Nothing ails Dyan Cannon. She is sitting by the pool of her elegantly pulled together, symphony-of-browns beach house, her favorite place in the entire world. And in her lap is a clipping from one of the nation's great newspapers calling her latest performance" the most revivifying comic spectacle of the current movie season." I don't feel badly about that," Dyan Cannon says, laughing. "Not badly at all."

There is more. Her brief turn as the murderous Mrs. Farnsworth in Warren Beatty's "Heaven Can Wait" has been applauded to pieces with words like "impeccable," "superb," "bravura," and even "hysterically hysterical" getting tossed around by critics like rice at a wedding. "Never," wrote Penelope Gilliatt, who ought to know, "have illicit love scenes been so unerotic as when she is playing them here."

"I turned that movie down three times. I told Warren, 'I think my part's awful; I don't want to do it,'" Cannon says, dressed in tight jeans and a black long-sleeved top decorated with a large red-satin apple. A floppy straw hat shields her face from the sun as she considers the outcome. "Really, I must tell you, I'm actually amazed by this," she says, starting to laugh again. "And I'm on the screen so little (more laughter). Warren has cut so much out (still more laughter). If everyone's getting so excited about this little shtick, wait till I give them the whole banana." This to a genuine torrent of laughs accompanied by assorted whoops and table poundings.

When Cannon laughs, obviously, it is brassy, vibrant, fierce, the kind of laugh that goes with the kind of person who is perfectly capable of leaping up and screaming in glee at a departing friend who is nominally fasting with her. "I knew it. I knew it. YOU'RE GOING TO EAT!"

This kind of opening act notwithstanding, Cannon is not really a walking whoopee cushion, nor do her boisterous spirits really stem from this success or the imminent release of her other current projects, "Revenge of the Pink Panther" and the made-for-NBC "Lady of the House."

My happiness is not dependent on whether something is a hit or not, it's not limited to any external thing," she says a bit later, comfortable in her hammock in her upstairs work area with its glassed-in view of the Pacific and pictures of daughter Jennifer, now 12, her child by former husband Cary Grant, on the wall. "I have my own joy now. No man gave it to me; no thing gave it to me; no place gave it to me, and no man, thing or place can take it away from me."

All this, one is made to understand, did not come easy but was rather the result of a four-year hiatus from film-making while Cannon worked with the problems left over from what People magazine, in its own inimitable fashion, once called "a life rolled by emotional upheaval."

And, indeed, her life has had that tabloid touch from the surprise early marriage to Cary Grant (she was 27, he was 61) to the bitter divorce with her charges about his use of LSD and enraged outbursts, to her search for salvation through primal scream and other therapies.

Now, at age 40, she is relentlessly upbeat about life but in a way that seems to work for her. "Let me share something a friend told me," she says, smiling. "'Regret of the past and fear of the future are robbers of the now.' I just love that."

The four-year career pause came as a result of a dissatisfaction with the roles offered to her, a distaste for playing women who were "one-note sambas."

"Even though I played wonderful parts (she especially likes her Oscar-nominated debut in "Bob & Carol and Ted & Alice") it was limiting," she explains. "It wasn't Hollywood limiting me; I had limited myself by accepting those limits. Then I started to realize I was going to have to get it together myself."

The final blow as a little-seen Canadian film called "Child Under a Leaf," which she had great hopes for but which turned out dismally.

"After that film I went to bed for a month. I mean alone," she is quick to add. "I'd worked my tushy off, given so much, and it hadn't worked. Something inside me was still churning, it had to do with realizing myself, my own being. I said, 'What am I going to do?' and since I always answer my own questions I said. 'Stop.' 'Stop what?' 'Stop acting.' 'Are your sure?' 'I'm sure I'm not happy this way.'"

What happened initially was that Cannon "spent a lot of time being really scared. I had been going from picture to picture, making a lot of money, and I really didn't know what I was giving it all up for. I didn't have the answer. It was like when everyone said I was crazy when I got my divorce. They said, 'You can still live your own life (and stay married), you can do what you want.' I said, 'What do you mean? This is my life.'"

The break almost ended after two years when Cannon was offered a part in a Charles Bronson movie, a part she tentatively accepted, because, among other htings lack of income meant that the market nearby had cut-off her credit.

"But I woke up the next morning so sick I could hardly get out of bed," she says. "I knew I was selling out, and I decided they could have anything they wanted, the house, anything, but they could never have me again. Never, never, never, never, never."

Right in the middle of all this came what she calls, "the most fulfilling experience of my life, aside from Jennifer," and that was making the transition from acting to directing. "I'd never thought about it a day in my life," she says, though memory did eventually call up a night spent directing an actor's workshop and "coming home so high."

But then Cannon heard about an American Film Institute directing workshop for women and ended up making a 40-plus-minute short called "Number One," a child's-eye view of sex and life which met with well-disposed reviews and an Oscar nomination for best live-action short.

"Directing was the most natural thing I've ever done in my life," she says with her usual enthusiasm. And her very next project will be to direct and produce a feature at Twentieth Century-Fox about a relationship between a woman and two brothers. In fact, just this very day, she announced gleefully, aftter a year and a half of interviewing potential candidates, she has made an important decision: "I'm going to write it myself, too."

So intoxicating is this prospect, so enthused is Cannon about her vision of things to come, that she is prone to saying, pretty much in total seriousness, "I figure the next 50 years will be concentrated on working all the time." She even has the dream situation worked out: a large yacht write and edit films and water-ski, a write and edit films and water-ski a much-favored activity, all at the same time.

"I worked very hard to get to the point where I live in the now," she says, almost daring you to contradict her. "I'm telling you, I have some things to do, my time has just begun."