After making druggie love stories ("Drugstore Cowboy" and "My Own Private Idaho"), a murder comedy ("To Die For"), a political biography ("Harvey Milk"), a shot-for-shot remake of a classic ("Psycho") and sensitive drama ("Good Will Hunting"), Gus Van Sant decided to base his 17th feature on something different.

Van Sant based "Don't Worry, He Won't Get Far on Foot" on the remarkable life of the late John Callahan. A friend of Van Sant, Callahan was an aimless alcoholic until the age of 21, when he was paralyzed in a car accident. Then he made a prolific career drawing taboo-shattering cartoons that were so far beyond the pale that they were practically ultraviolet.

He mocked his fellow quadriplegics, the homeless, feminists, amputees, nuns, Satan, the right wing, the left wing, Martin Luther King and the KKK. To deal with the thousands of complaints he received over his career, his website proudly established a "Hate Mail" section.

In an interview following the film's premiere at this year's Sundance Film Festival, Van Sant said he found the subject "irresistible."

The idea of making a film about this one-of-a kind life circulated in Hollywood for 20 years, with attention from actors like Robin Williams and John Hurt, before Van Sant acquired the rights. He proposed taking a different approach to interpreting Callahan's life.

"The others would have been more like a Seth Rogen, James Franco movie, where things are like, really crazy. I think I dialed it back in this version" into something that resembled Callahan's 1989 autobiography, which shares the film's title. "They sort of went off into fantastic areas, which are very nice and very funny, but there was something about John's book that was getting lost on that fancifulness that I came back to."

Though it had never been tried in a feature film, Van Sant never doubted that he could make effective comedy from images of a man in a wheelchair.

"His cartoons challenged that notion already. That was right up front sort of the theme," he said. "How much can you laugh at a disability in a cartoon or in a movie? Is a movie like a cartoon? Are cartoons serious?"

He approached Joaquin Phoenix with the role. Having played over-the-edge comedy long ago for Van Sant in "To Die For," Phoenix agreed wholeheartedly, the writer/director said.

Van Sant first discovered Callahan's work during the 1980s in the local paper of their hometown, Portland, Ore. They got to know each other a decade later, and Van Sant appreciated the cartoonist's delight at receiving derisive letters.

"When I got to know him he always grinned at these things. He liked to tease people and that was a way to tease the whole community." The two developed early screenplays as Van Sant visited him, hung out and recorded him. A small fraction of Callahan's "very unique life" made it to the film, he said. It omits eliminating hundreds of stories about his home attendants, some of whom "treated him like a chia pet" and wouldn't change his diapers at times when they would prefer to nap.

Van Sant said that Phoenix echoed Callahan's troublemaker spirit very capably. "He's a great inventor of a character, adjusting the scenes for what he thinks they should be."

Which is not to say that he always made the right choice. In one scene he drives his motorized wheelchair like a NASCAR racer and crashes it.

"He was unaware of how the gimmick works," Van Sant said. When it hit resistance and flipped, "he really fell out of the chair. He went a little too fast."