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 portalplanecount;
   9 static int ranoutofportalplanes;
  10 static int ranoutofportals;
  11 static float portaltemppoints[2][256][3];
  12 static float portaltemppoints2[256][3];
  13 static int portal_markid = 0;
  14 //float viewportalpoints[16*3];
  15 static float boxpoints[4*3];
  16
  17 int Portal_ClipPolygonToPlane(float *in, float *out, int inpoints, int maxoutpoints, tinyplane_t *p)
  18 {
  19         int i, outpoints, prevside, side;
  20         float *prevpoint, prevdist, dist, dot;
  21
  22         if (inpoints < 3)
  23                 return inpoints;
  24         // begin with the last point, then enter the loop with the first point as current
  25         prevpoint = in + 3 * (inpoints - 1);
  26         prevdist = DotProduct(prevpoint, p->normal) - p->dist;
  27         prevside = prevdist >= 0 ? SIDE_FRONT : SIDE_BACK;
  28         i = 0;
  29         outpoints = 0;
  30         goto begin;
  31         for (;i < inpoints;i++)
  32         {
  33                 prevpoint = in;
  34                 prevdist = dist;
  35                 prevside = side;
  36                 in += 3;
  37
  38 begin:
  39                 dist = DotProduct(in, p->normal) - p->dist;
  40                 side = dist >= 0 ? SIDE_FRONT : SIDE_BACK;
  41
  42                 if (prevside == SIDE_FRONT)
  43                 {
  44                         if (outpoints >= maxoutpoints)
  45                                 return -1;
  46                         VectorCopy(prevpoint, out);
  47                         out += 3;
  48                         outpoints++;
  49                         if (side == SIDE_FRONT)
  50                                 continue;
  51                 }
  52                 else if (side == SIDE_BACK)
  53                         continue;
  54
  55                 // generate a split point
  56                 if (outpoints >= maxoutpoints)
  57                         return -1;
  58                 dot = prevdist / (prevdist - dist);
  59                 out[0] = prevpoint[0] + dot * (in[0] - prevpoint[0]);
  60                 out[1] = prevpoint[1] + dot * (in[1] - prevpoint[1]);
  61                 out[2] = prevpoint[2] + dot * (in[2] - prevpoint[2]);
  62                 out += 3;
  63                 outpoints++;
  64         }
  65
  66         return outpoints;
  67 }
  68
  69 /*
  70 void Portal_TriangleToPlane(vec3_t point1, vec3_t point2, vec3_t point3, tinyplane_t *p)
  71 {
  72         vec3_t v1, v2;
  73         VectorSubtract(point1, point2, v1);
  74         VectorSubtract(point3, point2, v2);
  75         CrossProduct(v1, v2, p->normal);
  76 //      VectorNormalize(p->normal);
  77         VectorNormalizeFast(p->normal);
  78         p->dist = DotProduct(point1, p->normal);
  79 }
  80 */
  81
  82 int Portal_PortalThroughPortalPlanes(tinyplane_t *clipplanes, int clipnumplanes, float *targpoints, int targnumpoints, float *out, int maxpoints)
  83 {
  84         int numpoints, i;
  85         if (targnumpoints < 3)
  86                 return targnumpoints;
  87         if (maxpoints < 3)
  88                 return -1;
  89         numpoints = targnumpoints;
  90         memcpy(&portaltemppoints[0][0][0], targpoints, numpoints * 3 * sizeof(float));
  91         for (i = 0;i < clipnumplanes;i++)
  92         {
  93                 numpoints = Portal_ClipPolygonToPlane(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints, 256, clipplanes + i);
  94                 if (numpoints < 3)
  95                         return numpoints;
  96                 memcpy(&portaltemppoints[0][0][0], &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
  97         }
  98         if (numpoints > maxpoints)
  99                 return -1;
 100         memcpy(out, &portaltemppoints[1][0][0], numpoints * 3 * sizeof(float));
 101         return numpoints;
 102 }
 103
 104 int Portal_RecursiveFlowSearch (mleaf_t *leaf, vec3_t eye, int firstclipplane, int numclipplanes)
 105 {
 106         mportal_t *p;
 107         int newpoints, i, prev;
 108         vec3_t center, v1, v2;
 109         tinyplane_t *newplanes;
 110
 111         if (leaf->portalmarkid == portal_markid)
 112                 return true;
 113
 114         // follow portals into other leafs
 115         for (p = leaf->portals;p;p = p->next)
 116         {
 117                 // only flow through portals facing away from the viewer
 118                 if (PlaneDiff(eye, (&p->plane)) < 0)
