示例#1
0
        //
        // Arrow
        //
        public static HashSet <Triangle2> Arrow(MyVector2 p1, MyVector2 p2, float lineWidth, float arrowSize)
        {
            HashSet <Triangle2> arrowTriangles = new HashSet <Triangle2>();

            //An arrow consists of two parts: the pointy part and the rectangular part

            //First we have to see if we can fit the parts
            MyVector2 lineDir = p2 - p1;

            float lineLength = MyVector2.Magnitude(lineDir);

            if (lineLength < arrowSize)
            {
                Debug.Log("Cant make arrow because line is too short");

                return(null);
            }


            //Make the arrow tip
            MyVector2 lineDirNormalized = MyVector2.Normalize(lineDir);

            MyVector2 arrowBottom = p2 - lineDirNormalized * arrowSize;

            MyVector2 lineNormal = MyVector2.Normalize(new MyVector2(lineDirNormalized.y, -lineDirNormalized.x));

            MyVector2 arrowBottom_R = arrowBottom + lineNormal * arrowSize * 0.5f;
            MyVector2 arrowBottom_L = arrowBottom - lineNormal * arrowSize * 0.5f;

            Triangle2 arrowTipTriangle = new Triangle2(p2, arrowBottom_R, arrowBottom_L);

            arrowTriangles.Add(arrowTipTriangle);


            //Make the arrow rectangle
            float halfWidth = lineWidth * 0.5f;

            MyVector2 p1_T = p1 + lineNormal * halfWidth;
            MyVector2 p1_B = p1 - lineNormal * halfWidth;

            MyVector2 p2_T = arrowBottom + lineNormal * halfWidth;
            MyVector2 p2_B = arrowBottom - lineNormal * halfWidth;

            HashSet <Triangle2> rectangle = LineSegment(p1_T, p1_B, p2_T, p2_B);

            foreach (Triangle2 t in rectangle)
            {
                arrowTriangles.Add(t);
            }

            return(arrowTriangles);
        }