//! This crate provides a fully written in Rust memory allocator for Vulkan and DirectX 12.
//!
//! # [Windows-rs] and [winapi]
//!
//! `gpu-allocator` recently migrated from [winapi] to [windows-rs] but still provides convenient helpers to convert to and from [winapi] types, enabled when compiling with the `public-winapi` crate feature.
//!
//! [Windows-rs]: https://github.com/microsoft/windows-rs
//! [winapi]: https://github.com/retep998/winapi-rs
//!
//! # Setting up the Vulkan memory allocator
//!
//! ```no_run
//! # #[cfg(feature = "vulkan")]
//! # fn main() {
//! use gpu_allocator::vulkan::*;
//! # use ash::vk;
//! # let device = todo!();
//! # let instance = todo!();
//! # let physical_device = todo!();
//!
//! let mut allocator = Allocator::new(&AllocatorCreateDesc {
//!     instance,
//!     device,
//!     physical_device,
//!     debug_settings: Default::default(),
//!     buffer_device_address: true,  // Ideally, check the BufferDeviceAddressFeatures struct.
//!     allocation_sizes: Default::default(),
//! });
//! # }
//! # #[cfg(not(feature = "vulkan"))]
//! # fn main() {}
//! ```
//!
//! # Simple Vulkan allocation example
//!
//! ```no_run
//! # #[cfg(feature = "vulkan")]
//! # fn main() {
//! use gpu_allocator::vulkan::*;
//! use gpu_allocator::MemoryLocation;
//! # use ash::vk;
//! # let device = todo!();
//! # let instance = todo!();
//! # let physical_device = todo!();
//! # let mut allocator = Allocator::new(&AllocatorCreateDesc {
//! #     instance,
//! #     device,
//! #     physical_device,
//! #     debug_settings: Default::default(),
//! #     buffer_device_address: true,  // Ideally, check the BufferDeviceAddressFeatures struct.
//! #     allocation_sizes: Default::default(),
//! # }).unwrap();
//!
//! // Setup vulkan info
//! let vk_info = vk::BufferCreateInfo::builder()
//!     .size(512)
//!     .usage(vk::BufferUsageFlags::STORAGE_BUFFER);
//!
//! let buffer = unsafe { device.create_buffer(&vk_info, None) }.unwrap();
//! let requirements = unsafe { device.get_buffer_memory_requirements(buffer) };
//!
//! let allocation = allocator
//!     .allocate(&AllocationCreateDesc {
//!         name: "Example allocation",
//!         requirements,
//!         location: MemoryLocation::CpuToGpu,
//!         linear: true, // Buffers are always linear
//!         allocation_scheme: AllocationScheme::GpuAllocatorManaged,
//!     }).unwrap();
//!
//! // Bind memory to the buffer
//! unsafe { device.bind_buffer_memory(buffer, allocation.memory(), allocation.offset()).unwrap() };
//!
//! // Cleanup
//! allocator.free(allocation).unwrap();
//! unsafe { device.destroy_buffer(buffer, None) };
//! # }
//! # #[cfg(not(feature = "vulkan"))]
//! # fn main() {}
//! ```
//!
//! # Setting up the D3D12 memory allocator
//!
//! ```no_run
//! # #[cfg(feature = "d3d12")]
//! # fn main() {
//! use gpu_allocator::d3d12::*;
//! # let device = todo!();
//!
//! let mut allocator = Allocator::new(&AllocatorCreateDesc {
//!     device: ID3D12DeviceVersion::Device(device),
//!     debug_settings: Default::default(),
//!     allocation_sizes: Default::default(),
//! });
//! # }
//! # #[cfg(not(feature = "d3d12"))]
//! # fn main() {}
//! ```
//!
//! # Simple d3d12 allocation example
//!
//! ```no_run
//! # #[cfg(feature = "d3d12")]
//! # fn main() -> windows::core::Result<()> {
//! use gpu_allocator::d3d12::*;
//! use gpu_allocator::MemoryLocation;
//! # use windows::Win32::Graphics::{Dxgi, Direct3D12};
//! # let device = todo!();
//!
//! # let mut allocator = Allocator::new(&AllocatorCreateDesc {
//! #     device: ID3D12DeviceVersion::Device(device),
//! #     debug_settings: Default::default(),
//! #     allocation_sizes: Default::default(),
//! # }).unwrap();
//!
//! let buffer_desc = Direct3D12::D3D12_RESOURCE_DESC {
//!     Dimension: Direct3D12::D3D12_RESOURCE_DIMENSION_BUFFER,
//!     Alignment: 0,
//!     Width: 512,
//!     Height: 1,
//!     DepthOrArraySize: 1,
//!     MipLevels: 1,
//!     Format: Dxgi::Common::DXGI_FORMAT_UNKNOWN,
//!     SampleDesc: Dxgi::Common::DXGI_SAMPLE_DESC {
//!         Count: 1,
//!         Quality: 0,
//!     },
//!     Layout: Direct3D12::D3D12_TEXTURE_LAYOUT_ROW_MAJOR,
//!     Flags: Direct3D12::D3D12_RESOURCE_FLAG_NONE,
//! };
//! let allocation_desc = AllocationCreateDesc::from_d3d12_resource_desc(
//!     &allocator.device(),
//!     &buffer_desc,
//!     "Example allocation",
//!     MemoryLocation::GpuOnly,
//! );
//! let allocation = allocator.allocate(&allocation_desc).unwrap();
//! let mut resource: Option<Direct3D12::ID3D12Resource> = None;
//! let hr = unsafe {
//!     device.CreatePlacedResource(
//!         allocation.heap(),
//!         allocation.offset(),
//!         &buffer_desc,
//!         Direct3D12::D3D12_RESOURCE_STATE_COMMON,
//!         None,
//!         &mut resource,
//!     )
//! }?;
//!
//! // Cleanup
//! drop(resource);
//! allocator.free(allocation).unwrap();
//! # Ok(())
//! # }
//! # #[cfg(not(feature = "d3d12"))]
//! # fn main() {}
//! ```

