r_bsp.c

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/*
Copyright (C) 1997-2001 Id Software, Inc.
 
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
 
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
 
See the GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
*/
// r_bsp.c
 
#include "r_local.h"
 
//
// current entity info
//
qboolean        insubmodel;
entity_t        *currententity;
vec3_t          modelorg;       // modelorg is the viewpoint reletive to
                                // the currently rendering entity
vec3_t          r_entorigin;    // the currently rendering entity in world
                                // coordinates
 
float           entity_rotation[3][3];
 
int             r_currentbkey;
 
typedef enum {touchessolid, drawnode, nodrawnode} solidstate_t;
 
#define MAX_BMODEL_VERTS    500         // 6K
#define MAX_BMODEL_EDGES    1000        // 12K
 
static mvertex_t    *pbverts;
static bedge_t      *pbedges;
static int          numbverts, numbedges;
 
static mvertex_t    *pfrontenter, *pfrontexit;
 
static qboolean     makeclippededge;
 
 
//===========================================================================
 
/*
================
R_EntityRotate
================
*/
void R_EntityRotate (vec3_t vec)
{
    vec3_t  tvec;
 
    VectorCopy (vec, tvec);
    vec[0] = DotProduct (entity_rotation[0], tvec);
    vec[1] = DotProduct (entity_rotation[1], tvec);
    vec[2] = DotProduct (entity_rotation[2], tvec);
}
 
 
/*
================
R_RotateBmodel
================
*/
void R_RotateBmodel (void)
{
    float   angle, s, c, temp1[3][3], temp2[3][3], temp3[3][3];
 
// TODO: should use a look-up table
// TODO: should really be stored with the entity instead of being reconstructed
// TODO: could cache lazily, stored in the entity
// TODO: share work with R_SetUpAliasTransform
 
// yaw
    angle = currententity->angles[YAW];     
    angle = angle * M_PI*2 / 360;
    s = sin(angle);
    c = cos(angle);
 
    temp1[0][0] = c;
    temp1[0][1] = s;
    temp1[0][2] = 0;
    temp1[1][0] = -s;
    temp1[1][1] = c;
    temp1[1][2] = 0;
    temp1[2][0] = 0;
    temp1[2][1] = 0;
    temp1[2][2] = 1;
 
 
// pitch
    angle = currententity->angles[PITCH];       
    angle = angle * M_PI*2 / 360;
    s = sin(angle);
    c = cos(angle);
 
    temp2[0][0] = c;
    temp2[0][1] = 0;
    temp2[0][2] = -s;
    temp2[1][0] = 0;
    temp2[1][1] = 1;
    temp2[1][2] = 0;
    temp2[2][0] = s;
    temp2[2][1] = 0;
    temp2[2][2] = c;
 
    R_ConcatRotations (temp2, temp1, temp3);
 
// roll
    angle = currententity->angles[ROLL];        
    angle = angle * M_PI*2 / 360;
    s = sin(angle);
    c = cos(angle);
 
    temp1[0][0] = 1;
    temp1[0][1] = 0;
    temp1[0][2] = 0;
    temp1[1][0] = 0;
    temp1[1][1] = c;
    temp1[1][2] = s;
    temp1[2][0] = 0;
    temp1[2][1] = -s;
    temp1[2][2] = c;
 
    R_ConcatRotations (temp1, temp3, entity_rotation);
 
//
// rotate modelorg and the transformation matrix
//
    R_EntityRotate (modelorg);
    R_EntityRotate (vpn);
    R_EntityRotate (vright);
    R_EntityRotate (vup);
 
    R_TransformFrustum ();
}
 
 
/*
================
R_RecursiveClipBPoly
 
Clip a bmodel poly down the world bsp tree
================
*/
void R_RecursiveClipBPoly (bedge_t *pedges, mnode_t *pnode, msurface_t *psurf)
{
    bedge_t     *psideedges[2], *pnextedge, *ptedge;
    int         i, side, lastside;
    float       dist, frac, lastdist;
    mplane_t    *splitplane, tplane;
    mvertex_t   *pvert, *plastvert, *ptvert;
    mnode_t     *pn;
    int         area;
 
    psideedges[0] = psideedges[1] = NULL;
 
    makeclippededge = false;
 
// transform the BSP plane into model space
// FIXME: cache these?
    splitplane = pnode->plane;
    tplane.dist = splitplane->dist -
            DotProduct(r_entorigin, splitplane->normal);
    tplane.normal[0] = DotProduct (entity_rotation[0], splitplane->normal);
    tplane.normal[1] = DotProduct (entity_rotation[1], splitplane->normal);
    tplane.normal[2] = DotProduct (entity_rotation[2], splitplane->normal);
 
