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Fix screen scaling when window is resized (#25)

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* Refactor window creation and size handling

* Require pixel aspect ratio to be > 0

* Fix screen scaling when window is resized

- Ensure the screen retains its correct pixel aspect ratio
- Updated public API on `RenderPass` ... this will continue to be unstable until the initial release
- Add build instructions for the internal shaders
This commit is contained in:
Jay Oster 2019-10-27 16:35:22 -07:00 committed by GitHub
parent cc04f14a3d
commit 8bebb29a06
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GPG key ID: 4AEE18F83AFDEB23
7 changed files with 212 additions and 57 deletions
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79
examples/invaders/main.rs
View file

@ -3,6 +3,7 @@ use std::time::Instant;
use pixels::{Error, Pixels, SurfaceTexture};
use simple_invaders::{Controls, Direction, World, SCREEN_HEIGHT, SCREEN_WIDTH};
use winit::dpi::{LogicalPosition, LogicalSize, PhysicalSize};
use winit::event::{Event, VirtualKeyCode, WindowEvent};
use winit::event_loop::{ControlFlow, EventLoop};
use winit_input_helper::WinitInputHelper;
@ -18,29 +19,8 @@ fn main() -> Result<(), Error> {
.parse()
.unwrap_or(false);
let (window, surface, width, height, mut hidpi_factor) = {
let scale = 3.0;
let width = SCREEN_WIDTH as f64 * scale;
let height = SCREEN_HEIGHT as f64 * scale;
let window = winit::window::WindowBuilder::new()
.with_inner_size(winit::dpi::LogicalSize::new(width, height))
.with_title("pixel invaders")
.build(&event_loop)
.unwrap();
let surface = pixels::wgpu::Surface::create(&window);
let hidpi_factor = window.hidpi_factor();
let size = window.inner_size().to_physical(hidpi_factor);
(
window,
surface,
size.width.round() as u32,
size.height.round() as u32,
hidpi_factor,
)
};
let (window, surface, width, height, mut hidpi_factor) =
create_window("pixel invaders", &event_loop);
let surface_texture = SurfaceTexture::new(width, height, surface);
let mut pixels = Pixels::new(SCREEN_WIDTH as u32, SCREEN_HEIGHT as u32, surface_texture)?;
let mut invaders = World::new(debug);
@ -103,3 +83,56 @@ fn main() -> Result<(), Error> {
}
});
}
/// Create a window for the game.
///
/// Automatically scales the window to cover about 2/3 of the monitor height.
///
/// # Returns
///
/// Tuple of `(window, surface, width, height, hidpi_factor)`
/// `width` and `height` are in `LogicalSize` units.
fn create_window(
title: &str,
event_loop: &EventLoop<()>,
) -> (winit::window::Window, wgpu::Surface, u32, u32, f64) {
// Create a hidden window so we can estimate a good default window size
let window = winit::window::WindowBuilder::new()
.with_visible(false)
.with_title(title)
.build(&event_loop)
.unwrap();
let hidpi_factor = window.hidpi_factor();
// Get dimensions
let width = SCREEN_WIDTH as f64;
let height = SCREEN_HEIGHT as f64;
let (monitor_width, monitor_height) = {
let size = window.current_monitor().size();
(size.width / hidpi_factor, size.height / hidpi_factor)
};
let scale = (monitor_height / height * 2.0 / 3.0).round();
// Resize, center, and display the window
let min_size = PhysicalSize::new(width, height).to_logical(hidpi_factor);
let default_size = LogicalSize::new(width * scale, height * scale);
let center = LogicalPosition::new(
(monitor_width - width * scale) / 2.0,
(monitor_height - height * scale) / 2.0,
);
window.set_inner_size(default_size);
window.set_min_inner_size(Some(min_size));
window.set_outer_position(center);
window.set_visible(true);
let surface = pixels::wgpu::Surface::create(&window);
let size = default_size.to_physical(hidpi_factor);
(
window,
surface,
size.width.round() as u32,
size.height.round() as u32,
hidpi_factor,
)
}

13
shaders/README.md Normal file
View file

@ -0,0 +1,13 @@
# Shaders
The GLSL shader source is not compiled as part of the normal cargo build process. This was a conscious decision sparked by the current state of the ecosystem; compiling GLSL-to-SPIR-V requires a C++ toolchain including CMake, which is an unacceptable constraint for a simple crate providing a pixel buffer.
If you need to modify the GLSL sources, you must also recompile the SPIR-V as well. This can be done with `glslang`, `glslc`, etc.
Compile shaders with `glslangValidator`:
```bash
glslangValidator -V shader.frag && glslangValidator -V shader.vert
```
For mor information, see https://github.com/parasyte/pixels/issues/9

6
shaders/shader.vert
View file

@ -9,6 +9,10 @@ out gl_PerVertex {
layout(location = 0) out vec2 v_TexCoord;
layout(set = 0, binding = 2) uniform Locals {
mat4 u_Transform;
};
const vec2 positions[6] = vec2[6](
// Upper left triangle
vec2(-1.0, -1.0),
@ -35,5 +39,5 @@ const vec2 uv[6] = vec2[6](
void main() {
v_TexCoord = uv[gl_VertexIndex];
gl_Position = vec4(positions[gl_VertexIndex], 0.0, 1.0);
gl_Position = u_Transform * vec4(positions[gl_VertexIndex], 0.0, 1.0);
}

BIN
shaders/vert.spv
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Binary file not shown.

