// Shadow Volume BSP code written by Forest "LordHavoc" Hale on 2003-11-06 and placed into public domain.
// Modified by LordHavoc (to make it work and other nice things like that) on 2007-01-24 and 2007-01-25
+// Optimized by LordHavoc on 2009-12-24 and 2009-12-25
#include <math.h>
#include <string.h>
#include "polygon.h"
#define MAX_SVBSP_POLYGONPOINTS 64
-#define SVBSP_CLIP_EPSILON (1.0 / 1024.0)
+#define SVBSP_CLIP_EPSILON (1.0f / 1024.0f)
#define SVBSP_DotProduct(a,b) ((a)[0]*(b)[0]+(a)[1]*(b)[1]+(a)[2]*(b)[2])
+typedef struct svbsp_polygon_s
+{
+ float points[MAX_SVBSP_POLYGONPOINTS][3];
+ //unsigned char splitflags[MAX_SVBSP_POLYGONPOINTS];
+ int facesplitflag;
+ int numpoints;
+}
+svbsp_polygon_t;
+
static void SVBSP_PlaneFromPoints(float *plane4f, const float *p1, const float *p2, const float *p3)
{
float ilength;
plane4f[2] = (p1[0] - p2[0]) * (p3[1] - p2[1]) - (p1[1] - p2[1]) * (p3[0] - p2[0]);
plane4f[3] = SVBSP_DotProduct(plane4f, p1);
// normalize the plane normal and adjust distance accordingly
- ilength = sqrt(SVBSP_DotProduct(plane4f, plane4f));
+ ilength = (float)sqrt(SVBSP_DotProduct(plane4f, plane4f));
if (ilength)
- ilength = 1.0 / ilength;
+ ilength = 1.0f / ilength;
plane4f[0] *= ilength;
plane4f[1] *= ilength;
plane4f[2] *= ilength;
plane4f[3] *= ilength;
}
+static void SVBSP_DividePolygon(const svbsp_polygon_t *poly, const float *plane, svbsp_polygon_t *front, svbsp_polygon_t *back, const float *dists, const int *sides)
+{
+ int i, j, count = poly->numpoints, frontcount = 0, backcount = 0;
+ float frac, ifrac, c[3], pdist, ndist;
+ const float *nextpoint;
+ const float *points = poly->points[0];
+ float *outfront = front->points[0];
+ float *outback = back->points[0];
+ for(i = 0;i < count;i++, points += 3)
+ {
+ j = i + 1;
+ if (j >= count)
+ j = 0;
+ if (!(sides[i] & 2))
+ {
+ outfront[frontcount*3+0] = points[0];
+ outfront[frontcount*3+1] = points[1];
+ outfront[frontcount*3+2] = points[2];
+ frontcount++;
+ }
+ if (!(sides[i] & 1))
+ {
+ outback[backcount*3+0] = points[0];
+ outback[backcount*3+1] = points[1];
+ outback[backcount*3+2] = points[2];
+ backcount++;
+ }
+ if ((sides[i] | sides[j]) == 3)
+ {
+ // don't allow splits if remaining points would overflow point buffer
+ if (frontcount + (count - i) > MAX_SVBSP_POLYGONPOINTS - 1)
+ continue;
+ if (backcount + (count - i) > MAX_SVBSP_POLYGONPOINTS - 1)
+ continue;
+ nextpoint = poly->points[j];
+ pdist = dists[i];
+ ndist = dists[j];
+ frac = pdist / (pdist - ndist);
+ ifrac = 1.0f - frac;
+ c[0] = points[0] * ifrac + frac * nextpoint[0];
+ c[1] = points[1] * ifrac + frac * nextpoint[1];
+ c[2] = points[2] * ifrac + frac * nextpoint[2];
+ outfront[frontcount*3+0] = c[0];
+ outfront[frontcount*3+1] = c[1];
+ outfront[frontcount*3+2] = c[2];
+ frontcount++;
+ outback[backcount*3+0] = c[0];
+ outback[backcount*3+1] = c[1];
+ outback[backcount*3+2] = c[2];
+ backcount++;
+ }
+ }
+ front->numpoints = frontcount;
+ back->numpoints = backcount;
+}
+
void SVBSP_Init(svbsp_t *b, const float *origin, int maxnodes, svbsp_node_t *nodes)
