Setting out his stall in mischievous, blackly comic style, The Legend of Barney Thomson is Robert Carlyle's directorial debut. This home-grown effort, helmed by an iconic Scottish actor best known for his roles in Trainspotting and Hamish Macbeth, is a lovingly lensed tale of murder on the barbershop floor, and it's getting its world premiere at this year's Edinburgh International Film Festival.

Over the last 25 years, Carlyle's acting career has touched social realism (Angela's Ashes), comedy (The Full Monty), Bond (The World is Not Enough) and fairytales (the US TV series, Once Upon a Time, in which he currently stars), so the subject of his first film as director could have been anyone's guess. But he's plumped for crime, with this movie based on Douglas Lindsay's 2008 novel The Long Midnight of Barney Thomson, the first in a series of books about the barber-cum-killer.

Set in Carlyle's native Glasgow, it tells the story of the titular barber (played by Carlyle) whose dour existence is disrupted when he accidentally kills his boss. The story combines familial strife and serial murder, with the film's classy cast including Emma Thompson, Ray Winstone, Ashley Jensen and Martin Compston.

'It was first offered to me as an actor several years ago and it kept on reappearing at the wrong time over the next four or five years,' Carlyle tells me over the phone, as we chat ahead of the EIFF premiere. Eventually the project came back to him through friend and collaborator John G Lenic in the form of Canadian writer Richard Cowan's script. Feeling that it needed a more authentic Glaswegian voice, Carlyle brought fellow Scot Colin McLaren onboard and the two worked closely together as he took the helm.

Carlyle says his background in theatre direction gave him confidence directing actors, while he picked up tricks of the filmmaking trade from the best in the business. 'It was my experience with Ken Loach [on Riff-Raff / Carla's Song] and Danny Boyle [on Trainspotting / The Beach] that I was leaning on most,' he explains. 'I learned to be delicate, as encouraging as possible. You've got to love your collaborators and they'll love you. Danny is absolutely brilliant at that. Years ago I thought, if I ever direct, that's the guy I'll emulate.'

He got around the logistical difficulties of needing to be both behind and in front of the camera by ingeniously employing an on-set double, in the form of recent drama graduate Mark Barrett. 'He's a terrific young actor,' Carlyle says. 'I thought the only way to do this is to get someone in there, not just a stand-in but someone who's actually going to be Barney. He would rehearse with the actors and then at the last minute I would step in.'

Despite being just two years his senior, Carlyle made the bold decision to cast Emma Thompson as Barney's larger-than-life mother, Cemolina. Thanks to some impressive prosthetics (courtesy of The Grand Budapest Hotel's Oscar-winning make-up artist Mark Coulier), she's almost unrecognisable in the role.

'Cemolina is such a monstrous character,' he says, 'it was going to take someone really brave to do that, to expose themselves in that way. I've always loved Emma and she's not vain. She said yes within a day, she found the fun in it and understood it right away. It's not often actresses get a chance to let rip like that.'

Alongside them playing the fish-out-of-water detective making Barney squirm is Carlyle's buddy Ray Winstone. 'I just love Ray. He gives you 1000% in every single scene.'

Carlyle hasn't been afraid to put his own stamp on the story either; so fans of Lindsay's novels should beware, there are deviations from the book. 'I didn't have any hesitancy in changing stuff,' Carlyle admits. Most noticeably, despite its grim subject matter, the film is infused with affection for Glasgow. Carlyle wanted the film to 'show the city the way I see it'. Also, although it's set in the modern day, it boasts a retro aesthetic which pulls together influences from various eras. Carlyle explains that this reflects the way 'Barney limps through his present; he could have existed in any time.'

As well as the pressure of making his first film as a director, Carlyle was set the challenge of turning a misanthropic killer into a sympathetic protagonist: a feat he pulls off. 'A lot of Barney is my dad,' he reveals. 'Especially with the jacket, you never see him take it off; my dad had a terrible habit of permanently keeping his jacket on. I wanted to make this guy in some way likeable; there's no real malice in Barney.'

The prospect of premiering the film at other festivals was mooted but, although he's surprised and 'absolutely delighted' for the film to have been chosen to kick off the EIFF, Carlyle always had his sights set on Edinburgh. 'It's a Scottish film, and the Edinburgh Festival has played such a huge part in my career.'

He'll shortly be returning to Vancouver to shoot the fifth season of Once Upon a Time and is fortunate enough to be able to select his next directorial project from a number of possibilities. And with the glitz and prestige of EIFF's opening night on the horizon, as he puts it himself: 'I'm the luckiest man in the world.'

The Legend of Barney Thomson screens at the Edinburgh International Film Festival on Wed 17 Jun. General release from summer 2015.