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Diffstat (limited to 'engine/src/renderer/opengl/glutin_compat.rs')
| -rw-r--r-- | engine/src/renderer/opengl/glutin_compat.rs | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/engine/src/renderer/opengl/glutin_compat.rs b/engine/src/renderer/opengl/glutin_compat.rs new file mode 100644 index 0000000..cfd6ea7 --- /dev/null +++ b/engine/src/renderer/opengl/glutin_compat.rs @@ -0,0 +1,268 @@ +// Original file: +// https://github.com/rust-windowing/glutin/blob/ +// 0433af9018febe0696c485ed9d66c40dad41f2d4/glutin-winit/src/lib.rs +// +// Copyright © 2022 Kirill Chibisov +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the “Software”), to deal +// in the Software without restriction, including without limitation the rights to +// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies +// of the Software, and to permit persons to whom the Software is furnished to do +// so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in all +// copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL +// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +// SOFTWARE. + +//! This library provides helpers for cross-platform [`glutin`] bootstrapping +//! with [`winit`]. + +#![deny(rust_2018_idioms)] +#![deny(rustdoc::broken_intra_doc_links)] +#![deny(clippy::all)] +#![deny(missing_debug_implementations)] +#![deny(missing_docs)] +#![cfg_attr(clippy, deny(warnings))] + +use glutin::config::{Config, ConfigTemplateBuilder}; +use glutin::display::{Display, DisplayApiPreference}; +use glutin::error::Error as GlutinError; +#[cfg(x11_platform)] +use glutin::platform::x11::X11GlConfigExt; +use glutin::prelude::*; +use raw_window_handle::{DisplayHandle, RawWindowHandle, WindowHandle}; + +use crate::windowing::window::CreationAttributes as WindowCreationAttributes; + +#[cfg(all(not(egl_backend), not(glx_backend), not(wgl_backend), not(cgl_backend)))] +compile_error!("Please select at least one api backend"); + +/// The helper to perform [`Display`] creation and OpenGL platform +/// bootstrapping with the help of [`winit`] with little to no platform specific +/// code. +/// +/// This is only required for the initial setup. If you want to create +/// additional windows just use the [`finalize_window`] function and the +/// configuration you've used either for the original window or picked with the +/// existing [`Display`]. +/// +/// [`winit`]: winit +/// [`Display`]: glutin::display::Display +#[derive(Default, Debug, Clone)] +pub struct DisplayBuilder +{ + preference: ApiPreference, + window_attributes: WindowCreationAttributes, +} + +impl DisplayBuilder +{ + /// Create new display builder. + pub fn new() -> Self + { + Default::default() + } + + /// The preference in picking the configuration. + #[allow(dead_code)] + pub fn with_preference(mut self, preference: ApiPreference) -> Self + { + self.preference = preference; + self + } + + /// The window attributes to use when building a window. + /// + /// By default no window is created. + pub fn with_window_attributes( + mut self, + window_creation_attrs: WindowCreationAttributes, + ) -> Self + { + self.window_attributes = window_creation_attrs; + self + } + + /// Initialize the OpenGL platform and create a compatible window to use + /// with it when the [`WindowAttributes`] was passed with + /// [`Self::with_window_attributes()`]. It's optional, since on some + /// platforms like `Android` it is not available early on, so you want to + /// find configuration and later use it with the [`finalize_window`]. + /// But if you don't care about such platform you can always pass + /// [`WindowAttributes`]. + /// + /// # Api-specific + /// + /// **WGL:** - [`WindowAttributes`] **must** be passed in + /// [`Self::with_window_attributes()`] if modern OpenGL(ES) is desired, + /// otherwise only builtin functions like `glClear` will be available. + pub fn build<ConfigPickerFn>( + self, + window_handle: Option<WindowHandle<'_>>, + display_handle: &DisplayHandle<'_>, + template_builder: ConfigTemplateBuilder, + config_picker_fn: ConfigPickerFn, + ) -> Result<(WindowCreationAttributes, Config), Error> + where + ConfigPickerFn: FnOnce(Box<dyn Iterator<Item = Config> + '_>) -> Option<Config>, + { + // XXX with WGL backend window should be created first. + let raw_window_handle = if cfg!