{
memset(b, 0, sizeof(*b));
b->nodes[2].children[1] = -1;
}
-static void SVBSP_InsertOccluderPolygonNodes(svbsp_t *b, int *parentnodenumpointer, int parentnodenum, int numpoints, const float *points, void (*fragmentcallback)(void *fragmentcallback_pointer1, int fragmentcallback_number1, svbsp_t *b, int numpoints, const float *points), void *fragmentcallback_pointer1, int fragmentcallback_number1)
+static void SVBSP_InsertOccluderPolygonNodes(svbsp_t *b, int *parentnodenumpointer, int parentnodenum, const svbsp_polygon_t *poly, void (*fragmentcallback)(void *fragmentcallback_pointer1, int fragmentcallback_number1, svbsp_t *b, int numpoints, const float *points), void *fragmentcallback_pointer1, int fragmentcallback_number1)
{
// now we need to create up to numpoints + 1 new nodes, forming a BSP tree
// describing the occluder polygon's shadow volume
- int i, j, p, basenum;
+ int i, j, p;
svbsp_node_t *node;
-#if 1
- unsigned int sideflags[(MAX_SVBSP_POLYGONPOINTS+31)>>5];
-#endif
+
+ // points and lines are valid testers but not occluders
+ if (poly->numpoints < 3)
+ return;
// if there aren't enough nodes remaining, skip it
- if (b->numnodes + numpoints + 1 >= b->maxnodes)
+ if (b->numnodes + poly->numpoints + 1 >= b->maxnodes)
{
b->ranoutofnodes = 1;
return;
// note down the first available nodenum for the *parentnodenumpointer
// line which is done last to allow multithreaded queries during an
// insertion
- basenum = b->numnodes;
-#if 1
- // iterate parent planes and check if any sides of the polygon lie on their plane - if so the polygon can not contribute a new node for that side
- memset(sideflags, 0, sizeof(sideflags[0])*((numpoints+31)>>5));
- for (j = parentnodenum;j >= 0;j = b->nodes[j].parent)
+ for (i = 0, p = poly->numpoints - 1;i < poly->numpoints;p = i, i++)
{
- float *parentnodeplane = b->nodes[j].plane;
- float plane[4] = {parentnodeplane[0], parentnodeplane[1], parentnodeplane[2], parentnodeplane[3]};
- float mindist = plane[3] - SVBSP_CLIP_EPSILON;
- float maxdist = plane[3] + SVBSP_CLIP_EPSILON;
- float d;
- int i, p, n;
- // if a parent plane crosses the origin, it is a side plane
- // if it does not cross the origin, it is a face plane, and thus will
- // not match any side planes we could add
- d = SVBSP_DotProduct(b->origin , plane);
- if (d < mindist || d > maxdist)
- continue;
- // classify each side as belonging to this parent plane or not
- // do a distance check on the last point of the polygon first, and
- // then one distance check per point, reusing the previous point
- // distance check to classify this side as being on or off the plane
- i = numpoints-1;
- d = SVBSP_DotProduct(points + i * 3, plane);
- p = d >= mindist && d <= maxdist;
- for (i = 0;i < numpoints;i++)
+#if 1
+ // see if a parent plane describes this side
+ for (j = parentnodenum;j >= 0;j = b->nodes[j].parent)
{
- d = SVBSP_DotProduct(points + i * 3, plane);
- n = d >= mindist && d <= maxdist;
- if (p && n)
- sideflags[i>>5] |= 1<<(i&31);
- p = n;
+ float *parentnodeplane = b->nodes[j].plane;
