anvil: refacto buffer loading logic

Decouple it from the shell implementation and introduce specialised
shaders for various SHM buffer types.

anvil/src/glium_drawer.rs

@@ -1,20 +1,25 @@
 use glium;
-use glium::{Frame, GlObject, Surface};
 use glium::index::PrimitiveType;
 use glium::texture::{MipmapsOption, Texture2d, UncompressedFloatFormat};
+use glium::{Frame, GlObject, Surface};
 use smithay::backend::graphics::egl::EGLGraphicsBackend;
 use smithay::backend::graphics::egl::error::Result as EGLResult;
-use smithay::backend::graphics::egl::wayland::{EGLDisplay, EGLImages, EGLWaylandExtensions, Format};
+use smithay::backend::graphics::egl::wayland::{BufferAccessError, EGLDisplay, EGLImages,
+                                               EGLWaylandExtensions, Format};
 use smithay::backend::graphics::glium::GliumGraphicsBackend;
-use smithay::wayland::compositor::{SubsurfaceRole, TraversalAction};
 use smithay::wayland::compositor::roles::Role;
-use smithay::wayland_server::Display;
+use smithay::wayland::compositor::{SubsurfaceRole, TraversalAction};
+use smithay::wayland::shm::with_buffer_contents as shm_buffer_contents;
+use smithay::wayland_server::protocol::wl_buffer;
+use smithay::wayland_server::{Display, Resource};
 
-use std::cell::Ref;
+use std::cell::{Ref, RefCell};
+use std::rc::Rc;
 
 use slog::Logger;
 
-use shell::{Buffer, MyCompositorToken, MyWindowMap};
+use shaders;
+use shell::{MyCompositorToken, MyWindowMap};
 
 #[derive(Copy, Clone)]
 struct Vertex {
@@ -28,7 +33,9 @@ pub struct GliumDrawer<F: EGLGraphicsBackend + 'static> {
     display: GliumGraphicsBackend<F>,
     vertex_buffer: glium::VertexBuffer<Vertex>,
     index_buffer: glium::IndexBuffer<u16>,
-    program: glium::Program,
+    programs: [glium::Program; shaders::FRAGMENT_COUNT],
+    egl_display: Rc<RefCell<Option<EGLDisplay>>>,
+    log: Logger,
 }
 
 impl<F: EGLGraphicsBackend + 'static> GliumDrawer<F> {
@@ -37,8 +44,8 @@ impl<F: EGLGraphicsBackend + 'static> GliumDrawer<F> {
     }
 }
 
-impl<T: Into<GliumGraphicsBackend<T>> + EGLGraphicsBackend + 'static> From<T> for GliumDrawer<T> {
+impl<T: Into<GliumGraphicsBackend<T>> + EGLGraphicsBackend + 'static> GliumDrawer<T> {
-    fn from(backend: T) -> GliumDrawer<T> {
+    pub fn init(backend: T, egl_display: Rc<RefCell<Option<EGLDisplay>>>, log: Logger) -> GliumDrawer<T> {
         let display = backend.into();
 
         // building the vertex buffer, which contains all the vertices that we will draw
@@ -68,82 +75,93 @@ impl<T: Into<GliumGraphicsBackend<T>> + EGLGraphicsBackend + 'static> From<T> fo
         let index_buffer =
             glium::IndexBuffer::new(&display, PrimitiveType::TriangleStrip, &[1 as u16, 2, 0, 3]).unwrap();
 
-        // compiling shaders and linking them together
+        let programs = opengl_programs!(&display);
-        let program = program!(&display,
-            100 => {
-                vertex: "
-                    #version 100
-                    uniform lowp mat4 matrix;
-                    attribute lowp vec2 position;
-                    attribute lowp vec2 tex_coords;
-                    varying lowp vec2 v_tex_coords;
-                    void main() {
-                        gl_Position = matrix * vec4(position, 0.0, 1.0);
-                        v_tex_coords = tex_coords;
-                    }
-                ",
-
-                fragment: "
-                    #version 100
-                    uniform lowp sampler2D tex;
-                    varying lowp vec2 v_tex_coords;
-                    void main() {
-                        lowp vec4 color = texture2D(tex, v_tex_coords);
-                        gl_FragColor.r = color.x;
-                        gl_FragColor.g = color.y;
-                        gl_FragColor.b = color.z;
-                        gl_FragColor.a = color.w;
-                    }
-                ",
-            },
-        ).unwrap();
 
