fteqw/engine/common/q1bsp.c

#include "quakedef.h"

/*

============================================================================

Physics functions (common)
*/

#if	!id386

/*
==================
SV_HullPointContents

==================
*/
static int Q1_HullPointContents (hull_t *hull, int num, vec3_t p)
{
	float		d;
	dclipnode_t	*node;
	mplane_t	*plane;

	while (num >= 0)
	{
		if (num < hull->firstclipnode || num > hull->lastclipnode)
			Sys_Error ("SV_HullPointContents: bad node number");

		node = hull->clipnodes + num;
		plane = hull->planes + node->planenum;

		if (plane->type < 3)
			d = p[plane->type] - plane->dist;
		else
			d = DotProduct (plane->normal, p) - plane->dist;
		if (d < 0)
			num = node->children[1];
		else
			num = node->children[0];
	}

	return num;
}
#else
int VARGS Q1_HullPointContents (hull_t *hull, int num, vec3_t p);
#endif	// !id386



#define	DIST_EPSILON	(0.03125)
qboolean Q1BSP_RecursiveHullCheck (hull_t *hull, int num, float p1f, float p2f, vec3_t p1, vec3_t p2, trace_t *trace)
{
	dclipnode_t	*node;
	mplane_t	*plane;
	float		t1, t2;
	float		frac;
	int			i;
	vec3_t		mid;
	int			side;
	float		midf;

// check for empty
	if (num < 0)
	{
		if (num != Q1CONTENTS_SOLID)
		{
			trace->allsolid = false;
			if (num == Q1CONTENTS_EMPTY)
				trace->inopen = true;
			else
				trace->inwater = true;
		}
		else
			trace->startsolid = true;
		return true;		// empty
	}

	if (num < hull->firstclipnode || num > hull->lastclipnode)
		Sys_Error ("Q1BSP_RecursiveHullCheck: bad node number");

//
// find the point distances
//
	node = hull->clipnodes + num;
	plane = hull->planes + node->planenum;

	if (plane->type < 3)
	{
		t1 = p1[plane->type] - plane->dist;
		t2 = p2[plane->type] - plane->dist;
	}
	else
	{
		t1 = DotProduct (plane->normal, p1) - plane->dist;
		t2 = DotProduct (plane->normal, p2) - plane->dist;
	}

#if 1
	if (t1 >= 0 && t2 >= 0)
		return Q1BSP_RecursiveHullCheck (hull, node->children[0], p1f, p2f, p1, p2, trace);
	if (t1 < 0 && t2 < 0)
		return Q1BSP_RecursiveHullCheck (hull, node->children[1], p1f, p2f, p1, p2, trace);
#else
	if ( (t1 >= DIST_EPSILON && t2 >= DIST_EPSILON) || (t2 > t1 && t1 >= 0) )
		return Q1BSP_RecursiveHullCheck (hull, node->children[0], p1f, p2f, p1, p2, trace);
	if ( (t1 <= -DIST_EPSILON && t2 <= -DIST_EPSILON) || (t2 < t1 && t1 <= 0) )
		return Q1BSP_RecursiveHullCheck (hull, node->children[1], p1f, p2f, p1, p2, trace);
#endif

// put the crosspoint DIST_EPSILON pixels on the near side
	if (t1 < 0)
		frac = (t1 + DIST_EPSILON)/(t1-t2);
	else
		frac = (t1 - DIST_EPSILON)/(t1-t2);
	if (frac < 0)
		frac = 0;
	if (frac > 1)
		frac = 1;

	midf = p1f + (p2f - p1f)*frac;
	for (i=0 ; i<3 ; i++)
		mid[i] = p1[i] + frac*(p2[i] - p1[i]);

	side = (t1 < 0);

// move up to the node
	if (!Q1BSP_RecursiveHullCheck (hull, node->children[side], p1f, midf, p1, mid, trace) )
		return false;

