TORONTO -- When Canadian director Stephen S. Campanelli showed his new film "Indian Horse" to his mentor, Clint Eastwood, the four-time Oscar winner was in disbelief.

In theatres Friday, the drama is based on late Canadian author Richard Wagamese's acclaimed novel, about an Ojibwe residential school survivor who faces racism and systemic barriers as he becomes a formidable hockey player.

The story gives an unvarnished look at the brutal history of the residential school system in Canada, and Eastwood was floored.

"He didn't believe it," Campanelli, who grew up in Montreal and lives in California, recalled in an interview at last September's Toronto International Film Festival.

"He was like, 'What? You Canadians did this?' I said, 'Yeah, believe it or not.' He said, 'How come no one knows about this?' I said, 'Well, they will soon."'

Eastwood then signed on as an executive producer to help promote the film.

"He says, 'People need to see this movie,"' recalled Campanelli, who has been working with Eastwood as a camera operator for over 20 years.

Canadians Sladen Peltier and Ajuawak Kapashesit, along with American actor Forrest Goodluck, portray protagonist Saul Indian Horse at three different stages of his life.

The story spans 30 years as it follows the harrowing journey of Saul's family and his experiences in the late 1950s at an Ontario Catholic residential school, where students faced abuse and were forced to abandon their own language and culture.

Saul teaches himself to play hockey and moves up in the ranks of the sport, but after a string of racist attacks against him, he gives up and has to confront his painful past.

"I think a film like this will actually help a lot of people understand, because it doesn't really pull a lot of punches but it is still very cinematic," said Kapashesit, who is of Ojibwe and Cree heritage and was born in Moose Factory, Ont.

"I think this film is going to open up the floodgates of truths in terms of the history of this continent," added Goodluck, who is a member of the Dine, Mandan, Hidatsa and Tsimshian tribes and is based in Albuquerque, N.M.

Dennis Foon wrote the script for the film, which was shot in chilly winter temperatures and on rough terrain in Sudbury, Ont., and Peterborough, Ont.

The characters speak the Ojibwe language, which is translated in subtitles.

Other cast members include newcomer Edna Manitowabi, who plays Saul's grandmother and is a residential school survivor herself.

"It's not common you get roles like this that are very truthful and aren't exploitive in any way," said Kapashesit, noting his grandfather and other family members went through residential schools.

Campanelli said the goal was to stick to the book's roots and its Indigenous origins and "not Hollywoodize it."

At the same time, he wanted to give it "a big-budget look and not make it look like a small little Canadian movie."

"Our biggest goal for this movie is to keep the conversation going," said Campanelli, "to be able to give people an opinion to say, 'Wow, I can't believe this happened. How can I help? Let's have a call to action, let's do something about this, let's get mad, let's call the government or whatever we can do to help this go on.'

"Because it's going to take a while. Reconciliation is not a quick thing. It's going to take everybody's effort to make it work."