         GliumDrawer {
             display,
             vertex_buffer,
             index_buffer,
-            program,
+            programs,
+            egl_display,
+            log,
         }
     }
 }
 
 impl<F: EGLGraphicsBackend + 'static> GliumDrawer<F> {
-    pub fn texture_from_mem(&self, contents: &[u8], surface_dimensions: (u32, u32)) -> Texture2d {
+    pub fn texture_from_buffer(&self, buffer: Resource<wl_buffer::WlBuffer>) -> Result<TextureMetadata, ()> {
-        let image = glium::texture::RawImage2d {
+        // try to retrieve the egl contents of this buffer
-            data: contents.into(),
+        let images = if let Some(display) = &self.egl_display.borrow().as_ref() {
-            width: surface_dimensions.0,
+            display.egl_buffer_contents(buffer)
-            height: surface_dimensions.1,
+        } else {
-            format: glium::texture::ClientFormat::U8U8U8U8,
+            Err(BufferAccessError::NotManaged(buffer))
         };
-        Texture2d::new(&self.display, image).unwrap()
+        match images {
-    }
+            Ok(images) => {
-
+                // we have an EGL buffer
-    pub fn texture_from_egl(&self, images: &EGLImages) -> Option<Texture2d> {
+                let format = match images.format {
-        let format = match images.format {
+                    Format::RGB => UncompressedFloatFormat::U8U8U8,
-            Format::RGB => UncompressedFloatFormat::U8U8U8,
+                    Format::RGBA => UncompressedFloatFormat::U8U8U8U8,
-            Format::RGBA => UncompressedFloatFormat::U8U8U8U8,
+                    _ => {
-            _ => return None,
+                        warn!(self.log, "Unsupported EGL buffer format"; "format" => format!("{:?}", images.format));
-        };
+                        return Err(());
-
+                    }
-        let opengl_texture = Texture2d::empty_with_format(
+                };
-            &self.display,
+                let opengl_texture = Texture2d::empty_with_format(
-            format,
+                    &self.display,
-            MipmapsOption::NoMipmap,
+                    format,
-            images.width,
+                    MipmapsOption::NoMipmap,
-            images.height,
+                    images.width,
-        ).unwrap();
+                    images.height,
-        unsafe {
+                ).unwrap();
-            images
+                unsafe {
-                .bind_to_texture(0, opengl_texture.get_id())
+                    images
-                .expect("Failed to bind to texture");
+                        .bind_to_texture(0, opengl_texture.get_id())
+                        .expect("Failed to bind to texture");
+                }
+                Ok(TextureMetadata {
+                    texture: opengl_texture,
+                    fragment: ::shaders::BUFFER_RGBA,
+                    y_inverted: images.y_inverted,
+                    dimensions: (images.width, images.height),
+                    images: Some(images), // I guess we need to keep this alive ?
+                })
+            }
+            Err(BufferAccessError::NotManaged(buffer)) => {
+                // this is not an EGL buffer, try SHM
+                match shm_buffer_contents(&buffer, |slice, data| {
+                    ::shm_load::load_shm_buffer(data, slice)
+                        .map(|(image, kind)| (Texture2d::new(&self.display, image).unwrap(), kind, data))
+                }) {
+                    Ok(Ok((texture, kind, data))) => Ok(TextureMetadata {
+                        texture,
+                        fragment: kind,
+                        y_inverted: false,
+                        dimensions: (data.width as u32, data.height as u32),
+                        images: None,
+                    }),
+                    Ok(Err(format)) => {
+                        warn!(self.log, "Unsupported SHM buffer format"; "format" => format!("{:?}", format));
+                        Err(())
+                    }
+                    Err(err) => {
+                        warn!(self.log, "Unable to load buffer contents"; "err" => format!("{:?}", err));
+                        Err(())
+                    }
+                }
+            }
+            Err(err) => {
+                error!(self.log, "EGL error"; "err" => format!("{:?}", err));
+                Err(())
+            }
         }
-        Some(opengl_texture)
     }
 
