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Diffstat (limited to 'third_party/rust/png/examples/show.rs')
| -rw-r--r-- | third_party/rust/png/examples/show.rs | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/third_party/rust/png/examples/show.rs b/third_party/rust/png/examples/show.rs new file mode 100644 index 0000000000..9185b8f77e --- /dev/null +++ b/third_party/rust/png/examples/show.rs @@ -0,0 +1,199 @@ +extern crate glium; +extern crate glob; +extern crate png; + +use std::env; +use std::io; +use std::fs::File; +use std::borrow::Cow; +use std::path; +use std::error::Error; + +use glium::{Surface, Rect, BlitTarget}; +use glium::texture::{RawImage2d, ClientFormat}; +use glium::glutin::{self, Event, VirtualKeyCode, dpi}; +use glium::backend::glutin::Display; + +/// Load the image using `png` +fn load_image(path: &path::PathBuf) -> io::Result<RawImage2d<'static, u8>> { + use png::ColorType::*; + let decoder = png::Decoder::new(File::open(path)?); + let (info, mut reader) = decoder.read_info()?; + let mut img_data = vec![0; info.buffer_size()]; + reader.next_frame(&mut img_data)?; + + let (data, format) = match info.color_type { + RGB => (img_data, ClientFormat::U8U8U8), + RGBA => (img_data, ClientFormat::U8U8U8U8), + Grayscale => ( + { + let mut vec = Vec::with_capacity(img_data.len()*3); + for g in img_data { + vec.extend([g, g, g].iter().cloned()) + } + vec + }, + ClientFormat::U8U8U8 + ), + GrayscaleAlpha => ( + { + let mut vec = Vec::with_capacity(img_data.len()*3); + for ga in img_data.chunks(2) { + let g = ga[0]; let a = ga[1]; + vec.extend([g, g, g, a].iter().cloned()) + } + vec + }, + ClientFormat::U8U8U8U8 + ), + _ => unreachable!("uncovered color type") + }; + + Ok(RawImage2d { + data: Cow::Owned(data), + width: info.width, + height: info.height, + format: format + }) +} + +fn main_loop(files: Vec<path::PathBuf>) -> io::Result<()> { + use glium::glutin::{KeyboardInput, WindowEvent}; + + let mut files = files.iter(); + let image = load_image(files.next().unwrap())?; + + let mut events_loop = glutin::EventsLoop::new(); + let window = glutin::WindowBuilder::new(); + let context = glutin::ContextBuilder::new() + .with_vsync(true); + + let display = Display::new(window, context, &events_loop) + .map_err(|err| io::Error::new( + io::ErrorKind::Other, + err.description() + ))?; + // building the display, ie. the main object + resize_window(&display, &image); + let mut opengl_texture = glium::Texture2d::new(&display, image).unwrap(); + + let mut stop = false; + let mut res = Ok(()); + 'main: loop { + let frame = display.draw(); + fill_v_flipped(&opengl_texture.as_surface(), &frame, glium::uniforms::MagnifySamplerFilter::Linear); + frame.finish().unwrap(); + + // polling and handling the events received by the window + events_loop.poll_events(|event| { + if stop {return;} + match event { + Event::WindowEvent {event: WindowEvent::CloseRequested, ..} => { + stop = true; + return; + } + Event::WindowEvent { + event: WindowEvent::KeyboardInput { + input: KeyboardInput { + state: glutin::ElementState::Pressed, + virtual_keycode: code, + .. + }, + .. + }, + .. + } => match code { + Some(VirtualKeyCode::Escape) => { + stop = true; + return; + } + Some(VirtualKeyCode::Right) => { + match files.next() { + Some(path) => { + let image = match load_image(path) { + Ok(image) => image, + Err(err) => { + stop = true; + res = Err(err); + return; + } + }; + resize_window(&display, &image); + opengl_texture = glium::Texture2d::new(&display, image).unwrap(); + }, + None => { + stop = true; + return; + } + } + }, + _ => () + }, + _ => () + } + }); + + if stop {break 'main;} + } + res +} + +fn fill_v_flipped<S1, S2>(src: &S1, target: &S2, filter: glium::uniforms::MagnifySamplerFilter) +where S1: Surface, S2: Surface { + let src_dim = src.get_dimensions(); + let src_rect = Rect { left: 0, bottom: 0, width: src_dim.0 as u32, height: src_dim.1 as u32 }; + let target_dim = target.get_dimensions(); + let target_rect = BlitTarget { left: 0, bottom: target_dim.1, width: target_dim.0 as i32, height: -(target_dim.1 as i32) }; + src.blit_color(&src_rect, target, &target_rect, filter); +} + +fn resize_window(display: &Display, image: &RawImage2d<'static, u8>) { + let mut width = image.width; + let mut height = image.height; + if width < 50 && height < 50 { + width *= 10; + height *= 10; + } else if width < 5 && height < 5 { + width *= 10; + height *= 10; + } + display.gl_window().window().set_inner_size(dpi::LogicalSize::new(f64::from(width), f64::from(height))); +} + +fn main() { + let args: Vec<String> = env::args().collect(); + if args.len() < 2 { + println!("Usage: show files [...]"); + } else { + let mut files = vec![]; + for file in args.iter().skip(1) { + match if file.contains("*") { + (|| -> io::Result<_> { + for entry in glob::glob(&file).map_err(|err| { + io::Error::new(io::ErrorKind::Other, err.msg) + })? { + files.push(entry.map_err(|_| { + io::Error::new(io::ErrorKind::Other, "glob error") + })?) + } + Ok(()) + })() + } else { + files.push(path::PathBuf::from(file)); + Ok(()) + } { + Ok(_) => (), + Err(err) => { + println!("{}: {}", file, err); + break + } + } + + } + // "tests/pngsuite/pngsuite.png" + match main_loop(files) { + Ok(_) => (), + Err(err) => println!("Error: {}", err) + } + } +} |