#ifdef PARANOID
	if (Q1BSP_RecursiveHullCheck (sv_hullmodel, mid, node->children[side])
	== Q1CONTENTS_SOLID)
	{
		Con_Printf ("mid PointInHullSolid\n");
		return false;
	}
#endif

	if (Q1_HullPointContents (hull, node->children[side^1], mid)
	!= Q1CONTENTS_SOLID)
// go past the node
		return Q1BSP_RecursiveHullCheck (hull, node->children[side^1], midf, p2f, mid, p2, trace);

	if (trace->allsolid)
		return false;		// never got out of the solid area

//==================
// the other side of the node is solid, this is the impact point
//==================
	if (!side)
	{
		VectorCopy (plane->normal, trace->plane.normal);
		trace->plane.dist = plane->dist;
	}
	else
	{
		VectorNegate (plane->normal, trace->plane.normal);
		trace->plane.dist = -plane->dist;
	}

	while (Q1_HullPointContents (hull, hull->firstclipnode, mid)
	== Q1CONTENTS_SOLID)
	{ // shouldn't really happen, but does occasionally
		if (!(frac < 10000000) && !(frac > -10000000))
		{
			trace->fraction = 0;
			VectorClear (trace->endpos);
			Con_Printf ("nan in traceline\n");
			return false;
		}
		frac -= 0.1;
		if (frac < 0)
		{
			trace->fraction = midf;
			VectorCopy (mid, trace->endpos);
			Con_DPrintf ("backup past 0\n");
			return false;
		}
		midf = p1f + (p2f - p1f)*frac;
		for (i=0 ; i<3 ; i++)
			mid[i] = p1[i] + frac*(p2[i] - p1[i]);
	}

	trace->fraction = midf;
	VectorCopy (mid, trace->endpos);

	return false;
}

int Q1BSP_HullPointContents(hull_t *hull, vec3_t p)
{
	switch(Q1_HullPointContents(hull, hull->firstclipnode, p))
	{
	case Q1CONTENTS_EMPTY:
		return FTECONTENTS_EMPTY;
	case Q1CONTENTS_SOLID:
		return FTECONTENTS_SOLID;
	case Q1CONTENTS_WATER:
		return FTECONTENTS_WATER;
	case Q1CONTENTS_SLIME:
		return FTECONTENTS_SLIME;
	case Q1CONTENTS_LAVA:
		return FTECONTENTS_LAVA;
	case Q1CONTENTS_SKY:
		return FTECONTENTS_SKY;
	default:
		Sys_Error("Q1_PointContents: Unknown contents type");
		return FTECONTENTS_SOLID;
	}
}

void Q1BSP_SetHullFuncs(hull_t *hull)
{
//	hull->funcs.HullPointContents = Q1BSP_HullPointContents;
}

unsigned int Q1BSP_PointContents(model_t *model, vec3_t point)
{
	return Q1BSP_HullPointContents(&model->hulls[0], point);
}

qboolean Q1BSP_Trace(model_t *model, int forcehullnum, int frame, vec3_t start, vec3_t end, vec3_t mins, vec3_t maxs, trace_t *trace)
{
	hull_t *hull;
	vec3_t size;
	vec3_t start_l, end_l;
	vec3_t offset;

	memset (trace, 0, sizeof(trace_t));
	trace->fraction = 1;
	trace->allsolid = true;

	VectorSubtract (maxs, mins, size);
	if (forcehullnum >= 1 && forcehullnum <= MAX_MAP_HULLSM && model->hulls[forcehullnum-1].available)
		hull = &model->hulls[forcehullnum-1];
	else
	{
		if (model->hulls[5].available)
		{	//choose based on hexen2 sizes.

			if (size[0] < 3) // Point
				hull = &model->hulls[0];
			else if (size[0] <= 32 && size[2] <= 28)  // Half Player
				hull = &model->hulls[3];
			else if (size[0] <= 32)  // Full Player
				hull = &model->hulls[1];
			else // Golumn
				hull = &model->hulls[5];
		}
		else
		{
			if (size[0] < 3 || !model->hulls[1].available)
				hull = &model->hulls[0];
			else if (size[0] <= 32)
			{
				if (size[2] < 54 && model->hulls[3].available)
					hull = &model->hulls[3]; // 32x32x36 (half-life's crouch)
				else
					hull = &model->hulls[1];
			}
			else
				hull = &model->hulls[2];
		}
	}

// calculate an offset value to center the origin
	VectorSubtract (hull->clip_mins, mins, offset);
	VectorSubtract(start, offset, start_l);
	VectorSubtract(end, offset, end_l);
	Q1BSP_RecursiveHullCheck(hull, hull->firstclipnode, 0, 1, start_l, end_l, trace);
	if (trace->fraction == 1)
	{
		VectorCopy (end, trace->endpos);
	}
	else
	{
		VectorAdd (trace->endpos, offset, trace->endpos);
	}

	return trace->fraction != 1;
}

/*
Physics functions (common)

============================================================================

Rendering functions (Client only)
*/
#ifndef SERVERONLY

extern int	r_dlightframecount;

