2 #include "quakedef.h"
4 #define MAXRECURSIVEPORTALPLANES 1024
5 #define MAXRECURSIVEPORTALS 256
7 static tinyplane_t portalplanes[MAXRECURSIVEPORTALPLANES];
8 static int ranoutofportalplanes;
9 static int ranoutofportals;
10 static float portaltemppoints[2][256][3];
11 static float portaltemppoints2[256][3];
12 static int portal_markid = 0;
13 static float boxpoints[4*3];
15 int Portal_ClipPolygonToPlane(float *in, float *out, int inpoints, int maxoutpoints, tinyplane_t *p)
16 {
17         int i, outpoints, prevside, side;
18         float *prevpoint, prevdist, dist, dot;
20         if (inpoints < 3)
21                 return inpoints;
22         // begin with the last point, then enter the loop with the first point as current
23         prevpoint = in + 3 * (inpoints - 1);
24         prevdist = DotProduct(prevpoint, p->normal) - p->dist;
25         prevside = prevdist >= 0 ? SIDE_FRONT : SIDE_BACK;
26         i = 0;
27         outpoints = 0;
28         goto begin;
29         for (;i < inpoints;i++)
30         {
31                 prevpoint = in;
32                 prevdist = dist;
33                 prevside = side;
34                 in += 3;
36 begin:
37                 dist = DotProduct(in, p->normal) - p->dist;
38                 side = dist >= 0 ? SIDE_FRONT : SIDE_BACK;
40                 if (prevside == SIDE_FRONT)
41                 {
42                         if (outpoints >= maxoutpoints)
43                                 return -1;
44                         VectorCopy(prevpoint, out);
45                         out += 3;
46                         outpoints++;
47                         if (side == SIDE_FRONT)
48                                 continue;
49                 }
50                 else if (side == SIDE_BACK)
51                         continue;
53                 // generate a split point
54                 if (outpoints >= maxoutpoints)
55                         return -1;
56                 dot = prevdist / (prevdist - dist);
57                 out[0] = prevpoint[0] + dot * (in[0] - prevpoint[0]);
58                 out[1] = prevpoint[1] + dot * (in[1] - prevpoint[1]);
59                 out[2] = prevpoint[2] + dot * (in[2] - prevpoint[2]);
60                 out += 3;
61                 outpoints++;
62         }
64         return outpoints;
65 }
68 int Portal_PortalThroughPortalPlanes(tinyplane_t *clipplanes, int clipnumplanes, float *targpoints, int targnumpoints, float *out, int maxpoints)
69 {
70         int numpoints, i;
71         if (targnumpoints < 3)
72                 return targnumpoints;
73         if (maxpoints < 3)
74                 return -1;
75         numpoints = targnumpoints;
76         memcpy(&portaltemppoints[0][0][0], targpoints, numpoints * 3 * sizeof(float));
77         for (i = 0;i < clipnumplanes;i++)
78         {
79                 numpoints = Portal_ClipPolygonToPlane(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints, 256, clipplanes + i);
80                 if (numpoints < 3)
81                         return numpoints;
82                 memcpy(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
83         }
84         if (numpoints > maxpoints)
85                 return -1;
86         memcpy(out, &portaltemppoints[0][0][0], numpoints * 3 * sizeof(float));
87         return numpoints;
88 }
90 int Portal_RecursiveFlowSearch (mleaf_t *leaf, vec3_t eye, int firstclipplane, int numclipplanes)
91 {
92         mportal_t *p;
93         int newpoints, i, prev;
94         vec3_t center, v1, v2;
95         tinyplane_t *newplanes;
97         if (leaf->portalmarkid == portal_markid)
98                 return true;
100         // follow portals into other leafs
101         for (p = leaf->portals;p;p = p->next)
102         {
103                 // only flow through portals facing away from the viewer
104                 if (PlaneDiff(eye, (&p->plane)) < 0)
105                 {
106                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
107                         if (newpoints < 3)
108                                 continue;
109                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
110                                 ranoutofportalplanes = true;
111                         else
112                         {
113                                 // find the center by averaging
114                                 VectorClear(center);
115                                 for (i = 0;i < newpoints;i++)
117                                 // ixtable is a 1.0f / N table
118                                 VectorScale(center, ixtable[newpoints], center);
119                                 // calculate the planes, and make sure the polygon can see it's own center
120                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
121                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
122                                 {
123                                         VectorSubtract(eye, portaltemppoints2[i], v1);
124                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
125                                         CrossProduct(v1, v2, newplanes[i].normal);
126                                         VectorNormalizeFast(newplanes[i].normal);
127                                         newplanes[i].dist = DotProduct(eye, newplanes[i].normal);
128                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
129                                         {
130                                                 // polygon can't see it's own center, discard and use parent portal
131                                                 break;
132                                         }
133                                 }
134                                 if (i == newpoints)