     pub fn render_texture(
         &self,
         target: &mut glium::Frame,
         texture: &Texture2d,
+        texture_kind: usize,
         y_inverted: bool,
         surface_dimensions: (u32, u32),
         surface_location: (i32, i32),
@@ -175,7 +193,7 @@ impl<F: EGLGraphicsBackend + 'static> GliumDrawer<F> {
             .draw(
                 &self.vertex_buffer,
                 &self.index_buffer,
-                &self.program,
+                &self.programs[texture_kind],
                 &uniforms,
                 &glium::DrawParameters {
                     blend: blending,
@@ -197,6 +215,14 @@ impl<G: EGLWaylandExtensions + EGLGraphicsBackend + 'static> EGLWaylandExtension
     }
 }
 
+pub struct TextureMetadata {
+    pub texture: Texture2d,
+    pub fragment: usize,
+    pub y_inverted: bool,
+    pub dimensions: (u32, u32),
+    images: Option<EGLImages>,
+}
+
 impl<F: EGLGraphicsBackend + 'static> GliumDrawer<F> {
     pub fn draw_windows(&self, window_map: &MyWindowMap, compositor_token: MyCompositorToken, log: &Logger) {
         let mut frame = self.draw();
@@ -214,48 +240,26 @@ impl<F: EGLGraphicsBackend + 'static> GliumDrawer<F> {
                             |_surface, attributes, role, &(mut x, mut y)| {
                                 // there is actually something to draw !
                                 if attributes.user_data.texture.is_none() {
-                                    let mut remove = false;
+                                    if let Some(buffer) = attributes.user_data.buffer.take() {
-                                    match attributes.user_data.buffer {
+                                        if let Ok(m) = self.texture_from_buffer(buffer.clone()) {
-                                        Some(Buffer::Egl { ref images }) => {
+                                            attributes.user_data.texture = Some(m);
-                                            match images.format {
-                                                Format::RGB | Format::RGBA => {
-                                                    attributes.user_data.texture =
-                                                        self.texture_from_egl(&images);
-                                                }
-                                                _ => {
-                                                    // we don't handle the more complex formats here.
-                                                    attributes.user_data.texture = None;
-                                                    remove = true;
-                                                }
-                                            };
                                         }
-                                        Some(Buffer::Shm { ref data, ref size }) => {
+                                        // notify the client that we have finished reading the
-                                            attributes.user_data.texture =
+                                        // buffer
-                                                Some(self.texture_from_mem(data, *size));
+                                        buffer.send(wl_buffer::Event::Release);
-                                        }
-                                        _ => {}
-                                    }
-                                    if remove {
-                                        attributes.user_data.buffer = None;
                                     }
                                 }
-
+                                if let Some(ref metadata) = attributes.user_data.texture {
-                                if let Some(ref texture) = attributes.user_data.texture {
                                     if let Ok(subdata) = Role::<SubsurfaceRole>::data(role) {
                                         x += subdata.location.0;
                                         y += subdata.location.1;
                                     }
                                     self.render_texture(
                                         &mut frame,
-                                        texture,
+                                        &metadata.texture,
-                                        match *attributes.user_data.buffer.as_ref().unwrap() {
+                                        metadata.fragment,
-                                            Buffer::Egl { ref images } => images.y_inverted,
+                                        metadata.y_inverted,
-                                            Buffer::Shm { .. } => false,
+                                        metadata.dimensions,
-                                        },
-                                        match *attributes.user_data.buffer.as_ref().unwrap() {
-                                            Buffer::Egl { ref images } => (images.width, images.height),
-                                            Buffer::Shm { ref size, .. } => *size,
-                                        },
                                         (x, y),
                                         screen_dimensions,
                                         ::glium::Blend {

anvil/src/main.rs

@@ -12,6 +12,8 @@ extern crate xkbcommon;
 use slog::Drain;
 use smithay::wayland_server::Display;
 
+#[macro_use]
+mod shaders;
 mod glium_drawer;
 mod input_handler;
 #[cfg(feature = "tty_launch")]

anvil/src/raw_drm.rs

@@ -75,11 +75,18 @@ pub fn run_raw_drm(mut display: Display, mut event_loop: EventLoop, log: Logger)
     let mode = connector_info.modes()[0]; // Use first mode (usually highest resoltion, but in reality you should filter and sort and check and match with other connectors, if you use more then one.)
 
