Xash3D FWGS engine.
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/*
gl_frustum.cpp - frustum test implementation
Copyright (C) 2016 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 "gl_local.h"
#include "xash3d_mathlib.h"
void GL_FrustumEnablePlane( gl_frustum_t *out, int side )
{
Assert( side >= 0 && side < FRUSTUM_PLANES );
// make sure what plane is ready
if( !VectorIsNull( out->planes[side].normal ))
SetBits( out->clipFlags, BIT( side ));
}
void GL_FrustumDisablePlane( gl_frustum_t *out, int side )
{
Assert( side >= 0 && side < FRUSTUM_PLANES );
ClearBits( out->clipFlags, BIT( side ));
}
void GL_FrustumSetPlane( gl_frustum_t *out, int side, const vec3_t vecNormal, float flDist )
{
Assert( side >= 0 && side < FRUSTUM_PLANES );
out->planes[side].type = PlaneTypeForNormal( vecNormal );
out->planes[side].signbits = SignbitsForPlane( vecNormal );
VectorCopy( vecNormal, out->planes[side].normal );
out->planes[side].dist = flDist;
SetBits( out->clipFlags, BIT( side ));
}
void GL_FrustumNormalizePlane( gl_frustum_t *out, int side )
{
float length;
Assert( side >= 0 && side < FRUSTUM_PLANES );
// normalize
length = VectorLength( out->planes[side].normal );
if( length )
{
float ilength = (1.0f / length);
out->planes[side].normal[0] *= ilength;
out->planes[side].normal[1] *= ilength;
out->planes[side].normal[2] *= ilength;
out->planes[side].dist *= ilength;
}
out->planes[side].type = PlaneTypeForNormal( out->planes[side].normal );
out->planes[side].signbits = SignbitsForPlane( out->planes[side].normal );
SetBits( out->clipFlags, BIT( side ));
}
void GL_FrustumInitProj( gl_frustum_t *out, float flZNear, float flZFar, float flFovX, float flFovY )
{
float xs, xc;
vec3_t farpoint, nearpoint;
vec3_t normal, iforward;
// horizontal fov used for left and right planes
SinCos( DEG2RAD( flFovX ) * 0.5f, &xs, &xc );
// setup left plane
VectorMAM( xs, RI.cull_vforward, -xc, RI.cull_vright, normal );
GL_FrustumSetPlane( out, FRUSTUM_LEFT, normal, DotProduct( RI.cullorigin, normal ));
// setup right plane
VectorMAM( xs, RI.cull_vforward, xc, RI.cull_vright, normal );
GL_FrustumSetPlane( out, FRUSTUM_RIGHT, normal, DotProduct( RI.cullorigin, normal ));
// vertical fov used for top and bottom planes
SinCos( DEG2RAD( flFovY ) * 0.5f, &xs, &xc );
VectorNegate( RI.cull_vforward, iforward );
// setup bottom plane
VectorMAM( xs, RI.cull_vforward, -xc, RI.cull_vup, normal );
GL_FrustumSetPlane( out, FRUSTUM_BOTTOM, normal, DotProduct( RI.cullorigin, normal ));
// setup top plane
VectorMAM( xs, RI.cull_vforward, xc, RI.cull_vup, normal );
GL_FrustumSetPlane( out, FRUSTUM_TOP, normal, DotProduct( RI.cullorigin, normal ));
// setup far plane
VectorMA( RI.cullorigin, flZFar, RI.cull_vforward, farpoint );
GL_FrustumSetPlane( out, FRUSTUM_FAR, iforward, DotProduct( iforward, farpoint ));
// no need to setup backplane for general view.