//goes through the nodes marking the surfaces near the dynamic light as lit.
void Q1BSP_MarkLights (dlight_t *light, int bit, mnode_t *node)
{
	mplane_t	*splitplane;
	float		dist;
	msurface_t	*surf;
	int			i;

	float		l, maxdist;
	int			j, s, t;
	vec3_t		impact;

	if (node->contents < 0)
		return;

	splitplane = node->plane;
	if (splitplane->type < 3)
		dist = light->origin[splitplane->type] - splitplane->dist;
	else
		dist = DotProduct (light->origin, splitplane->normal) - splitplane->dist;

	if (dist > light->radius)
	{
		Q1BSP_MarkLights (light, bit, node->children[0]);
		return;
	}
	if (dist < -light->radius)
	{
		Q1BSP_MarkLights (light, bit, node->children[1]);
		return;
	}

	maxdist = light->radius*light->radius;

// mark the polygons
	surf = currentmodel->surfaces + node->firstsurface;
	for (i=0 ; i<node->numsurfaces ; i++, surf++)
	{
		//Yeah, you can blame LordHavoc for this alternate code here.
		for (j=0 ; j<3 ; j++)
			impact[j] = light->origin[j] - surf->plane->normal[j]*dist;

		// clamp center of light to corner and check brightness
		l = DotProduct (impact, surf->texinfo->vecs[0]) + surf->texinfo->vecs[0][3] - surf->texturemins[0];
		s = l+0.5;if (s < 0) s = 0;else if (s > surf->extents[0]) s = surf->extents[0];
		s = l - s;
		l = DotProduct (impact, surf->texinfo->vecs[1]) + surf->texinfo->vecs[1][3] - surf->texturemins[1];
		t = l+0.5;if (t < 0) t = 0;else if (t > surf->extents[1]) t = surf->extents[1];
		t = l - t;
		// compare to minimum light
		if ((s*s+t*t+dist*dist) < maxdist)
		{
			if (surf->dlightframe != r_dlightframecount)
			{
				surf->dlightbits = bit;
				surf->dlightframe = r_dlightframecount;
			}
			else
				surf->dlightbits |= bit;
		}
	}

	Q1BSP_MarkLights (light, bit, node->children[0]);
	Q1BSP_MarkLights (light, bit, node->children[1]);
}

#define MAXFRAGMENTTRIS 256
vec3_t decalfragmentverts[MAXFRAGMENTTRIS*3];

typedef struct {
	vec3_t center;

	vec3_t normal;
//	vec3_t tangent1;
//	vec3_t tangent2;

	vec3_t planenorm[6];
	float planedist[6];
	int numplanes;

	vec_t radius;
	int numtris;

} fragmentdecal_t;

#define FloatInterpolate(a, bness, b, c) (c) = (a)*(1-bness) + (b)*bness
#define VectorInterpolate(a, bness, b, c) FloatInterpolate((a)[0], bness, (b)[0], (c)[0]),FloatInterpolate((a)[1], bness, (b)[1], (c)[1]),FloatInterpolate((a)[2], bness, (b)[2], (c)[2])

//#define SHOWCLIPS
//#define FRAGMENTASTRIANGLES	//works, but produces more fragments.

#ifdef FRAGMENTASTRIANGLES

//if the triangle is clipped away, go recursive if there are tris left.
void Fragment_ClipTriToPlane(int trinum, float *plane, float planedist, fragmentdecal_t *dec)
{
	float *point[3];
	float dotv[3];

	vec3_t impact1, impact2;
	float t;

	int i, i2, i3;
	int clippedverts = 0;

	for (i = 0; i < 3; i++)
	{
		point[i] = decalfragmentverts[trinum*3+i];
		dotv[i] = DotProduct(point[i], plane)-planedist;
		clippedverts += dotv[i] < 0;
	}

	//if they're all clipped away, scrap the tri
	switch (clippedverts)
	{
	case 0:
		return;	//plane does not clip the triangle.

	case 1:	//split into 3, disregard the clipped vert
		for (i = 0; i < 3; i++)
		{
			if (dotv[i] < 0)
			{	//This is the vertex that's getting clipped.

				if (dotv[i] > -DIST_EPSILON)
					return;	//it's only over the line by a tiny ammount.

				i2 = (i+1)%3;
				i3 = (i+2)%3;

				if (dotv[i2] < DIST_EPSILON)
					return;
				if (dotv[i3] < DIST_EPSILON)
					return;

				//work out where the two lines impact the plane
				t = (dotv[i]) / (dotv[i]-dotv[i2]);
				VectorInterpolate(point[i], t, point[i2], impact1);

				t = (dotv[i]) / (dotv[i]-dotv[i3]);
				VectorInterpolate(point[i], t, point[i3], impact2);

