/*
============
idSurface_Patch::LerpVert
============
*/
void idSurface_Patch::LerpVert( const idDrawVert& a, const idDrawVert& b, idDrawVert& out ) const
{
out.xyz[0] = 0.5f * ( a.xyz[0] + b.xyz[0] );
out.xyz[1] = 0.5f * ( a.xyz[1] + b.xyz[1] );
out.xyz[2] = 0.5f * ( a.xyz[2] + b.xyz[2] );
out.SetNormal( ( a.GetNormal() + b.GetNormal() ) * 0.5f );
out.SetTexCoord( ( a.GetTexCoord() + b.GetTexCoord() ) * 0.5f );
}
/*
====================
sdTraceSurface::RayIntersection
====================
*/
bool sdTraceSurface::RayIntersection( const idVec3& start, const idVec3& end, idDrawVert& dv ) const {
idVec3 p;
int linkNum;
unsigned int i;
unsigned int maxTraceBins;
int hashBin[3];
int separatorAxis;
float faceDist, traceDist;
float separatorDist;
idVec3 normal, invNormal;
// clear the result in case nothing is hit
dv.Clear();
if ( numLinkBlocks == 0 ) {
return false;
}
// get trace normal and normalize
normal = end - start;
faceDist = traceDist = normal.Normalize();
// inverse normal
invNormal[0] = ( normal[0] != 0.0f ) ? 1.0f / normal[0] : 1.0f;
invNormal[1] = ( normal[1] != 0.0f ) ? 1.0f / normal[1] : 1.0f;
invNormal[2] = ( normal[2] != 0.0f ) ? 1.0f / normal[2] : 1.0f;
// maximum number of hash bins the trace can go through
maxTraceBins = 1 + idMath::Ftoi( traceDist * (
fabs( normal[0] ) * invBinSize[0] +
fabs( normal[1] ) * invBinSize[1] +
fabs( normal[2] ) * invBinSize[2] ) );
// get the first hash bin for the trace
p = start - _bounds[0];
hashBin[0] = idMath::Ftoi( idMath::Floor( p[0] * invBinSize[0] ) );
hashBin[1] = idMath::Ftoi( idMath::Floor( p[1] * invBinSize[1] ) );
hashBin[2] = idMath::Ftoi( idMath::Floor( p[2] * invBinSize[2] ) );
separatorAxis = 0;
separatorDist = 0.0f;
bool insideHash = false;
for ( i = 0; i < maxTraceBins; i++, GetNextHashBin( start, normal, hashBin, separatorAxis, separatorDist ) ) {
// if this bin is outside the valid hash space
if ( ( hashBin[0] | hashBin[1] | hashBin[2] ) & ~( binsPerAxis - 1 ) ) {
if ( insideHash ) {
break; // left valid hash space
}
continue; // not yet in valid hash space
}
insideHash = true;
// if a triangle was hit before the plane that separates this hash bin from the previous hash bin
if ( faceDist < traceDist && faceDist < separatorDist * invNormal[separatorAxis] ) {
break;
}
const triLink_t *link;
// test all the triangles in this hash bin
for ( linkNum = binLinks[hashBin[0]][hashBin[1]][hashBin[2]]; linkNum != -1; linkNum = link->nextLink ) {
link = &linkBlocks[ linkNum / MAX_LINKS_PER_BLOCK ][ linkNum % MAX_LINKS_PER_BLOCK ];
faceDist = TraceToMeshFace( link->faceNum, start, normal, faceDist, traceDist, dv );
}
}
// FIXME: SD_USE_DRAWVERT_SIZE_32
#if defined( SD_USE_DRAWVERT_SIZE_32 )
idVec3 n = dv.GetNormal();
n.Normalize();
dv.SetNormal( n );
#else
dv._normal.Normalize();
#endif
return ( faceDist < traceDist );
}
ID_INLINE float sdTraceSurface::TraceToMeshFace( const int faceNum, const idVec3& point, const idVec3 &normal, const float faceDist, const float traceDist, idDrawVert& dv ) const {