if( flZNear == 0.0f ) return;
// setup near plane
VectorMA( RI.cullorigin, flZNear, RI.cull_vforward, nearpoint );
GL_FrustumSetPlane( out, FRUSTUM_NEAR, RI.cull_vforward, DotProduct( RI.cull_vforward, nearpoint ));
}
void GL_FrustumInitOrtho( gl_frustum_t *out, float xLeft, float xRight, float yTop, float yBottom, float flZNear, float flZFar )
{
vec3_t iforward, iright, iup;
// setup the near and far planes
float orgOffset = DotProduct( RI.cullorigin, RI.cull_vforward );
VectorNegate( RI.cull_vforward, iforward );
// because quake ortho is inverted and far and near should be swaped
GL_FrustumSetPlane( out, FRUSTUM_FAR, iforward, -flZNear - orgOffset );
GL_FrustumSetPlane( out, FRUSTUM_NEAR, RI.cull_vforward, flZFar + orgOffset );
// setup left and right planes
orgOffset = DotProduct( RI.cullorigin, RI.cull_vright );
VectorNegate( RI.cull_vright, iright );
GL_FrustumSetPlane( out, FRUSTUM_LEFT, RI.cull_vright, xLeft + orgOffset );
GL_FrustumSetPlane( out, FRUSTUM_RIGHT, iright, -xRight - orgOffset );
// setup top and buttom planes
orgOffset = DotProduct( RI.cullorigin, RI.cull_vup );
VectorNegate( RI.cull_vup, iup );
GL_FrustumSetPlane( out, FRUSTUM_TOP, RI.cull_vup, yTop + orgOffset );
GL_FrustumSetPlane( out, FRUSTUM_BOTTOM, iup, -yBottom - orgOffset );
}
void GL_FrustumInitBox( gl_frustum_t *out, const vec3_t org, float radius )
{
vec3_t normal;
int i;
for( i = 0; i < FRUSTUM_PLANES; i++ )
{
// setup normal for each direction
VectorClear( normal );
normal[((i >> 1) + 1) % 3] = (i & 1) ? 1.0f : -1.0f;
GL_FrustumSetPlane( out, i, normal, DotProduct( org, normal ) - radius );
}
}
void GL_FrustumInitProjFromMatrix( gl_frustum_t *out, const matrix4x4 projection )
{
int i;
// left
out->planes[FRUSTUM_LEFT].normal[0] = projection[0][3] + projection[0][0];
out->planes[FRUSTUM_LEFT].normal[1] = projection[1][3] + projection[1][0];
out->planes[FRUSTUM_LEFT].normal[2] = projection[2][3] + projection[2][0];
out->planes[FRUSTUM_LEFT].dist = -(projection[3][3] + projection[3][0]);
// right
out->planes[FRUSTUM_RIGHT].normal[0] = projection[0][3] - projection[0][0];
out->planes[FRUSTUM_RIGHT].normal[1] = projection[1][3] - projection[1][0];
out->planes[FRUSTUM_RIGHT].normal[2] = projection[2][3] - projection[2][0];
out->planes[FRUSTUM_RIGHT].dist = -(projection[3][3] - projection[3][0]);
// bottom
out->planes[FRUSTUM_BOTTOM].normal[0] = projection[0][3] + projection[0][1];
out->planes[FRUSTUM_BOTTOM].normal[1] = projection[1][3] + projection[1][1];
out->planes[FRUSTUM_BOTTOM].normal[2] = projection[2][3] + projection[2][1];
out->planes[FRUSTUM_BOTTOM].dist = -(projection[3][3] + projection[3][1]);
// top
out->planes[FRUSTUM_TOP].normal[0] = projection[0][3] - projection[0][1];
out->planes[FRUSTUM_TOP].normal[1] = projection[1][3] - projection[1][1];
out->planes[FRUSTUM_TOP].normal[2] = projection[2][3] - projection[2][1];
out->planes[FRUSTUM_TOP].dist = -(projection[3][3] - projection[3][1]);
// near
out->planes[FRUSTUM_NEAR].normal[0] = projection[0][3] + projection[0][2];
out->planes[FRUSTUM_NEAR].normal[1] = projection[1][3] + projection[1][2];
out->planes[FRUSTUM_NEAR].normal[2] = projection[2][3] + projection[2][2];
out->planes[FRUSTUM_NEAR].dist = -(projection[3][3] + projection[3][2]);
// far
out->planes[FRUSTUM_FAR].normal[0] = projection[0][3] - projection[0][2];
out->planes[FRUSTUM_FAR].normal[1] = projection[1][3] - projection[1][2];
out->planes[FRUSTUM_FAR].normal[2] = projection[2][3] - projection[2][2];
out->planes[FRUSTUM_FAR].dist = -(projection[3][3] - projection[3][2]);
for( i = 0; i < FRUSTUM_PLANES; i++ )
{
GL_FrustumNormalizePlane( out, i );
}
}
void GL_FrustumComputeCorners( gl_frustum_t *out, vec3_t corners[8] )
{
