谁能帮我解释一下(300)

inline float SignedTriangleArea2D( const VECTOR2& a, const VECTOR2& b, const VECTOR2& c ){ //(+ve: cclockwise, -ve: clockwise, 0: degenerate[collinear or coincident]) return ( ( a.x - c.x ) * ( b.y - c.y ) - ( a.y - c.y ) * ( b.x - c.x ) );}inline int TestSegmentSegment2D( const VECTOR2& a, const VECTOR2& b, const VECTOR2& c, const VECTOR2& d, float& isect_coeff, VECTOR2& isect_point ){// check segment(a,b) isect against segment(c,d), coeff_ab is isect_value along ab float abd = SignedTriangleArea2D( a, b, d ), abc = SignedTriangleArea2D( a, b, c ); if ( abc * abd < EPSILON ) // abc & abd have different signs >> isect { float cda = SignedTriangleArea2D( c, d, a ), // constant area: abd - abc = cda - cdb //cdb = SignedTriangleArea2D( c, d, b ), cdb = cda + abc - abd; if ( cda * cdb < EPSILON ) // cda & cdb have different signs >> isect {// segments intersect isect_coeff = cda / ( cda - cdb ); isect_point = a + isect_coeff * ( b - a ); return 1; } } return 0; // segment not intersecting}急，盼

没人会吗？有开发过游戏的高手吗，帮帮忙！小弟先谢谢了！

没人会的，给分吧！

接受答案了.