     // Initialize the hardware backend
-    let renderer = GliumDrawer::from(
+    let backend = device
-        device
+        .create_backend(crtc, mode, vec![connector_info.handle()])
-            .create_backend(crtc, mode, vec![connector_info.handle()])
+        .unwrap();
-            .unwrap(),
+    let egl_display = Rc::new(RefCell::new(
-    );
+        if let Ok(egl_display) = backend.bind_wl_display(&display) {
+            info!(log, "EGL hardware-acceleration enabled");
+            Some(egl_display)
+        } else {
+            None
+        },
+    ));
+    let renderer = GliumDrawer::init(backend, egl_display, log.clone());
     {
         /*
          * Initialize glium
@@ -89,23 +96,13 @@ pub fn run_raw_drm(mut display: Display, mut event_loop: EventLoop, log: Logger)
         frame.finish().unwrap();
     }
 
-    let egl_display = Rc::new(RefCell::new(
-        if let Ok(egl_display) = renderer.bind_wl_display(&display) {
-            info!(log, "EGL hardware-acceleration enabled");
-            Some(egl_display)
-        } else {
-            None
-        },
-    ));
-
     /*
      * Initialize the globals
      */
 
     init_shm_global(&mut display, event_loop.token(), vec![], log.clone());
 
-    let (compositor_token, _, _, window_map) =
+    let (compositor_token, _, _, window_map) = init_shell(&mut display, event_loop.token(), log.clone());
-        init_shell(&mut display, event_loop.token(), log.clone(), egl_display);
 
     /*
      * Add a listening socket:

anvil/src/shaders.rs

@@ -0,0 +1,120 @@
+/*
+ * This file is the single point of definition of the opengl shaders
+ * and their indexes.
+ *
+ * The opengl_programs!() macro must call make_program!() in the correct
+ * order matching the indices stored in the BUFFER_* constants, if it
+ * does not, things will be drawn on screen with wrong colors.
+ */
+
+// create a set of shaders for various loading types
+macro_rules! make_program(
+    ($display: expr, $fragment_shader:expr) => {
+        program!($display,
+            100 => {
+                vertex: ::shaders::VERTEX_SHADER,
+                fragment: $fragment_shader,
+            },
+        ).unwrap()
+    }
+);
+
+#[macro_escape]
+macro_rules! opengl_programs(
+    ($display: expr) => {
+        [
+            make_program!($display, ::shaders::FRAGMENT_SHADER_RGBA),
+            make_program!($display, ::shaders::FRAGMENT_SHADER_ABGR),
+            make_program!($display, ::shaders::FRAGMENT_SHADER_XBGR),
+            make_program!($display, ::shaders::FRAGMENT_SHADER_BGRA),
+            make_program!($display, ::shaders::FRAGMENT_SHADER_BGRX),
+        ]
+    }
+);
+
+/*
+ * OpenGL Shaders
+ */
+
+pub const VERTEX_SHADER: &'static str = r#"
+#version 100
+uniform lowp mat4 matrix;
+attribute lowp vec2 position;
+attribute lowp vec2 tex_coords;
+varying lowp vec2 v_tex_coords;
+void main() {
+    gl_Position = matrix * vec4(position, 0.0, 1.0);
+    v_tex_coords = tex_coords;
+}"#;
+
+pub const FRAGMENT_COUNT: usize = 5;
+
+pub const BUFFER_RGBA: usize = 0;
+pub const FRAGMENT_SHADER_RGBA: &'static str = r#"
+#version 100
+uniform lowp sampler2D tex;
+varying lowp vec2 v_tex_coords;
+void main() {
+    lowp vec4 color = texture2D(tex, v_tex_coords);
+    gl_FragColor.r = color.x;
+    gl_FragColor.g = color.y;
+    gl_FragColor.b = color.z;
+    gl_FragColor.a = color.w;
+}
+"#;
+
+pub const BUFFER_ABGR: usize = 1;
+pub const FRAGMENT_SHADER_ABGR: &'static str = r#"
+#version 100
+uniform lowp sampler2D tex;
+varying lowp vec2 v_tex_coords;
+void main() {
+    lowp vec4 color = texture2D(tex, v_tex_coords);
+    gl_FragColor.r = color.w;
+    gl_FragColor.g = color.z;
+    gl_FragColor.b = color.y;
+    gl_FragColor.a = color.x;
+}
+"#;
+
+pub const BUFFER_XBGR: usize = 2;
+pub const FRAGMENT_SHADER_XBGR: &'static str = r#"
+#version 100
+uniform lowp sampler2D tex;
+varying lowp vec2 v_tex_coords;
+void main() {
+    lowp vec4 color = texture2D(tex, v_tex_coords);
+    gl_FragColor.r = color.w;
+    gl_FragColor.g = color.z;
+    gl_FragColor.b = color.y;
+    gl_FragColor.a = 1.0;
+}
+"#;
+
+pub const BUFFER_BGRA: usize = 3;
+pub const FRAGMENT_SHADER_BGRA: &'static str = r#"
+#version 100
+uniform lowp sampler2D tex;
+varying lowp vec2 v_tex_coords;
+void main() {
+    lowp vec4 color = texture2D(tex, v_tex_coords);
+    gl_FragColor.r = color.z;
+    gl_FragColor.g = color.y;
+    gl_FragColor.b = color.x;
+    gl_FragColor.a = color.w;
+}
+"#;
+
+pub const BUFFER_BGRX: usize = 4;
+pub const FRAGMENT_SHADER_BGRX: &'static str = r#"
+#version 100
+uniform lowp sampler2D tex;
+varying lowp vec2 v_tex_coords;
+void main() {
+    lowp vec4 color = texture2D(tex, v_tex_coords);
+    gl_FragColor.r = color.z;
+    gl_FragColor.g = color.y;
+    gl_FragColor.b = color.x;
+    gl_FragColor.a = 1.0;
+}
+"#;

anvil/src/shell.rs

@@ -2,20 +2,15 @@ use std::cell::RefCell;
 use std::rc::Rc;
 use std::sync::{Arc, Mutex};
 
-use glium::texture::Texture2d;
-
 use rand;
 
-use smithay::backend::graphics::egl::wayland::{BufferAccessError, Format};
-use smithay::backend::graphics::egl::wayland::{EGLDisplay, EGLImages};
 use smithay::wayland::compositor::{compositor_init, CompositorToken, SurfaceAttributes, SurfaceEvent};
-use smithay::wayland::shell::xdg::{xdg_shell_init, PopupConfigure, ShellState as XdgShellState,
-                                   ToplevelConfigure, XdgRequest, XdgSurfaceRole};
 use smithay::wayland::shell::legacy::{wl_shell_init, ShellRequest, ShellState as WlShellState,
                                       ShellSurfaceKind, ShellSurfaceRole};
-use smithay::wayland::shm::with_buffer_contents as shm_buffer_contents;
+use smithay::wayland::shell::xdg::{xdg_shell_init, PopupConfigure, ShellState as XdgShellState,
-use smithay::wayland_server::{Display, LoopToken, Resource};
+                                   ToplevelConfigure, XdgRequest, XdgSurfaceRole};
 use smithay::wayland_server::protocol::{wl_buffer, wl_callback, wl_shell_surface, wl_surface};
+use smithay::wayland_server::{Display, LoopToken, Resource};
 
 use window_map::{Kind as SurfaceKind, WindowMap};
 
