WisDeviceMemoryProperties Struct Reference

Detailed Description

Structure describing memory properties of the device. Pass it to wisDeviceQueryProperties either directly or chained to another query structure for it to be filled.

Specification

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C version:

// Provided by Wisdom 0.7.0.
typedef struct  WisDeviceMemoryProperties {
    WisQueryPropertyType property_type;
    void*                next_in_chain;
    bool                 gpu_upload_supported;
    bool                 host_image_copy_supported;
} WisDeviceMemoryProperties;

C++ version:

namespace wis{
// Provided by Wisdom 0.7.0.
struct  DeviceMemoryProperties {
    wis::QueryPropertyType property_type;
    void*                  next_in_chain;
    bool                   gpu_upload_supported;
    bool                   host_image_copy_supported;
};
}

Members

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• property_type specifies the type of the queried property. must be WisQueryPropertyTypeDeviceMemoryProperties..
• next_in_chain indicates pointer to the next queried data struct.
• gpu_upload_supported describes if GPU upload memory type is supported. This memory type allows mapping the memory and writing to it from CPU, while being accessible from GPU. It is usually implemented as write-combined memory on integrated GPUs and as a part of shared system memory on discrete GPUs.
• host_image_copy_supported indicates if host image copy is supported. This feature allows copying data directly from CPU memory to optimal tiled image layout on GPU, without the need for an intermediate staging buffer. It is supported on Windows 10 22H2 and later with WDDM 3.0 or later. On Vulkan it requires VK_EXT_host_image_copy extension.

Description

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gpu_upload_supported means that the device has a memory type that is both HOST_VISIBLE and DEVICE_LOCAL. That allows writes to memory directly using CPU mapping. host_image_copy_supported means that the device supports copying data directly from CPU memory to optimal tiled image layout on GPU, without the need for an intermediate staging buffer. This can improve performance and reduce memory usage when uploading textures from CPU to GPU.

DirectX 12 supports both of these feature simultaneusly. That means that on DirectX 12, if gpu_upload_supported is true, then host_image_copy_supported will also be true. On Vulkan, these features are independent and may be supported separately. On Vulkan, host_image_copy_supported requires the VK_EXT_host_image_copy extension, while gpu_upload_supported depends on the presence of a memory type that is both HOST_VISIBLE and DEVICE_LOCAL.

If gpu_upload_supported is true, WisMemoryTypeGPUUpload memory type can be used for resource allocation. This memory type allows mapping the memory and writing to it from CPU, while being accessible from GPU.

If host_image_copy_supported is true, wisTextureWriteSubresource function can be used to write texture data directly from CPU memory to optimal tiled image layout on GPU.

See Also

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