+ if (fabs(SVBSP_DotProduct(poly->points[p], parentnodeplane) - parentnodeplane[3]) < SVBSP_CLIP_EPSILON
+ && fabs(SVBSP_DotProduct(poly->points[i], parentnodeplane) - parentnodeplane[3]) < SVBSP_CLIP_EPSILON
+ && fabs(SVBSP_DotProduct(b->origin , parentnodeplane) - parentnodeplane[3]) < SVBSP_CLIP_EPSILON)
+ break;
}
+ if (j >= 0)
+ continue; // already have a matching parent plane
#endif
- }
-
- for (i = 0, p = numpoints - 1;i < numpoints;p = i, i++)
- {
-#if 1
+#if 0
// skip any sides that were classified as belonging to a parent plane
- if (sideflags[i>>5] & (1<<(i&31)))
+ if (poly->splitflags[i])
continue;
#endif
// create a side plane
// anything infront of this is not inside the shadow volume
node = b->nodes + b->numnodes++;
- SVBSP_PlaneFromPoints(node->plane, b->origin, points + p * 3, points + i * 3);
+ SVBSP_PlaneFromPoints(node->plane, b->origin, poly->points[p], poly->points[i]);
// we need to flip the plane if it puts any part of the polygon on the
// wrong side
// (in this way this code treats all polygons as float sided)
// (we know that the plane is on one edge of the polygon, so there is
// never a case where points lie on both sides, so the first hint is
// sufficient)
- for (j = 0;j < numpoints;j++)
+ for (j = 0;j < poly->numpoints;j++)
{
- float d = SVBSP_DotProduct(points + j * 3, node->plane) - node->plane[3];
+ float d = SVBSP_DotProduct(poly->points[j], node->plane) - node->plane[3];
if (d < -SVBSP_CLIP_EPSILON)
break;
if (d > SVBSP_CLIP_EPSILON)
}
#if 1
- // see if a parent plane describes the face plane
- for (j = parentnodenum;j >= 0;j = b->nodes[j].parent)
- {
- float *parentnodeplane = b->nodes[j].plane;
- if (fabs(SVBSP_DotProduct(points , parentnodeplane) - parentnodeplane[3]) < SVBSP_CLIP_EPSILON
- && fabs(SVBSP_DotProduct(points + 3, parentnodeplane) - parentnodeplane[3]) < SVBSP_CLIP_EPSILON
- && fabs(SVBSP_DotProduct(points + 6, parentnodeplane) - parentnodeplane[3]) < SVBSP_CLIP_EPSILON)
- break;
- }
- if (j < 0)
+ // skip the face plane if it lies on a parent plane
+ if (!poly->facesplitflag)
#endif
{
// add the face-plane node
// infront is empty, behind is shadow
node = b->nodes + b->numnodes++;
- SVBSP_PlaneFromPoints(node->plane, points, points + 3, points + 6);
+ SVBSP_PlaneFromPoints(node->plane, poly->points[0], poly->points[1], poly->points[2]);
// this is a flip check similar to the one above
// this one checks if the plane faces the origin, if not, flip it
if (SVBSP_DotProduct(b->origin, node->plane) - node->plane[3] < -SVBSP_CLIP_EPSILON)
}
}
-static int SVBSP_AddPolygonNode(svbsp_t *b, int *parentnodenumpointer, int parentnodenum, int numpoints, const float *points, int insertoccluder, void (*fragmentcallback)(void *fragmentcallback_pointer1, int fragmentcallback_number1, svbsp_t *b, int numpoints, const float *points), void *fragmentcallback_pointer1, int fragmentcallback_number1)