@@ -30,7 +25,6 @@ pub fn init_shell(
     display: &mut Display,
     looptoken: LoopToken,
     log: ::slog::Logger,
-    egl_display: Rc<RefCell<Option<EGLDisplay>>>,
 ) -> (
     CompositorToken<SurfaceData, Roles>,
     Arc<Mutex<XdgShellState<SurfaceData, Roles, ()>>>,
@@ -38,13 +32,11 @@ pub fn init_shell(
     Rc<RefCell<MyWindowMap>>,
 ) {
     // Create the compositor
-    let c_egl_display = egl_display.clone();
-    let log2 = log.clone();
     let (compositor_token, _, _) = compositor_init(
         display,
         looptoken.clone(),
         move |request, (surface, ctoken)| match request {
-            SurfaceEvent::Commit => surface_commit(&surface, ctoken, &*c_egl_display, &log2),
+            SurfaceEvent::Commit => surface_commit(&surface, ctoken),
             SurfaceEvent::Frame { callback } => callback
                 .implement(|e, _| match e {}, None::<fn(_, _)>)
                 .send(wl_callback::Event::Done { callback_data: 0 }),
@@ -118,64 +110,24 @@ pub fn init_shell(
         log.clone(),
     );
 
-    (
+    (compositor_token, xdg_shell_state, wl_shell_state, window_map)
-        compositor_token,
-        xdg_shell_state,
-        wl_shell_state,
-        window_map,
-    )
 }
 
 #[derive(Default)]
 pub struct SurfaceData {
-    pub buffer: Option<Buffer>,
+    pub buffer: Option<Resource<wl_buffer::WlBuffer>>,
-    pub texture: Option<Texture2d>,
+    pub texture: Option<::glium_drawer::TextureMetadata>,
 }
 
-pub enum Buffer {
+fn surface_commit(surface: &Resource<wl_surface::WlSurface>, token: CompositorToken<SurfaceData, Roles>) {
-    Egl { images: EGLImages },
-    Shm { data: Vec<u8>, size: (u32, u32) },
-}
-
-fn surface_commit(
-    surface: &Resource<wl_surface::WlSurface>,
-    token: CompositorToken<SurfaceData, Roles>,
-    display: &RefCell<Option<EGLDisplay>>,
-    log: &::slog::Logger,
-) {
     // we retrieve the contents of the associated buffer and copy it
     token.with_surface_data(surface, |attributes| {
         match attributes.buffer.take() {
             Some(Some((buffer, (_x, _y)))) => {
-                // we ignore hotspot coordinates in this simple example
+                // new contents
-                match if let Some(display) = display.borrow().as_ref() {
+                // TODO: handle hotspot coordinates
-                    display.egl_buffer_contents(buffer)
+                attributes.user_data.buffer = Some(buffer);
-                } else {
+                attributes.user_data.texture = None;
-                    Err(BufferAccessError::NotManaged(buffer))
-                } {
-                    Ok(images) => {
-                        match images.format {
-                            Format::RGB => {}
-                            Format::RGBA => {}
-                            _ => {
-                                // we don't handle the more complex formats here.
-                                attributes.user_data.buffer = None;
-                                attributes.user_data.texture = None;
-                                return;
-                            }
-                        };
-                        attributes.user_data.texture = None;
-                        attributes.user_data.buffer = Some(Buffer::Egl { images });
-                    }
-                    Err(BufferAccessError::NotManaged(buffer)) => {
-                        shm_buffer_contents(&buffer, |slice, data| {
-                            attributes.user_data.texture = None;
-                            attributes.user_data.buffer = Some(::shm_load::load_shm_buffer(data, slice, log));
-                        }).expect("Got EGL buffer with no set EGLDisplay. You need to unbind your EGLContexts before dropping them!");
-                        buffer.send(wl_buffer::Event::Release);
-                    }
-                    Err(err) => panic!("EGL error: {}", err),
-                }
             }
             Some(None) => {
                 // erase the contents
@@ -190,11 +142,8 @@ fn surface_commit(
 fn get_size(attrs: &SurfaceAttributes<SurfaceData>) -> Option<(i32, i32)> {
     attrs
         .user_data
-        .buffer
+        .texture
         .as_ref()
-        .map(|ref buffer| match **buffer {
+        .map(|ref meta| meta.dimensions)
-            Buffer::Shm { ref size, .. } => *size,
-            Buffer::Egl { ref images } => (images.width, images.height),
-        })
         .map(|(x, y)| (x as i32, y as i32))
 }

anvil/src/shm_load.rs

@@ -1,58 +1,52 @@
-use shell::Buffer;
+use std::borrow::Cow;
+
 use smithay::wayland::shm::BufferData;
 use smithay::wayland_server::protocol::wl_shm::Format;
 
