The past is so bright - he's got to wear shades

They call him ... cool. Ever since Chungking Express streaked its phosphorescent path across the face of the film world in the mid-1990s, wafting the Mamas and Papas' "California Dreamin'" like heady perfume in its wake, Wong Kar-Wai has been so fêted with the "c" word, you wonder if the Hong Kong film-maker himself were sneaking into his interviewers' offices and replacing their dingy copy with bright fulsome fan mail.

They call him ... cool. Ever since Chungking Express streaked its phosphorescent path across the face of the film world in the mid-1990s, wafting the Mamas and Papas' "California Dreamin'" like heady perfume in its wake, Wong Kar-Wai has been so fêted with the "c" word, you wonder if the Hong Kong film-maker himself were sneaking into his interviewers' offices and replacing their dingy copy with bright fulsome fan mail.

But just '"cool" won't do. Sure, Wong's aesthetic sensibilities - the jazzy camerawork and free-style editing, the luscious leads and jukebox arrangements - are so judiciously and affectionately pop that they're bound to entice pop criticism in turn. And many will be impressed by the man's immovable sunglasses (he claims they're his work clothes; I'd guess they're a wink to Wong's hero John Ford, and his signature eye-patch). Regardless of all that, there's much more to Wong's films than what first meets the eye.

Most immediately, there's the emotional melancholia: Wong the dolorous romantic. "His stories are basically all the same," suggests Maggie Cheung, star of Wong's first three films and his latest, In the Mood for Love. "They're about love, missed moments, time passing, people who can't have each other ... I think it's true that a lot of film-makers are only interested in one subject, and spend their lives modifying it - and that's very romantic." The titles speak for themselves: As Tears Go By, Days of Being Wild, Ashes of Time..., Happy Together (an ironic one). If it weren't for the snappy ditties and tongue-in-cheek humour, one might almost call the films earnest. They're certainly heartfelt.

Increasingly, too, they assert a fidelity toward time and place as the foundation of feeling: Wong the annalist. The point may have been obscured in the present-tense Chungking Express and its companion-piece Fallen Angels, both fleet, hyper-stylised mosaics of the night's young and restless, but his films have steadily moved away from genre to inscriptions of his cultural roots - elliptical though the approach may be. Wong's not exactly one for establishing shots. Happy Together absconded to Buenos Aires, Hong Kong's antipodes, to take the pulse of the colony at the time of its handover to China. The new film reverts to the 1960s, and manages to take stock of both past and present. He's slipped back a generation before - his second film, Days of Being Wild, offered a moody phantasm of the period - but the deference is newfound.

"It was 10 years ago we did Days of Being Wild," Wong observes, 'and at the time we thought that it would be very boring just to recreate something exactly as it was, so we tried to invent things, even down to the lighting. But with In the Mood for Love, we wanted to make a film that was like Hong Kong in 1962. It should be authentic. I wanted to make a film about my childhood, the people I knew and liked - and about neighbours, because we don't have neighbours any more. Maybe 10 years ago we could still find those people and locations in Hong Kong, but now it's gone. There's something missing in our lives now, and I wanted to recreate that."

In the film, what's missing from the lives of Mr Chow (Tony Leung) and Mrs Chen (Maggie Cheung), new neighbours in adjacent apartments of a communal housing block, is their respective spouses. Reluctantly putting two and two together (two identical ties, two matching handbags - Wong likes his dualities), they pull together for consolation and, as time passes, furtively fail to get it on. It's less a brief encounter than a languorous, longing flirtation, the conscience-struck conspirators yo-yoing up and down staircases, to and fro along corridors and around street corners - physical delimits held in the frame of the film like the subconscious architecture of customs and convention that bounds its protagonists. Their most intimate moments revolve around food: consumption in lieu of consummation.

"Initially we were calling it a story about food," notes Wong. "We wanted to tell the story at restaurants and shops, and over dinner. I even tried to find some old lady to make all those dishes, because the Shanghainese have their own cuisine, which varies with the seasons, and we tried to recreate that. Of course, it's not so obvious to people who are not Chinese. I tried to describe all these things to Tony Rayns, who subtitled the film, but it seems it's very difficult to convey through the subtitles. He said: 'Okay, I give up. I have no idea.'

"After Happy Together," he continues, "we thought we should make an easier film, a simple story with an actor and an actress we knew well, shot in Hong Kong on set. But things turn out differently, you know; we grew more involved in the story, and greedy. At first we thought we'd only film inside the house, and then we decided, well, we want to see the streets where they work. We thought we'd like to follow the story from 1962 through to 1972, but in the end we had to stop that, and concluded it in 1966. It was meant to be a quick meal at McDonald's, and it turned into a feast. Fifty-five persons coming to the party!"

Wong's in the habit of making a meal of his shoots. You wouldn't know it from the elegantly turned finished article, but In the Mood for Love took 15 months to film while he pondered - and shot - different story lines, identified a mood and generally wound up his actors. By default, he scripts from the hip - like Godard in his nouvelle vague prime - writing his screenplays piecemeal during the shoot, and sometimes still constructing his stories in the edit suite. Still, if it produces an ending as moving as the film's coda, an awe-inspiring contemplation of the proud, forlorn proscenium arches of Cambodia's ancient Angkor Wat temple - well, who's complaining?

"The whole process was very enjoyable. In fact we hated to say stop," says Wong, speaking for himself.

"One of the reasons I wanted to show the film in Cannes was because I thought it would help with the schedule. It gave us a deadline, you know?" The final scenes were shot just 10 days before the film's premiÿre, scheduled for the last day of the festival.

"Actually, I'm not a very good writer," he offers. "The reason I write my own scripts is because I can't find anyone who wants to work with me. But you know, as a screenwriter, when you write for someone else, you always want to leave a mark, to make your work outstanding. But I'm making the film myself, and I don't want to do that, because I think nothing should stand out, everything should be in one direction and just enough, not too much."

I wonder if he's now resigned to his protracted working methods. He looks at me for a moment, and says: "You know, when I was very young, I always wanted to keep my schoolbag very tidy. Before every term I would ask my mother to buy me a new bag, and I'd say: Okay, this time I'm going to keep it very tidy; but somehow it always messed up. It's the same directing. It's very demanding, both physically and mentally, to shoot and write at the same time, and that means you can spend a lot of money. And I try to be disciplined, but somehow it doesn't work out. And like before, for the next one I want to make things more organised.

"But wait and see."

'In the Mood for Love' (PG) is out on Friday