#ifdef SHOWCLIPS
				if (dec->numtris != MAXFRAGMENTTRIS)
				{
					VectorCopy(impact2,					decalfragmentverts[dec->numtris*3+0]);
					VectorCopy(decalfragmentverts[trinum*3+i],	decalfragmentverts[dec->numtris*3+1]);
					VectorCopy(impact1,					decalfragmentverts[dec->numtris*3+2]);
					dec->numtris++;
				}
#endif


				//shrink the tri, putting the impact into the killed vertex.
				VectorCopy(impact2, point[i]);


				if (dec->numtris == MAXFRAGMENTTRIS)
					return;	//:(

				//build the second tri
				VectorCopy(impact1,					decalfragmentverts[dec->numtris*3+0]);
				VectorCopy(decalfragmentverts[trinum*3+i2],	decalfragmentverts[dec->numtris*3+1]);
				VectorCopy(impact2,					decalfragmentverts[dec->numtris*3+2]);
				dec->numtris++;

				return;
			}
		}
		Sys_Error("Fragment_ClipTriToPlane: Clipped vertex not founc\n");
		return;	//can't handle it
	case 2:	//split into 3, disregarding both the clipped.
		for (i = 0; i < 3; i++)
		{
			if (!(dotv[i] < 0))
			{	//This is the vertex that's staying.

				if (dotv[i] < DIST_EPSILON)
					break;	//only just inside

				i2 = (i+1)%3;
				i3 = (i+2)%3;

				//work out where the two lines impact the plane
				t = (dotv[i]) / (dotv[i]-dotv[i2]);
				VectorInterpolate(point[i], t, point[i2], impact1);

				t = (dotv[i]) / (dotv[i]-dotv[i3]);
				VectorInterpolate(point[i], t, point[i3], impact2);

				//shrink the tri, putting the impact into the killed vertex.

#ifdef SHOWCLIPS
				if (dec->numtris != MAXFRAGMENTTRIS)
				{
					VectorCopy(impact1,					decalfragmentverts[dec->numtris*3+0]);
					VectorCopy(point[i2],	decalfragmentverts[dec->numtris*3+1]);
					VectorCopy(point[i3],					decalfragmentverts[dec->numtris*3+2]);
					dec->numtris++;
				}
				if (dec->numtris != MAXFRAGMENTTRIS)
				{
					VectorCopy(impact1,					decalfragmentverts[dec->numtris*3+0]);
					VectorCopy(point[i3],	decalfragmentverts[dec->numtris*3+1]);
					VectorCopy(impact2,					decalfragmentverts[dec->numtris*3+2]);
					dec->numtris++;
				}
#endif

				VectorCopy(impact1, point[i2]);
				VectorCopy(impact2, point[i3]);
				return;
			}
		}
	case 3://scrap it
		//fill the verts with the verts of the last and go recursive (due to the nature of Fragment_ClipTriangle, which doesn't actually know if we clip them away)
#ifndef SHOWCLIPS
		dec->numtris--;
		VectorCopy(decalfragmentverts[dec->numtris*3+0], decalfragmentverts[trinum*3+0]);
		VectorCopy(decalfragmentverts[dec->numtris*3+1], decalfragmentverts[trinum*3+1]);
		VectorCopy(decalfragmentverts[dec->numtris*3+2], decalfragmentverts[trinum*3+2]);
		if (trinum < dec->numtris)
			Fragment_ClipTriToPlane(trinum, plane, planedist, dec);
#endif
		return;
	}
}

void Fragment_ClipTriangle(fragmentdecal_t *dec, float *a, float *b, float *c)
{
	//emit the triangle, and clip it's fragments.
	int start, i;

	int p;

	if (dec->numtris == MAXFRAGMENTTRIS)
		return;	//:(

	start = dec->numtris;

	VectorCopy(a, decalfragmentverts[dec->numtris*3+0]);
	VectorCopy(b, decalfragmentverts[dec->numtris*3+1]);
	VectorCopy(c, decalfragmentverts[dec->numtris*3+2]);
	dec->numtris++;

	//clip all the fragments to all of the planes.
	//This will produce a quad if the source triangle was big enough.

	for (p = 0; p < 6; p++)
	{
		for (i = start; i < dec->numtris; i++)
			Fragment_ClipTriToPlane(i, dec->planenorm[p], dec->plantdist[p], dec);
	}
}

