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"
#include "ref_common.h"
#undef FRAC_EPSILON
#define FRAC_EPSILON (1.0f / 32.0f)
typedef struct
{
float fraction;
int contents;
msurface_t *surface;
} linetrace_t;
/*
==============
fix_coord
converts the reletive tex coords to absolute
==============
*/
static uint fix_coord( vec_t in, uint width )
{
if( in > 0 ) return (uint)in % width;
return width - ((uint)fabs( in ) % width);
}
/*
=============
SampleMiptex
fence texture testing
=============
*/
int PM_SampleMiptex( const msurface_t *surf, const vec3_t point )
{
mextrasurf_t *info = surf->info;
mfacebevel_t *fb = info->bevel;
int contents;
vec_t ds, dt;
int x, y;
mtexinfo_t *tx;
texture_t *mt;
// fill the default contents
if( fb ) contents = fb->contents;
else contents = CONTENTS_SOLID;
if( !surf->texinfo || !surf->texinfo->texture )
return contents;
tx = surf->texinfo;
mt = tx->texture;
if( mt->name[0] != '{' )
return contents;
// TODO: this won't work under dedicated
// should we bring up imagelib and keep original buffers?
if( !Host_IsDedicated() )
{
const byte *data;
data = ref.dllFuncs.R_GetTextureOriginalBuffer( mt->gl_texturenum );
if( !data ) return contents; // original doesn't kept
ds = DotProduct( point, tx->vecs[0] ) + tx->vecs[0][3];
dt = DotProduct( point, tx->vecs[1] ) + tx->vecs[1][3];
// convert ST to real pixels position
x = fix_coord( ds, mt->width - 1 );
y = fix_coord( dt, mt->height - 1 );
ASSERT( x >= 0 && y >= 0 );
if( data[(mt->width * y) + x] == 255 )
return CONTENTS_EMPTY;
return CONTENTS_SOLID;
}
return contents;
}
/*
==================
PM_RecursiveSurfCheck
==================
*/
msurface_t *PM_RecursiveSurfCheck( model_t *mod, mnode_t *node, vec3_t p1, vec3_t p2 )
{
float t1, t2, frac;
int i, side;
msurface_t *surf;
vec3_t mid;
loc0:
if( node->contents < 0 )
return NULL;
t1 = PlaneDiff( p1, node->plane );
t2 = PlaneDiff( p2, node->plane );
if( t1 >= -FRAC_EPSILON && t2 >= -FRAC_EPSILON )
{
node = node->children[0];
goto loc0;
}
if( t1 < FRAC_EPSILON && t2 < FRAC_EPSILON )
{
node = node->children[1];
goto loc0;
}
side = (t1 < 0.0f);
frac = t1 / ( t1 - t2 );
frac = bound( 0.0f, frac, 1.0f );
VectorLerp( p1, frac, p2, mid );
if(( surf = PM_RecursiveSurfCheck( mod, node->children[side], p1, mid )) != NULL )
return surf;
// walk through real faces
for( i = 0; i < node->numsurfaces; i++ )
{
msurface_t *surf = &mod->surfaces[node->firstsurface + i];
mextrasurf_t *info = surf->info;
mfacebevel_t *fb = info->bevel;
int j, contents;
vec3_t delta;
if( !fb ) continue; // ???
VectorSubtract( mid, fb->origin, delta );
if( DotProduct( delta, delta ) >= fb->radius )
continue; // no intersection
for( j = 0; j < fb->numedges; j++ )
{
if( PlaneDiff( mid, &fb->edges[j] ) > FRAC_EPSILON )
break; // outside the bounds
}
if( j != fb->numedges )
continue; // we are outside the bounds of the facet
// hit the surface
contents = PM_SampleMiptex( surf, mid );
if( contents != CONTENTS_EMPTY )
return surf;
return NULL; // through the fence
}
return PM_RecursiveSurfCheck( mod, 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( model_t *mod, 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 i, r, side;
vec3_t mid;
loc0:
if( node->contents < 0 )
{
// water, slime or lava interpret as empty
if( node->contents == CONTENTS_SOLID )
return CONTENTS_SOLID;
if( node->contents == CONTENTS_SKY )
return CONTENTS_SKY;
trace->fraction = 1.0f;
return CONTENTS_EMPTY;
}
front = PlaneDiff( start, node->plane );
back = PlaneDiff( stop, node->plane );
if( front >= -FRAC_EPSILON && back >= -FRAC_EPSILON )
{
node = node->children[0];
goto loc0;
}
if( front < FRAC_EPSILON && back < FRAC_EPSILON )
{
node = node->children[1];
goto loc0;
}
side = (front < 0);
frac = front / (front - back);
frac = bound( 0.0f, frac, 1.0f );
VectorLerp( start, frac, stop, mid );
midf = p1f + ( p2f - p1f ) * frac;
r = PM_TestLine_r( mod, node->children[side], p1f, midf, start, mid, trace );
if( r != CONTENTS_EMPTY )
{
if( trace->surface == NULL )
trace->fraction = midf;
trace->contents = r;
return r;
}
// walk through real faces
for( i = 0; i < node->numsurfaces; i++ )
{
msurface_t *surf = &mod->surfaces[node->firstsurface + i];
mextrasurf_t *info = surf->info;
mfacebevel_t *fb = info->bevel;
int j, contents;
vec3_t delta;
if( !fb ) continue;
VectorSubtract( mid, fb->origin, delta );
if( DotProduct( delta, delta ) >= fb->radius )
continue; // no intersection
for( j = 0; j < fb->numedges; j++ )
{
if( PlaneDiff( mid, &fb->edges[j] ) > FRAC_EPSILON )
break; // outside the bounds
}
if( j != fb->numedges )
continue; // we are outside the bounds of the facet
// hit the surface
contents = PM_SampleMiptex( surf, mid );
// fill the trace and out
trace->contents = contents;
trace->fraction = midf;
if( contents != CONTENTS_EMPTY )
trace->surface = surf;
return contents;
}
return PM_TestLine_r( mod, 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;
trace.surface = NULL;
for( i = 0; i < numents; i++ )
{
pe = &ents[i];
if( i != 0 && FBitSet( flags, PM_WORLD_ONLY ))
break;
if( !pe->model || pe->model->type != mod_brush || pe->solid != SOLID_BSP )
continue;
if( FBitSet( flags, PM_GLASS_IGNORE ) && 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;
trace_bbox.surface = NULL;
PM_TestLine_r( pe->model, &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;
}