135                                 {
136                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane + numclipplanes, newpoints))
137                                                 return true;
138                                 }
139                                 else
140                                 {
141                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane, numclipplanes))
142                                                 return true;
143                                 }
144                         }
145                 }
146         }
148         return false;
149 }
151 void Portal_PolygonRecursiveMarkLeafs(mnode_t *node, float *polypoints, int numpoints)
152 {
153         int i, front;
154         float *p;
156 loc0:
157         if (!node->plane)
158         {
159                 ((mleaf_t *)node)->portalmarkid = portal_markid;
160                 return;
161         }
163         front = 0;
164         for (i = 0, p = polypoints;i < numpoints;i++, p += 3)
165         {
166                 if (DotProduct(p, node->plane->normal) > node->plane->dist)
167                         front++;
168         }
169         if (front > 0)
170         {
171                 if (front == numpoints)
172                 {
173                         node = node->children[0];
174                         goto loc0;
175                 }
176                 else
177                         Portal_PolygonRecursiveMarkLeafs(node->children[0], polypoints, numpoints);
178         }
179         node = node->children[1];
180         goto loc0;
181 }
183 int Portal_CheckPolygon(model_t *model, vec3_t eye, float *polypoints, int numpoints)
184 {
185         int i, prev, returnvalue;
186         mleaf_t *eyeleaf;
187         vec3_t center, v1, v2;
189         // if there is no model, it can not block visibility
190         if (model == NULL)
191                 return true;
193         portal_markid++;
196         Portal_PolygonRecursiveMarkLeafs(model->brush.data_nodes, polypoints, numpoints);
198         eyeleaf = model->brushq1.PointInLeaf(model, eye);
200         // find the center by averaging
201         VectorClear(center);
202         for (i = 0;i < numpoints;i++)
203                 VectorAdd(center, (&polypoints[i * 3]), center);
204         // ixtable is a 1.0f / N table
205         VectorScale(center, ixtable[numpoints], center);
207         // calculate the planes, and make sure the polygon can see it's own center
208         for (prev = numpoints - 1, i = 0;i < numpoints;prev = i, i++)
209         {
210                 VectorSubtract(eye, (&polypoints[i * 3]), v1);
211                 VectorSubtract((&polypoints[prev * 3]), (&polypoints[i * 3]), v2);
212                 CrossProduct(v1, v2, portalplanes[i].normal);
213                 VectorNormalizeFast(portalplanes[i].normal);
214                 portalplanes[i].dist = DotProduct(eye, portalplanes[i].normal);
215                 if (DotProduct(portalplanes[i].normal, center) <= portalplanes[i].dist)
216                 {
217                         // polygon can't see it's own center, discard
218                         return false;
219                 }
220         }
222         ranoutofportalplanes = false;
223         ranoutofportals = false;
225         returnvalue = Portal_RecursiveFlowSearch(eyeleaf, eye, 0, numpoints);
227         if (ranoutofportalplanes)
228                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
229         if (ranoutofportals)
230                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
232         return returnvalue;
233 }
235 #define Portal_MinsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
236 {\
237         if (eye[(axis)] < ((axisvalue) - 0.5f))\
238         {\
239                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
240                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
241                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
242                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
243                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
244                         return true;\
245         }\
246 }
248 #define Portal_MaxsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
249 {\
250         if (eye[(axis)] > ((axisvalue) + 0.5f))\
251         {\
252                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
253                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
254                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
255                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
256                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
257                         return true;\
258         }\
259 }
261 int Portal_CheckBox(model_t *model, vec3_t eye, vec3_t a, vec3_t b)
262 {
263         if (eye[0] >= (a[0] - 1.0f) && eye[0] < (b[0] + 1.0f)
264          && eye[1] >= (a[1] - 1.0f) && eye[1] < (b[1] + 1.0f)
265          && eye[2] >= (a[2] - 1.0f) && eye[2] < (b[2] + 1.0f))
266                 return true;
268         Portal_MinsBoxPolygon
269         (
270                 0, a[0],
271                 a[0], a[1], a[2],
272                 a[0], b[1], a[2],
273                 a[0], b[1], b[2],
274                 a[0], a[1], b[2]
275         );
276         Portal_MaxsBoxPolygon
277         (
278                 0, b[0],
279                 b[0], b[1], a[2],
280                 b[0], a[1], a[2],
281                 b[0], a[1], b[2],
282                 b[0], b[1], b[2]
283         );
284         Portal_MinsBoxPolygon
285         (
286                 1, a[1],
287                 b[0], a[1], a[2],
288                 a[0], a[1], a[2],
289                 a[0], a[1], b[2],