#else

#define MAXFRAGMENTVERTS 128
int Fragment_ClipPolyToPlane(float *inverts, float *outverts, int incount, float *plane, float planedist)
{
	float dotv[MAXFRAGMENTVERTS];
	int i, i2, i3;
	int outcount = 0;
	int clippedcount = 0;
	vec3_t impact;

	float *lastvalid = NULL;	//the reason these arn't just an index is because it'd need to be a special case for the first vert.
	float lastvaliddot = 0;
#define FRAG_EPSILON 0.5

	for (i = 0; i < incount; i++)
	{
		dotv[i] = DotProduct((inverts+i*3), plane) - planedist;
		if (dotv[i]<-FRAG_EPSILON)
			clippedcount++;
		else
		{
			lastvalid = inverts+i*3;
			lastvaliddot = dotv[i];
		}
	}

	if (clippedcount == incount)
		return 0;	//all were clipped
	if (clippedcount == 0)
	{	//none were clipped
		memcpy(outverts, inverts, sizeof(float)*3*incount);
		return incount;
	}

	//FIXME:
/*

  We should end up with a nicly clipped quad.
  If a vertex is on the other side of the place, we remove it, and add two in it's place, on the lines between the verts not chopped.
  we work out the last remaining vert in the above loop
  the loop below loops through all verts, if it's to be removed, it does a nested loop to find the next vert that is not going to be removed
  it then adds two new verts on the right two lines.
  Due to using four clipplanes, this should result in a perfect quad. It doesn't.

*/
	for (i = 0; i < incount; )
	{
		if (dotv[i] < -FRAG_EPSILON)	//clipped
		{
			//work out where the line impacts the plane
			lastvaliddot = (dotv[i]) / (dotv[i]-lastvaliddot);
			VectorInterpolate((inverts+i*3), lastvaliddot, lastvalid, impact);

			if (outcount+1 >= MAXFRAGMENTVERTS)	//bum
				break;

			//generate a vertex where the line crosses the plane
			outverts[outcount*3 + 0] = impact[0];
			outverts[outcount*3 + 1] = impact[1];
			outverts[outcount*3 + 2] = impact[2];
			outcount++;

			i3 = (i+1);
			while (dotv[i3%incount] < -FRAG_EPSILON)	//clipped
				i3++;

			//take away any verticies on the other side of the plane

			i = (i3-1)%incount;
			i2=i3%incount;

			lastvaliddot = (dotv[i]) / (dotv[i]-dotv[i2]);
			VectorInterpolate((inverts+i*3), lastvaliddot, (inverts+i2*3), impact);

			//generate a vertex where the line crosses back onto our plane
			outverts[outcount*3 + 0] = impact[0];
			outverts[outcount*3 + 1] = impact[1];
			outverts[outcount*3 + 2] = impact[2];
			outcount++;
			lastvalid = outverts+outcount*3;
			lastvaliddot = 0;		// :)

			i = i3;
		}
		else
		{	//this vertex wasn't clipped. Just copy to the output.

			if (outcount == MAXFRAGMENTVERTS)	//bum
				break;

			outverts[outcount*3 + 0] = inverts[i*3 + 0];
			outverts[outcount*3 + 1] = inverts[i*3 + 1];
			outverts[outcount*3 + 2] = inverts[i*3 + 2];
			lastvalid = inverts+i*3;
			lastvaliddot = dotv[i];

			outcount++;
			i++;
		}
	}

	return outcount;
}

void Fragment_ClipTriangle(fragmentdecal_t *dec, float *a, float *b, float *c)
{
	//emit the triangle, and clip it's fragments.
	int p;
	float verts[MAXFRAGMENTVERTS*3];
	float verts2[MAXFRAGMENTVERTS*3];
	float *cverts;
	int numverts;
	int flip;


	if (dec->numtris == MAXFRAGMENTTRIS)
		return;	//don't bother

	VectorCopy(a, (verts+0*3));
	VectorCopy(b, (verts+1*3));
	VectorCopy(c, (verts+2*3));
	numverts = 3;

	//clip the triangle to the 6 planes.
	flip = 0;
	for (p = 0; p < dec->numplanes; p++)
	{
		flip^=1;
		if (flip)
			numverts = Fragment_ClipPolyToPlane(verts, verts2, numverts, dec->planenorm[p], dec->planedist[p]);
		else
			numverts = Fragment_ClipPolyToPlane(verts2, verts, numverts, dec->planenorm[p], dec->planedist[p]);

		if (numverts < 3)	//totally clipped.
			return;
	}

	if (flip)
		cverts = verts2;
	else
		cverts = verts;

	//decompose the resultant polygon into triangles.