58
src/lib.rs
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@ -17,7 +17,7 @@ use std::fmt;
use std::rc::Rc;
pub use wgpu;
use wgpu::TextureView;
use wgpu::{Extent3d, TextureView};
mod render_pass;
pub use render_pass::{BoxedRenderPass, Device, Queue, RenderPass};
@ -25,7 +25,7 @@ pub use render_pass::{BoxedRenderPass, Device, Queue, RenderPass};
mod renderers;
use renderers::Renderer;
type RenderPassFactory = Box<dyn Fn(Device, Queue, &TextureView) -> BoxedRenderPass>;
type RenderPassFactory = Box<dyn Fn(Device, Queue, &TextureView, &Extent3d) -> BoxedRenderPass>;
/// A logical texture for a window surface.
#[derive(Debug)]
@ -148,7 +148,7 @@ impl Pixels {
/// Call this method in response to a resize event from your window manager. The size expected
/// is in physical pixel units.
pub fn resize(&mut self, width: u32, height: u32) {
// TODO: Scaling with a uniform transformation matrix
// TODO: Call `update_bindings` on each render pass to create a texture chain
// Update SurfaceTexture dimensions
self.surface_texture.width = width;
@ -165,6 +165,16 @@ impl Pixels {
present_mode: wgpu::PresentMode::Vsync,
},
);
// Update state for all render passes
let mut encoder = self
.device
.create_command_encoder(&wgpu::CommandEncoderDescriptor { todo: 0 });
for renderer in self.renderers.iter_mut() {
renderer.resize(&mut encoder, width, height);
}
self.queue.borrow_mut().submit(&[encoder.finish()]);
}
/// Draw this pixel buffer to the configured [`SurfaceTexture`].
@ -205,7 +215,7 @@ impl Pixels {
// Execute all render passes
for renderer in self.renderers.iter() {
// TODO: Create a texture chain so that each pass receives the texture drawn by the previous
renderer.render_pass(&mut encoder, &frame.view);
renderer.render(&mut encoder, &frame.view);
}
self.queue.borrow_mut().submit(&[encoder.finish()]);
@ -247,13 +257,13 @@ impl PixelsBuilder {
///
/// impl pixels::RenderPass for MyRenderPass {
/// // ...
/// # fn update_bindings(&mut self, _: &wgpu::TextureView) {}
/// # fn render_pass(&self, _: &mut wgpu::CommandEncoder, _: &wgpu::TextureView) {}
/// # fn update_bindings(&mut self, _: &wgpu::TextureView, _: &wgpu::Extent3d) {}
/// # fn render(&self, _: &mut wgpu::CommandEncoder, _: &wgpu::TextureView) {}
/// }
///
/// let mut pixels = PixelsBuilder::new(256, 240, surface_texture)
/// .pixel_aspect_ratio(8.0 / 7.0)
/// .add_render_pass(|device, queue, texture| {
/// .add_render_pass(|device, queue, texture, texture_size| {
/// // Create reources for MyRenderPass here
/// Box::new(MyRenderPass {
/// // ...
@ -306,7 +316,13 @@ impl PixelsBuilder {
/// factor.
///
/// E.g. set this to `8.0 / 7.0` for an 8:7 pixel aspect ratio.
pub const fn pixel_aspect_ratio(mut self, pixel_aspect_ratio: f64) -> PixelsBuilder {
///
/// # Panics
///
/// The aspect ratio must be > 0.
pub fn pixel_aspect_ratio(mut self, pixel_aspect_ratio: f64) -> PixelsBuilder {
assert!(pixel_aspect_ratio > 0.0);
self.pixel_aspect_ratio = pixel_aspect_ratio;
self
}
@ -331,12 +347,13 @@ impl PixelsBuilder {
/// * `queue` - A reference-counted [`wgpu::Queue`] which can execute command buffers.
/// * `texture` - A [`wgpu::TextureView`] reference that is used as the texture input for the
/// render pass.
/// * `texture_size` - A [`wgpu::Extent3d`] providing the input texture size.
///
/// # Examples
///
/// ```no_run
/// use pixels::{BoxedRenderPass, Device, PixelsBuilder, Queue, RenderPass};
/// use wgpu::TextureView;
/// use wgpu::{Extent3d, TextureView};
///
/// struct MyRenderPass {
/// device: Device,
@ -344,7 +361,12 @@ impl PixelsBuilder {
/// }
///
/// impl MyRenderPass {
/// fn factory(device: Device, queue: Queue, texture: &TextureView) -> BoxedRenderPass {
/// fn factory(
/// device: Device,
/// queue: Queue,
/// texture: &TextureView,
/// texture_size: &Extent3d,
/// ) -> BoxedRenderPass {
/// // Create a bind group, pipeline, etc. and store all of the necessary state...
/// Box::new(MyRenderPass { device, queue })
/// }
@ -352,8 +374,8 @@ impl PixelsBuilder {
///
/// impl RenderPass for MyRenderPass {
/// // ...
/// # fn update_bindings(&mut self, _: &wgpu::TextureView) {}
/// # fn render_pass(&self, _: &mut wgpu::CommandEncoder, _: &wgpu::TextureView) {}
/// # fn update_bindings(&mut self, _: &wgpu::TextureView, _: &wgpu::Extent3d) {}
/// # fn render(&self, _: &mut wgpu::CommandEncoder, _: &wgpu::TextureView) {}
/// }
///
/// # let surface = wgpu::Surface::create(&pixels_mocks::RWH);
@ -365,7 +387,7 @@ impl PixelsBuilder {
/// ```
pub fn add_render_pass(
mut self,
factory: impl Fn(Device, Queue, &TextureView) -> BoxedRenderPass + 'static,
factory: impl Fn(Device, Queue, &TextureView, &Extent3d) -> BoxedRenderPass + 'static,
) -> PixelsBuilder {
self.renderer_factories.push(Box::new(factory));
self
@ -430,20 +452,26 @@ impl PixelsBuilder {
device.clone(),
queue.clone(),
&texture_view,
&texture_extent,
)];
// Create all render passes
renderers.extend(self.renderer_factories.iter().map(|f| {
// TODO: Create a texture chain so that each pass recieves the texture drawn by the previous
f(device.clone(), queue.clone(), &texture_view)
f(
device.clone(),
queue.clone(),
&texture_view,
&texture_extent,
)
}));
Ok(Pixels {
device,
queue,
swap_chain,
renderers,
surface_texture,
renderers,
texture,
texture_extent,
texture_format_size,

