Add graphics backend configuration

Hopefully #74, #73, #56

objdiff-gui/src/views/graphics.rs

@@ -0,0 +1,158 @@
+use std::{
+    fs::File,
+    path::{Path, PathBuf},
+};
+
+use anyhow::Result;
+use egui::{text::LayoutJob, Context, FontId, RichText, TextFormat, TextStyle, Window};
+use serde::{Deserialize, Serialize};
+use strum::{EnumIter, EnumMessage, IntoEnumIterator};
+
+use crate::views::{appearance::Appearance, frame_history::FrameHistory};
+
+#[derive(Default)]
+pub struct GraphicsViewState {
+    pub active_backend: String,
+    pub active_device: String,
+    pub graphics_config: GraphicsConfig,
+    pub graphics_config_path: Option<PathBuf>,
+    pub should_relaunch: bool,
+}
+
+#[derive(
+    Copy, Clone, Debug, Default, PartialEq, Eq, EnumIter, EnumMessage, Serialize, Deserialize,
+)]
+pub enum GraphicsBackend {
+    #[default]
+    #[strum(message = "Auto")]
+    Auto,
+    #[strum(message = "Vulkan")]
+    Vulkan,
+    #[strum(message = "Metal")]
+    Metal,
+    #[strum(message = "DirectX 12")]
+    Dx12,
+    #[strum(message = "OpenGL")]
+    OpenGL,
+}
+
+#[derive(Debug, Default, serde::Deserialize, serde::Serialize)]
+pub struct GraphicsConfig {
+    #[serde(default)]
+    pub desired_backend: GraphicsBackend,
+}
+
+pub fn load_graphics_config(path: &Path) -> Result<Option<GraphicsConfig>> {
+    if !path.exists() {
+        return Ok(None);
+    }
+    let file = File::open(path)?;
+    let config: GraphicsConfig = ron::de::from_reader(file)?;
+    Ok(Some(config))
+}
+
+pub fn save_graphics_config(path: &Path, config: &GraphicsConfig) -> Result<()> {
+    let file = File::create(path)?;
+    ron::ser::to_writer(file, config)?;
+    Ok(())
+}
+
+impl GraphicsBackend {
+    pub fn is_supported(&self) -> bool {
+        match self {
+            GraphicsBackend::Auto => true,
+            GraphicsBackend::Vulkan => {
+                cfg!(all(feature = "wgpu", any(target_os = "windows", target_os = "linux")))
+            }
+            GraphicsBackend::Metal => cfg!(all(feature = "wgpu", target_os = "macos")),
+            GraphicsBackend::Dx12 => cfg!(all(feature = "wgpu", target_os = "windows")),
+            GraphicsBackend::OpenGL => true,
+        }
+    }
+}
+
+pub fn graphics_window(
+    ctx: &Context,
+    show: &mut bool,
+    frame_history: &mut FrameHistory,
+    state: &mut GraphicsViewState,
+    appearance: &Appearance,
+) {
+    Window::new("Graphics").open(show).show(ctx, |ui| {
+        ui.label("Graphics backend:");
+        ui.label(
+            RichText::new(&state.active_backend)
+                .color(appearance.emphasized_text_color)
+                .text_style(TextStyle::Monospace),
+        );
+        ui.label("Graphics device:");
+        ui.label(
+            RichText::new(&state.active_device)
+                .color(appearance.emphasized_text_color)
+                .text_style(TextStyle::Monospace),
+        );
+        ui.label(format!("FPS: {:.1}", frame_history.fps()));
+
+        ui.separator();
+        let mut job = LayoutJob::default();
+        job.append(
+            "WARNING: ",
+            0.0,
+            TextFormat::simple(appearance.ui_font.clone(), appearance.delete_color),
+        );
+        job.append(
+            "Changing the graphics backend may cause the application\nto no longer start or display correctly. Use with caution!",
+            0.0,
+            TextFormat::simple(appearance.ui_font.clone(), appearance.emphasized_text_color),
+        );
+        if let Some(config_path) = &state.graphics_config_path {
+            job.append(
+                "\n\nDelete the following file to reset:\n",
+                0.0,
+                TextFormat::simple(appearance.ui_font.clone(), appearance.emphasized_text_color),
+            );
+            job.append(
+                config_path.to_string_lossy().as_ref(),
+                0.0,
+                TextFormat::simple(
+                    FontId {
+                        family: appearance.code_font.family.clone(),
+                        size: appearance.ui_font.size,
+                    },
+                    appearance.emphasized_text_color,
+                ),
+            );
+        }
+        job.append(
+            "\n\nChanging the graphics backend will restart the application.",
+            0.0,
+            TextFormat::simple(appearance.ui_font.clone(), appearance.replace_color),
+        );
+        ui.label(job);
+
+        ui.add_enabled_ui(state.graphics_config_path.is_some(), |ui| {
+            ui.horizontal(|ui| {
+                ui.label("Desired backend:");
+                for backend in GraphicsBackend::iter().filter(GraphicsBackend::is_supported) {
+                    let selected = state.graphics_config.desired_backend == backend;
+                    if ui.selectable_label(selected, backend.get_message().unwrap()).clicked() {
+                        let prev_backend = state.graphics_config.desired_backend;
+                        state.graphics_config.desired_backend = backend;
+                        match save_graphics_config(
+                            state.graphics_config_path.as_ref().unwrap(),
+                            &state.graphics_config,
+                        ) {
+                            Ok(()) => {
+                                state.should_relaunch = true;
+                            }
+                            Err(e) => {
+                                log::error!("Failed to save graphics config: {:?}", e);
+                                state.graphics_config.desired_backend = prev_backend;
+                            }
+                        }
+                    }
+                }
+            });
+        });
+    });
+}