	while(numverts>2)
	{
		if (dec->numtris == MAXFRAGMENTTRIS)
			return;

		numverts--;

		VectorCopy((cverts+3*0),			decalfragmentverts[dec->numtris*3+0]);
		VectorCopy((cverts+3*(numverts-1)),	decalfragmentverts[dec->numtris*3+1]);
		VectorCopy((cverts+3*numverts),		decalfragmentverts[dec->numtris*3+2]);
		dec->numtris++;
	}
}

#endif

//this could be inlined, but I'm lazy.
void Fragment_Mesh (fragmentdecal_t *dec, mesh_t *mesh)
{
	int i;

	float *a, *b, *c;

	for (i = 0; i < mesh->numindexes; i+=3)
	{
		if (dec->numtris == MAXFRAGMENTTRIS)
			break;
		a = mesh->xyz_array[mesh->indexes[i+0]];
		b = mesh->xyz_array[mesh->indexes[i+1]];
		c = mesh->xyz_array[mesh->indexes[i+2]];

		Fragment_ClipTriangle(dec, a, b, c);
	}
}

void Q1BSP_ClipDecalToNodes (fragmentdecal_t *dec, mnode_t *node)
{
	mplane_t	*splitplane;
	float		dist;
	msurface_t	*surf;
	int			i;

	if (node->contents < 0)
		return;

	splitplane = node->plane;
	dist = DotProduct (dec->center, splitplane->normal) - splitplane->dist;

	if (dist > dec->radius)
	{
		Q1BSP_ClipDecalToNodes (dec, node->children[0]);
		return;
	}
	if (dist < -dec->radius)
	{
		Q1BSP_ClipDecalToNodes (dec, node->children[1]);
		return;
	}

// mark the polygons
	surf = cl.worldmodel->surfaces + node->firstsurface;
	for (i=0 ; i<node->numsurfaces ; i++, surf++)
	{

		if (surf->flags & SURF_PLANEBACK)
		{
			if (-DotProduct(surf->plane->normal, dec->normal) > -0.5)
				continue;
		}
		else
		{
			if (DotProduct(surf->plane->normal, dec->normal) > -0.5)
				continue;
		}
		Fragment_Mesh(dec, surf->mesh);
	}

	Q1BSP_ClipDecalToNodes (dec, node->children[0]);
	Q1BSP_ClipDecalToNodes (dec, node->children[1]);
}

int Q1BSP_ClipDecal(vec3_t center, vec3_t normal, vec3_t tangent1, vec3_t tangent2, float size, float **out)
{	//quad marks a full, independant quad
	int p;
	fragmentdecal_t dec;

	VectorCopy(center, dec.center);
	VectorCopy(normal, dec.normal);
	dec.radius = size/2;
	dec.numtris = 0;

	VectorCopy(tangent1,	dec.planenorm[0]);
	VectorNegate(tangent1,	dec.planenorm[1]);
	VectorCopy(tangent2,	dec.planenorm[2]);
	VectorNegate(tangent2,	dec.planenorm[3]);
	VectorCopy(dec.normal,		dec.planenorm[4]);
	VectorNegate(dec.normal,	dec.planenorm[5]);
	for (p = 0; p < 6; p++)
		dec.planedist[p] = -(dec.radius - DotProduct(dec.center, dec.planenorm[p]));
	dec.numplanes = 6;

	Q1BSP_ClipDecalToNodes(&dec, cl.worldmodel->nodes);

	*out = (float *)decalfragmentverts;
	return dec.numtris;
}

//This is spike's testing function, and is only usable by gl. :)
/*
void Q1BSP_TestClipDecal(void)
{
	int i;
	int numtris;
	vec3_t fwd;
	vec3_t start;
	vec3_t center, normal, tangent;
	float *verts;

	if (cls.state != ca_active)
		return;

	VectorCopy(cl.simorg[0], start);
	start[2]+=22;
	VectorMA(start, 10000, vpn, fwd);

	TraceLineN(start, fwd, center, normal);