// clip edges to BSP plane
    for ( ; pedges ; pedges = pnextedge)
    {
        pnextedge = pedges->pnext;
 
    // set the status for the last point as the previous point
    // FIXME: cache this stuff somehow?
        plastvert = pedges->v[0];
        lastdist = DotProduct (plastvert->position, tplane.normal) -
                   tplane.dist;
 
        if (lastdist > 0)
            lastside = 0;
        else
            lastside = 1;
 
        pvert = pedges->v[1];
 
        dist = DotProduct (pvert->position, tplane.normal) - tplane.dist;
 
        if (dist > 0)
            side = 0;
        else
            side = 1;
 
        if (side != lastside)
        {
        // clipped
            if (numbverts >= MAX_BMODEL_VERTS)
                return;
 
        // generate the clipped vertex
            frac = lastdist / (lastdist - dist);
            ptvert = &pbverts[numbverts++];
            ptvert->position[0] = plastvert->position[0] +
                    frac * (pvert->position[0] -
                    plastvert->position[0]);
            ptvert->position[1] = plastvert->position[1] +
                    frac * (pvert->position[1] -
                    plastvert->position[1]);
            ptvert->position[2] = plastvert->position[2] +
                    frac * (pvert->position[2] -
                    plastvert->position[2]);
 
        // split into two edges, one on each side, and remember entering
        // and exiting points
        // FIXME: share the clip edge by having a winding direction flag?
            if (numbedges >= (MAX_BMODEL_EDGES - 1))
            {
                ri.Con_Printf (PRINT_ALL,"Out of edges for bmodel\n");
                return;
            }
 
            ptedge = &pbedges[numbedges];
            ptedge->pnext = psideedges[lastside];
            psideedges[lastside] = ptedge;
            ptedge->v[0] = plastvert;
            ptedge->v[1] = ptvert;
 
            ptedge = &pbedges[numbedges + 1];
            ptedge->pnext = psideedges[side];
            psideedges[side] = ptedge;
            ptedge->v[0] = ptvert;
            ptedge->v[1] = pvert;
 
            numbedges += 2;
 
            if (side == 0)
            {
            // entering for front, exiting for back
                pfrontenter = ptvert;
                makeclippededge = true;
            }
            else
            {
                pfrontexit = ptvert;
                makeclippededge = true;
            }
        }
        else
        {
        // add the edge to the appropriate side
            pedges->pnext = psideedges[side];
            psideedges[side] = pedges;
        }
    }
 
// if anything was clipped, reconstitute and add the edges along the clip
// plane to both sides (but in opposite directions)
    if (makeclippededge)
    {
        if (numbedges >= (MAX_BMODEL_EDGES - 2))
        {
            ri.Con_Printf (PRINT_ALL,"Out of edges for bmodel\n");
            return;
        }
 
        ptedge = &pbedges[numbedges];
        ptedge->pnext = psideedges[0];
        psideedges[0] = ptedge;
        ptedge->v[0] = pfrontexit;
        ptedge->v[1] = pfrontenter;
 
        ptedge = &pbedges[numbedges + 1];
        ptedge->pnext = psideedges[1];
        psideedges[1] = ptedge;
        ptedge->v[0] = pfrontenter;
        ptedge->v[1] = pfrontexit;
 
        numbedges += 2;
    }
 
// draw or recurse further
    for (i=0 ; i<2 ; i++)
    {
        if (psideedges[i])
        {
        // draw if we've reached a non-solid leaf, done if all that's left is a
        // solid leaf, and continue down the tree if it's not a leaf
            pn = pnode->children[i];
 
        // we're done with this branch if the node or leaf isn't in the PVS
            if (pn->visframe == r_visframecount)
            {
                if (pn->contents != CONTENTS_NODE)
                {
                    if (pn->contents != CONTENTS_SOLID)
                    {
                        if (r_newrefdef.areabits)
                        {
                            area = ((mleaf_t *)pn)->area;
                            if (! (r_newrefdef.areabits[area>>3] & (1<<(area&7)) ) )
                                continue;       // not visible
                        }
 
                        r_currentbkey = ((mleaf_t *)pn)->key;
                        R_RenderBmodelFace (psideedges[i], psurf);
                    }
                }
                else
                {
                    R_RecursiveClipBPoly (psideedges[i], pnode->children[i],
                                      psurf);
                }
            }
        }
    }
}
 