-pub fn load_shm_buffer(data: BufferData, pool: &[u8], log: &::slog::Logger) -> Buffer {
+use glium::texture::{ClientFormat, RawImage2d};
-    // ensure consistency, the SHM handler of smithay should ensure this
-    debug_assert!(((data.offset + data.stride * data.height) as usize) <= pool.len());
-
-    let mut out = Vec::with_capacity((data.width * data.height * 4) as usize);
 
+pub fn load_shm_buffer<'a>(data: BufferData, pool: &'a [u8]) -> Result<(RawImage2d<'a, u8>, usize), Format> {
     let offset = data.offset as usize;
     let width = data.width as usize;
     let height = data.height as usize;
     let stride = data.stride as usize;
 
-    match data.format {
+    // number of bytes per pixel
-        Format::Argb8888 => {
+    // TODO: compute from data.format
-            // TODO: this is so slooooow
+    let pixelsize = 4;
-            for j in 0..height {
-                for i in 0..width {
-                    // value must be read as native endianness
-                    let val: u32 =
-                        unsafe { *(&pool[offset + j * stride + i * 4] as *const u8 as *const u32) };
-                    out.push(((val & 0x00FF0000) >> 16) as u8); //r
-                    out.push(((val & 0x0000FF00) >> 8) as u8); //g
-                    out.push(((val & 0x000000FF) >> 0) as u8); //b
-                    out.push(((val & 0xFF000000) >> 24) as u8); //a
-                }
-            }
-        }
-        Format::Xrgb8888 => {
-            // TODO: this is so slooooow
-            for j in 0..height {
-                for i in 0..width {
-                    // value must be read as native endianness
-                    let val: u32 =
-                        unsafe { *(&pool[offset + j * stride + i * 4] as *const u8 as *const u32) };
-                    out.push(((val & 0x00FF0000) >> 16) as u8); //r
-                    out.push(((val & 0x0000FF00) >> 8) as u8); //g
-                    out.push(((val & 0x000000FF) >> 0) as u8); //b
-                    out.push(255); // a
-                }
-            }
-        }
-        _ => {
-            error!(log, "Unsupported buffer format"; "format" => format!("{:?}", data.format));
-            // fill in with black
-            for _ in 0..(data.height * data.width) {
-                out.extend(&[0, 0, 0, 255])
-            }
-        }
-    }
 
-    Buffer::Shm {
+    // ensure consistency, the SHM handler of smithay should ensure this
-        data: out,
+    assert!(offset + (height - 1) * stride + width * pixelsize <= pool.len());
-        size: (data.width as u32, data.height as u32),
+
-    }
+    let slice: Cow<[u8]> = if stride == width * pixelsize {
+        // the buffer is cleanly continuous, use as-is
+        Cow::Borrowed(&pool[offset..(offset + height * width * pixelsize)])
+    } else {
+        // the buffer is discontinuous or lines overlap
+        // we need to make a copy as unfortunately glium does not
+        // expose the OpenGL APIs we would need to load this buffer :/
+        let mut data = Vec::with_capacity(height * width * pixelsize);
+        for i in 0..height {
+            data.extend(&pool[(offset + i * stride)..(offset + i * stride + width * pixelsize)]);
+        }
+        Cow::Owned(data)
+    };
+
+    // sharders format need to be reversed to account for endianness
+    let (client_format, fragment) = match data.format {
+        Format::Argb8888 => (ClientFormat::U8U8U8U8, ::shaders::BUFFER_BGRA),
+        Format::Xrgb8888 => (ClientFormat::U8U8U8U8, ::shaders::BUFFER_BGRX),
+        Format::Rgba8888 => (ClientFormat::U8U8U8U8, ::shaders::BUFFER_ABGR),
+        Format::Rgbx8888 => (ClientFormat::U8U8U8U8, ::shaders::BUFFER_XBGR),
+        _ => return Err(data.format),
+    };
+    Ok((
+        RawImage2d {
+            data: slice,
+            width: width as u32,
+            height: height as u32,
+            format: client_format,
+        },
+        fragment,
+    ))
 }