(wgl_backend) { + let Some(window_handle) = window_handle else { + return Err(Error::WindowRequired); + }; + + Some(window_handle.as_raw()) + } else { + None + }; + + let gl_display = + create_display(display_handle, self.preference, raw_window_handle) + .map_err(Error::CreateDisplayFailed)?; + + // XXX the native window must be passed to config picker when WGL is used + // otherwise very limited OpenGL features will be supported. + #[cfg(wgl_backend)] + let template_builder = if let Some(raw_window_handle) = raw_window_handle { + template_builder.compatible_with_native_window(raw_window_handle) + } else { + template_builder + }; + + let template = template_builder.build(); + + // SAFETY: The RawWindowHandle passed on the config template + // (when cfg(wgl_backend)) will always point to a valid object since it is + // derived from the window_handle argument which when Some is a WindowHandle and + // WindowHandles always point to a valid object + let gl_configs = unsafe { gl_display.find_configs(template) } + .map_err(Error::FindConfigsFailed)?; + + let picked_gl_config = + config_picker_fn(gl_configs).ok_or(Error::NoConfigPicked)?; + + #[cfg(not(wgl_backend))] + let window_attrs = + { finalize_window_creation_attrs(self.window_attributes, &picked_gl_config) }; + + #[cfg(wgl_backend)] + let window_attrs = self.window_attributes; + + Ok((window_attrs, picked_gl_config)) + } +} + +#[derive(Debug, thiserror::Error)] +pub enum Error +{ + #[error("Failed to create display")] + CreateDisplayFailed(#[source] GlutinError), + + #[error("Failed to find configs")] + FindConfigsFailed(#[source] GlutinError), + + #[error("No config was picked by config picker function")] + NoConfigPicked, + + #[error("Window required for building display on current platform")] + WindowRequired, +} + +fn create_display( + display_handle: &DisplayHandle<'_>, + _api_preference: ApiPreference, + _raw_window_handle: Option<RawWindowHandle>, +) -> Result<Display, GlutinError> +{ + #[cfg(egl_backend)] + let _preference = DisplayApiPreference::Egl; + + #[cfg(glx_backend)] + let _preference = DisplayApiPreference::Glx(Box::new( + crate::windowing::window::platform::x11::register_xlib_error_hook, + )); + + #[cfg(cgl_backend)] + let _preference = DisplayApiPreference::Cgl; + + #[cfg(wgl_backend)] + let _preference = DisplayApiPreference::Wgl(_raw_window_handle); + + #[cfg(all(egl_backend, glx_backend))] + let _preference = match _api_preference { + ApiPreference::PreferEgl => DisplayApiPreference::EglThenGlx(Box::new( + crate::windowing::window::platform::x11::register_xlib_error_hook, + )), + ApiPreference::FallbackEgl => DisplayApiPreference::GlxThenEgl(Box::new( + crate::windowing::window::platform::x11::register_xlib_error_hook, + )), + }; + + #[cfg(all(wgl_backend, egl_backend))] + let _preference = match _api_preference { + ApiPreference::PreferEgl => DisplayApiPreference::EglThenWgl(_raw_window_handle), + ApiPreference::FallbackEgl => { + DisplayApiPreference::WglThenEgl(_raw_window_handle) + } + }; + + let handle = display_handle.as_raw(); + unsafe { Ok(Display::new(handle, _preference)?) } +} + +/// Finalize [`Window`] creation by applying the options from the [`Config`], be +/// aware that it could remove incompatible options from the window builder like +/// `transparency`, when the provided config doesn't support it. +/// +/// [`Window`]: winit::window::Window +/// [`Config`]: glutin::config::Config +#[cfg(not(wgl_backend))] +fn finalize_window_creation_attrs( + mut attributes: WindowCreationAttributes, + gl_config: &Config, +) -> WindowCreationAttributes +{ + // Disable transparency if the end config doesn't support it. + if gl_config.supports_transparency() == Some(false) { + attributes = attributes.with_transparent(false); + } + + #[cfg(x11_platform)] + let attributes = if let Some(x11_visual) = gl_config.x11_visual() { + attributes.with_x11_visual(x11_visual.visual_id() as _) + } else { + attributes + }; + + attributes +} + +/// Simplified version of the [`DisplayApiPreference`] which is used to simplify +/// cross platform window creation. +/// +/// To learn about platform differences the [`DisplayApiPreference`] variants. +/// +/// [`DisplayApiPreference`]: glutin::display::DisplayApiPreference +#[allow(dead_code)] +#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)] +pub enum ApiPreference +{ + /// Prefer `EGL` over system provider like `GLX` and `WGL`. + PreferEgl, + + /// Fallback to `EGL` when failed to create the system profile. + /// + /// This behavior is used by default. However consider using + /// [`Self::PreferEgl`] if you don't care about missing EGL features. + #[default] + FallbackEgl, +} |