public static boolean isFaceDirectionOnEdgeCorrect(IVec2 edgePt1, IVec2 edgePt2, IVec2 vertexPt) {
// this is under assumption of outer trim loop goes counter-clockwise and
// inner trim hole loop goes clockwise always.
// return edgePt2.diff(edgePt1).cross(vertexPt.diff(edgePt1)).z > 0;
double z = edgePt2.diff(edgePt1).cross(vertexPt.diff(edgePt1)).z;
// IOut.p("edge1 = "+edgePt1 +", edge2 = "+edgePt2+", vertexPt = "+vertexPt);
// if(z>0) IOut.p("correct direction"); //
// else IOut.p("wrong direction"); //
// return z > 0;
return z >= 0; // changed 2011/07/11
}
public static boolean isPointInsideEdge(IVec2 pt, IVec2 edgePt1, IVec2 edgePt2, IVec2 edgePt3) {
// inside of edge is left side of the edge formed by edgePt1, edgePt2, edgePt3
IVec2 diff1 = edgePt2.diff(edgePt1);
IVec2 diff2 = edgePt3.diff(edgePt2);
// edge bent inward
if (diff1.cross(diff2).z >= 0) {
if (!isFaceDirectionOnEdgeCorrect(edgePt1, edgePt2, pt)
|| !isFaceDirectionOnEdgeCorrect(edgePt2, edgePt3, pt)) return false;
return true;
}
if (!isFaceDirectionOnEdgeCorrect(edgePt1, edgePt2, pt)
&& !isFaceDirectionOnEdgeCorrect(edgePt2, edgePt3, pt)) return false;
return true;
}
public static boolean isPointsIntersectiongWithEdge(
IVec2 pt1, IVec2 pt2, IVec2 edgePt1, IVec2 edgePt2, IVec2 edgePt3) {
IVec2 diff1 = edgePt2.diff(edgePt1);
IVec2 diff2 = edgePt3.diff(edgePt2);
// edge bent inward; no intersection
if (diff1.cross(diff2).z >= 0) return false;
// edge bent outward
if (isFaceDirectionOnEdgeCorrect(edgePt1, edgePt2, pt1)
&& isFaceDirectionOnEdgeCorrect(edgePt1, edgePt2, pt2)) return false;
if (isFaceDirectionOnEdgeCorrect(edgePt2, edgePt3, pt1)
&& isFaceDirectionOnEdgeCorrect(edgePt2, edgePt3, pt2)) return false;
IVec2 bisector1 = diff1.neg().bisect(diff2);
IVec2 bisector2 = pt1.diff(edgePt2).bisect(pt2.diff(edgePt2));
if (bisector1.dot(bisector2) > 0) return true;
return false;
}
public static boolean isVertexOnSameSide(
IVec2 edgePt1, IVec2 edgePt2, IVec2 vertexPt1, IVec2 vertexPt2) {
IVec2 diff = edgePt2.diff(edgePt1);
return diff.cross(vertexPt1.diff(edgePt1)).z * diff.cross(vertexPt2.diff(edgePt1)).z >= 0;
}
public static boolean isClockwise(IVec2 pt1, IVec2 pt2, IVec2 pt3) {
return pt2.diff(pt1).cross(pt3.diff(pt2)).z < 0;
}