 119                 {
 120                         newpoints = Portal_PortalThroughPortalPlanes(&portalplanes[firstclipplane], numclipplanes, (float *) p->points, p->numpoints, &portaltemppoints2[0][0], 256);
 121                         if (newpoints < 3)
 122                                 continue;
 123                         else if (firstclipplane + numclipplanes + newpoints > MAXRECURSIVEPORTALPLANES)
 124                                 ranoutofportalplanes = true;
 125                         else
 126                         {
 127                                 // find the center by averaging
 128                                 VectorClear(center);
 129                                 for (i = 0;i < newpoints;i++)
 130                                         VectorAdd(center, portaltemppoints2[i], center);
 131                                 // ixtable is a 1.0f / N table
 132                                 VectorScale(center, ixtable[newpoints], center);
 133                                 // calculate the planes, and make sure the polygon can see it's own center
 134                                 newplanes = &portalplanes[firstclipplane + numclipplanes];
 135                                 for (prev = newpoints - 1, i = 0;i < newpoints;prev = i, i++)
 136                                 {
 137 //                                      Portal_TriangleToPlane(eye, portaltemppoints2[i], portaltemppoints2[prev], newplanes + i);
 138                                         VectorSubtract(eye, portaltemppoints2[i], v1);
 139                                         VectorSubtract(portaltemppoints2[prev], portaltemppoints2[i], v2);
 140                                         CrossProduct(v1, v2, newplanes[i].normal);
 141                                         VectorNormalizeFast(newplanes[i].normal);
 142                                         newplanes[i].dist = DotProduct(eye, newplanes[i].normal);
 143                                         if (DotProduct(newplanes[i].normal, center) <= newplanes[i].dist)
 144                                         {
 145                                                 // polygon can't see it's own center, discard and use parent portal
 146                                                 break;
 147                                         }
 148                                 }
 149                                 if (i == newpoints)
 150                                 {
 151                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane + numclipplanes, newpoints))
 152                                                 return true;
 153                         }
 154                                 else
 155                                 {
 156                                         if (Portal_RecursiveFlowSearch(p->past, eye, firstclipplane, numclipplanes))
 157                                                 return true;
 158                         }
 159                         }
 160                 }
 161         }
 162
 163         return false;
 164 }
 165
 166 void Portal_PolygonRecursiveMarkLeafs(mnode_t *node, float *polypoints, int numpoints)
 167 {
 168         int i, front;
 169         float *p;
 170
 171 loc0:
 172         if (node->contents < 0)
 173         {
 174                 ((mleaf_t *)node)->portalmarkid = portal_markid;
 175                 return;
 176         }
 177
 178         front = 0;
 179         for (i = 0, p = polypoints;i < numpoints;i++, p += 3)
 180         {
 181                 if (DotProduct(p, node->plane->normal) > node->plane->dist)
 182                         front++;
 183         }
 184         if (front > 0)
 185         {
 186                 if (front == numpoints)
 187                 {
 188                         node = node->children[0];
 189                         goto loc0;
 190                 }
 191                 else
 192                         Portal_PolygonRecursiveMarkLeafs(node->children[0], polypoints, numpoints);
 193         }
 194         node = node->children[1];
 195         goto loc0;
 196 }
 197
 198 int Portal_CheckPolygon(model_t *model, vec3_t eye, float *polypoints, int numpoints)
 199 {
 200         int i, prev, returnvalue;
 201         mleaf_t *eyeleaf;
 202         vec3_t center, v1, v2;
 203
 204         portal_markid++;
 205
 206         Mod_CheckLoaded(model);
 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 //              Portal_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 }