minimal Qt6 UI

CMakeLists.txt

@@ -5,7 +5,10 @@ project(photon_light VERSION 1.0.0 LANGUAGES CXX)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
+find_package(Qt6 REQUIRED COMPONENTS Gui Widgets)
 find_program(CARGO cargo REQUIRED)
 set(CARGO_TARGET_DIR "${CMAKE_BINARY_DIR}/cargo")
 
+qt_standard_project_setup()
+
 add_subdirectory(ui)

Cargo.lock

@@ -1169,7 +1169,11 @@ dependencies = [
 name = "photon-light-impl"
 version = "0.1.0"
 dependencies = [
+ "glam",
  "photon-light",
+ "pollster",
+ "raw-window-handle",
+ "wgpu",
 ]
 
 [[package]]

src/lib.rs

@@ -207,6 +207,7 @@ impl Core {
 		self.queue.submit(std::iter::once(encoder.finish()));
 	}
 
+	/// Configures the renderer for a given target size.
 	pub fn configure(&mut self, pixel_size: UVec2) {
 		self.surface.configure(
 			&self.device,
@@ -223,6 +224,9 @@ impl Core {
 		);
 	}
 
+	/// Redraws the entire surface.
+	///
+	/// [`Self::configure`] must be called at least once before this.
 	pub fn redraw(&mut self) {
 		let output = self.surface.get_current_texture().unwrap();
 		self.render(&output.texture);

ui/CMakeLists.txt

@@ -1,7 +1,13 @@
 include(impl.cmake)
 
-add_executable(photon_light
+qt_add_executable(photon_light
+	src/api.cxx
 	src/main.cxx
+	src/main_window.cxx
+	src/main_window.ui
+	src/viewport.cxx
 )
 
+target_link_libraries(photon_light PRIVATE Qt6::Gui Qt6::Widgets)
 target_link_libraries(photon_light PRIVATE photon_light_impl)
+target_include_directories(photon_light PRIVATE src)

ui/Cargo.toml

@@ -8,3 +8,8 @@ crate-type = ["staticlib"]
 
 [dependencies]
 photon-light = {path = "../"}
+
+glam = { version = "0.30" }
+pollster = "0.4.0"
+raw-window-handle = "0.6.2"
+wgpu = "27.0.1"

ui/src/api.cxx

@@ -0,0 +1,56 @@
+#include "api.hxx"
+
+#include <utility>
+#include <stdexcept>
+
+extern "C" Core* rt4_viewport_create(xcb_connection_t* connection, std::uint32_t window);
+extern "C" void rt4_viewport_destroy(Core* viewport);
+extern "C" void rt4_viewport_configure(Core* viewport, std::uint32_t width, std::uint32_t height);
+extern "C" void rt4_viewport_redraw(Core* viewport);
+
+BoxCore::BoxCore(BoxCore&& b)
+	: ptr(std::exchange(b.ptr, nullptr))
+{
+}
+
+BoxCore::~BoxCore() {
+	reset();
+}
+
+BoxCore& BoxCore::operator= (BoxCore&& b) {
+	if (&b == this)
+		return *this;
+	std::swap(ptr, b.ptr);
+	b.reset();
+	return *this;
+}
+
+BoxCore BoxCore::from_xcb(xcb_connection_t* connection, std::uint32_t window) {
+	if (!connection)
+		throw std::logic_error("attempt to use a null connection");
+	if (!window)
+		throw std::logic_error("attempt to use a null window");
+	BoxCore out;
+	out.ptr = rt4_viewport_create(connection, window);
+	return out;
+}
+
+void BoxCore::reset() {
+	auto viewport = std::exchange(ptr, nullptr);
+	if (viewport)
+		rt4_viewport_destroy(viewport);
+}
+
+Core* BoxCore::use() const {
+	if (!ptr)
+		throw std::logic_error("attempt to use a null Core");
+	return ptr;
+}
+
+void BoxCore::configure(std::uint32_t width, std::uint32_t height) {
+	rt4_viewport_configure(use(), width, height);
+}
+
+void BoxCore::redraw() {
+	rt4_viewport_redraw(use());
+}

ui/src/api.hxx

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <cstdint>
+
+struct xcb_connection_t;
+
+struct Core;
+
+class BoxCore {
+public:
+	BoxCore() = default;
+	BoxCore(const BoxCore&) = delete;
+	BoxCore(BoxCore&&);
+	BoxCore& operator= (const BoxCore&) = delete;
+	BoxCore& operator= (BoxCore&&);
+	~BoxCore();
+
+	explicit operator bool() const { return ptr; }
+
+	void reset();
+
+	static BoxCore from_xcb(xcb_connection_t* connection, std::uint32_t window);
+	void configure(std::uint32_t width, std::uint32_t height);
+	void redraw();
+
+private:
+	Core* ptr = nullptr;
+
+	Core* use() const;
+};

