/**
* Check if a Portal is in view of the frustum.
*
* @return Returns true if the portal is visible by this frustum
*/
public boolean isPortalInFrustum(E3DPortal portal) {
E3DVector3F[] proj = new E3DVector3F[4];
E3DVector3F portalA = portal.getA();
E3DVector3F portalB = portal.getB();
E3DVector3F portalC = portal.getC();
E3DVector3F portalD = portal.getD();
// Project all the corners of the portal that we are trying to see is in this frustum
proj[0] = viewport.projectPoint(portalA);
proj[0].setZ(0.0);
proj[1] = viewport.projectPoint(portalB);
proj[1].setZ(0.0);
proj[2] = viewport.projectPoint(portalC);
proj[2].setZ(0.0);
proj[3] = viewport.projectPoint(portalD);
proj[3].setZ(0.0);
/** 1. Check if a portal corner point is in the frustum */
for (int i = 0; i < 4; i++) {
if (projectedPointInFrustum(proj[i])) return true;
}
/** 2. Check if a frustum corner point is in the portal */
E3DTriangle portalTriA = new E3DTriangle(getEngine(), proj[0], proj[1], proj[3]);
E3DTriangle portalTriB = new E3DTriangle(getEngine(), proj[1], proj[2], proj[3]);
if (portalTriA.isPointInTriangle(a)
|| portalTriB.isPointInTriangle(a)
|| portalTriA.isPointInTriangle(b)
|| portalTriB.isPointInTriangle(b)
|| portalTriA.isPointInTriangle(c)
|| portalTriB.isPointInTriangle(c)
|| portalTriA.isPointInTriangle(d)
|| portalTriB.isPointInTriangle(d)) return true;
/** 3. Check if any of the line segments intersect */
if (get2DLineIntersectionPt(a, b, proj[0], proj[1]) != null
|| get2DLineIntersectionPt(a, b, proj[1], proj[2]) != null
|| get2DLineIntersectionPt(a, b, proj[2], proj[3]) != null
|| get2DLineIntersectionPt(a, b, proj[3], proj[0]) != null
|| get2DLineIntersectionPt(b, c, proj[0], proj[1]) != null
|| get2DLineIntersectionPt(b, c, proj[1], proj[2]) != null
|| get2DLineIntersectionPt(b, c, proj[2], proj[3]) != null
|| get2DLineIntersectionPt(b, c, proj[3], proj[0]) != null
|| get2DLineIntersectionPt(c, d, proj[0], proj[1]) != null
|| get2DLineIntersectionPt(c, d, proj[1], proj[2]) != null
|| get2DLineIntersectionPt(c, d, proj[2], proj[3]) != null
|| get2DLineIntersectionPt(c, d, proj[3], proj[0]) != null
|| get2DLineIntersectionPt(d, a, proj[0], proj[1]) != null
|| get2DLineIntersectionPt(d, a, proj[1], proj[2]) != null
|| get2DLineIntersectionPt(d, a, proj[2], proj[3]) != null
|| get2DLineIntersectionPt(d, a, proj[3], proj[0]) != null) return true;
return false;
}
