Refactor gravity parsing

options/processing_options.go

@@ -220,19 +220,27 @@ func isGravityOffcetValid(gravity GravityType, offset float64) bool {
 func parseGravity(g *GravityOptions, args []string, allowedTypes []GravityType) error {
 	nArgs := len(args)
 
-	if nArgs > 3 {
-		return fmt.Errorf("Invalid gravity arguments: %v", args)
-	}
-
 	if t, ok := gravityTypes[args[0]]; ok && slices.Contains(allowedTypes, t) {
 		g.Type = t
 	} else {
 		return fmt.Errorf("Invalid gravity: %s", args[0])
 	}
 
-	if g.Type == GravitySmart && nArgs > 1 {
+	switch g.Type {
+	case GravitySmart:
+		if nArgs > 1 {
 			return fmt.Errorf("Invalid gravity arguments: %v", args)
-	} else if g.Type == GravityFocusPoint && nArgs != 3 {
+		}
+		g.X, g.Y = 0.0, 0.0
+
+	case GravityFocusPoint:
+		if nArgs != 3 {
+			return fmt.Errorf("Invalid gravity arguments: %v", args)
+		}
+		fallthrough
+
+	default:
+		if nArgs > 3 {
 			return fmt.Errorf("Invalid gravity arguments: %v", args)
 		}
 
@@ -251,6 +259,7 @@ func parseGravity(g *GravityOptions, args []string, allowedTypes []GravityType)
 				return fmt.Errorf("Invalid gravity Y: %s", args[2])
 			}
 		}
+	}
 
 	return nil
 }