structure optimization

utils/g2d/coordinate.go

@@ -1 +1,13 @@
 package g2d
+
+import "math"
+
+// CalcDistance 计算两点之间的距离
+func CalcDistance(x1, y1, x2, y2 float64) float64 {
+	return math.Sqrt(math.Pow(x2-x1, 2) + math.Pow(y2-y1, 2))
+}
+
+// CalcAngle 计算点2位于点1之间的角度
+func CalcAngle(x1, y1, x2, y2 float64) float64 {
+	return math.Atan2(y2-y1, x2-x1) * 180 / math.Pi
+}

utils/g2d/direction.go

@@ -0,0 +1,25 @@
+package g2d
+
+type Direction uint8
+
+const (
+	DirectionUp = Direction(iota)
+	DirectionDown
+	DirectionLeft
+	DirectionRight
+)
+
+// CalcDirection 计算点2位于点1的方向
+func CalcDirection(x1, y1, x2, y2 float64) Direction {
+	angle := CalcAngle(x1, y1, x2, y2)
+	if angle > -45 && angle < 45 {
+		return DirectionRight
+	} else if angle > 135 && angle < -135 {
+		return DirectionLeft
+	} else if angle > 45 && angle < 135 {
+		return DirectionUp
+	} else if angle > -135 && angle < -45 {
+		return DirectionDown
+	}
+	return 0
+}