Remove the generic "graphics" module.

- Cursor is not necessary anymore as rendering hardware vs software
  cursors just depends on "where" you render the cursor.
- Format is replaced by drm-fourcc and more related to buffers and
  therefor the allocator module anyway.
- GL/Glium are replaced by the renderer module.
- Software was unused and very small anyway and can be implemented
  with the new renderer api.
- SwapBuffersError is (for now) just moved into the top-level backend module.

src/backend/graphics/cursor.rs

@@ -1,40 +0,0 @@
-/// Functions to render cursors on graphics backend independently from it's rendering techique.
-///
-/// In the most cases this will be the fastest available implementation utilizing hardware composing
-/// where possible. This may however be quite restrictive in terms of supported formats.
-///
-/// For those reasons you may always choose to render your cursor(s) (partially) in software instead.
-pub trait CursorBackend {
-    /// Format representing the image drawn for the cursor.
-    type CursorFormat: ?Sized;
-
-    /// Error the underlying backend throws if operations fail
-    type Error: 'static;
-
-    /// Sets the cursor position and therefore updates the drawn cursors position.
-    /// Useful as well for e.g. pointer wrapping.
-    ///
-    /// Not guaranteed to be supported on every backend. The result usually
-    /// depends on the backend, the cursor might be "owned" by another more privileged
-    /// compositor (running nested).
-    ///
-    /// In these cases setting the position is actually not required, as movement is done
-    /// by the higher compositor and not by the backend. It is still good practice to update
-    /// the position after every recieved event, but don't rely on pointer wrapping working.
-    ///
-    fn set_cursor_position(&self, x: u32, y: u32) -> Result<(), Self::Error>;
-
-    /// Set the cursor drawn on the [`CursorBackend`].
-    ///
-    /// The format is entirely dictated by the concrete implementation and might range
-    /// from raw image buffers over a fixed list of possible cursor types to simply the
-    /// void type () to represent no possible customization of the cursor itself.
-    fn set_cursor_representation(
-        &self,
-        cursor: &Self::CursorFormat,
-        hotspot: (u32, u32),
-    ) -> Result<(), Self::Error>;
-
-    /// Clear the current cursor image drawn on the [`CursorBackend`].
-    fn clear_cursor_representation(&self) -> Result<(), Self::Error>;
-}

src/backend/graphics/format.rs

@@ -1,20 +0,0 @@
-/// Describes the pixel format of a framebuffer
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub struct PixelFormat {
-    /// is the format hardware accelerated
-    pub hardware_accelerated: bool,
-    /// number of bits used for colors
-    pub color_bits: u8,
-    /// number of bits used for alpha channel
-    pub alpha_bits: u8,
-    /// number of bits used for depth channel
-    pub depth_bits: u8,
-    /// number of bits used for stencil buffer
-    pub stencil_bits: u8,
-    /// is stereoscopy enabled
-    pub stereoscopy: bool,
-    /// number of samples used for multisampling if enabled
-    pub multisampling: Option<u16>,
-    /// is srgb enabled
-    pub srgb: bool,
-}

src/backend/graphics/mod.rs

@@ -1,48 +0,0 @@
-//! Common traits for various ways to renderer on a given graphics backend.
-//!
-//! Note: Not every API may be supported by every backend
-
-mod cursor;
-pub use self::cursor::*;
-
-mod format;
-pub use self::format::*;
-
-#[cfg(feature = "renderer_gl")]
-pub mod gl;
-#[cfg(feature = "renderer_glium")]
-pub mod glium;
-#[cfg(feature = "renderer_software")]
-pub mod software;
-
-/// Error that can happen when swapping buffers.
-#[derive(Debug, thiserror::Error)]
-pub enum SwapBuffersError {
-    /// The buffers have already been swapped.
-    ///
-    /// This error can be returned when `swap_buffers` has been called multiple times
-    /// without any modification in between.
-    #[error("Buffers are already swapped, swap_buffers was called too many times")]
-    AlreadySwapped,
-    /// The corresponding context has been lost and needs to be recreated.
-    ///
-    /// All the objects associated to it (textures, buffers, programs, etc.)
-    /// need to be recreated from scratch. Underlying resources like native surfaces
-    /// might also need to be recreated.
-    ///
-    /// Operations will have no effect. Functions that read textures, buffers, etc.
-    /// will return uninitialized data instead.
-    #[error("The context has been lost, it needs to be recreated: {0}")]
-    ContextLost(Box<dyn std::error::Error>),
-    /// A temporary condition caused to rendering to fail.
-    ///
-    /// Depending on the underlying error this *might* require fixing internal state of the rendering backend,
-    /// but failures mapped to `TemporaryFailure` are always recoverable without re-creating the entire stack,
-    /// as is represented by `ContextLost`.
-    ///
-    /// Proceed after investigating the source to reschedule another full rendering step or just this page_flip at a later time.
-    /// If the root cause cannot be discovered and subsequent renderings also fail, it is advised to fallback to
-    /// recreation.
-    #[error("A temporary condition caused the page flip to fail: {0}")]
-    TemporaryFailure(Box<dyn std::error::Error>),
-}

src/backend/mod.rs

@@ -14,8 +14,13 @@
 //! - winit
 //! - libinput
 
-pub mod graphics;
+// TODO TEMPORARY
+#![allow(missing_docs)]
+
+//pub mod graphics;
 pub mod input;
+pub mod allocator;
+pub mod renderer;
 
 #[cfg(feature = "backend_drm")]
 pub mod drm;
@@ -27,5 +32,38 @@ pub mod libinput;
 pub mod session;
 #[cfg(feature = "backend_udev")]
 pub mod udev;
+
 #[cfg(feature = "backend_winit")]
 pub mod winit;
+
+/// Error that can happen when swapping buffers.
+#[derive(Debug, thiserror::Error)]
+pub enum SwapBuffersError {
+    /// The buffers have already been swapped.
+    ///
+    /// This error can be returned when `swap_buffers` has been called multiple times
+    /// without any modification in between.
+    #[error("Buffers are already swapped, swap_buffers was called too many times")]
+    AlreadySwapped,
+    /// The corresponding context has been lost and needs to be recreated.
+    ///
+    /// All the objects associated to it (textures, buffers, programs, etc.)
+    /// need to be recreated from scratch. Underlying resources like native surfaces
+    /// might also need to be recreated.
+    ///
+    /// Operations will have no effect. Functions that read textures, buffers, etc.
+    /// will return uninitialized data instead.
+    #[error("The context has been lost, it needs to be recreated: {0}")]
+    ContextLost(Box<dyn std::error::Error>),
+    /// A temporary condition caused to rendering to fail.
+    ///
+    /// Depending on the underlying error this *might* require fixing internal state of the rendering backend,
+    /// but failures mapped to `TemporaryFailure` are always recoverable without re-creating the entire stack,
+    /// as is represented by `ContextLost`.
+    ///
+    /// Proceed after investigating the source to reschedule another full rendering step or just this page_flip at a later time.
+    /// If the root cause cannot be discovered and subsequent renderings also fail, it is advised to fallback to
+    /// recreation.
+    #[error("A temporary condition caused the page flip to fail: {0}")]
+    TemporaryFailure(Box<dyn std::error::Error>),
+}