memset( corners, 0, sizeof( vec3_t ) * 8 );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_LEFT], &out->planes[FRUSTUM_TOP], &out->planes[FRUSTUM_FAR], corners[0] );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_RIGHT], &out->planes[FRUSTUM_TOP], &out->planes[FRUSTUM_FAR], corners[1] );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_LEFT], &out->planes[FRUSTUM_BOTTOM], &out->planes[FRUSTUM_FAR], corners[2] );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_RIGHT], &out->planes[FRUSTUM_BOTTOM], &out->planes[FRUSTUM_FAR], corners[3] );
if( FBitSet( out->clipFlags, BIT( FRUSTUM_NEAR )))
{
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_LEFT], &out->planes[FRUSTUM_TOP], &out->planes[FRUSTUM_NEAR], corners[4] );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_RIGHT], &out->planes[FRUSTUM_TOP], &out->planes[FRUSTUM_NEAR], corners[5] );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_LEFT], &out->planes[FRUSTUM_BOTTOM], &out->planes[FRUSTUM_NEAR], corners[6] );
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_RIGHT], &out->planes[FRUSTUM_BOTTOM], &out->planes[FRUSTUM_NEAR], corners[7] );
}
else
{
PlanesGetIntersectionPoint( &out->planes[FRUSTUM_LEFT], &out->planes[FRUSTUM_RIGHT], &out->planes[FRUSTUM_TOP], corners[4] );
VectorCopy( corners[4], corners[5] );
VectorCopy( corners[4], corners[6] );
VectorCopy( corners[4], corners[7] );
}
}
void GL_FrustumComputeBounds( gl_frustum_t *out, vec3_t mins, vec3_t maxs )
{
vec3_t corners[8];
int i;
GL_FrustumComputeCorners( out, corners );
ClearBounds( mins, maxs );
for( i = 0; i < 8; i++ )
AddPointToBounds( corners[i], mins, maxs );
}
void GL_FrustumDrawDebug( gl_frustum_t *out )
{
vec3_t bbox[8];
int i;
GL_FrustumComputeCorners( out, bbox );
// g-cont. frustum must be yellow :-)
pglColor4f( 1.0f, 1.0f, 0.0f, 1.0f );
pglDisable( GL_TEXTURE_2D );
pglBegin( GL_LINES );
for( i = 0; i < 2; i += 1 )
{
pglVertex3fv( bbox[i+0] );
pglVertex3fv( bbox[i+2] );
pglVertex3fv( bbox[i+4] );
pglVertex3fv( bbox[i+6] );
pglVertex3fv( bbox[i+0] );
pglVertex3fv( bbox[i+4] );
pglVertex3fv( bbox[i+2] );
pglVertex3fv( bbox[i+6] );
pglVertex3fv( bbox[i*2+0] );
pglVertex3fv( bbox[i*2+1] );
pglVertex3fv( bbox[i*2+4] );
pglVertex3fv( bbox[i*2+5] );
}
pglEnd();
pglEnable( GL_TEXTURE_2D );
}
// cull methods
qboolean GL_FrustumCullBox( gl_frustum_t *out, const vec3_t mins, const vec3_t maxs, int userClipFlags )
{
int iClipFlags;
int i, bit;
if( r_nocull->value )
return false;
if( userClipFlags != 0 )
iClipFlags = userClipFlags;
else iClipFlags = out->clipFlags;
for( i = FRUSTUM_PLANES, bit = 1; i > 0; i--, bit <<= 1 )
{
const mplane_t *p = &out->planes[FRUSTUM_PLANES - i];
if( !FBitSet( iClipFlags, bit ))
continue;
switch( p->signbits )
{
case 0:
if( p->normal[0] * maxs[0] + p->normal[1] * maxs[1] + p->normal[2] * maxs[2] < p->dist )
return true;
break;
case 1:
if( p->normal[0] * mins[0] + p->normal[1] * maxs[1] + p->normal[2] * maxs[2] < p->dist )
return true;
break;
case 2:
if( p->normal[0] * maxs[0] + p->normal[1] * mins[1] + p->normal[2] * maxs[2] < p->dist )
return true;
break;
case 3:
if( p->normal[0] * mins[0] + p->normal[1] * mins[1] + p->normal[2] * maxs[2] < p->dist )
return true;
break;
case 4:
if( p->normal[0] * maxs[0] + p->normal[1] * maxs[1] + p->normal[2] * mins[2] < p->dist )
return true;
break;
case 5:
if( p->normal[0] * mins[0] + p->normal[1] * maxs[1] + p->normal[2] * mins[2] < p->dist )
return true;
break;
case 6:
if( p->normal[0] * maxs[0] + p->normal[1] * mins[1] + p->normal[2] * mins[2] < p->dist )
return true;
break;
case 7:
if( p->normal[0] * mins[0] + p->normal[1] * mins[1] + p->normal[2] * mins[2] < p->dist )
return true;
break;
default:
return false;
}
}
return false;
}
qboolean GL_FrustumCullSphere( gl_frustum_t *out, const vec3_t center, float radius, int userClipFlags )
{
int iClipFlags;
int i, bit;
if( r_nocull->value )
return false;
if( userClipFlags != 0 )
iClipFlags = userClipFlags;
else iClipFlags = out->clipFlags;
for( i = FRUSTUM_PLANES, bit = 1; i > 0; i--, bit <<= 1 )
{
const mplane_t *p = &out->planes[FRUSTUM_PLANES - i];
if( !FBitSet( iClipFlags, bit ))
continue;
if( DotProduct( center, p->normal ) - p->dist <= -radius )
return true;
}
return false;
}