gbm: allow to import dmabufs

src/backend/allocator/dmabuf.rs

@@ -15,10 +15,10 @@ pub(crate) struct DmabufInternal {
 }
 
 #[derive(Clone)]
-pub struct Dmabuf(Arc<DmabufInternal>);
+pub struct Dmabuf(pub(crate) Arc<DmabufInternal>);
 
 #[derive(Clone)]
-pub struct WeakDmabuf(Weak<DmabufInternal>);
+pub struct WeakDmabuf(pub(crate) Weak<DmabufInternal>);
 
 impl PartialEq for Dmabuf {
     fn eq(&self, other: &Self) -> bool {
@@ -60,9 +60,8 @@ impl Buffer for Dmabuf {
 }
 
 impl Dmabuf {
-    pub fn new(
-        src: impl Buffer + 'static,
-
+    pub(crate) fn new(
+        src: impl Buffer,
         planes: usize,
         offsets: &[u32],
         strides: &[u32],

src/backend/allocator/gbm.rs

@@ -80,4 +80,32 @@ impl<T> std::convert::TryFrom<GbmBuffer<T>> for Dmabuf {
 
         Ok(Dmabuf::new(buf, planes as usize, &offsets, &strides, &fds).unwrap())
     }
+}
+
+impl Dmabuf {
+    pub fn import<A: AsRawFd + 'static, T>(&self, gbm: &GbmDevice<A>, usage: BufferObjectFlags) -> std::io::Result<GbmBuffer<T>> {
+        let buf = &*self.0;
+        if self.has_modifier() || buf.num_planes > 1 || buf.offsets[0] != 0 {
+            gbm.import_buffer_object_from_dma_buf_with_modifiers(
+                buf.num_planes as u32,
+                buf.fds,
+                buf.width,
+                buf.height,
+                buf.format.code,
+                usage,
+                unsafe { std::mem::transmute::<[u32; 4], [i32; 4]>(buf.strides) },
+                unsafe { std::mem::transmute::<[u32; 4], [i32; 4]>(buf.offsets) },
+                buf.format.modifier,
+            )
+        } else {
+            gbm.import_buffer_object_from_dma_buf(
+                buf.fds[0],
+                buf.width,
+                buf.height,
+                buf.strides[0],
+                buf.format.code,
+                if buf.format.modifier == Modifier::Linear { usage | BufferObjectFlags::LINEAR } else { usage },
+            )
+        }
+    }
 }