42
src/render_pass.rs
View file

@ -1,7 +1,7 @@
use std::cell::RefCell;
use std::fmt;
use std::rc::Rc;
use wgpu::TextureView;
use wgpu::{Extent3d, TextureView};
/// A reference-counted [`wgpu::Device`]
pub type Device = Rc<wgpu::Device>;
@ -29,17 +29,6 @@ pub type BoxedRenderPass = Box<dyn RenderPass>;
///
/// [`Pixels`]: ./struct.Pixels.html
pub trait RenderPass {
/// This method will be called when the input [`wgpu::TextureView`] needs to be rebinded.
///
/// A [`wgpu::TextureView`] is provided to the `RenderPass` factory as an input texture with
/// the original [`SurfaceTexture`] size. This method is called in response to resizing the
/// [`SurfaceTexture`], where your `RenderPass` impl can update its input texture for the new
/// size.
///
/// [`Pixels`]: ./struct.Pixels.html
/// [`SurfaceTexture`]: ./struct.SurfaceTexture.html
fn update_bindings(&mut self, input_texture: &TextureView);
/// Called when it is time to execute this render pass. Use the `encoder` to encode all
/// commands related to this render pass. The result must be stored to the `render_target`.
///
@ -47,7 +36,34 @@ pub trait RenderPass {
/// * `encoder` - Command encoder for the render pass
/// * `render_target` - A reference to the output texture
/// * `texels` - The byte slice passed to `Pixels::render`
fn render_pass(&self, encoder: &mut wgpu::CommandEncoder, render_target: &TextureView);
fn render(&self, encoder: &mut wgpu::CommandEncoder, render_target: &TextureView);
/// This method will be called when the input [`wgpu::TextureView`] needs to be rebinded.
///
/// A [`wgpu::TextureView`] is provided to the `RenderPass` factory as an input texture with
/// the original [`SurfaceTexture`] size. This method is called in response to resizing the
/// [`SurfaceTexture`], where your `RenderPass` impl can update its input texture for the new
/// size.
///
/// # Arguments
/// * `input_texture` - A reference to the `TextureView` for this render pass's input
/// * `input_texture_size` - The `input_texture` size
///
/// [`Pixels`]: ./struct.Pixels.html
/// [`SurfaceTexture`]: ./struct.SurfaceTexture.html
fn update_bindings(&mut self, input_texture: &TextureView, input_texture_size: &Extent3d);
/// When the window is resized, this method will be called, allowing the render pass to
/// customize itself to the display size.
///
/// The default implementation is a no-op.
///
/// # Arguments
/// * `encoder` - Command encoder for the render pass
/// * `width` - Render target width in physical pixel units
/// * `height` - Render target height in physical pixel units
#[allow(unused_variables)]
fn resize(&mut self, encoder: &mut wgpu::CommandEncoder, width: u32, height: u32) {}
/// This function implements [`Debug`](fmt::Debug) for trait objects.
///