anvil/src/udev.rs

@@ -62,7 +62,6 @@ pub fn run_udev(mut display: Display, mut event_loop: EventLoop, log: Logger) ->
         &mut display.borrow_mut(),
         event_loop.token(),
         log.clone(),
-        active_egl_context.clone(),
     );
 
     /*
@@ -215,6 +214,7 @@ impl UdevHandlerImpl {
     pub fn scan_connectors(
         &self,
         device: &mut DrmDevice<SessionFdDrmDevice>,
+        egl_display: Rc<RefCell<Option<EGLDisplay>>>,
     ) -> HashMap<crtc::Handle, GliumDrawer<DrmBackend<SessionFdDrmDevice>>> {
         // Get a set of all modesetting resource handles (excluding planes):
         let res_handles = device.resource_handles().unwrap();
@@ -242,10 +242,12 @@ impl UdevHandlerImpl {
                     if !backends.contains_key(&crtc) {
                         let mode = connector_info.modes()[0]; // Use first mode (usually highest resoltion, but in reality you should filter and sort and check and match with other connectors, if you use more then one.)
                                                               // create a backend
-                        let renderer = GliumDrawer::from(
+                        let renderer = GliumDrawer::init(
                             device
                                 .create_backend(crtc, mode, vec![connector_info.handle()])
                                 .unwrap(),
+                            egl_display.clone(),
+                            self.logger.clone(),
                         );
 
                         // create cursor
@@ -279,7 +281,10 @@ impl UdevHandler<DrmHandlerImpl> for UdevHandlerImpl {
             *self.active_egl_context.borrow_mut() = device.bind_wl_display(&*self.display.borrow()).ok();
         }
 
-        let backends = Rc::new(RefCell::new(self.scan_connectors(device)));
+        let backends = Rc::new(RefCell::new(self.scan_connectors(
+            device,
+            self.active_egl_context.clone(),
+        )));
         self.backends.insert(device.device_id(), backends.clone());
 
         Some(DrmHandlerImpl {
@@ -294,7 +299,7 @@ impl UdevHandler<DrmHandlerImpl> for UdevHandlerImpl {
     fn device_changed(&mut self, device: &mut DrmDevice<SessionFdDrmDevice>) {
         //quick and dirt, just re-init all backends
         let backends = self.backends.get(&device.device_id()).unwrap();
-        *backends.borrow_mut() = self.scan_connectors(device);
+        *backends.borrow_mut() = self.scan_connectors(device, self.active_egl_context.clone());
     }
 
     fn device_removed(&mut self, device: &mut DrmDevice<SessionFdDrmDevice>) {

anvil/src/winit.rs

@@ -32,7 +32,7 @@ pub fn run_winit(display: &mut Display, event_loop: &mut EventLoop, log: Logger)
     ));
 
     let (w, h) = renderer.get_framebuffer_dimensions();
-    let drawer = GliumDrawer::from(renderer);
+    let drawer = GliumDrawer::init(renderer, egl_display, log.clone());
 
     let name = display.add_socket_auto().unwrap().into_string().unwrap();
     info!(log, "Listening on wayland socket"; "name" => name.clone());
@@ -46,8 +46,7 @@ pub fn run_winit(display: &mut Display, event_loop: &mut EventLoop, log: Logger)
 
     init_shm_global(display, event_loop.token(), vec![], log.clone());
 
-    let (compositor_token, _, _, window_map) =
+    let (compositor_token, _, _, window_map) = init_shell(display, event_loop.token(), log.clone());
-        init_shell(display, event_loop.token(), log.clone(), egl_display);
 
     let (mut seat, _) = Seat::new(display, event_loop.token(), "winit".into(), log.clone());