ui/src/lib.rs

@@ -0,0 +1,45 @@
+use std::{ffi::c_void, num::NonZero, ptr::NonNull};
+
+use glam::uvec2;
+use photon_light::{Core, init_gpu_inner};
+use raw_window_handle::{RawDisplayHandle, RawWindowHandle, XcbDisplayHandle, XcbWindowHandle};
+
+unsafe fn create_viewport(
+	display: impl Into<RawDisplayHandle>,
+	window: impl Into<RawWindowHandle>,
+) -> Box<Core> {
+	let target = wgpu::SurfaceTargetUnsafe::RawHandle {
+		raw_display_handle: display.into(),
+		raw_window_handle: window.into(),
+	};
+	let gpu = pollster::block_on(init_gpu_inner(|instance| unsafe {
+		instance.create_surface_unsafe(target)
+	}))
+	.unwrap();
+	Box::new(Core::new(gpu))
+}
+
+#[unsafe(no_mangle)]
+unsafe extern "C" fn rt4_viewport_create(
+	connection: NonNull<c_void>,
+	window: NonZero<u32>,
+) -> Box<Core> {
+	let display = XcbDisplayHandle::new(Some(connection), 0);
+	let window = XcbWindowHandle::new(window);
+	unsafe { create_viewport(display, window) }
+}
+
+#[unsafe(no_mangle)]
+unsafe extern "C" fn rt4_viewport_destroy(viewport: Box<Core>) {
+	drop(viewport);
+}
+
+#[unsafe(no_mangle)]
+unsafe extern "C" fn rt4_viewport_configure(viewport: &mut Core, width: u32, height: u32) {
+	viewport.configure(uvec2(width, height));
+}
+
+#[unsafe(no_mangle)]
+unsafe extern "C" fn rt4_viewport_redraw(viewport: &mut Core) {
+	viewport.redraw();
+}

ui/src/main.cxx

@@ -1,3 +1,13 @@
-int main() {
-	return 0;
+#include "main_window.hxx"
+
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+
+    auto w = new PhotonLight;
+    w->show();
+
+    return app.exec();
 }

ui/src/main_window.cxx

@@ -0,0 +1,14 @@
+#include "main_window.hxx"
+
+#include "ui_main_window.h"
+
+PhotonLight::PhotonLight(QWidget *parent)
+	: QMainWindow(parent)
+	, m_ui(new Ui::MainWindow)
+{
+	m_ui->setupUi(this);
+}
+
+PhotonLight::~PhotonLight() = default;
+
+#include "moc_main_window.cpp"

ui/src/main_window.hxx

@@ -0,0 +1,20 @@
+#pragma once
+#include <QMainWindow>
+
+#include <memory>
+
+namespace Ui {
+class MainWindow;
+}
+
+class PhotonLight : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    explicit PhotonLight(QWidget *parent = nullptr);
+    ~PhotonLight() override;
+
+private:
+    const std::unique_ptr<Ui::MainWindow> m_ui;
+};

ui/src/main_window.ui

@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>1220</width>
+    <height>823</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralwidget">
+   <layout class="QHBoxLayout" name="horizontalLayout_2">
+    <item>
+     <widget class="Viewport" name="widget" native="true"/>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menubar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>1220</width>
+     <height>38</height>
+    </rect>
+   </property>
+  </widget>
+  <widget class="QStatusBar" name="statusbar"/>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>Viewport</class>
+   <extends>QWidget</extends>
+   <header>viewport.hxx</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>

ui/src/viewport.cxx

@@ -0,0 +1,67 @@
+#include "viewport.hxx"
+
+#include <QApplication>
+#include <QEvent>
+#include <QGuiApplication>
+
+Viewport::Viewport(QWidget* parent, Qt::WindowFlags f) : QWidget(parent, f) {
+	setAttribute(Qt::WA_NativeWindow);
+	setAttribute(Qt::WA_PaintOnScreen);
+	setAttribute(Qt::WA_NoSystemBackground);
+}
+
+Viewport::~Viewport() = default;
+
+QPaintEngine* Viewport::paintEngine() const {
+	return nullptr;
+}
+
+bool Viewport::event(QEvent* event) {
+	switch (event->type()) {
+	case QEvent::Type::WinIdChange:
+		recreate();
+		break;
+	default:
+		break;
+	}
+	return QWidget::event(event);
+}
+
+void Viewport::paintEvent(QPaintEvent* event) {
+	if (!core)
+		recreate();
+	core.redraw();
+}
+
+void Viewport::resizeEvent(QResizeEvent* event) {
+	if (!core)
+		return;
+	updateSize();
+	QWidget::resizeEvent(event);
+}
+
+void Viewport::recreate() try {
+	auto* app = qobject_cast<QGuiApplication*>(QApplication::instance());
+	if (!app)
+		throw std::runtime_error("not a GUI application (WTF?)");
+
+	auto* native = app->nativeInterface<QNativeInterface::QX11Application>();
+	if (!native)
+		throw std::runtime_error("X11 interface is not available");
+
+	auto* xcb_connection = native->connection();
+	std::uint32_t x11_window = winId();
+
+	fprintf(stderr, "connection %p, window %#08x\n", xcb_connection, x11_window);
+
+	core.reset();
+	core = BoxCore::from_xcb(xcb_connection, x11_window);
+	updateSize();
+} catch (const std::exception& e) {
+	fprintf(stderr, "failed to recreate the viewport: %s", e.what());
+}
+
+void Viewport::updateSize() {
+	const QSize device_size = size() * devicePixelRatio();
+	core.configure(device_size.width(), device_size.height());
+}

ui/src/viewport.hxx

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <QWidget>
+
+#include "api.hxx"
+
+class Viewport: public QWidget {
+	Q_OBJECT
+
+public:
+	explicit Viewport(QWidget* parent = nullptr, Qt::WindowFlags f = Qt::WindowFlags());
+	~Viewport() override;
+	QPaintEngine* paintEngine() const override;
+
+protected:
+	bool event(QEvent* event) override;
+	void paintEvent(QPaintEvent* event) override;
+	void resizeEvent(QResizeEvent* event) override;
+
+private:
+	BoxCore core;
+
+	void recreate();
+	void updateSize();
+};