/*
================
R_AliasCheckBBox
================
*/
qboolean R_AliasCheckBBox(void)
{
int i, flags, frame, numv;
aliashdr_t *pahdr;
float zi, basepts[8][3], v0, v1, frac;
finalvert_t *pv0, *pv1, viewpts[16];
auxvert_t *pa0, *pa1, viewaux[16];
maliasframedesc_t *pframedesc;
qboolean zclipped, zfullyclipped;
unsigned anyclip, allclip;
int minz;
// expand, rotate, and translate points into worldspace
currententity->trivial_accept = 0;
pmodel = currententity->model;
pahdr = Mod_Extradata(pmodel);
pmdl = (mdl_t *)((byte *)pahdr + pahdr->model);
R_AliasSetUpTransform(0);
// construct the base bounding box for this frame
frame = currententity->frame;
// TODO: don't repeat this check when drawing?
if ((frame >= pmdl->numframes) || (frame < 0))
{
Con_DPrintf("No such frame %d %s\n", frame,
pmodel->name);
frame = 0;
}
pframedesc = &pahdr->frames[frame];
// x worldspace coordinates
basepts[0][0] = basepts[1][0] = basepts[2][0] = basepts[3][0] =
(float)pframedesc->bboxmin.v[0];
basepts[4][0] = basepts[5][0] = basepts[6][0] = basepts[7][0] =
(float)pframedesc->bboxmax.v[0];
// y worldspace coordinates
basepts[0][1] = basepts[3][1] = basepts[5][1] = basepts[6][1] =
(float)pframedesc->bboxmin.v[1];
basepts[1][1] = basepts[2][1] = basepts[4][1] = basepts[7][1] =
(float)pframedesc->bboxmax.v[1];
// z worldspace coordinates
basepts[0][2] = basepts[1][2] = basepts[4][2] = basepts[5][2] =
(float)pframedesc->bboxmin.v[2];
basepts[2][2] = basepts[3][2] = basepts[6][2] = basepts[7][2] =
(float)pframedesc->bboxmax.v[2];
zclipped = false;
zfullyclipped = true;
minz = 9999;
for (i=0; i<8 ; i++)
{
R_AliasTransformVector(&basepts[i][0], &viewaux[i].fv[0]);
if (viewaux[i].fv[2] < ALIAS_Z_CLIP_PLANE)
{
// we must clip points that are closer than the near clip plane
viewpts[i].flags = ALIAS_Z_CLIP;
zclipped = true;
}
else
{
if (viewaux[i].fv[2] < minz)
{
minz = viewaux[i].fv[2];
}
viewpts[i].flags = 0;
zfullyclipped = false;
}
}
if (zfullyclipped)
{
return false; // everything was near-z-clipped
}
numv = 8;
if (zclipped)
{
// organize points by edges, use edges to get new points (possible trivial
// reject)
for (i=0 ; i<12 ; i++)
{
// edge endpoints
pv0 = &viewpts[aedges[i].index0];
pv1 = &viewpts[aedges[i].index1];
pa0 = &viewaux[aedges[i].index0];
pa1 = &viewaux[aedges[i].index1];
// if one end is clipped and the other isn't, make a new point
if (pv0->flags ^ pv1->flags)
{
frac = (ALIAS_Z_CLIP_PLANE - pa0->fv[2]) /
(pa1->fv[2] - pa0->fv[2]);
viewaux[numv].fv[0] = pa0->fv[0] +
(pa1->fv[0] - pa0->fv[0]) * frac;
viewaux[numv].fv[1] = pa0->fv[1] +
(pa1->fv[1] - pa0->fv[1]) * frac;
viewaux[numv].fv[2] = ALIAS_Z_CLIP_PLANE;
viewpts[numv].flags = 0;
numv++;
}
}
}
// project the vertices that remain after clipping
anyclip = 0;
allclip = ALIAS_XY_CLIP_MASK;
// TODO: probably should do this loop in ASM, especially if we use floats
for (i=0 ; i<numv ; i++)
{
// we don't need to bother with vertices that were z-clipped
if (viewpts[i].flags & ALIAS_Z_CLIP)
{
continue;
}
zi = 1.0 / viewaux[i].fv[2];
// FIXME: do with chop mode in ASM, or convert to float
v0 = (viewaux[i].fv[0] * xscale * zi) + xcenter;
v1 = (viewaux[i].fv[1] * yscale * zi) + ycenter;
flags = 0;
if (v0 < r_refdef.fvrectx)
{
flags |= ALIAS_LEFT_CLIP;
}
if (v1 < r_refdef.fvrecty)
{
flags |= ALIAS_TOP_CLIP;
}
if (v0 > r_refdef.fvrectright)
{
flags |= ALIAS_RIGHT_CLIP;
}
if (v1 > r_refdef.fvrectbottom)
{
flags |= ALIAS_BOTTOM_CLIP;
}
anyclip |= flags;
allclip &= flags;
}
if (allclip)
{
return false; // trivial reject off one side
}
currententity->trivial_accept = !anyclip & !zclipped;
if (currententity->trivial_accept)
{
if (minz > (r_aliastransition + (pmdl->size * r_resfudge)))
{
currententity->trivial_accept |= 2;
}
}
return true;
}
/*
** R_AliasCheckFrameBBox
**
** Checks a specific alias frame bounding box
*/
static unsigned long
R_AliasCheckFrameBBox( daliasframe_t *frame, float worldxf[3][4] )
{
unsigned long aggregate_and_clipcode = ~0U,
aggregate_or_clipcode = 0;
int i;
vec3_t mins, maxs;
vec3_t transformed_min, transformed_max;
qboolean zclipped = false, zfullyclipped = true;
/*
** get the exact frame bounding box
*/
for (i=0 ; i<3 ; i++)
{
mins[i] = frame->translate[i];
maxs[i] = mins[i] + frame->scale[i]*255;
}
/*
** transform the min and max values into view space
*/
R_AliasTransformVector( mins, transformed_min, aliastransform );
R_AliasTransformVector( maxs, transformed_max, aliastransform );
if ( transformed_min[2] >= ALIAS_Z_CLIP_PLANE )
zfullyclipped = false;
if ( transformed_max[2] >= ALIAS_Z_CLIP_PLANE )
zfullyclipped = false;
if ( zfullyclipped )
{
return BBOX_TRIVIAL_REJECT;
}
if ( zclipped )
{
return ( BBOX_MUST_CLIP_XY | BBOX_MUST_CLIP_Z );
}
/*
** build a transformed bounding box from the given min and max
*/
for ( i = 0; i < 8; i++ )
{
int j;
vec3_t tmp, transformed;
unsigned long clipcode = 0;
if ( i & 1 )
tmp[0] = mins[0];
else
tmp[0] = maxs[0];
if ( i & 2 )
tmp[1] = mins[1];
else
tmp[1] = maxs[1];
if ( i & 4 )
tmp[2] = mins[2];
else
tmp[2] = maxs[2];
R_AliasTransformVector( tmp, transformed, worldxf );
for ( j = 0; j < 4; j++ )
{
float dp = DotProduct( transformed, view_clipplanes[j].normal );
if ( ( dp - view_clipplanes[j].dist ) < 0.0F )
clipcode |= 1 << j;
}
aggregate_and_clipcode &= clipcode;
aggregate_or_clipcode |= clipcode;
}
if ( aggregate_and_clipcode )
{
return BBOX_TRIVIAL_REJECT;
}
if ( !aggregate_or_clipcode )
{
return BBOX_TRIVIAL_ACCEPT;
}
return BBOX_MUST_CLIP_XY;
}
