1 files changed, 192 insertions, 0 deletions
diff --git a/third_party/rust/gfx-hal/src/buffer.rs b/third_party/rust/gfx-hal/src/buffer.rs
new file mode 100644
index 0000000000..a772ae2a9d
--- /dev/null
+++ b/third_party/rust/gfx-hal/src/buffer.rs
@@ -0,0 +1,192 @@
+//! Memory buffers.
+//!
+//! Buffers interpret memory slices as linear contiguous data array.
+//!
+//! They can be used as shader resources, vertex buffers, index buffers or for
+//! specifying the action commands for indirect execution.
+
+use crate::{device::OutOfMemory, format::Format};
+
+/// An offset inside a buffer, in bytes.
+pub type Offset = u64;
+
+/// A subrange of the buffer.
+#[derive(Clone, Debug, Default, Hash, PartialEq, Eq)]
+#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+pub struct SubRange {
+    /// Offset to the subrange.
+    pub offset: Offset,
+    /// Size of the subrange, or None for the remaining size of the buffer.
+    pub size: Option<Offset>,
+}
+
+impl SubRange {
+    /// Whole buffer subrange.
+    pub const WHOLE: Self = SubRange {
+        offset: 0,
+        size: None,
+    };
+
+    /// Return the stored size, if present, or computed size based on the limit.
+    pub fn size_to(&self, limit: Offset) -> Offset {
+        self.size.unwrap_or(limit - self.offset)
+    }
+}
+
+/// Buffer state.
+pub type State = Access;
+
+/// Error creating a buffer.
+#[derive(Clone, Debug, PartialEq)]
+pub enum CreationError {
+    /// Out of either host or device memory.
+    OutOfMemory(OutOfMemory),
+
+    /// Requested buffer usage is not supported.
+    ///
+    /// Older GL version don't support constant buffers or multiple usage flags.
+    UnsupportedUsage {
+        /// Unsupported usage passed on buffer creation.
+        usage: Usage,
+    },
+}
+
+impl From<OutOfMemory> for CreationError {
+    fn from(error: OutOfMemory) -> Self {
+        CreationError::OutOfMemory(error)
+    }
+}
+
+impl std::fmt::Display for CreationError {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            CreationError::OutOfMemory(err) => write!(fmt, "Failed to create buffer: {}", err),
+            CreationError::UnsupportedUsage { usage } => write!(
+                fmt,
+                "Failed to create buffer: Unsupported usage: {:?}",
+                usage
+            ),
+        }
+    }
+}
+
+impl std::error::Error for CreationError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            CreationError::OutOfMemory(err) => Some(err),
+            _ => None,
+        }
+    }
+}
+
+/// Error creating a buffer view.
+#[derive(Clone, Debug, PartialEq)]
+pub enum ViewCreationError {
+    /// Out of either host or device memory.
+    OutOfMemory(OutOfMemory),
+
+    /// Buffer view format is not supported.
+    UnsupportedFormat(Option<Format>),
+}
+
+impl From<OutOfMemory> for ViewCreationError {
+    fn from(error: OutOfMemory) -> Self {
+        ViewCreationError::OutOfMemory(error)
+    }
+}
+
+impl std::fmt::Display for ViewCreationError {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ViewCreationError::OutOfMemory(err) => {
+                write!(fmt, "Failed to create buffer view: {}", err)
+            }
+            ViewCreationError::UnsupportedFormat(Some(format)) => write!(
+                fmt,
+                "Failed to create buffer view: Unsupported format {:?}",
+                format
+            ),
+            ViewCreationError::UnsupportedFormat(None) => {
+                write!(fmt, "Failed to create buffer view: Unspecified format")
+            }
+        }
+    }
+}
+
+impl std::error::Error for ViewCreationError {
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
+        match self {
+            ViewCreationError::OutOfMemory(err) => Some(err),
+            _ => None,
+        }
+    }
+}
+
+bitflags!(
+    /// Buffer usage flags.
+    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+    pub struct Usage: u32 {
+        ///
+        const TRANSFER_SRC  = 0x1;
+        ///
+        const TRANSFER_DST = 0x2;
+        ///
+        const UNIFORM_TEXEL = 0x4;
+        ///
+        const STORAGE_TEXEL = 0x8;
+        ///
+        const UNIFORM = 0x10;
+        ///
+        const STORAGE = 0x20;
+        ///
+        const INDEX = 0x40;
+        ///
+        const VERTEX = 0x80;
+        ///
+        const INDIRECT = 0x100;
+    }
+);
+
+impl Usage {
+    /// Returns if the buffer can be used in transfer operations.
+    pub fn can_transfer(&self) -> bool {
+        self.intersects(Usage::TRANSFER_SRC | Usage::TRANSFER_DST)
+    }
+}
+
+bitflags!(
+    /// Buffer access flags.
+    ///
+    /// Access of buffers by the pipeline or shaders.
+    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+    pub struct Access: u32 {
+        /// Read commands instruction for indirect execution.
+        const INDIRECT_COMMAND_READ = 0x1;
+        /// Read index values for indexed draw commands.
+        ///
+        /// See [`draw_indexed`](../command/trait.RawCommandBuffer.html#tymethod.draw_indexed)
+        /// and [`draw_indexed_indirect`](../command/trait.RawCommandBuffer.html#tymethod.draw_indexed_indirect).
+        const INDEX_BUFFER_READ = 0x2;
+        /// Read vertices from vertex buffer for draw commands in the [`VERTEX_INPUT`](
+        /// ../pso/struct.PipelineStage.html#associatedconstant.VERTEX_INPUT) stage.
+        const VERTEX_BUFFER_READ = 0x4;
+        ///
+        const UNIFORM_READ = 0x8;
+        ///
+        const SHADER_READ = 0x20;
+        ///
+        const SHADER_WRITE = 0x40;
+        ///
+        const TRANSFER_READ = 0x800;
+        ///
+        const TRANSFER_WRITE = 0x1000;
+        ///
+        const HOST_READ = 0x2000;
+        ///
+        const HOST_WRITE = 0x4000;
+        ///
+        const MEMORY_READ = 0x8000;
+        ///
+        const MEMORY_WRITE = 0x10000;
+    }
+);