void Collision::CheckBrush( Q3BspBrush *brush )
{
float startFraction = -1.0f;
float endFraction = 1.0f;
bool startsOut = false;
bool endsOut = false;
vec3f collNormal;
float endDistSaved = 0.0f;
collNormal = vec3f(0.0f, 0.0f, 0.0f);
for (int i = 0; i < brush->n_brushsides; i++)
{
Q3BspBrushSide *brushSide = &mQ3Map->m_pBrushSides[brush->brushside + i];
Q3BspPlane *plane = &mQ3Map->m_pPlanes[brushSide->plane];
float startDistance, endDistance;
vec3f planeNormal = vec3f(plane->normal);
if (mTraceType == TT_RAY)
{
startDistance = vec3dot( &mInputStart, &planeNormal ) - plane->dist;
endDistance = vec3dot( &mInputEnd, &planeNormal ) - plane->dist;
}
else /*if (mTraceType == TT_SPHERE)*/
{
startDistance = vec3dot( &mInputStart, &planeNormal ) - (plane->dist + mTraceRadius);
endDistance = vec3dot( &mInputEnd, &planeNormal ) - (plane->dist + mTraceRadius);
}
if (startDistance > 0)
startsOut = true;
if (endDistance > 0)
endsOut = true;
// make sure the trace isn't completely on one side of the brush
if (startDistance > 0 && endDistance > 0)
{ // both are in front of the plane, its outside of this brush
return;
}
if (startDistance <= 0 && endDistance <= 0)
{ // both are behind this plane, it will get clipped by another one
continue;
}
if (startDistance > endDistance)
{ // line is entering into the brush
float fraction = (startDistance - EPSILON) / (startDistance - endDistance);
if (fraction < 0)
fraction = 0;
if (fraction > startFraction)
{
startFraction = fraction;
collNormal = vec3f(plane->normal);
endDistSaved = endDistance;
}
}
else
{ // line is leaving the brush
float fraction = (startDistance + EPSILON) / (startDistance - endDistance);
if (fraction < endFraction)
endFraction = fraction;
}
}
if (startsOut == false)
{
mOutputStartOut = false;
if (endsOut == false)
mOutputAllSolid = true;
return;
}
if (startFraction < endFraction)
{
if (startFraction > -1 && startFraction < mOutputFraction)
{
if (startFraction < 0)
startFraction = 0;
mGoodPos = false;
mOutputFraction = startFraction;
mCollisionNormal = collNormal;
mEndDistance = endDistSaved;
}
}
}
vec_t vec3distfastvec(const vec3_t b, const vec3_t c){
vec3_t math;
vec3subvec(math, b, c);
return vec3dot(math, math);
}
void Collision::CheckNode( int nodeIndex, float startFraction, float endFraction, vec3f start, vec3f end)
{
if (nodeIndex < 0)
{
// this is a leaf
Q3BspLeaf *leaf = &mQ3Map->m_pLeafs[-(nodeIndex + 1)];
for (int i = 0; i < leaf->n_leafbrushes; i++)
{
Q3BspBrush *brush = &mQ3Map->m_pBrushes[mQ3Map->m_pLeafBrushes[leaf->leafbrush + i]];
if (brush->n_brushsides > 0 && (mQ3Map->m_pTextures[brush->texture].contents & 1) )
{
CheckBrush( brush );
}
}
// don't have to do anything else for leaves
return;
}
// this is a node
Q3BspNode *node = &mQ3Map->m_pNodes[nodeIndex];
Q3BspPlane *plane = &mQ3Map->m_pPlanes[node->plane];
vec3f normal = vec3f(plane->normal);
vec3f startDX = vec3f(start);
vec3f endDX = vec3f(end);
float startDistance = vec3dot( &startDX, &normal ) - plane->dist;
float endDistance = vec3dot( &endDX, &normal ) - plane->dist;
float offset;
if (mTraceType == TT_RAY)
{
offset = 0.0f;
}
else if (mTraceType == TT_SPHERE)
{
offset = mTraceRadius;
}
else
{
offset = 0.0f;
}
if (startDistance >= offset && endDistance >= offset)
{ // both points are in front of the plane
// so check the front child
CheckNode( node->children[0], startFraction, endFraction, start, end );
}
else if (startDistance < -offset && endDistance < -offset)
{ // both points are behind the plane
// so check the back child
CheckNode( node->children[1], startFraction, endFraction, start, end );
}
else
{ // the line spans the splitting plane
int side;
float fraction1, fraction2, middleFraction;
vec3f middle;
// split the segment into two
if (startDistance < endDistance)
{
side = 1; // back
float inverseDistance = 1.0f / (startDistance - endDistance);
fraction1 = (startDistance - offset + EPSILON) * inverseDistance;
fraction2 = (startDistance + offset + EPSILON) * inverseDistance;
}
else if (endDistance < startDistance)
{
side = 0; // front
float inverseDistance = 1.0f / (startDistance - endDistance);
fraction1 = (startDistance + offset + EPSILON) * inverseDistance;
fraction2 = (startDistance - offset - EPSILON) * inverseDistance;
}
else
{
side = 0; // front
fraction1 = 1.0f;
fraction2 = 0.0f;
}
// make sure the numbers are valid
if (fraction1 < 0.0f) fraction1 = 0.0f;
else if (fraction1 > 1.0f) fraction1 = 1.0f;
if (fraction2 < 0.0f) fraction2 = 0.0f;
else if (fraction2 > 1.0f) fraction2 = 1.0f;
// calculate the middle point for the first side
middleFraction = startFraction + (endFraction - startFraction) * fraction1;
/*for (int i = 0; i < 3; i++)
middle[i] = start[i] + fraction1 * (end[i] - start[i]);*/
middle = start + fraction1 * (end - start);
// check the first side
CheckNode( node->children[side], startFraction, middleFraction, start, middle );
// calculate the middle point for the second side
middleFraction = startFraction + (endFraction - startFraction) * fraction2;
/*for (int i = 0; i < 3; i++)
middle[i] = start[i] + fraction2 * (end[i] - start[i]);*/
middle = start + fraction2 * (end - start);
// check the second side
CheckNode( node->children[!side], middleFraction, endFraction, middle, end );
}
}
