James Patterson’s books just keep selling, so it’s no surprise that the movies keep calling.

After two films featuring Morgan Freeman as his Washington D.C. detective Alex Cross, an adaptation of Patterson’s “Alex Cross” opens Friday with the brave counter-casting of Tyler Perry in the lead.

Initially, Madea as an action hero seemed as risible as casting the diminutive Tom Cruise as the unstoppable man-mountain Jack Reacher in the upcoming adaptation of the Lee Child novels, but early word indicates that Perry has pulled it off.

It’s not that Palm Beach novelist Patterson hated the two Alex Cross movies that starred Morgan Freeman, although he says, “I always think they could have been better. ‘Kiss the Girls’ had some scenes I liked a lot. They reshot the ending and it was good. ‘Along Came a Spider’ had a good pace. But I think [director] Lee Tamahori wanted to do an old-fashioned noir, and he didn’t really have the money he needed.”

Because of Morgan Freeman’s age, gravitas and moral authority, he is always going to be more of a philosopher king than an action hero, so “Alex Cross” moves in a very different direction and has a different rhythm than the previous Alex Cross movies.

“What I liked about making the picture was that everybody was hungry,” says Patterson. “They [the producers] took a run at Tyler and word came back that he would be interested. I went to Atlanta to talk to him. ‘I wouldn’t attempt this if I wasn’t sure I could do it,’ he said. And Matthew Fox has always been a good guy on shows like ‘Lost,’ and he really liked the idea of being a bad guy. Rob Cohen, the director, made ‘The Fast and the Furious’ and he wanted to get back to action.”

Patterson’s capsule description of Perry sounds a lot like a capsule description of Patterson: “He’s very smart and very focused. I had seen him perform live and I thought he was spellbinding. And physically he’s closer to Cross than Morgan Freeman.”

With the creative pieces assembled, Patterson oversaw the process carefully. “I had approval of the cast, the script and the director. Once it got going, it was a very smooth process. It was made outside the studio system, and we only spent $25 million, which is not a lot of money. I own 40 percent of the picture, and break-even is $30 million.”

The Morgan Freeman movies departed from the books in many ways, and so does “Alex Cross,” which is all right with Patterson. “The book is there, and people can read it if they want. The movie takes off from the book. The Cross books are basically built around his family, and Morgan was older so he couldn’t have kids running around. But Tyler is much younger. And the bad guy is different in the movie, too.”

Patterson generates an enormous amount of what the trade calls “content,” and with a large audience predisposed toward buying anything with his name attached, financing is not a problem. A movie of “Maximum Ride” is close to happening at Universal, and Gaumont has optioned Patterson’s novels featuring Michael Bennett for a TV series. Patterson cautions that Bennett isn’t a done deal yet - “Gaumont wants to see one more script.”

He says he’s actually obsessed with the movie versions of the kids books he’s been writing - he’s done a script for “Middle School: The Worst Years of My Life” that he’s high on.

In a sense all this is a natural extension of his own interests - Patterson is a movieholic, and sees everything that runs through a projector. He liked “Frankenweenie,” and even liked “The Master,” although he says “I couldn’t recommend it to a soul.”

Not surprisingly, he doesn’t have the same problem with “Alex Cross.”

“It was a pleasure to put together,” he says.