portals.c

   1
   2 #include "quakedef.h"
   3
   4 #define MAXRECURSIVEPORTALPLANES 1024
   5 #define MAXRECURSIVEPORTALS 256
   6
   7 static tinyplane_t portalplanes[MAXRECURSIVEPORTALPLANES];
   8 static int portalplanestack[MAXRECURSIVEPORTALS];
   9 static int portalplanecount;
  10 static int ranoutofportalplanes;
  11 static int ranoutofportals;
  12 static float portaltemppoints[2][256][3];
  13 static float portaltemppoints2[256][3];
  14 static int portal_markid = 0;
  15 //float viewportalpoints[16*3];
  16 static float boxpoints[4*3];
  17
  18 int R_ClipPolygonToPlane(float *in, float *out, int inpoints, int maxoutpoints, tinyplane_t *p)
  19 {
  20         int i, outpoints, prevside, side;
  21         float *prevpoint, prevdist, dist, dot;
  22
  23         if (inpoints < 3)
  24                 return inpoints;
  25         // begin with the last point, then enter the loop with the first point as current
  26         prevpoint = in + 3 * (inpoints - 1);
  27         prevdist = DotProduct(prevpoint, p->normal) - p->dist;
  28         prevside = prevdist >= 0 ? SIDE_FRONT : SIDE_BACK;
  29         i = 0;
  30         outpoints = 0;
  31         goto begin;
  32         for (;i < inpoints;i++)
  33         {
  34                 prevpoint = in;
  35                 prevdist = dist;
  36                 prevside = side;
  37                 in += 3;
  38
  39 begin:
  40                 dist = DotProduct(in, p->normal) - p->dist;
  41                 side = dist >= 0 ? SIDE_FRONT : SIDE_BACK;
  42
  43                 if (prevside == SIDE_FRONT)
  44                 {
  45                         if (outpoints >= maxoutpoints)
  46                                 return -1;
  47                         VectorCopy(prevpoint, out);
  48                         out += 3;
  49                         outpoints++;
  50                         if (side == SIDE_FRONT)
  51                                 continue;
  52                 }
  53                 else if (side == SIDE_BACK)
  54                         continue;
  55
  56                 // generate a split point
  57                 if (outpoints >= maxoutpoints)
  58                         return -1;
  59                 dot = prevdist / (prevdist - dist);
  60                 out[0] = prevpoint[0] + dot * (in[0] - prevpoint[0]);
  61                 out[1] = prevpoint[1] + dot * (in[1] - prevpoint[1]);
  62                 out[2] = prevpoint[2] + dot * (in[2] - prevpoint[2]);
  63                 out += 3;
  64                 outpoints++;
  65         }
  66
  67         return outpoints;
  68 }
  69
  70 /*
  71 void R_TriangleToPlane(vec3_t point1, vec3_t point2, vec3_t point3, tinyplane_t *p)
  72 {
  73         vec3_t v1, v2;
  74         VectorSubtract(point1, point2, v1);
  75         VectorSubtract(point3, point2, v2);
  76         CrossProduct(v1, v2, p->normal);
  77 //      VectorNormalize(p->normal);
  78         VectorNormalizeFast(p->normal);
  79         p->dist = DotProduct(point1, p->normal);
  80 }
  81 */
  82
  83 int R_PortalThroughPortalPlanes(tinyplane_t *clipplanes, int clipnumplanes, float *targpoints, int targnumpoints, float *out, int maxpoints)
  84 {
  85         int numpoints, i;
  86         if (targnumpoints < 3)
  87                 return targnumpoints;
  88         if (maxpoints < 3)
  89                 return -1;
  90         numpoints = targnumpoints;
  91         memcpy(&portaltemppoints[0][0][0], targpoints, numpoints * 3 * sizeof(float));
  92         for (i = 0;i < clipnumplanes;i++)
  93         {
  94                 numpoints = R_ClipPolygonToPlane(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints, 256, clipplanes + i);
  95                 if (numpoints < 3)
  96                         return numpoints;
  97                 memcpy(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
  98         }
  99         if (numpoints > maxpoints)
 100                 return -1;
 101         memcpy(out, &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
 102         return numpoints;
 103 }
 104
 105 int Portal_RecursiveFlowSearch (mleaf_t *leaf, vec3_t eye, int firstclipplane, int numclipplanes)
 106 {
 107         mportal_t *p;
 108         int newpoints, i, prev;
 109         vec3_t center, v1, v2;
 110         tinyplane_t *newplanes;
 111
 112         if (leaf->portalmarkid == portal_markid)
 113                 return true;
 114
