Xash3D FWGS engine.
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/*
pm_surface.c - surface tracing
Copyright (C) 2010 Uncle Mike
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 3 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.
*/
#include "common.h"
#include "mathlib.h"
#include "pm_local.h"
typedef struct
{
float fraction;
int contents;
} linetrace_t;
/*
==================
PM_RecursiveSurfCheck
==================
*/
msurface_t *PM_RecursiveSurfCheck( model_t *model, mnode_t *node, vec3_t p1, vec3_t p2 )
{
float t1, t2, frac;
int side, ds, dt;
mplane_t *plane;
msurface_t *surf;
vec3_t mid;
int i;
if( node->contents < 0 )
return NULL;
plane = node->plane;
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( t1 >= 0.0f && t2 >= 0.0f )
return PM_RecursiveSurfCheck( model, node->children[0], p1, p2 );
if( t1 < 0.0f && t2 < 0.0f )
return PM_RecursiveSurfCheck( model, node->children[1], p1, p2 );
frac = t1 / ( t1 - t2 );
if( frac < 0.0f ) frac = 0.0f;
if( frac > 1.0f ) frac = 1.0f;
VectorLerp( p1, frac, p2, mid );
side = (t1 < 0.0f);
// now this is weird.
surf = PM_RecursiveSurfCheck( model, node->children[side], p1, mid );
if( surf != NULL || ( t1 >= 0.0f && t2 >= 0.0f ) || ( t1 < 0.0f && t2 < 0.0f ))
{
return surf;
}
surf = model->surfaces + node->firstsurface;
for( i = 0; i < node->numsurfaces; i++, surf++ )
{
ds = (int)((float)DotProduct( mid, surf->texinfo->vecs[0] ) + surf->texinfo->vecs[0][3] );
dt = (int)((float)DotProduct( mid, surf->texinfo->vecs[1] ) + surf->texinfo->vecs[1][3] );
if( ds >= surf->texturemins[0] && dt >= surf->texturemins[1] )
{
int s = ds - surf->texturemins[0];
int t = dt - surf->texturemins[1];
if( s <= surf->extents[0] && t <= surf->extents[1] )
return surf;
}
}
return PM_RecursiveSurfCheck( model, node->children[side^1], mid, p2 );
}
/*
==================
PM_TraceTexture
find the face where the traceline hit
assume physentity is valid
==================
*/
msurface_t *PM_TraceSurface( physent_t *pe, vec3_t start, vec3_t end )
{
matrix4x4 matrix;
model_t *bmodel;
hull_t *hull;
vec3_t start_l, end_l;
vec3_t offset;
bmodel = pe->model;
if( !bmodel || bmodel->type != mod_brush )
return NULL;
hull = &pe->model->hulls[0];
VectorSubtract( hull->clip_mins, vec3_origin, offset );
VectorAdd( offset, pe->origin, offset );
VectorSubtract( start, offset, start_l );
VectorSubtract( end, offset, end_l );
// rotate start and end into the models frame of reference
if( !VectorIsNull( pe->angles ))
{
Matrix4x4_CreateFromEntity( matrix, pe->angles, offset, 1.0f );
Matrix4x4_VectorITransform( matrix, start, start_l );
Matrix4x4_VectorITransform( matrix, end, end_l );
}
return PM_RecursiveSurfCheck( bmodel, &bmodel->nodes[hull->firstclipnode], start_l, end_l );
}
/*
==================
PM_TraceTexture
find the face where the traceline hit
assume physentity is valid
==================
*/
const char *PM_TraceTexture( physent_t *pe, vec3_t start, vec3_t end )
{
msurface_t *surf = PM_TraceSurface( pe, start, end );
if( !surf || !surf->texinfo || !surf->texinfo->texture )
return NULL;
return surf->texinfo->texture->name;
}
/*
==================
PM_TestLine_r
optimized trace for light gathering
==================
*/
int PM_TestLine_r( mnode_t *node, vec_t p1f, vec_t p2f, const vec3_t start, const vec3_t stop, linetrace_t *trace )
{
float front, back;
float frac, midf;
int r, side;
vec3_t mid;
loc0:
if( node->contents < 0 )
trace->contents = node->contents;
if( node->contents == CONTENTS_SOLID )
return CONTENTS_SOLID;
if( node->contents == CONTENTS_SKY )
return CONTENTS_SKY;
if( node->contents < 0 )
return CONTENTS_EMPTY;
front = PlaneDiff( start, node->plane );
back = PlaneDiff( stop, node->plane );
if( front >= -ON_EPSILON && back >= -ON_EPSILON )
{
node = node->children[0];
goto loc0;
}
if( front < ON_EPSILON && back < ON_EPSILON )
{
node = node->children[1];
goto loc0;
}
side = (front < 0);
frac = front / (front - back);
frac = bound( 0.0, frac, 1.0 );
VectorLerp( start, frac, stop, mid );
midf = p1f + ( p2f - p1f ) * frac;
r = PM_TestLine_r( node->children[side], p1f, midf, start, mid, trace );
if( r != CONTENTS_EMPTY )
{
trace->fraction = midf;
return r;
}
return PM_TestLine_r( node->children[!side], midf, p2f, mid, stop, trace );
}
int PM_TestLineExt( playermove_t *pmove, physent_t *ents, int numents, const vec3_t start, const vec3_t end, int flags )
{
linetrace_t trace, trace_bbox;
matrix4x4 matrix;
hull_t *hull = NULL;
vec3_t offset, start_l, end_l;
qboolean rotated;
physent_t *pe;
int i;
trace.contents = CONTENTS_EMPTY;
trace.fraction = 1.0f;
for( i = 0; i < numents; i++ )
{
pe = &ents[i];
if( i != 0 && ( flags & PM_WORLD_ONLY ))
break;
if( !pe->model || pe->model->type != mod_brush || pe->solid != SOLID_BSP )
continue;
if( pe->rendermode != kRenderNormal )
continue;
hull = &pe->model->hulls[0];
hull = PM_HullForBsp( pe, pmove, offset );
if( pe->solid == SOLID_BSP && !VectorIsNull( pe->angles ))
rotated = true;
else rotated = false;
if( rotated )
{
Matrix4x4_CreateFromEntity( matrix, pe->angles, offset, 1.0f );
Matrix4x4_VectorITransform( matrix, start, start_l );
Matrix4x4_VectorITransform( matrix, end, end_l );
}
else
{
VectorSubtract( start, pe->origin, start_l );
VectorSubtract( end, pe->origin, end_l );
}
trace_bbox.contents = CONTENTS_EMPTY;
trace_bbox.fraction = 1.0f;
PM_TestLine_r( &pe->model->nodes[hull->firstclipnode], 0.0f, 1.0f, start_l, end_l, &trace_bbox );
if( trace_bbox.contents != CONTENTS_EMPTY || trace_bbox.fraction < trace.fraction )
{
trace = trace_bbox;
}
}
return trace.contents;
}