use cbindgen for FFI

.clang-format

@@ -0,0 +1,9 @@
+BasedOnStyle: LLVM
+UseTab: Always
+TabWidth: 4
+IndentWidth: 4
+AccessModifierOffset: -4
+IndentCaseLabels: false
+ColumnLimit: 0
+PointerAlignment: Left
+PackConstructorInitializers: Never

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.18)
+cmake_minimum_required(VERSION 4.2)
 
 project(PROJECT-NAME VERSION 1.0.0 LANGUAGES CXX)
 
@@ -9,10 +9,7 @@ find_package(Qt6 REQUIRED COMPONENTS Gui Widgets)
 find_program(CARGO cargo REQUIRED)
 set(CARGO_TARGET_DIR "${CMAKE_BINARY_DIR}/cargo")
 
-# KDE-specific
-find_package(ECM REQUIRED NO_MODULE)
-set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH})
-find_package(KF6 REQUIRED COMPONENTS WidgetsAddons)
+include(cbindgen.cmake)
 
 qt_standard_project_setup()
 

cbindgen.cmake

@@ -0,0 +1,13 @@
+option(LOCAL_CBINDGEN "Download and build `cbindgen` even if one can be found on the system")
+
+if(NOT LOCAL_CBINDGEN)
+	find_program(CBINDGEN cbindgen)
+endif()
+
+if(NOT CBINDGEN)
+	message(CONFIGURE_LOG "cbindgen not found, downloading...")
+	set(crates "${CMAKE_BINARY_DIR}/crates")
+	file(MAKE_DIRECTORY ${crates})
+	execute_process(COMMAND ${CARGO} install --root ${crates} cbindgen@0.29.4)
+	set(CACHE{CBINDGEN} TYPE FILEPATH FORCE VALUE "${crates}/bin/cbindgen")
+endif()

format.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+find src/ ui/ \
+	\( \
+		-name '*.cxx' -o \
+		-name '*.hxx' -o \
+		-name '*.c' -o \
+		-name '*.h' \
+	\) \
+	-print \
+	-exec 'clang-format' '-i' '{}' \;

src/camera.rs

@@ -9,11 +9,11 @@ pub(crate) fn rotation(yaw: f32, pitch: f32) -> Mat3 {
 }
 
 pub(crate) fn view(yaw: f32, pitch: f32, distance: f32) -> Affine3A {
-	Affine3A::from_mat3_translation(rotation(yaw, pitch), vec3(0., 0., distance))
+	Affine3A::from_mat3_translation(rotation(-yaw, -pitch), vec3(0., 0., -distance))
 }
 
 pub(crate) fn projection(fovy: f32, aspect: f32) -> Mat4 {
-	Mat4::perspective_lh(fovy, aspect, 0.1, 10.0)
+	Mat4::perspective_rh(fovy, aspect, 0.1, 10.0)
 }
 
 #[cfg(test)]

src/lib.rs

@@ -5,10 +5,11 @@ use glam::{Mat4, UVec2, Vec3, Vec4, vec3, vec4};
 mod camera;
 mod render;
 
+const BACKGROUND: Vec4 = vec4(0.00, 0.39, 0.52, 1.00);
+
 #[derive(Debug, Clone, Copy)]
 #[repr(C)]
 pub struct RedrawArgs {
-	pub background: Vec4,
 	pub cam_yaw: f32,
 	pub cam_pitch: f32,
 	pub cam_distance: f32,
@@ -18,8 +19,7 @@ pub struct RedrawArgs {
 impl Default for RedrawArgs {
 	fn default() -> Self {
 		Self {
-			background: vec4(0.25, 0.49, 0.93, 1.00),
-			cam_yaw: std::f32::consts::FRAC_PI_4,
+			cam_yaw: 3. * std::f32::consts::FRAC_PI_4,
 			cam_pitch: std::f32::consts::FRAC_PI_6,
 			cam_distance: 3.,
 			cam_fovy: std::f32::consts::FRAC_PI_2,
@@ -56,7 +56,7 @@ fn cube(a: f32, b: f32) -> render::mesh::CpuMeshIndexed {
 	] {
 		for m in [1., -1.] {
 			let base = mesh.vertices.len() as u16;
-			for offset in [m * v + u, -m * v + u, -m * v - u, m * v - u] {
+			for offset in [m * v + u, m * v - u, -m * v - u, -m * v + u] {
 				let vertex = render::mesh::Vertex {
 					position: (m * w + offset),
 					color: gray + color_level * m * w,
@@ -158,7 +158,7 @@ impl Core {
 				depth_slice: None,
 				resolve_target: None,
 				ops: wgpu::Operations {
-					load: wgpu::LoadOp::Clear(color_to_wgpu(srgba_to_linear(args.background))),
+					load: wgpu::LoadOp::Clear(color_to_wgpu(srgba_to_linear(BACKGROUND))),
 					store: wgpu::StoreOp::Store,
 				},
 			})],

ui/CMakeLists.txt

@@ -9,6 +9,5 @@ qt_add_executable(PROJECT-NAME
 )
 
 target_link_libraries(PROJECT-NAME PRIVATE Qt6::Gui Qt6::Widgets)
-target_link_libraries(PROJECT-NAME PRIVATE KF6::WidgetsAddons)
 target_link_libraries(PROJECT-NAME PRIVATE PROJECT_NAME_impl)
 target_include_directories(PROJECT-NAME PRIVATE src)

ui/cbindgen.toml

@@ -0,0 +1,14 @@
+includes = ["types.hxx"]
+sys_includes = ["cstdint"]
+pragma_once = true
+no_includes = true
+namespace = "ffi"
+tab_width = 4
+language = "C++"
+
+[parse]
+parse_deps = true
+include = ["PROJECT-NAME"]
+
+[export]
+exclude = ["Box"]

ui/impl.cmake

@@ -1,3 +1,4 @@
+# build the Rust side as a static library
 set(impl_basename "${CARGO_TARGET_DIR}/release/libPROJECT_NAME_impl")
 
 add_custom_command(
@@ -6,7 +7,8 @@ add_custom_command(
 	WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
 	DEPFILE ${impl_basename}.d
 	USES_TERMINAL
-	JOB_SERVER_AWARE
+	JOB_SERVER_AWARE TRUE
+	VERBATIM
 	DEPENDS_EXPLICIT_ONLY
 )
 
