diff --git a/examples/imgui-winit/src/main.rs b/examples/imgui-winit/src/main.rs index aeebc1c..e5036ab 100644 --- a/examples/imgui-winit/src/main.rs +++ b/examples/imgui-winit/src/main.rs @@ -17,7 +17,12 @@ const HEIGHT: u32 = 480; const BOX_SIZE: i16 = 64; /// Representation of the application state. In this example, a box will bounce around the screen. +/// +/// The world is resizable, meaning the backing pixel buffer can be resized without creating a +/// border around the screen. struct World { + width: i16, + height: i16, box_x: i16, box_y: i16, velocity_x: i16, @@ -26,12 +31,10 @@ struct World { fn main() -> Result<(), Error> { env_logger::init(); - let mut width = WIDTH; - let mut height = HEIGHT; let event_loop = EventLoop::new(); let mut input = WinitInputHelper::new(); let window = { - let size = LogicalSize::new(width as f64, height as f64); + let size = LogicalSize::new(WIDTH as f64, HEIGHT as f64); WindowBuilder::new() .with_title("Hello Pixels + Dear ImGui") .with_inner_size(size) @@ -40,12 +43,14 @@ fn main() -> Result<(), Error> { .unwrap() }; + let mut scale_factor = window.scale_factor(); + let mut pixels = { let window_size = window.inner_size(); let surface_texture = SurfaceTexture::new(window_size.width, window_size.height, &window); - Pixels::new(width, height, surface_texture)? + Pixels::new(WIDTH, HEIGHT, surface_texture)? }; - let mut world = World::new(); + let mut world = World::new(WIDTH, HEIGHT); // Set up Dear ImGui let mut gui = Gui::new(&window, &pixels); @@ -54,7 +59,7 @@ fn main() -> Result<(), Error> { // Draw the current frame if let Event::RedrawRequested(_) = event { // Draw the world - world.draw(pixels.get_frame(), width); + world.draw(pixels.get_frame()); // Prepare Dear ImGui gui.prepare(&window).expect("gui.prepare() failed"); @@ -88,16 +93,24 @@ fn main() -> Result<(), Error> { return; } + // Update the scale factor + if let Some(factor) = input.scale_factor() { + scale_factor = factor; + } + // Resize the window if let Some(size) = input.window_resized() { + // Resize the surface texture pixels.resize(size.width, size.height); - width = size.width; - height = size.height; + + // Resize the world + let LogicalSize { width, height } = size.to_logical(scale_factor); + world.resize(width, height); pixels.resize_buffer(width, height); } // Update internal state and request a redraw - world.update(width, height); + world.update(); window.request_redraw(); } }); @@ -105,8 +118,10 @@ fn main() -> Result<(), Error> { impl World { /// Create a new `World` instance that can draw a moving box. - fn new() -> Self { + fn new(width: u32, height: u32) -> Self { Self { + width: width as i16, + height: height as i16, box_x: 24, box_y: 16, velocity_x: 1, @@ -115,17 +130,17 @@ impl World { } /// Update the `World` internal state; bounce the box around the screen. - fn update(&mut self, width: u32, height: u32) { + fn update(&mut self) { if self.box_x <= 0 { self.velocity_x = 1; } - if self.box_x + BOX_SIZE > width as i16 { + if self.box_x + BOX_SIZE > self.width { self.velocity_x = -1; } if self.box_y <= 0 { self.velocity_y = 1; } - if self.box_y + BOX_SIZE > height as i16 { + if self.box_y + BOX_SIZE > self.height { self.velocity_y = -1; } @@ -133,13 +148,19 @@ impl World { self.box_y += self.velocity_y; } + /// Resize the world + fn resize(&mut self, width: u32, height: u32) { + self.width = width as i16; + self.height = height as i16; + } + /// Draw the `World` state to the frame buffer. /// /// Assumes the default texture format: `wgpu::TextureFormat::Rgba8UnormSrgb` - fn draw(&self, frame: &mut [u8], width: u32) { + fn draw(&self, frame: &mut [u8]) { for (i, pixel) in frame.chunks_exact_mut(4).enumerate() { - let x = (i % width as usize) as i16; - let y = (i / width as usize) as i16; + let x = (i % self.width as usize) as i16; + let y = (i / self.width as usize) as i16; let inside_the_box = x >= self.box_x && x < self.box_x + BOX_SIZE