131 lines
3.8 KiB
Rust
131 lines
3.8 KiB
Rust
#![deny(clippy::all)]
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#![forbid(unsafe_code)]
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use pixels::{wgpu::Surface, Error, Pixels, SurfaceTexture};
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use winit::dpi::LogicalSize;
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use winit::event::{Event, VirtualKeyCode, WindowEvent};
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use winit::event_loop::{ControlFlow, EventLoop};
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use winit::window::WindowBuilder;
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use winit_input_helper::WinitInputHelper;
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const WIDTH: u32 = 320;
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const HEIGHT: u32 = 240;
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const BOX_SIZE: i16 = 64;
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/// Representation of the application state. In this example, a box will bounce around the screen.
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struct World {
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box_x: i16,
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box_y: i16,
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velocity_x: i16,
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velocity_y: i16,
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}
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fn main() -> Result<(), Error> {
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let event_loop = EventLoop::new();
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let mut input = WinitInputHelper::new();
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let window = {
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let size = LogicalSize::new(WIDTH as f64, HEIGHT as f64);
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WindowBuilder::new()
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.with_title("Hello Pixels")
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.with_inner_size(size)
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.with_min_inner_size(size)
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.build(&event_loop)
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.unwrap()
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};
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let mut hidpi_factor = window.hidpi_factor();
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let mut pixels = {
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let surface = Surface::create(&window);
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let surface_texture = SurfaceTexture::new(WIDTH, HEIGHT, surface);
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Pixels::new(WIDTH, HEIGHT, surface_texture)?
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};
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let mut world = World::new();
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event_loop.run(move |event, _, control_flow| {
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// Draw the current frame
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if let Event::WindowEvent {
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event: WindowEvent::RedrawRequested,
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..
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} = event
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{
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world.draw(pixels.get_frame());
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pixels.render();
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}
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// Handle input events
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if input.update(event) {
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// Close events
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if input.key_pressed(VirtualKeyCode::Escape) || input.quit() {
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*control_flow = ControlFlow::Exit;
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return;
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}
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// Adjust high DPI factor
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if let Some(factor) = input.hidpi_changed() {
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hidpi_factor = factor;
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}
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// Resize the window
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if let Some(size) = input.window_resized() {
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let size = size.to_physical(hidpi_factor);
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let width = size.width.round() as u32;
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let height = size.height.round() as u32;
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pixels.resize(width, height);
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}
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// Update internal state and request a redraw
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world.update();
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window.request_redraw();
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}
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});
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}
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impl World {
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/// Create a new `World` instance that can draw a moving box.
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fn new() -> Self {
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Self {
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box_x: 24,
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box_y: 16,
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velocity_x: 1,
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velocity_y: 1,
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}
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}
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/// Update the `World` internal state; bounce the box around the screen.
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fn update(&mut self) {
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if self.box_x < 0 || self.box_x + BOX_SIZE >= WIDTH as i16 {
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self.velocity_x *= -1;
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}
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if self.box_y < 0 || self.box_y + BOX_SIZE >= HEIGHT as i16 {
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self.velocity_y *= -1;
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}
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self.box_x += self.velocity_x;
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self.box_y += self.velocity_y;
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}
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/// Draw the `World` state to the frame buffer.
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///
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/// Assumes the default texture format: [`wgpu::TextureFormat::Rgba8UnormSrgb`]
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fn draw(&self, frame: &mut [u8]) {
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for (i, pixel) in frame.chunks_exact_mut(4).enumerate() {
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let x = (i % WIDTH as usize) as i16;
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let y = (i / WIDTH as usize) as i16;
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let inside_the_box = x >= self.box_x
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&& x < self.box_x + BOX_SIZE
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&& y >= self.box_y
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&& y < self.box_y + BOX_SIZE;
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let rgba = if inside_the_box {
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[0x5e, 0x48, 0xe8, 0xff]
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} else {
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[0x48, 0xb2, 0xe8, 0xff]
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};
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pixel.copy_from_slice(&rgba);
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}
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}
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}
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