mod result;
pub use result::*;

pub(crate) mod allocator;

#[cfg(feature = "visualizer")]
pub mod visualizer;

#[cfg(feature = "vulkan")]
pub mod vulkan;

#[cfg(all(windows, feature = "d3d12"))]
pub mod d3d12;

#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
pub enum MemoryLocation {
    /// The allocated resource is stored at an unknown memory location; let the driver decide what's the best location
    Unknown,
    /// Store the allocation in GPU only accessible memory - typically this is the faster GPU resource and this should be
    /// where most of the allocations live.
    GpuOnly,
    /// Memory useful for uploading data to the GPU and potentially for constant buffers
    CpuToGpu,
    /// Memory useful for CPU readback of data
    GpuToCpu,
}

#[derive(Copy, Clone, Debug)]
pub struct AllocatorDebugSettings {
    /// Logs out debugging information about the various heaps the current device has on startup
    pub log_memory_information: bool,
    /// Logs out all memory leaks on shutdown with log level Warn
    pub log_leaks_on_shutdown: bool,
    /// Stores a copy of the full backtrace for every allocation made, this makes it easier to debug leaks
    /// or other memory allocations, but storing stack traces has a RAM overhead so should be disabled
    /// in shipping applications.
    pub store_stack_traces: bool,
    /// Log out every allocation as it's being made with log level Debug, rather spammy so off by default
    pub log_allocations: bool,
    /// Log out every free that is being called with log level Debug, rather spammy so off by default
    pub log_frees: bool,
    /// Log out stack traces when either `log_allocations` or `log_frees` is enabled.
    pub log_stack_traces: bool,
}

impl Default for AllocatorDebugSettings {
    fn default() -> Self {
        Self {
            log_memory_information: false,
            log_leaks_on_shutdown: true,
            store_stack_traces: false,
            log_allocations: false,
            log_frees: false,
            log_stack_traces: false,
        }
    }
}

/// The sizes of the memory blocks that the allocator will create.
///
/// Useful for tuning the allocator to your application's needs. For example most games will be fine with the default
/// values, but eg. an app might want to use smaller block sizes to reduce the amount of memory used.
///
/// Clamped between 4MB and 256MB, and rounds up to the nearest multiple of 4MB for alignment reasons.
#[derive(Clone, Copy, Debug)]
pub struct AllocationSizes {
    /// The size of the memory blocks that will be created for the GPU only memory type.
    ///
    /// Defaults to 256MB.
    device_memblock_size: u64,
    /// The size of the memory blocks that will be created for the CPU visible memory types.
    ///
    /// Defaults to 64MB.
    host_memblock_size: u64,
}

impl AllocationSizes {
    pub fn new(device_memblock_size: u64, host_memblock_size: u64) -> Self {
        const FOUR_MB: u64 = 4 * 1024 * 1024;
        const TWO_HUNDRED_AND_FIFTY_SIX_MB: u64 = 256 * 1024 * 1024;

        let mut device_memblock_size =
            device_memblock_size.clamp(FOUR_MB, TWO_HUNDRED_AND_FIFTY_SIX_MB);
        let mut host_memblock_size =
            host_memblock_size.clamp(FOUR_MB, TWO_HUNDRED_AND_FIFTY_SIX_MB);

        if device_memblock_size % FOUR_MB != 0 {
            let val = device_memblock_size / FOUR_MB + 1;
            device_memblock_size = val * FOUR_MB;
            log::warn!(
                "Device memory block size must be a multiple of 4MB, clamping to {}MB",
                device_memblock_size / 1024 / 1024
            )
        }

        if host_memblock_size % FOUR_MB != 0 {
            let val = host_memblock_size / FOUR_MB + 1;
            host_memblock_size = val * FOUR_MB;
            log::warn!(
                "Host memory block size must be a multiple of 4MB, clamping to {}MB",
                host_memblock_size / 1024 / 1024
            )
        }

        Self {
            device_memblock_size,
            host_memblock_size,
        }
    }
}

impl Default for AllocationSizes {
    fn default() -> Self {
        Self {
            device_memblock_size: 256 * 1024 * 1024,
            host_memblock_size: 64 * 1024 * 1024,
        }
    }
}