290                 b[0], a[1], b[2]
291         );
292         Portal_MaxsBoxPolygon
293         (
294                 1, b[1],
295                 a[0], b[1], a[2],
296                 b[0], b[1], a[2],
297                 b[0], b[1], b[2],
298                 a[0], b[1], b[2]
299         );
300         Portal_MinsBoxPolygon
301         (
302                 2, a[2],
303                 a[0], a[1], a[2],
304                 b[0], a[1], a[2],
305                 b[0], b[1], a[2],
306                 a[0], b[1], a[2]
307         );
308         Portal_MaxsBoxPolygon
309         (
310                 2, b[2],
311                 b[0], a[1], b[2],
312                 a[0], a[1], b[2],
313                 a[0], b[1], b[2],
314                 b[0], b[1], b[2]
315         );
317         return false;
318 }
320 vec3_t trianglepoints[3];
322 typedef struct portalrecursioninfo_s
323 {
324         int exact;
325         int numfrustumplanes;
326         vec3_t boxmins;
327         vec3_t boxmaxs;
328         qbyte *surfacemark;
329         qbyte *leafmark;
330         model_t *model;
331         vec3_t eye;
332         float *updateleafsmins;
333         float *updateleafsmaxs;
334 }
335 portalrecursioninfo_t;
337 void Portal_RecursiveFlow_ExactLeafFaces(portalrecursioninfo_t *info, int *mark, int numleafsurfaces, int firstclipplane, int numclipplanes)
338 {
339         int i, j, *elements;
340         vec3_t trimins, trimaxs;
341         msurface_t *surface;
342         for (i = 0;i < numleafsurfaces;i++, mark++)
343         {
344                 if (!info->surfacemark[*mark])
345                 {
346                         // FIXME?  this assumes q1bsp polygon surfaces
347                         surface = info->model->brushq1.surfaces + *mark;
348                         if (surface->mesh.num_vertices)
349                         {
350                                 if (surface->flags & SURF_PLANEBACK)
351                                 {
352                                         if (DotProduct(info->eye, surface->plane->normal) > surface->plane->dist)
353                                                 continue;
354                                 }
355                                 else
356                                 {
357                                         if (DotProduct(info->eye, surface->plane->normal) < surface->plane->dist)
358                                                 continue;
359                                 }
360                                 if (Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, surface->mesh.data_vertex3f, surface->mesh.num_vertices, &portaltemppoints2[0][0], 256) < 3)
361                                         continue;
362                         }
363                         else
364                         {
365                                 for (j = 0, elements = surface->mesh.data_element3i;j < surface->mesh.num_triangles;j++, elements += 3)
366                                 {
367                                         VectorCopy((surface->mesh.data_vertex3f + elements[0] * 3), trianglepoints[0]);
368                                         VectorCopy((surface->mesh.data_vertex3f + elements[1] * 3), trianglepoints[1]);
369                                         VectorCopy((surface->mesh.data_vertex3f + elements[2] * 3), trianglepoints[2]);
370                                         if (PointInfrontOfTriangle(info->eye, trianglepoints[0], trianglepoints[1], trianglepoints[2]))
371                                         {
372                                                 trimins[0] = min(trianglepoints[0][0], min(trianglepoints[1][0], trianglepoints[2][0]));
373                                                 trimaxs[0] = max(trianglepoints[0][0], max(trianglepoints[1][0], trianglepoints[2][0]));
374                                                 trimins[1] = min(trianglepoints[0][1], min(trianglepoints[1][1], trianglepoints[2][1]));
375                                                 trimaxs[1] = max(trianglepoints[0][1], max(trianglepoints[1][1], trianglepoints[2][1]));
376                                                 trimins[2] = min(trianglepoints[0][2], min(trianglepoints[1][2], trianglepoints[2][2]));
377                                                 trimaxs[2] = max(trianglepoints[0][2], max(trianglepoints[1][2], trianglepoints[2][2]));
378                                                 if (BoxesOverlap(trimins, trimaxs, info->boxmins, info->boxmaxs))
379                                                         if (Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, trianglepoints[0], 3, &portaltemppoints2[0][0], 256) >= 3)
380                                                                 break;
381                                         }
382                                 }
383                                 if (j == surface->mesh.num_triangles)
384                                         continue;
385                         }
386                         info->surfacemark[*mark] = true;
387                 }
388         }
389 }
391 void Portal_RecursiveFlow (portalrecursioninfo_t *info, mleaf_t *leaf, int firstclipplane, int numclipplanes)
392 {
393         mportal_t *p;
394         int newpoints, i, prev;
395         float dist;
396         vec3_t center, v1, v2;
397         tinyplane_t *newplanes;
399         for (i = 0;i < 3;i++)
400         {
401                 if (info->updateleafsmins && info->updateleafsmins[i] > leaf->mins[i]) info->updateleafsmins[i] = leaf->mins[i];
402                 if (info->updateleafsmaxs && info->updateleafsmaxs[i] < leaf->maxs[i]) info->updateleafsmaxs[i] = leaf->maxs[i];
403         }
405         if (info->leafmark)
406                 info->leafmark[leaf - info->model->brush.data_leafs] = true;