69
src/renderers.rs
View file

@ -1,7 +1,7 @@
use byteorder::{ByteOrder, LittleEndian};
use std::fmt;
use std::rc::Rc;
use wgpu::{self, TextureView};
use wgpu::{self, Extent3d, TextureView};
use crate::render_pass::{BoxedRenderPass, Device, Queue, RenderPass};
@ -9,8 +9,11 @@ use crate::render_pass::{BoxedRenderPass, Device, Queue, RenderPass};
#[derive(Debug)]
pub(crate) struct Renderer {
device: Rc<wgpu::Device>,
uniform_buffer: wgpu::Buffer,
bind_group: wgpu::BindGroup,
render_pipeline: wgpu::RenderPipeline,
width: f32,
height: f32,
}
impl Renderer {
@ -19,6 +22,7 @@ impl Renderer {
device: Device,
_queue: Queue,
texture_view: &TextureView,
texture_size: &Extent3d,
) -> BoxedRenderPass {
let vert_spv = include_bytes!("../shaders/vert.spv");
let mut vert = Vec::new();
@ -52,6 +56,18 @@ impl Renderer {
compare_function: wgpu::CompareFunction::Always,
});
// Create uniform buffer
#[rustfmt::skip]
let transform: [f32; 16] = [
1.0, 0.0, 0.0, 0.0,
0.0, 1.0, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0,
];
let uniform_buffer = device
.create_buffer_mapped(16, wgpu::BufferUsage::UNIFORM | wgpu::BufferUsage::COPY_DST)
.fill_from_slice(&transform);
// Create bind group
let bind_group_layout = device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
bindings: &[
@ -68,6 +84,11 @@ impl Renderer {
visibility: wgpu::ShaderStage::FRAGMENT,
ty: wgpu::BindingType::Sampler,
},
wgpu::BindGroupLayoutBinding {
binding: 2,
visibility: wgpu::ShaderStage::VERTEX,
ty: wgpu::BindingType::UniformBuffer { dynamic: false },
},
],
});
let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
@ -81,6 +102,13 @@ impl Renderer {
binding: 1,
resource: wgpu::BindingResource::Sampler(&sampler),
},
wgpu::Binding {
binding: 2,
resource: wgpu::BindingResource::Buffer {
buffer: &uniform_buffer,
range: 0..64,
},
},
],
});
@ -122,16 +150,17 @@ impl Renderer {
Box::new(Renderer {
device,
uniform_buffer,
bind_group,
render_pipeline,
width: texture_size.width as f32,
height: texture_size.height as f32,
})
}
}
impl RenderPass for Renderer {
fn update_bindings(&mut self, _input_texture: &TextureView) {}
fn render_pass(&self, encoder: &mut wgpu::CommandEncoder, render_target: &TextureView) {
fn render(&self, encoder: &mut wgpu::CommandEncoder, render_target: &TextureView) {
// Draw the updated texture to the render target
let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
color_attachments: &[wgpu::RenderPassColorAttachmentDescriptor {
@ -148,6 +177,38 @@ impl RenderPass for Renderer {
rpass.draw(0..6, 0..1);
}
fn resize(&mut self, encoder: &mut wgpu::CommandEncoder, width: u32, height: u32) {
let width = width as f32;
let height = height as f32;
// Get smallest scale size
let scale = (width / self.width)
.min(height / self.height)
.max(1.0)
.floor();
// Update transformation matrix
let sw = self.width * scale / width;
let sh = self.height * scale / height;
#[rustfmt::skip]
let transform: [f32; 16] = [
sw, 0.0, 0.0, 0.0,
0.0, sh, 0.0, 0.0,
0.0, 0.0, 1.0, 0.0,
0.0, 0.0, 0.0, 1.0,
];
let temp_buf = self
.device
.create_buffer_mapped(16, wgpu::BufferUsage::COPY_SRC)
.fill_from_slice(&transform);
encoder.copy_buffer_to_buffer(&temp_buf, 0, &self.uniform_buffer, 0, 64);
}
// We don't actually have to rebind the TextureView here.
// It's guaranteed that the initial texture never changes.
fn update_bindings(&mut self, _input_texture: &TextureView, _input_texture_size: &Extent3d) {}
fn debug(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", self)
}