int i;
float dist;
const idPlane* plane;
idVec3 edge;
float d, t;
idVec3 dir[3];
float baseArea;
float bary[3];
idVec3 testVert;
plane = facePlanes + faceNum;
// only test against planes facing the opposite direction as our trace normal
d = -( plane->Normal() * normal );
if ( d <= TRIANGLE_NORMAL_EPSILON ) {
return faceDist;
}
// get the distance to the plane
dist = plane->Distance( point );
if ( dist >= traceDist * d ) {
return faceDist;
}
const vertIndex_t* index = indexes + faceNum * 3;
const idDrawVert &v0 = verts[ index[ 0 ] ];
const idDrawVert &v1 = verts[ index[ 1 ] ];
const idDrawVert &v2 = verts[ index[ 2 ] ];
// if normal is inside all edge planes, this face is hit
dir[0] = v0.xyz - point;
dir[1] = v1.xyz - point;
edge = dir[0].Cross( dir[1] );
t = normal * edge;
if ( t < -TRIANGLE_EDGE_EPSILON ) {
return faceDist;
}
dir[2] = v2.xyz - point;
edge = dir[1].Cross( dir[2] );
t = normal * edge;
if ( t < -TRIANGLE_EDGE_EPSILON ) {
return faceDist;
}
edge = dir[2].Cross( dir[0] );
t = normal * edge;
if ( t < -TRIANGLE_EDGE_EPSILON ) {
return faceDist;
}
// find the point of impact on the triangle plane
dist /= d;
testVert = point + dist * normal;
// calculate barycentric coordinates of the impact point on the high poly triangle
baseArea = 1.0f / idWinding::TriangleArea( v0.xyz, v1.xyz, v2.xyz );
bary[0] = idWinding::TriangleArea( testVert, v1.xyz, v2.xyz ) * baseArea;
bary[1] = idWinding::TriangleArea( v0.xyz, testVert, v2.xyz ) * baseArea;
bary[2] = idWinding::TriangleArea( v0.xyz, v1.xyz, testVert ) * baseArea;
if ( bary[0] + bary[1] + bary[2] > 1.1f ) {
return faceDist;
}
dv.xyz = testVert;
// triangularly interpolate the texture coordinates, normals and colors to the sample point
// FIXME: SD_USE_DRAWVERT_SIZE_32
for ( i = 0; i < 2; i++ ) {
dv._st[ i ] = bary[0] * v0._st[i] + bary[1] * v1._st[i] + bary[2] * v2._st[i];
}
#if defined( SD_USE_DRAWVERT_SIZE_32 )
idVec3 n;
idVec3 n0 = v0.GetNormal();
idVec3 n1 = v1.GetNormal();
idVec3 n2 = v2.GetNormal();
for ( i = 0; i < 3; i++ ) {
n[ i ] = bary[0] * n0[i] + bary[1] * n1[i] + bary[2] * n2[i];
}
n.Normalize();
dv.SetNormal( n );
idVec3 tgnt;
idVec3 tgnt0 = v0.GetTangent();
idVec3 tgnt1 = v1.GetTangent();
idVec3 tgnt2 = v2.GetTangent();
for ( i = 0; i < 3; i++ ) {
tgnt[ i ] = bary[0] * tgnt0[i] + bary[1] * tgnt1[i] + bary[2] * tgnt2[i];
}
tgnt.Normalize();
dv.SetTangent( tgnt );
float s0 = v0.GetBiTangentSign();
float s1 = v1.GetBiTangentSign();
float s2 = v2.GetBiTangentSign();
dv.SetBiTangentSign( bary[0] * s0 + bary[1] * s1 + bary[2] * s2 );
#else
for ( i = 0; i < 3; i++ ) {
dv._normal[ i ] = bary[0] * v0._normal[i] + bary[1] * v1._normal[i] + bary[2] * v2._normal[i];
}
dv._normal.Normalize();
for ( i = 0; i < 4; i++ ) {
dv._tangent[i] = bary[0] * v0._tangent[i] + bary[1] * v1._tangent[i] + bary[2] * v2._tangent[i];
}
#endif
for ( i = 0; i < 4; i++ ) {
dv.color[i] = idMath::ClampInt( 0, 255, idMath::FtoiFast( bary[0] * v0.color[i] + bary[1] * v1.color[i] + bary[2] * v2.color[i] ) );
}
return dist;
}