 115         // follow portals into other leafs
 116         for (p = leaf->portals;p;p = p->next)
 117         {
 118                 // only flow through portals facing away from the viewer
 119                 if (PlaneDiff(eye, (&p->plane)) < 0)
 120                 {
 121                         newpoints = R_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
 122                         if (newpoints < 3)
 123                                 continue;
 124                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
 125                                 ranoutofportalplanes = true;
 126                         else
 127                         {
 128                                 // find the center by averaging
 129                                 VectorClear(center);
 130                                 for (i = 0;i < newpoints;i++)
 131                                         VectorAdd(center, portaltemppoints2[i], center);
 132                                 // ixtable is a 1.0f / N table
 133                                 VectorScale(center, ixtable[newpoints], center);
 134                                 // calculate the planes, and make sure the polygon can see it's own center
 135                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
 136                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
 137                                 {
 138 //                                      R_TriangleToPlane(eye, portaltemppoints2[i], portaltemppoints2[prev], newplanes + i);
 139                                         VectorSubtract(eye, portaltemppoints2[i], v1);
 140                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
 141                                         CrossProduct(v1, v2, newplanes[i].normal);
 142                                         VectorNormalizeFast(newplanes[i].normal);
 143                                         newplanes[i].dist = DotProduct(eye, newplanes[i].normal);
 144                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
 145                                         {
 146                                                 // polygon can't see it's own center, discard and use parent portal
 147                                                 break;
 148                                         }
 149                                 }
 150                                 if (i == newpoints)
 151                                 {
 152                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane + numclipplanes, newpoints))
 153                                                 return true;
 154                         }
 155                                 else
 156                                 {
 157                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane, numclipplanes))
 158                                                 return true;
 159                         }
 160                         }
 161                 }
 162         }
 163
 164         return false;
 165 }
 166
 167 void Portal_PolygonRecursiveMarkLeafs(mnode_t *node, float *polypoints, int numpoints)
 168 {
 169         int i, front;
 170         float *p;
 171
 172 loc0:
 173         if (node->contents < 0)
 174         {
 175                 ((mleaf_t *)node)->portalmarkid = portal_markid;
 176                 return;
 177         }
 178
 179         front = 0;
 180         for (i = 0, p = polypoints;i < numpoints;i++, p += 3)
 181         {
 182                 if (DotProduct(p, node->plane->normal) > node->plane->dist)
 183                         front++;
 184         }
 185         if (front > 0)
 186         {
 187                 if (front == numpoints)
 188                 {
 189                         node = node->children[0];
 190                         goto loc0;
 191                 }
 192                 else
 193                         Portal_PolygonRecursiveMarkLeafs(node->children[0], polypoints, numpoints);
 194         }
 195         node = node->children[1];
 196         goto loc0;
 197 }
 198
 199 int Portal_CheckPolygon(model_t *model, vec3_t eye, float *polypoints, int numpoints)
 200 {
 201         int i, prev, returnvalue;
 202         mleaf_t *eyeleaf;
 203         vec3_t center, v1, v2;
 204
 205         portal_markid++;
 206
 207         Portal_PolygonRecursiveMarkLeafs(model->nodes, polypoints, numpoints);
 208
 209         eyeleaf = Mod_PointInLeaf(eye, model);
 210
