glyphon/examples/hello-world.rs
2023-01-29 22:11:54 -03:30

146 lines
5 KiB
Rust

use cosmic_text::{Attrs, Buffer, Color, Family, FontSystem, Metrics, SwashCache};
use glyphon::{Resolution, TextAtlas, TextRenderer};
use wgpu::{
Backends, CommandEncoderDescriptor, CompositeAlphaMode, DeviceDescriptor, Features, Instance,
Limits, LoadOp, Operations, PresentMode, RenderPassColorAttachment, RenderPassDescriptor,
RequestAdapterOptions, SurfaceConfiguration, TextureFormat, TextureUsages,
TextureViewDescriptor,
};
use winit::{
dpi::LogicalSize,
event::{Event, WindowEvent},
event_loop::{ControlFlow, EventLoop},
window::WindowBuilder,
};
fn main() {
pollster::block_on(run());
}
static mut FONT_SYSTEM: Option<FontSystem> = None;
async fn run() {
// Set up window
let (width, height) = (800, 600);
let event_loop = EventLoop::new();
let window = WindowBuilder::new()
.with_inner_size(LogicalSize::new(width as f64, height as f64))
.with_title("glyphon hello world")
.build(&event_loop)
.unwrap();
let size = window.inner_size();
let scale_factor = window.scale_factor();
// Set up surface
let instance = Instance::new(Backends::all());
let adapter = instance
.request_adapter(&RequestAdapterOptions::default())
.await
.unwrap();
let (device, queue) = adapter
.request_device(
&DeviceDescriptor {
label: None,
features: Features::empty(),
limits: Limits::downlevel_defaults(),
},
None,
)
.await
.unwrap();
let surface = unsafe { instance.create_surface(&window) };
// TODO: handle srgb
let swapchain_format = TextureFormat::Bgra8Unorm;
let mut config = SurfaceConfiguration {
usage: TextureUsages::RENDER_ATTACHMENT,
format: swapchain_format,
width: size.width,
height: size.height,
present_mode: PresentMode::Fifo,
alpha_mode: CompositeAlphaMode::Opaque,
};
surface.configure(&device, &config);
// Set up text renderer
let mut text_renderer = TextRenderer::new(&device, &queue);
unsafe {
FONT_SYSTEM = Some(FontSystem::new());
}
let mut cache = SwashCache::new(unsafe { FONT_SYSTEM.as_ref().unwrap() });
let mut atlas = TextAtlas::new(&device, &queue, swapchain_format);
let mut buffer = Buffer::new(
unsafe { FONT_SYSTEM.as_ref().unwrap() },
Metrics::new(14, 20),
);
buffer.set_size((width as f64 * scale_factor) as i32, (height as f64) as i32);
buffer.set_text(
include_str!("./emoji.txt"),
Attrs::new().monospaced(true).family(Family::Monospace),
);
buffer.shape_until_scroll();
event_loop.run(move |event, _, control_flow| {
let _ = (&instance, &adapter);
*control_flow = ControlFlow::Poll;
match event {
Event::WindowEvent {
event: WindowEvent::Resized(size),
..
} => {
config.width = size.width;
config.height = size.height;
surface.configure(&device, &config);
window.request_redraw();
}
Event::RedrawRequested(_) => {
text_renderer
.prepare(
&device,
&queue,
&mut atlas,
Resolution {
width: config.width,
height: config.height,
},
&mut buffer,
Color::rgb(255, 255, 255),
&mut cache,
)
.unwrap();
let frame = surface.get_current_texture().unwrap();
let view = frame.texture.create_view(&TextureViewDescriptor::default());
let mut encoder =
device.create_command_encoder(&CommandEncoderDescriptor { label: None });
{
let mut pass = encoder.begin_render_pass(&RenderPassDescriptor {
label: None,
color_attachments: &[Some(RenderPassColorAttachment {
view: &view,
resolve_target: None,
ops: Operations {
load: LoadOp::Clear(wgpu::Color::BLACK),
store: true,
},
})],
depth_stencil_attachment: None,
});
text_renderer.render(&atlas, &mut pass).unwrap();
}
queue.submit(Some(encoder.finish()));
frame.present();
}
Event::WindowEvent {
event: WindowEvent::CloseRequested,
..
} => *control_flow = ControlFlow::Exit,
Event::MainEventsCleared => {
window.request_redraw();
}
_ => {}
}
});
}