float BoidManager::getDistanceBetween(XMVECTOR vectorBetween)
{
float distanceBetween;
distanceBetween = XMVectorGetX(XMVector4Length((vectorBetween)));
return distanceBetween;
}
FLOAT32 CFVec4::Distance( CFVec4Arg fv4To ) const
{
CFVec4 v4Temp;
v4Temp = fv4To - *this;
XMVECTOR& v4V = *reinterpret_cast<XMVECTOR*>( &v4Temp );
return XMVectorGetX( XMVector4Length( v4V ) );
}
/**
* @param vMagnitude Contains the scalar magnitude in each component.
*/
void CFVec4::Normalise( CFVec4 &vMagnitude )
{
XMVECTOR& v4V = *reinterpret_cast<XMVECTOR*>( this );
XMVECTOR& v4VMag = *reinterpret_cast<XMVECTOR*>( &vMagnitude );
//TODO: Is there a cheaper way of doing this?
v4VMag = XMVector4Length( v4V );
v4V = XMVector4Normalize( v4V );
}
/**
* @return A vector quantity with the scalar in each component.
*/
CFVec4 CFVec4::MagnitudeV( void ) const
{
CFVec4 v4Return;
const XMVECTOR& v4V = *reinterpret_cast<const XMVECTOR*>( this );
XMVECTOR& v4Result = *reinterpret_cast<XMVECTOR*>( &v4Return );
v4Result = XMVector4Length( v4V );
return v4Return;
}
/**
* @return A vector quantity with the scalar in each component.
*/
CFVec4 CFVec4::DistanceV( CFVec4Arg fv4To ) const
{
CFVec4 v4Temp;
v4Temp = fv4To - *this;
XMVECTOR& v4V = *reinterpret_cast<XMVECTOR*>( &v4Temp );
v4V = XMVector4Length( v4V );
return v4Temp;
}
CFVec4 CFVec4::GetNormal( FLOAT32 &fMagnitude ) const
{
CFVec4 v4Return;
const XMVECTOR& v4V = *reinterpret_cast<const XMVECTOR*>( this );
XMVECTOR& v4Result = *reinterpret_cast<XMVECTOR*>( &v4Return );
//TODO: Is there a cheaper way of doing this?
fMagnitude = XMVectorGetX( XMVector4Length( v4V ) );
v4Result = XMVector4Normalize( v4V );
return v4Return;
}
bool WorldEntity::circlePointIntersect( XMVECTOR point, XMVECTOR circleCenter, float circleRadius )
{
XMVECTOR diff = point - circleCenter;
XMVECTOR len = XMVector4Length( diff );
XMFLOAT4 realLen;
XMStoreFloat4( &realLen, len );
if( realLen.x < circleRadius ){
return true;
}
return false;
}
FLOAT32 CFVec4::Magnitude( void ) const
{
const XMVECTOR& v4V = *reinterpret_cast<const XMVECTOR*>( this );
return XMVectorGetX( XMVector4Length( v4V ) );
}
bool WorldEntity::circleAALineIntersect( XMVECTOR start, XMVECTOR end, XMVECTOR circleCenter, float circleRadius )
{
//A collision function we actually understand...
//Create a vector from the start to the circle position
XMVECTOR cToStart = circleCenter - start;
XMVECTOR cToEnd = circleCenter - end;
XMVECTOR lenToStart = XMVector4Length( cToStart );
XMVECTOR lenToEnd = XMVector4Length( cToEnd );
XMFLOAT4 ans;
XMStoreFloat4( &ans, lenToStart );
if( ans.x <= circleRadius ){
return true;
}
XMStoreFloat4( &ans, lenToEnd );
if( ans.x <= circleRadius ){
return true;
}
//Calculate the start to end
XMVECTOR endToStart = end - start;
XMVECTOR endToStartLen = XMVector4Length( endToStart );
XMFLOAT4 tmp;
XMStoreFloat4(&tmp, endToStartLen);
tmp.x = 1.0f / tmp.x;
XMVECTOR tmpA = XMVectorScale(endToStart, tmp.x);
XMVECTOR tmpB = XMVectorScale(cToStart, tmp.x);
//Project it onto the start -> end vector
XMVECTOR dot = XMVector4Dot( tmpA, tmpB );
//Calculate the Perpendicular point
XMVECTOR per = start + ( endToStart * dot );
//If the perpendicular point is within range of the circle, there is a collision
XMVECTOR perDist = XMVector4Length( circleCenter - per );
XMStoreFloat4( &ans, perDist );
if( ans.x > circleRadius ){
return false;
}
//Store the dot product to see how far down the line the collision happens
XMStoreFloat4( &ans, dot );
//If the dot product is negative, the collision is outside the range
if( ans.x < 0.0f ){
return false;
}
//If the dot product is bigger than 1.0f, meaning it scaled the vector passed the segment, the collision is outside the range
if( ans.x > 1.0f ){
return false;
}
return true;
}
