Index: /issm/trunk-jpl/src/m/contrib/larour/isintriangle.m
===================================================================
--- /issm/trunk-jpl/src/m/contrib/larour/isintriangle.m	(revision 24845)
+++ /issm/trunk-jpl/src/m/contrib/larour/isintriangle.m	(revision 24845)
@@ -0,0 +1,29 @@
+function isin=isintriangle(x0,x1,x2,x3,y0,y1,y2,y3)
+
+	isin=1; %default choice;
+
+	dx = x0 - x3; dy = y0 - y3;
+	y23 = y2 - y3; x32 = x3 - x2; y31 = y3 - y1; x13 = x1 - x3; det = y23 * x13 - x32 * y31;
+	det = y23 * x13 - x32 * y31;
+	minD = min(det, 0); maxD = max(det, 0);
+
+
+	a = y23 * dx + x32 * dy;
+	if (a < minD || a > maxD)
+		isin=0; 
+		return;
+	end
+					
+	b = y31 * dx + x13 * dy;
+	if (b < minD || b > maxD)
+		isin=0;
+		return;
+	end
+						
+	c = det - a - b;
+	if (c < minD || c > maxD)
+		isin=0;
+		return;
+	end
+	return;
+end