1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131

//! Types to describe the properties of memory allocated for gfx resources.

use crate::{buffer, image, queue, Backend};
use std::{mem, ops::Range};

/// A trait for plain-old-data types.
///
/// A POD type does not have invalid bit patterns and can be safely
/// created from arbitrary bit pattern.
/// The `Pod` trait is implemented for standard integer and floating point numbers as well as
/// common arrays of them (for example `[f32; 2]`).
pub unsafe trait Pod: Copy {}

macro_rules! impl_pod {
    ( ty = $($ty:ty)* ) => { $( unsafe impl Pod for $ty {} )* };
    ( ar = $($tt:expr)* ) => { $( unsafe impl<T: Pod> Pod for [T; $tt] {} )* };
}

impl_pod! { ty = isize usize i8 u8 i16 u16 i32 u32 i64 u64 f32 f64 }
impl_pod! { ar =
    0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32
}

unsafe impl<T: Pod, U: Pod> Pod for (T, U) {}

/// Cast a slice from one POD type to another.
pub fn cast_slice<A: Pod, B: Pod>(slice: &[A]) -> &[B] {
    use std::slice;

    let raw_len = mem::size_of::<A>().wrapping_mul(slice.len());
    let len = raw_len / mem::size_of::<B>();
    assert_eq!(raw_len, mem::size_of::<B>().wrapping_mul(len));
    unsafe { slice::from_raw_parts(slice.as_ptr() as *const B, len) }
}

bitflags!(
    /// Memory property flags.
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    pub struct Properties: u16 {
        /// Device local memory on the GPU.
        const DEVICE_LOCAL   = 0x1;

        /// Host visible memory can be accessed by the CPU.
        ///
        /// Backends must provide at least one cpu visible memory.
        const CPU_VISIBLE   = 0x2;

        /// CPU-GPU coherent.
        ///
        /// Non-coherent memory requires explicit flushing.
        const COHERENT     = 0x4;

        /// Cached memory by the CPU
        const CPU_CACHED = 0x8;

        /// Memory that may be lazily allocated as needed on the GPU
        /// and *must not* be visible to the CPU.
        const LAZILY_ALLOCATED = 0x10;
    }
);

bitflags!(
    /// Barrier dependency flags.
    #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
    pub struct Dependencies: u32 {
        /// Specifies the memory dependency to be framebuffer-local.
        const BY_REGION    = 0x1;
        //const VIEW_LOCAL   = 0x2;
        //const DEVICE_GROUP = 0x4;
    }
);

// DOC TODO: Could be better, but I don't know how to do this without
// trying to explain the whole synchronization model.
/// A [memory barrier](https://www.khronos.org/registry/vulkan/specs/1.0/html/vkspec.html#synchronization-memory-barriers)
/// type for either buffers or images.
#[allow(missing_docs)]
#[derive(Clone, Debug)]
pub enum Barrier<'a, B: Backend> {
    /// Applies the given access flags to all buffers in the range.
    AllBuffers(Range<buffer::Access>),
    /// Applies the given access flags to all images in the range.
    AllImages(Range<image::Access>),
    /// A memory barrier that defines access to a buffer.
    Buffer {
        /// The access flags controlling the buffer.
        states: Range<buffer::State>,
        /// The buffer the barrier controls.
        target: &'a B::Buffer,
        /// The source and destination Queue family IDs, for a [queue family ownership transfer](https://www.khronos.org/registry/vulkan/specs/1.0/html/vkspec.html#synchronization-queue-transfers)
        /// Can be `None` to indicate no ownership transfer.
        families: Option<Range<queue::QueueFamilyId>>,
        /// Range of the buffer the barrier applies to.
        range: Range<Option<u64>>,
    },
    /// A memory barrier that defines access to (a subset of) an image.
    Image {
        /// The access flags controlling the image.
        states: Range<image::State>,
        /// The image the barrier controls.
        target: &'a B::Image,
        /// The source and destination Queue family IDs, for a [queue family ownership transfer](https://www.khronos.org/registry/vulkan/specs/1.0/html/vkspec.html#synchronization-queue-transfers)
        /// Can be `None` to indicate no ownership transfer.
        families: Option<Range<queue::QueueFamilyId>>,
        /// A `SubresourceRange` that defines which section of an image the barrier applies to.
        range: image::SubresourceRange,
    },
}

impl<'a, B: Backend> Barrier<'a, B> {
    /// Create a barrier for the whole buffer between the given states.
    pub fn whole_buffer(target: &'a B::Buffer, states: Range<buffer::State>) -> Self {
        Barrier::Buffer {
            states,
            target,
            families: None,
            range: None .. None,
        }
    }
}

/// Memory requirements for a certain resource (buffer/image).
#[derive(Clone, Copy, Debug)]
pub struct Requirements {
    /// Size in the memory.
    pub size: u64,
    /// Memory alignment.
    pub alignment: u64,
    /// Supported memory types.
    pub type_mask: u64,
}