@@ -20,3 +22,24 @@ add_library(PROJECT_NAME_impl STATIC IMPORTED)
 set_target_properties(PROJECT_NAME_impl PROPERTIES
 	IMPORTED_LOCATION ${impl_basename}.a
 )
+
+# generate the bindings
+file(MAKE_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/include")
+set(bindings_basename "${CMAKE_CURRENT_BINARY_DIR}/include/bindings")
+
+add_custom_command(
+	OUTPUT ${bindings_basename}.hxx
+	COMMAND ${CBINDGEN} --only-target-dependencies --output "${bindings_basename}.hxx" --depfile "${bindings_basename}.d"
+	WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+	DEPFILE ${bindings_basename}.d
+	VERBATIM
+	CODEGEN
+	DEPENDS_EXPLICIT_ONLY
+)
+
+target_sources(PROJECT_NAME_impl INTERFACE
+	${bindings_basename}.hxx
+)
+target_include_directories(PROJECT_NAME_impl INTERFACE
+	"${CMAKE_CURRENT_BINARY_DIR}/include"
+)

ui/src/api.cxx

@@ -3,13 +3,6 @@
 #include <stdexcept>
 #include <utility>
 
-namespace ffi {
-extern "C" Core* rt4_viewport_create(xcb_connection_t* connection, std::uint32_t window, std::uint32_t width, std::uint32_t height);
-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, const RedrawArgs* args);
-} // namespace ffi
-
 BoxCore::BoxCore(BoxCore&& b)
 	: ptr(std::exchange(b.ptr, {})) {
 }

ui/src/api.hxx

@@ -2,24 +2,10 @@
 
 #include <cstdint>
 
+#include "bindings.hxx"
+
 struct xcb_connection_t;
 
-struct alignas(16) Vec4 {
-	float x, y, z, w;
-};
-
-namespace ffi {
-struct Core;
-
-struct RedrawArgs {
-	Vec4 background;
-	float cam_yaw;
-	float cam_pitch;
-	float cam_distance;
-	float cam_fovy;
-};
-} // namespace ffi
-
 using ffi::RedrawArgs;
 
 class MutCore {

ui/src/main_window.cxx

@@ -12,9 +12,7 @@ PROJECTNAME::PROJECTNAME(QWidget* parent)
 PROJECTNAME::~PROJECTNAME() = default;
 
 void PROJECTNAME::updateView() {
-	const auto color = m_ui->inBackground->color();
 	RedrawArgs args{
-		.background = { color.redF(), color.greenF(), color.blueF(), 1.00 },
 		.cam_yaw = qDegreesToRadians((float)m_ui->camYaw->value()),
 		.cam_pitch = qDegreesToRadians((float)m_ui->camPitch->value()),
 		.cam_distance = (float)m_ui->camDistance->value(),

ui/src/main_window.ui

@@ -71,7 +71,7 @@
            <double>5.000000000000000</double>
           </property>
           <property name="value">
-           <double>45.000000000000000</double>
+           <double>135.000000000000000</double>
           </property>
          </widget>
         </item>
@@ -156,24 +156,6 @@
        </layout>
       </widget>
      </item>
-     <item>
-      <widget class="QLabel" name="label">
-       <property name="text">
-        <string>Background color</string>
-       </property>
-      </widget>
-     </item>
-     <item>
-      <widget class="KColorCombo" name="inBackground">
-       <property name="color">
-        <color>
-         <red>0</red>
-         <green>99</green>
-         <blue>133</blue>
-        </color>
-       </property>
-      </widget>
-     </item>
      <item>
       <spacer name="verticalSpacer">
        <property name="orientation">
@@ -192,11 +174,6 @@
   </widget>
  </widget>
  <customwidgets>
-  <customwidget>
-   <class>KColorCombo</class>
-   <extends>QComboBox</extends>
-   <header>kcolorcombo.h</header>
-  </customwidget>
   <customwidget>
    <class>Viewport</class>
    <extends>QWidget</extends>
@@ -206,22 +183,6 @@
  </customwidgets>
  <resources/>
  <connections>
-  <connection>
-   <sender>inBackground</sender>
-   <signal>highlighted(QColor)</signal>
-   <receiver>MainWindow</receiver>
-   <slot>updateView()</slot>
-   <hints>
-    <hint type="sourcelabel">
-     <x>1531</x>
-     <y>115</y>
-    </hint>
-    <hint type="destinationlabel">
-     <x>799</x>
-     <y>599</y>
-    </hint>
-   </hints>
-  </connection>
   <connection>
    <sender>camYaw</sender>
    <signal>valueChanged(double)</signal>

ui/src/types.hxx

@@ -0,0 +1,12 @@
+#pragma once
+
+struct alignas(16) Vec4 {
+	float x, y, z, w;
+};
+
+namespace ffi {
+
+template <typename T>
+using Box = T*;
+
+} // namespace ffi