 
/*
================
R_DrawSolidClippedSubmodelPolygons
 
Bmodel crosses multiple leafs
================
*/
void R_DrawSolidClippedSubmodelPolygons (model_t *pmodel, mnode_t *topnode)
{
    int         i, j, lindex;
    vec_t       dot;
    msurface_t  *psurf;
    int         numsurfaces;
    mplane_t    *pplane;
    mvertex_t   bverts[MAX_BMODEL_VERTS];
    bedge_t     bedges[MAX_BMODEL_EDGES], *pbedge;
    medge_t     *pedge, *pedges;
 
// FIXME: use bounding-box-based frustum clipping info?
 
    psurf = &pmodel->surfaces[pmodel->firstmodelsurface];
    numsurfaces = pmodel->nummodelsurfaces;
    pedges = pmodel->edges;
 
    for (i=0 ; i<numsurfaces ; i++, psurf++)
    {
    // find which side of the node we are on
        pplane = psurf->plane;
 
        dot = DotProduct (modelorg, pplane->normal) - pplane->dist;
 
    // draw the polygon
        if (( !(psurf->flags & SURF_PLANEBACK) && (dot < -BACKFACE_EPSILON)) ||
            ((psurf->flags & SURF_PLANEBACK) && (dot > BACKFACE_EPSILON)))
            continue;
 
    // FIXME: use bounding-box-based frustum clipping info?
 
    // copy the edges to bedges, flipping if necessary so always
    // clockwise winding
    // FIXME: if edges and vertices get caches, these assignments must move
    // outside the loop, and overflow checking must be done here
        pbverts = bverts;
        pbedges = bedges;
        numbverts = numbedges = 0;
        pbedge = &bedges[numbedges];
        numbedges += psurf->numedges;
 
        for (j=0 ; j<psurf->numedges ; j++)
        {
           lindex = pmodel->surfedges[psurf->firstedge+j];
 
            if (lindex > 0)
            {
                pedge = &pedges[lindex];
                pbedge[j].v[0] = &r_pcurrentvertbase[pedge->v[0]];
                pbedge[j].v[1] = &r_pcurrentvertbase[pedge->v[1]];
            }
            else
            {
                lindex = -lindex;
                pedge = &pedges[lindex];
                pbedge[j].v[0] = &r_pcurrentvertbase[pedge->v[1]];
                pbedge[j].v[1] = &r_pcurrentvertbase[pedge->v[0]];
            }
 
            pbedge[j].pnext = &pbedge[j+1];
        }
 
        pbedge[j-1].pnext = NULL;   // mark end of edges
 
        if ( !( psurf->texinfo->flags & ( SURF_TRANS66 | SURF_TRANS33 ) ) )
            R_RecursiveClipBPoly (pbedge, topnode, psurf);
        else
            R_RenderBmodelFace( pbedge, psurf );
    }
}
 
 
/*
================
R_DrawSubmodelPolygons
 
All in one leaf
================
*/
void R_DrawSubmodelPolygons (model_t *pmodel, int clipflags, mnode_t *topnode)
{
    int         i;
    vec_t       dot;
    msurface_t  *psurf;
    int         numsurfaces;
    mplane_t    *pplane;
 
// FIXME: use bounding-box-based frustum clipping info?
 
    psurf = &pmodel->surfaces[pmodel->firstmodelsurface];
    numsurfaces = pmodel->nummodelsurfaces;
 
    for (i=0 ; i<numsurfaces ; i++, psurf++)
    {
    // find which side of the node we are on
        pplane = psurf->plane;
 
        dot = DotProduct (modelorg, pplane->normal) - pplane->dist;
 
    // draw the polygon
        if (((psurf->flags & SURF_PLANEBACK) && (dot < -BACKFACE_EPSILON)) ||
            (!(psurf->flags & SURF_PLANEBACK) && (dot > BACKFACE_EPSILON)))
        {
            r_currentkey = ((mleaf_t *)topnode)->key;
 
        // FIXME: use bounding-box-based frustum clipping info?
            R_RenderFace (psurf, clipflags);
        }
    }
}
 
 
int c_drawnode;
 
/*
================
R_RecursiveWorldNode
================
*/
void R_RecursiveWorldNode (mnode_t *node, int clipflags)
{
    int         i, c, side, *pindex;
    vec3_t      acceptpt, rejectpt;
    mplane_t    *plane;
    msurface_t  *surf, **mark;
    float       d, dot;
    mleaf_t     *pleaf;
 
    if (node->contents == CONTENTS_SOLID)
        return;     // solid
 
    if (node->visframe != r_visframecount)
        return;
 