 211         // find the center by averaging
 212         VectorClear(center);
 213         for (i = 0;i < numpoints;i++)
 214                 VectorAdd(center, (&polypoints[i * 3]), center);
 215         // ixtable is a 1.0f / N table
 216         VectorScale(center, ixtable[numpoints], center);
 217
 218         // calculate the planes, and make sure the polygon can see it's own center
 219         for (prev = numpoints - 1, i = 0;i < numpoints;prev = i, i++)
 220         {
 221 //              R_TriangleToPlane(eye, portaltemppoints2[i], portaltemppoints2[prev], newplanes + i);
 222                 VectorSubtract(eye, (&polypoints[i * 3]), v1);
 223                 VectorSubtract((&polypoints[prev * 3]), (&polypoints[i * 3]), v2);
 224                 CrossProduct(v1, v2, portalplanes[i].normal);
 225                 VectorNormalizeFast(portalplanes[i].normal);
 226                 portalplanes[i].dist = DotProduct(eye, portalplanes[i].normal);
 227                 if (DotProduct(portalplanes[i].normal, center) <= portalplanes[i].dist)
 228                 {
 229                         // polygon can't see it's own center, discard
 230                         return false;
 231                 }
 232         }
 233
 234         portalplanecount = 0;
 235         ranoutofportalplanes = false;
 236         ranoutofportals = false;
 237
 238         returnvalue = Portal_RecursiveFlowSearch(eyeleaf, eye, 0, numpoints);
 239
 240         if (ranoutofportalplanes)
 241                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d plane stack when recursing through portals\n", MAXRECURSIVEPORTALPLANES);
 242         if (ranoutofportals)
 243                 Con_Printf("Portal_RecursiveFlowSearch: ran out of %d portal stack when recursing through portals\n", MAXRECURSIVEPORTALS);
 244
 245         return returnvalue;
 246 }
 247
 248 #define Portal_MinsBoxPolygon(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 }
 260
 261 #define Portal_MaxsBoxPolygon(axis, axisvalue, x1, y1, z1, x2, y2, z2, x3, y3, z3, x4, y4, z4) \
 262 {\
 263         if (eye[(axis)] > ((axisvalue) + 0.5f))\
 264         {\
 265                 boxpoints[ 0] = x1;boxpoints[ 1] = y1;boxpoints[ 2] = z1;\
 266                 boxpoints[ 3] = x2;boxpoints[ 4] = y2;boxpoints[ 5] = z2;\
 267                 boxpoints[ 6] = x3;boxpoints[ 7] = y3;boxpoints[ 8] = z3;\
 268                 boxpoints[ 9] = x4;boxpoints[10] = y4;boxpoints[11] = z4;\
 269                 if (Portal_CheckPolygon(model, eye, boxpoints, 4))\
 270                         return true;\
 271         }\
 272 }
 273
 274 int Portal_CheckBox(model_t *model, vec3_t eye, vec3_t a, vec3_t b)
 275 {
 276         if (eye[0] >= (a[0] - 1.0f) && eye[0] < (b[0] + 1.0f)
 277          && eye[1] >= (a[1] - 1.0f) && eye[1] < (b[1] + 1.0f)
 278          && eye[2] >= (a[2] - 1.0f) && eye[2] < (b[2] + 1.0f))
 279                 return true;
 280
 281         Portal_MinsBoxPolygon
 282         (
 283                 0, a[0],
 284                 a[0], a[1], a[2],
 285                 a[0], b[1], a[2],
 286                 a[0], b[1], b[2],
 287                 a[0], a[1], b[2]
 288         );
 289         Portal_MaxsBoxPolygon
 290         (
 291                 0, b[0],
 292                 b[0], b[1], a[2],
 293                 b[0], a[1], a[2],
 294                 b[0], a[1], b[2],
 295                 b[0], b[1], b[2]
 296         );
 297         Portal_MinsBoxPolygon
 298         (
 299                 1, a[1],
 300                 b[0], a[1], a[2],
 301                 a[0], a[1], a[2],
 302                 a[0], a[1], b[2],
 303                 b[0], a[1], b[2]
 304         );
 305         Portal_MaxsBoxPolygon
 306         (
 307                 1, b[1],
 308                 a[0], b[1], a[2],
 309                 b[0], b[1], a[2],
 310                 b[0], b[1], b[2],
 311                 a[0], b[1], b[2]
 312         );
 313         Portal_MinsBoxPolygon
 314         (
 315                 2, a[2],
 316                 a[0], a[1], a[2],
 317                 b[0], a[1], a[2],
 318                 b[0], b[1], a[2],
 319                 a[0], b[1], a[2]
 320         );
 321         Portal_MaxsBoxPolygon
 322         (
 323                 2, b[2],
 324                 b[0], a[1], b[2],
 325                 a[0], a[1], b[2],
 326                 a[0], b[1], b[2],
 327                 b[0], b[1], b[2]
 328         );
 329
 330         return false;
 331 }