+static int SVBSP_AddPolygonNode(svbsp_t *b, int *parentnodenumpointer, int parentnodenum, const svbsp_polygon_t *poly, int insertoccluder, void (*fragmentcallback)(void *fragmentcallback_pointer1, int fragmentcallback_number1, svbsp_t *b, int numpoints, const float *points), void *fragmentcallback_pointer1, int fragmentcallback_number1)
{
int i;
- int frontnumpoints, backnumpoints;
+ int s;
+ int facesplitflag = poly->facesplitflag;
+ int bothsides;
float plane[4];
- float frontpoints[MAX_SVBSP_POLYGONPOINTS * 3], backpoints[MAX_SVBSP_POLYGONPOINTS * 3];
float d;
- if (numpoints < 3)
+ svbsp_polygon_t front;
+ svbsp_polygon_t back;
+ svbsp_node_t *node;
+ int sides[MAX_SVBSP_POLYGONPOINTS];
+ float dists[MAX_SVBSP_POLYGONPOINTS];
+ if (poly->numpoints < 1)
return 0;
// recurse through plane nodes
while (*parentnodenumpointer >= 0)
{
- // do a quick check to see if there is any need to split the polygon
- svbsp_node_t *node = b->nodes + *parentnodenumpointer;
+ // get node info
parentnodenum = *parentnodenumpointer;
-#if 1
+ node = b->nodes + parentnodenum;
plane[0] = node->plane[0];
plane[1] = node->plane[1];
plane[2] = node->plane[2];
plane[3] = node->plane[3];
- d = SVBSP_DotProduct(points, plane) - plane[3];
- if (d >= SVBSP_CLIP_EPSILON)
+ // calculate point dists for clipping
+ bothsides = 0;
+ for (i = 0;i < poly->numpoints;i++)
{
- for (i = 1;i < numpoints && SVBSP_DotProduct(points + i * 3, plane) - plane[3] >= SVBSP_CLIP_EPSILON;i++);
- if (i == numpoints)
- {
- // no need to split, just go to one side
- parentnodenumpointer = &node->children[0];
- continue;
- }
+ d = SVBSP_DotProduct(poly->points[i], plane) - plane[3];
+ s = 0;
+ if (d > SVBSP_CLIP_EPSILON)
+ s = 1;
+ if (d < -SVBSP_CLIP_EPSILON)
+ s = 2;
+ bothsides |= s;
+ dists[i] = d;
+ sides[i] = s;
}
- else if (d <= -SVBSP_CLIP_EPSILON)
+ // see which side the polygon is on
+ switch(bothsides)
{
- for (i = 1;i < numpoints && SVBSP_DotProduct(points + i * 3, plane) - plane[3] <= -SVBSP_CLIP_EPSILON;i++);
- if (i == numpoints)
- {
- // no need to split, just go to one side
- parentnodenumpointer = &node->children[1];
- continue;
- }
- }
+ default:
+ case 0:
+ // no need to split, this polygon is on the plane
+ // this case only occurs for polygons on the face plane, usually
+ // the same polygon (inserted twice - once as occluder, once as
+ // tester)
+ // if this is an occluder, it is redundant
+ if (insertoccluder)
+ return 1; // occluded
+ // if this is a tester, test the front side, because it is
+ // probably the same polygon that created this node...
+ facesplitflag = 1;
+ parentnodenumpointer = &node->children[0];
+ continue;
+ case 1:
+ // no need to split, just go to one side
+ parentnodenumpointer = &node->children[0];
+ continue;
+ case 2:
+ // no need to split, just go to one side
+ parentnodenumpointer = &node->children[1];
+ continue;
+ case 3:
+ // lies on both sides of the plane, we need to split it
+#if 1
+ SVBSP_DividePolygon(poly, plane, &front, &back, dists, sides);
+#else
+ PolygonF_Divide(poly->numpoints, poly->points[0], plane[0], plane[1], plane[2], plane[3], SVBSP_CLIP_EPSILON, MAX_SVBSP_POLYGONPOINTS, front.points[0], &front.numpoints, MAX_SVBSP_POLYGONPOINTS, back.points[0], &back.numpoints, NULL);
