1. 程式人生 > >C# 已知圓心和兩點,用DrawArc()畫圓弧(演算法)

C# 已知圓心和兩點,用DrawArc()畫圓弧(演算法)

            //oa和X軸上向量的點乘積
            int Point_Mul_a = (Vector_ax * Vector_Xx) + (Vector_ay * Vector_Xy);
            double Mul_a = Math.Sqrt(Vector_ax * Vector_ax + Vector_ay * Vector_ay) * Math.Sqrt(Vector_Xx * Vector_Xx + Vector_Xy * Vector_Xy);
            
            
            //計算oa和x軸夾角餘弦值
            double Cos_a = Point_Mul_a / Mul_a;
            double A_Cos = Math.Acos(Cos_a);