int Collision::RectVsCircle(RECT rect, float xO, float yO, float R)
{
//AB
//CD
//Hình chữ nhật ABCD, đường tròn tâm O, bán kính R
//Tìm điểm M, là điểm gần O nhất
float xM, yM, xA, yA, xB, yB, xC, yC, xD, yD;
xA=xD=rect.left;
xB=xC=rect.right;
yA=yB=rect.top;
yC=yD=rect.bottom;
xM = MiddleNumber(xA, xO, xC); //Tìm tọa độ M
yM = MiddleNumber(yA, yO, yC);
if (Distance(xM,yM,xO,yO) < R) //Xảy ra va chạm
{
if (PointInLine(xM,yM,xA,yA,xB,yB)==0) //Nếu M nằm trên AB
{
if (PointInLine(xM,yM, xB, yB, xC, yC)==0) return 6; //Va chạm tại B
if(PointInLine(xM,yM,xA,yA,xD,yD)==0)return 5; //Va chạm tại A
else return 1; //Va chạm tại AB
}
if(PointInLine(xM,yM,xC,yC,xD,yD)==0)
{
if(PointInLine(xM,yM,xB,yB,xC,yC)==0)return 7; //C
if (PointInLine(xM,yM, xA, yA, xD,yD)==0) return 8; //D
else return 3; //CD
}
if (PointInLine(xM,yM, xB,yB, xC,yC)==0) return 2; //BC
if (PointInLine(xM,yM, xD,yD, xA,yA) == 0) return 4;
else return 9; //Nằm trọn trong ABCD
}
else return 0;
}
// Checks if a line intersect with another line
// inout Line : another line
// Marge: optional, standard on MARGE (declared in MISC.CPP)
//
// return true : lines are crossing
// false: lines are not crossing
//
int kbLine::CheckIntersect ( kbLine * lijn, double Marge )
{
double distance = 0;
// link must exist
assert( m_link );
// lijn must exist
assert( lijn );
// points may not be equal
// must be an if statement because if an assert is used there will
// be a macro expansion error
if ( m_link->GetBeginNode() == m_link->GetEndNode() )
assert( !m_link );
int Take_Action1, Take_Action2, Total_Result;
kbNode *bp, *ep;
PointStatus Result_beginnode, Result_endnode;
bp = lijn->m_link->GetBeginNode();
ep = lijn->m_link->GetEndNode();
Result_beginnode = PointInLine( bp, distance, Marge );
Result_endnode = PointInLine( ep, distance, Marge );
Take_Action1 = ActionOnTable1( Result_beginnode, Result_endnode );
switch ( Take_Action1 )
{
case 0: Total_Result = false ; break;
case 1:
{
bp = m_link->GetBeginNode();
ep = m_link->GetEndNode();
Result_beginnode = lijn->PointInLine( bp, distance, Marge );
Result_endnode = lijn->PointInLine( ep, distance, Marge );
Take_Action2 = ActionOnTable2( Result_beginnode, Result_endnode );
switch ( Take_Action2 )
{
case 0: Total_Result = false; break;
case 1: case 2: case 3: case 4: Total_Result = true; break;
default: Total_Result = false; assert( Total_Result );
}
}
; break; // This break belongs to the switch(Take_Action1)
case 2: case 3: case 4: case 5: case 6: Total_Result = true; break;
default: Total_Result = false; assert( Total_Result );
}
return Total_Result; //This is the final decision
}
// Intersects two lines
// input Line : another line
// Marge: optional, standard on MARGE
//
// return 0: If there are no crossings
// 1: If there is one crossing
// 2: If there are two crossings
int kbLine::Intersect( kbLine * lijn, double Marge )
{
double distance = 0;
// lijn must exist
assert( lijn );
// points may not be equal
// must be an if statement because if an assert is used there will
// be a macro expansion error
if ( m_link->GetBeginNode() == m_link->GetEndNode() )
assert( !m_link );
kbNode *bp, *ep;
PointStatus Result_beginnode, Result_endnode;
int Take_Action1, Take_Action2, Number_of_Crossings = 0;
// Get the nodes from lijn via the link
bp = lijn->m_link->GetBeginNode();
ep = lijn->m_link->GetEndNode();
Result_beginnode = PointInLine( bp, distance, Marge );
Result_endnode = PointInLine( ep, distance, Marge );
Take_Action1 = ActionOnTable1( Result_beginnode, Result_endnode );
// The first switch will insert a crosspoint immediatly
switch ( Take_Action1 )
{
// for the cases see the returnvalue of ActionTable1
case 2: case 6: AddCrossing( ep );
Number_of_Crossings = 1;
break;
case 3: case 5: AddCrossing( bp );
Number_of_Crossings = 1;
break;
case 4: AddCrossing( bp );
AddCrossing( ep );
Number_of_Crossings = 2;
break;
}
// This switch wil investigate the points of this line in relation to lijn
switch ( Take_Action1 )
{
// for the cases see the returnvalue of ActionTable1
case 1: case 5: case 6:
{
// Get the nodes from this line via the link
bp = m_link->GetBeginNode();
ep = m_link->GetEndNode();
Result_beginnode = lijn->PointInLine( bp, distance, Marge );
Result_endnode = lijn->PointInLine( ep, distance, Marge );
Take_Action2 = ActionOnTable2( Result_beginnode, Result_endnode );
switch ( Take_Action2 )
{
// for the cases see the returnvalue of ActionTable2
case 1:
{ // begin of scope to calculate the intersection
double X, Y, Denominator;
CalculateLineParameters();
Denominator = ( m_AA * lijn->m_BB ) - ( lijn->m_AA * m_BB );
// Denominator may not be 0
assert( Denominator != 0.0 );
// Calculate intersection of both linesegments
X = ( ( m_BB * lijn->m_CC ) - ( lijn->m_BB * m_CC ) ) / Denominator;
Y = ( ( lijn->m_AA * m_CC ) - ( m_AA * lijn->m_CC ) ) / Denominator;
//make a decent rounding to B_INT
AddLineCrossing( ( B_INT )X, ( B_INT )Y, lijn );
} // end of scope to calculate the intersection
Number_of_Crossings++;
break;
case 2: lijn->AddCrossing( ep );
Number_of_Crossings++;
break;
case 3: lijn->AddCrossing( bp );
Number_of_Crossings++;
break;
case 4: lijn->AddCrossing( bp );
lijn->AddCrossing( ep );
Number_of_Crossings = 2;
break;
}
}
; break; // This break belongs to the outer switch
}
return Number_of_Crossings; //This is de final number of crossings
}