+ if (front.numpoints > MAX_SVBSP_POLYGONPOINTS)
+ front.numpoints = MAX_SVBSP_POLYGONPOINTS;
+ if (back.numpoints > MAX_SVBSP_POLYGONPOINTS)
+ back.numpoints = MAX_SVBSP_POLYGONPOINTS;
#endif
- // at this point we know it crosses the plane, so we need to split it
- PolygonF_Divide(numpoints, points, node->plane[0], node->plane[1], node->plane[2], node->plane[3], SVBSP_CLIP_EPSILON, MAX_SVBSP_POLYGONPOINTS, frontpoints, &frontnumpoints, MAX_SVBSP_POLYGONPOINTS, backpoints, &backnumpoints, NULL);
- if (frontnumpoints > MAX_SVBSP_POLYGONPOINTS)
- frontnumpoints = MAX_SVBSP_POLYGONPOINTS;
- if (backnumpoints > MAX_SVBSP_POLYGONPOINTS)
- backnumpoints = MAX_SVBSP_POLYGONPOINTS;
- // recurse the sides and return the resulting bit flags
- i = 0;
- if (frontnumpoints >= 3)
- i |= SVBSP_AddPolygonNode(b, &node->children[0], (int)(node - b->nodes), frontnumpoints, frontpoints, insertoccluder, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
- if (backnumpoints >= 3)
- i |= SVBSP_AddPolygonNode(b, &node->children[1], (int)(node - b->nodes), backnumpoints , backpoints , insertoccluder, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
- return i;
+ front.facesplitflag = facesplitflag;
+ back.facesplitflag = facesplitflag;
+ // recurse the sides and return the resulting occlusion flags
+ i = SVBSP_AddPolygonNode(b, &node->children[0], *parentnodenumpointer, &front, insertoccluder, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
+ i |= SVBSP_AddPolygonNode(b, &node->children[1], *parentnodenumpointer, &back , insertoccluder, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
+ return i;
+ }
}
// leaf node
if (*parentnodenumpointer == -1)
// empty leaf node; and some geometry survived
// if inserting an occluder, replace this empty leaf with a shadow volume
#if 0
- for (i = 0;i < numpoints-2;i++)
+ for (i = 0;i < poly->numpoints-2;i++)
{
Debug_PolygonBegin(NULL, DRAWFLAG_ADDITIVE);
- Debug_PolygonVertex(points[0], points[1], points[2], 0, 0, 0.25, 0, 0, 1);
- Debug_PolygonVertex(points[0 + (i + 1) * 3], points[1 + (i + 1) * 3], points[2 + (i + 1) * 3], 0, 0, 0.25, 0, 0, 1);
- Debug_PolygonVertex(points[0 + (i + 2) * 3], points[1 + (i + 2) * 3], points[2 + (i + 2) * 3], 0, 0, 0.25, 0, 0, 1);
+ Debug_PolygonVertex(poly->points[ 0][0], poly->points[ 0][1], poly->points[ 0][2], 0.0f, 0.0f, 0.25f, 0.0f, 0.0f, 1.0f);
+ Debug_PolygonVertex(poly->points[i+1][0], poly->points[i+1][1], poly->points[i+1][2], 0.0f, 0.0f, 0.25f, 0.0f, 0.0f, 1.0f);
+ Debug_PolygonVertex(poly->points[i+2][0], poly->points[i+2][1], poly->points[i+2][2], 0.0f, 0.0f, 0.25f, 0.0f, 0.0f, 1.0f);
Debug_PolygonEnd();
}
#endif
if (insertoccluder)
{
b->stat_occluders_fragments_accepted++;
- SVBSP_InsertOccluderPolygonNodes(b, parentnodenumpointer, parentnodenum, numpoints, points, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
+ SVBSP_InsertOccluderPolygonNodes(b, parentnodenumpointer, parentnodenum, poly, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
}
else
