAP-5)
			return false;
	}

	if( !(x==x1 && y==y1) ) // will never happen...
		return false;
	
	for(len=0,i=rp;len<100 && i!=calc_index(x0,y0);i=tp[i].before,len++);
	if(len==100 || len>=sizeof(wpd->path))
		return false;

	wpd->path_len = len;
	wpd->path_pos = 0;
	for(i=rp,j=len-1;j>=0;i=tp[i].before,j--) {
		int dx  = tp[i].x - tp[tp[i].before].x;
		int dy  = tp[i].y - tp[tp[i].before].y;
		int dir;
		if( dx == 0 ) {
			dir = (dy > 0 ? 0 : 4);
		} else if( dx > 0 ) {
			dir = (dy == 0 ? 6 : (dy < 0 ? 5 : 7) );
		} else {
			dir = (dy == 0 ? 2 : (dy > 0 ? 1 : 3) );
		}
		wpd->path[j] = dir;
	}

	return true;
}