408         // mark surfaces in leaf that can be seen through portal
409         if (leaf->numleafsurfaces && info->surfacemark)
410         {
411                 if (info->exact)
412                         Portal_RecursiveFlow_ExactLeafFaces(info, leaf->firstleafsurface, leaf->numleafsurfaces, firstclipplane, numclipplanes);
413                 else
414                         for (i = 0;i < leaf->numleafsurfaces;i++)
415                                 info->surfacemark[leaf->firstleafsurface[i]] = true;
416         }
418         // follow portals into other leafs
419         for (p = leaf->portals;p;p = p->next)
420         {
421                 // only flow through portals facing the viewer
422                 dist = PlaneDiff(info->eye, (&p->plane));
423                 if (dist < 0 && BoxesOverlap(p->past->mins, p->past->maxs, info->boxmins, info->boxmaxs))
424                 {
425                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
426                         if (newpoints < 3)
427                                 continue;
428                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
429                                 ranoutofportalplanes = true;
430                         else
431                         {
432                                 // find the center by averaging
433                                 VectorClear(center);
434                                 for (i = 0;i < newpoints;i++)
436                                 // ixtable is a 1.0f / N table
437                                 VectorScale(center, ixtable[newpoints], center);
438                                 // calculate the planes, and make sure the polygon can see it's own center
439                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
440                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
441                                 {
442                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v1);
443                                         VectorSubtract(info->eye, portaltemppoints2[i], v2);
444                                         CrossProduct(v1, v2, newplanes[i].normal);
445                                         VectorNormalizeFast(newplanes[i].normal);
446                                         newplanes[i].dist = DotProduct(info->eye, newplanes[i].normal);
447                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
448                                         {
449                                                 // polygon can't see it's own center, discard and use parent portal
450                                                 break;
451                                         }
452                                 }
453                                 if (i == newpoints)
454                                         Portal_RecursiveFlow(info, p->past, firstclipplane + numclipplanes, newpoints);
455                                 else
456                                         Portal_RecursiveFlow(info, p->past, firstclipplane, numclipplanes);
457                         }
458                 }
459         }
460 }
462 void Portal_RecursiveFindLeafForFlow(portalrecursioninfo_t *info, mnode_t *node)
463 {
464         if (node->plane)
465         {
466                 float f = DotProduct(info->eye, node->plane->normal) - node->plane->dist;
467                 if (f > -0.1)
468                         Portal_RecursiveFindLeafForFlow(info, node->children[0]);
469                 if (f < 0.1)
470                         Portal_RecursiveFindLeafForFlow(info, node->children[1]);
471         }
472         else
473         {
474                 mleaf_t *leaf = (mleaf_t *)node;
475                 if (leaf->portals)
476                         Portal_RecursiveFlow(info, leaf, 0, info->numfrustumplanes);
477         }
478 }
480 void Portal_Visibility(model_t *model, const vec3_t eye, qbyte *leafmark, qbyte *surfacemark, const mplane_t *frustumplanes, int numfrustumplanes, int exact, const float *boxmins, const float *boxmaxs, float *updateleafsmins, float *updateleafsmaxs)
481 {
482         int i;
483         portalrecursioninfo_t info;
485         // if there is no model, it can not block visibility
486         if (model == NULL)
487         {
488                 Con_Print("Portal_Visibility: NULL model\n");
489                 return;
490         }
494         if (!model->brush.num_portals)
495         {
496                 Con_Print("Portal_Visibility: not a brush model\n");
497                 return;
498         }
500         // put frustum planes (if any) into tinyplane format at start of buffer
501         for (i = 0;i < numfrustumplanes;i++)
502         {
503                 VectorCopy(frustumplanes[i].normal, portalplanes[i].normal);
504                 portalplanes[i].dist = frustumplanes[i].dist;
505         }
507         ranoutofportalplanes = false;
508         ranoutofportals = false;
510         VectorCopy(boxmins, info.boxmins);
511         VectorCopy(boxmaxs, info.boxmaxs);
512         info.exact = exact;
513         info.surfacemark = surfacemark;
514         info.leafmark = leafmark;
515         info.model = model;
516         VectorCopy(eye, info.eye);
517         info.numfrustumplanes = numfrustumplanes;
518         info.updateleafsmins = updateleafsmins;
519         info.updateleafsmaxs = updateleafsmaxs;
521         Portal_RecursiveFindLeafForFlow(&info, model->brush.data_nodes);
523         if (ranoutofportalplanes)
524                 Con_Printf("Portal_RecursiveFlow: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
525         if (ranoutofportals)
526                 Con_Printf("Portal_RecursiveFlow: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
527 }