b->stat_queries_fragments_accepted++;
if (fragmentcallback)
- fragmentcallback(fragmentcallback_pointer1, fragmentcallback_number1, b, numpoints, points);
+ fragmentcallback(fragmentcallback_pointer1, fragmentcallback_number1, b, poly->numpoints, poly->points[0]);
return 2;
}
else
else
b->stat_queries_fragments_rejected++;
#if 0
- for (i = 0;i < numpoints-2;i++)
+ for (i = 0;i < poly->numpoints-2;i++)
{
Debug_PolygonBegin(NULL, DRAWFLAG_ADDITIVE);
- Debug_PolygonVertex(points[0], points[1], points[2], 0, 0, 0, 0, 0.25, 1);
- Debug_PolygonVertex(points[0 + (i + 1) * 3], points[1 + (i + 1) * 3], points[2 + (i + 1) * 3], 0, 0, 0, 0, 0.25, 1);
- Debug_PolygonVertex(points[0 + (i + 2) * 3], points[1 + (i + 2) * 3], points[2 + (i + 2) * 3], 0, 0, 0, 0, 0.25, 1);
+ Debug_PolygonVertex(poly->points[ 0][0], poly->points[ 0][1], poly->points[ 0][2], 0.0f, 0.0f, 0.0f, 0.0f, 0.25f, 1.0f);
+ Debug_PolygonVertex(poly->points[i+1][0], poly->points[i+1][1], poly->points[i+1][2], 0.0f, 0.0f, 0.0f, 0.0f, 0.25f, 1.0f);
+ Debug_PolygonVertex(poly->points[i+2][0], poly->points[i+2][1], poly->points[i+2][2], 0.0f, 0.0f, 0.0f, 0.0f, 0.25f, 1.0f);
Debug_PolygonEnd();
}
#endif
{
int i;
int nodenum;
+ svbsp_polygon_t poly;
// don't even consider an empty polygon
- if (numpoints < 3)
+ // note we still allow points and lines to be tested...
+ if (numpoints < 1)
return 0;
+ // if the polygon has too many points, we would crash
+ if (numpoints > MAX_SVBSP_POLYGONPOINTS)
+ return 0;
+ poly.numpoints = numpoints;
+ for (i = 0;i < numpoints;i++)
+ {
+ poly.points[i][0] = points[i*3+0];
+ poly.points[i][1] = points[i*3+1];
+ poly.points[i][2] = points[i*3+2];
+ //poly.splitflags[i] = 0; // this edge is a valid BSP splitter - clipped edges are not (because they lie on a bsp plane)
+ poly.facesplitflag = 0; // this face is a valid BSP Splitter - if it lies on a bsp plane it is not
+ }
#if 0
//if (insertoccluder)
- for (i = 0;i < numpoints-2;i++)
+ for (i = 0;i < poly.numpoints-2;i++)
{
Debug_PolygonBegin(NULL, DRAWFLAG_ADDITIVE);
- Debug_PolygonVertex(points[0], points[1], points[2], 0, 0, 0, 0.25, 0, 1);
- Debug_PolygonVertex(points[0 + (i + 1) * 3], points[1 + (i + 1) * 3], points[2 + (i + 1) * 3], 0, 0, 0, 0.25, 0, 1);
- Debug_PolygonVertex(points[0 + (i + 2) * 3], points[1 + (i + 2) * 3], points[2 + (i + 2) * 3], 0, 0, 0, 0.25, 0, 1);
+ Debug_PolygonVertex(poly.points[ 0][0], poly.points[ 0][1], poly.points[ 0][2], 0.0f, 0.0f, 0.0f, 0.25f, 0.0f, 1.0f);
+ Debug_PolygonVertex(poly.points[i+1][0], poly.points[i+1][1], poly.points[i+1][2], 0.0f, 0.0f, 0.0f, 0.25f, 0.0f, 1.0f);
+ Debug_PolygonVertex(poly.points[i+2][0], poly.points[i+2][1], poly.points[i+2][2], 0.0f, 0.0f, 0.0f, 0.25f, 0.0f, 1.0f);
Debug_PolygonEnd();
}
#endif
nodenum = 0;
- i = SVBSP_AddPolygonNode(b, &nodenum, -1, numpoints, points, insertoccluder, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
+ i = SVBSP_AddPolygonNode(b, &nodenum, -1, &poly, insertoccluder, fragmentcallback, fragmentcallback_pointer1, fragmentcallback_number1);
if (insertoccluder)
{
if (i & 2)