// cull the clipping planes if not trivial accept
// FIXME: the compiler is doing a lousy job of optimizing here; it could be
//  twice as fast in ASM
    if (clipflags)
    {
        for (i=0 ; i<4 ; i++)
        {
            if (! (clipflags & (1<<i)) )
                continue;   // don't need to clip against it
 
        // generate accept and reject points
        // FIXME: do with fast look-ups or integer tests based on the sign bit
        // of the floating point values
 
            pindex = pfrustum_indexes[i];
 
            rejectpt[0] = (float)node->minmaxs[pindex[0]];
            rejectpt[1] = (float)node->minmaxs[pindex[1]];
            rejectpt[2] = (float)node->minmaxs[pindex[2]];
            
            d = DotProduct (rejectpt, view_clipplanes[i].normal);
            d -= view_clipplanes[i].dist;
            if (d <= 0)
                return;
            acceptpt[0] = (float)node->minmaxs[pindex[3+0]];
            acceptpt[1] = (float)node->minmaxs[pindex[3+1]];
            acceptpt[2] = (float)node->minmaxs[pindex[3+2]];
 
            d = DotProduct (acceptpt, view_clipplanes[i].normal);
            d -= view_clipplanes[i].dist;
 
            if (d >= 0)
                clipflags &= ~(1<<i);   // node is entirely on screen
        }
    }
 
c_drawnode++;
 
// if a leaf node, draw stuff
    if (node->contents != -1)
    {
        pleaf = (mleaf_t *)node;
 
        // check for door connected areas
        if (r_newrefdef.areabits)
        {
            if (! (r_newrefdef.areabits[pleaf->area>>3] & (1<<(pleaf->area&7)) ) )
                return;     // not visible
        }
 
        mark = pleaf->firstmarksurface;
        c = pleaf->nummarksurfaces;
 
        if (c)
        {
            do
            {
                (*mark)->visframe = r_framecount;
                mark++;
            } while (--c);
        }
 
        pleaf->key = r_currentkey;
        r_currentkey++;     // all bmodels in a leaf share the same key
    }
    else
    {
    // node is just a decision point, so go down the apropriate sides
 
    // find which side of the node we are on
        plane = node->plane;
 
        switch (plane->type)
        {
        case PLANE_X:
            dot = modelorg[0] - plane->dist;
            break;
        case PLANE_Y:
            dot = modelorg[1] - plane->dist;
            break;
        case PLANE_Z:
            dot = modelorg[2] - plane->dist;
            break;
        default:
            dot = DotProduct (modelorg, plane->normal) - plane->dist;
            break;
        }
    
        if (dot >= 0)
            side = 0;
        else
            side = 1;
 
    // recurse down the children, front side first
        R_RecursiveWorldNode (node->children[side], clipflags);
 
    // draw stuff
        c = node->numsurfaces;
 
        if (c)
        {
            surf = r_worldmodel->surfaces + node->firstsurface;
 
            if (dot < -BACKFACE_EPSILON)
            {
                do
                {
                    if ((surf->flags & SURF_PLANEBACK) &&
                        (surf->visframe == r_framecount))
                    {
                        R_RenderFace (surf, clipflags);
                    }
 
                    surf++;
                } while (--c);
            }
            else if (dot > BACKFACE_EPSILON)
            {
                do
                {
                    if (!(surf->flags & SURF_PLANEBACK) &&
                        (surf->visframe == r_framecount))
                    {
                        R_RenderFace (surf, clipflags);
                    }
 
                    surf++;
                } while (--c);
            }
 
        // all surfaces on the same node share the same sequence number
            r_currentkey++;
        }
 
    // recurse down the back side
        R_RecursiveWorldNode (node->children[!side], clipflags);
    }
}
 
 
 
/*
================
R_RenderWorld
================
*/
void R_RenderWorld (void)
{
 
    if (!r_drawworld->value)
        return;
    if ( r_newrefdef.rdflags & RDF_NOWORLDMODEL )
        return;
 
    c_drawnode=0;
 
    // auto cycle the world frame for texture animation
    r_worldentity.frame = (int)(r_newrefdef.time*2);
    currententity = &r_worldentity;
 
    VectorCopy (r_origin, modelorg);
    currentmodel = r_worldmodel;
    r_pcurrentvertbase = currentmodel->vertexes;
 
    R_RecursiveWorldNode (currentmodel->nodes, 15);
}