	CrossProduct(fwd, normal, tangent);
	VectorNormalize(tangent);

	numtris = Q1BSP_ClipDecal(center, normal, tangent, 128, &verts);
	qglDisable(GL_TEXTURE_2D);
	qglDisable(GL_BLEND);
	qglDisable(GL_DEPTH_TEST);

	qglColor3f(1, 0, 0);
	qglShadeModel(GL_SMOOTH);
	qglBegin(GL_TRIANGLES);
	for (i = 0; i < numtris; i++)
	{
		qglVertex3fv(verts+i*9+0);
		qglVertex3fv(verts+i*9+3);
		qglVertex3fv(verts+i*9+6);
	}
	qglEnd();

	qglColor3f(1, 1, 1);
	qglBegin(GL_LINES);
	for (i = 0; i < numtris; i++)
	{
		qglVertex3fv(verts+i*9+0);
		qglVertex3fv(verts+i*9+3);
		qglVertex3fv(verts+i*9+3);
		qglVertex3fv(verts+i*9+6);
		qglVertex3fv(verts+i*9+6);
		qglVertex3fv(verts+i*9+0);
	}

	qglVertex3fv(center);
	VectorMA(center, 10, normal, fwd);
	qglVertex3fv(fwd);

	qglColor3f(0, 1, 0);
	qglVertex3fv(center);
	VectorMA(center, 10, tangent, fwd);
	qglVertex3fv(fwd);

	qglColor3f(0, 0, 1);
	qglVertex3fv(center);
	CrossProduct(tangent, normal, fwd);
	VectorMA(center, 10, fwd, fwd);
	qglVertex3fv(fwd);

	qglColor3f(1, 1, 1);

	qglEnd();
	qglEnable(GL_TEXTURE_2D);
	qglEnable(GL_DEPTH_TEST);
}
*/

#endif
/*
Rendering functions (Client only)

==============================================================================

Server only functions
*/
#ifndef CLIENTONLY

//does the recursive work of Q1BSP_FatPVS
void SV_Q1BSP_AddToFatPVS (model_t *mod, vec3_t org, mnode_t *node, qbyte *buffer, unsigned int buffersize)
{
	int		i;
	qbyte	*pvs;
	mplane_t	*plane;
	float	d;

	while (1)
	{
	// if this is a leaf, accumulate the pvs bits
		if (node->contents < 0)
		{
			if (node->contents != Q1CONTENTS_SOLID)
			{
				pvs = Q1BSP_LeafPVS (mod, (mleaf_t *)node, NULL, 0);
				for (i=0; i<buffersize; i++)
					buffer[i] |= pvs[i];
			}
			return;
		}

		plane = node->plane;
		d = DotProduct (org, plane->normal) - plane->dist;
		if (d > 8)
			node = node->children[0];
		else if (d < -8)
			node = node->children[1];
		else
		{	// go down both
			SV_Q1BSP_AddToFatPVS (mod, org, node->children[0], buffer, buffersize);
			node = node->children[1];
		}
	}
}

/*
=============
Q1BSP_FatPVS

Calculates a PVS that is the inclusive or of all leafs within 8 pixels of the
given point.
=============
*/
unsigned int Q1BSP_FatPVS (model_t *mod, vec3_t org, qbyte *pvsbuffer, unsigned int buffersize, qboolean add)
{
	unsigned int fatbytes = (mod->numleafs+31)>>3;
	if (fatbytes > buffersize)
		Sys_Error("map had too much pvs data (too many leaves)\n");;
	if (!add)
		Q_memset (pvsbuffer, 0, fatbytes);
	SV_Q1BSP_AddToFatPVS (mod, org, mod->nodes, pvsbuffer, fatbytes);
	return fatbytes;
}

qboolean Q1BSP_EdictInFatPVS(model_t *mod, edict_t *ent, qbyte *pvs)
{
	int i;

	if (ent->num_leafs == MAX_ENT_LEAFS+1)
		return true;	//it's in too many leafs for us to cope with. Just trivially accept it.

	for (i=0 ; i < ent->num_leafs ; i++)
		if (pvs[ent->leafnums[i] >> 3] & (1 << (ent->leafnums[i]&7) ))
			return true;	//we might be able to see this one.

	return false;	//none of this ents leafs were visible, so neither is the ent.
}

/*
===============
SV_FindTouchedLeafs

Links the edict to the right leafs so we can get it's potential visability.
===============
*/
void Q1BSP_RFindTouchedLeafs (edict_t *ent, mnode_t *node, float *mins, float *maxs)
{
	mplane_t	*splitplane;
	mleaf_t		*leaf;
	int			sides;
	int			leafnum;

	if (node->contents == Q1CONTENTS_SOLID)
		return;

// add an efrag if the node is a leaf

	if ( node->contents < 0)
	{
		if (ent->num_leafs >= MAX_ENT_LEAFS)
		{
			ent->num_leafs = MAX_ENT_LEAFS+1;	//too many. mark it as such so we can trivially accept huge mega-big brush models.
			return;
		}

		leaf = (mleaf_t *)node;
		leafnum = leaf - sv.worldmodel->leafs - 1;

		ent->leafnums[ent->num_leafs] = leafnum;
		ent->num_leafs++;
		return;
	}

// NODE_MIXED

	splitplane = node->plane;
	sides = BOX_ON_PLANE_SIDE(mins, maxs, splitplane);

