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->contents < 0)
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->nodes, polypoints, numpoints);
198         eyeleaf = Mod_PointInLeaf(eye, model);
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;
326         qbyte *surfacemark;
327         qbyte *leafmark;
328         model_t *model;
329         vec3_t eye;
330 }
331 portalrecursioninfo_t;
333 void Portal_RecursiveFlow_ExactMarkSurfaces(portalrecursioninfo_t *info, int *mark, int nummarksurfaces, int firstclipplane, int numclipplanes)
334 {
335         int i, j, *elements;
336         msurface_t *surf;
337         surfmesh_t *surfmesh;
338         for (i = 0;i < nummarksurfaces;i++, mark++)
339         {
340                 if (!info->surfacemark[*mark])
341                 {
342                         surf = info->model->surfaces + *mark;
343                         if (surf->poly_numverts)
344                         {
345                                 if (surf->flags & SURF_PLANEBACK)
346                                 {
347                                         if (DotProduct(info->eye, surf->plane->normal) > surf->plane->dist)
348                                                 continue;
349                                 }
350                                 else
351                                 {
352                                         if (DotProduct(info->eye, surf->plane->normal) < surf->plane->dist)
353                                                 continue;
354                                 }
355                                 if (Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, surf->poly_verts, surf->poly_numverts, &portaltemppoints2[0][0], 256) < 3)
356                                         continue;
357                         }
358                         else
359                         {
360                                 for (surfmesh = surf->mesh;surfmesh;surfmesh = surfmesh->chain)
361                                 {
362                                         for (j = 0, elements = surfmesh->index;j < surfmesh->numtriangles;j++, elements += 3)
363                                         {
364                                                 VectorCopy((surfmesh->verts + elements[0] * 4), trianglepoints[0]);
365                                                 VectorCopy((surfmesh->verts + elements[1] * 4), trianglepoints[1]);
366                                                 VectorCopy((surfmesh->verts + elements[2] * 4), trianglepoints[2]);
367                                                 if ((info->eye[0] - trianglepoints[0][0]) * ((trianglepoints[0][1] - trianglepoints[1][1]) * (trianglepoints[2][2] - trianglepoints[1][2]) - (trianglepoints[0][2] - trianglepoints[1][2]) * (trianglepoints[2][1] - trianglepoints[1][1]))
368                                                   + (info->eye[1] - trianglepoints[0][1]) * ((trianglepoints[0][2] - trianglepoints[1][2]) * (trianglepoints[2][0] - trianglepoints[1][0]) - (trianglepoints[0][0] - trianglepoints[1][0]) * (trianglepoints[2][2] - trianglepoints[1][2]))
369                                                   + (info->eye[2] - trianglepoints[0][2]) * ((trianglepoints[0][0] - trianglepoints[1][0]) * (trianglepoints[2][1] - trianglepoints[1][1]) - (trianglepoints[0][1] - trianglepoints[1][1]) * (trianglepoints[2][0] - trianglepoints[1][0])) > 0
370                                                  && Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, trianglepoints[0], 3, &portaltemppoints2[0][0], 256) >= 3)
371                                                         break;
372                                         }
373                                         if (j < surfmesh->numtriangles)
374                                                 break;
375                                 }
376                                 if (surfmesh == NULL)
377                                         continue;
378                         }
379                         info->surfacemark[*mark] = true;
380                 }
381         }
382 }
384 void Portal_RecursiveFlow (portalrecursioninfo_t *info, mleaf_t *leaf, int firstclipplane, int numclipplanes)
385 {
386         mportal_t *p;
387         int newpoints, i, prev;
388         float dist;
389         vec3_t center, v1, v2;
390         tinyplane_t *newplanes;
392         if (info->leafmark)
393                 info->leafmark[leaf - info->model->leafs] = true;
395         // mark surfaces in leaf that can be seen through portal
396         if (leaf->nummarksurfaces && info->surfacemark)
397         {
398                 if (info->exact)
399                         Portal_RecursiveFlow_ExactMarkSurfaces(info, leaf->firstmarksurface, leaf->nummarksurfaces, firstclipplane, numclipplanes);
400                 else
401                         for (i = 0;i < leaf->nummarksurfaces;i++)
402                                 info->surfacemark[leaf->firstmarksurface[i]] = true;
403         }
405         // follow portals into other leafs
406         for (p = leaf->portals;p;p = p->next)
407         {
408                 // only flow through portals facing away from the viewer
409                 dist = PlaneDiff(info->eye, (&p->plane));
410                 if (dist < 0 && dist >= info->nradius)
411                 {
412                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
413                         if (newpoints < 3)
414                                 continue;
415                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
416                                 ranoutofportalplanes = true;
417                         else
418                         {
419                                 // find the center by averaging
420                                 VectorClear(center);
421                                 for (i = 0;i < newpoints;i++)
423                                 // ixtable is a 1.0f / N table
424                                 VectorScale(center, ixtable[newpoints], center);
425                                 // calculate the planes, and make sure the polygon can see it's own center
426                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
427                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
428                                 {
429                                         VectorSubtract(info->eye, portaltemppoints2[i], v1);
430                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
431                                         CrossProduct(v1, v2, newplanes[i].normal);
432                                         VectorNormalizeFast(newplanes[i].normal);
433                                         newplanes[i].dist = DotProduct(info->eye, newplanes[i].normal);
434                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
435                                         {
436                                                 // polygon can't see it's own center, discard and use parent portal
437                                                 break;
438                                         }
439                                 }
440                                 if (i == newpoints)
441                                         Portal_RecursiveFlow(info, p->past, firstclipplane + numclipplanes, newpoints);
442                                 else
443                                         Portal_RecursiveFlow(info, p->past, firstclipplane, numclipplanes);
444                         }
445                 }
446         }
447 }
449 void Portal_Visibility(model_t *model, const vec3_t eye, qbyte *leafmark, qbyte *surfacemark, const mplane_t *frustumplanes, int numfrustumplanes, int exact, float radius)
450 {
451         int i;
452         portalrecursioninfo_t info;
454         // if there is no model, it can not block visibility
455         if (model == NULL)
456                 Host_Error("Portal_Visibility: NULL model\n");
460         if (model->type != mod_brush)
461                 Host_Error("Portal_Visibility: not a brush model\n");
463         // put frustum planes (if any) into tinyplane format at start of buffer
464         for (i = 0;i < numfrustumplanes;i++)
465         {
466                 VectorCopy(frustumplanes[i].normal, portalplanes[i].normal);
467                 portalplanes[i].dist = frustumplanes[i].dist;
468         }
470         ranoutofportalplanes = false;
471         ranoutofportals = false;