// recurse down the contacted sides
	if (sides & 1)
		Q1BSP_RFindTouchedLeafs (ent, node->children[0], mins, maxs);

	if (sides & 2)
		Q1BSP_RFindTouchedLeafs (ent, node->children[1], mins, maxs);
}
void Q1BSP_FindTouchedLeafs(model_t *mod, edict_t *ent, float *mins, float *maxs)
{
	ent->num_leafs = 0;
	if (ent->v->modelindex)
		Q1BSP_RFindTouchedLeafs (ent, mod->nodes, mins, maxs);
}

#endif

/*
Server only functions

==============================================================================

PVS type stuff
*/

/*
===================
Mod_DecompressVis
===================
*/
qbyte *Q1BSP_DecompressVis (qbyte *in, model_t *model, qbyte *decompressed, unsigned int buffersize)
{
	int		c;
	qbyte	*out;
	int		row;

	row = (model->numleafs+7)>>3;
	out = decompressed;

	if (buffersize < row)
		row = buffersize;

#if 0
	memcpy (out, in, row);
#else
	if (!in)
	{	// no vis info, so make all visible
		while (row)
		{
			*out++ = 0xff;
			row--;
		}
		return decompressed;
	}

	do
	{
		if (*in)
		{
			*out++ = *in++;
			continue;
		}

		c = in[1];
		in += 2;
		while (c)
		{
			*out++ = 0;
			c--;
		}
	} while (out - decompressed < row);
#endif

	return decompressed;
}

static qbyte	mod_novis[MAX_MAP_LEAFS/8];

qbyte *Q1BSP_LeafPVS (model_t *model, mleaf_t *leaf, qbyte *buffer, unsigned int buffersize)
{

	static qbyte	decompressed[MAX_MAP_LEAFS/8];

	if (leaf == model->leafs)
		return mod_novis;

	if (!buffer)
	{
		buffer = decompressed;
		buffersize = sizeof(decompressed);
	}

	return Q1BSP_DecompressVis (leaf->compressed_vis, model, buffer, buffersize);
}

qbyte *Q1BSP_LeafnumPVS (model_t *model, int leafnum, qbyte *buffer, unsigned int buffersize)
{
	return Q1BSP_LeafPVS(model, model->leafs + leafnum, buffer, buffersize);
}

//returns the leaf number, which is used as a bit index into the pvs.
int Q1BSP_LeafnumForPoint (model_t *model, vec3_t p)
{
	mnode_t		*node;
	float		d;
	mplane_t	*plane;

	if (!model)
	{
		Sys_Error ("Mod_PointInLeaf: bad model");
	}
	if (!model->nodes)
		return 0;

	node = model->nodes;
	while (1)
	{
		if (node->contents < 0)
			return (mleaf_t *)node - model->leafs;
		plane = node->plane;
		d = DotProduct (p,plane->normal) - plane->dist;
		if (d > 0)
			node = node->children[0];
		else
			node = node->children[1];
	}

	return 0;	// never reached
}

mleaf_t *Q1BSP_LeafForPoint (model_t *model, vec3_t p)
{
	return model->leafs + Q1BSP_LeafnumForPoint(model, p);
}



/*
PVS type stuff

==============================================================================

Init stuff
*/

void Q1BSP_Init(void)
{
	memset (mod_novis, 0xff, sizeof(mod_novis));
}


//sets up the functions a server needs.
//fills in bspfuncs_t
void Q1BSP_SetModelFuncs(model_t *mod)
{
#ifndef CLIENTONLY
	mod->funcs.FatPVS				= Q1BSP_FatPVS;
	mod->funcs.EdictInFatPVS		= Q1BSP_EdictInFatPVS;
	mod->funcs.FindTouchedLeafs_Q1	= Q1BSP_FindTouchedLeafs;
#endif
	mod->funcs.LightPointValues		= NULL;
	mod->funcs.StainNode			= NULL;
	mod->funcs.MarkLights			= NULL;

	mod->funcs.LeafnumForPoint		= Q1BSP_LeafnumForPoint;
	mod->funcs.LeafPVS				= Q1BSP_LeafnumPVS;
	mod->funcs.Trace				= Q1BSP_Trace;
	mod->funcs.PointContents		= Q1BSP_PointContents;
}