vkGetImageMemoryRequirementsVkDevice

vkGetImageMemoryRequirements is a Vulkan function that returns the memory requirements for a specific VkImage object. It is used to determine how much memory to allocate for the image, what alignment is required, and which memory types are compatible, before binding memory to the image.

Prototype: void vkGetImageMemoryRequirements(VkDevice device, VkImage image, VkMemoryRequirements* pMemoryRequirements);

Parameters: device is the logical device, image is the image whose requirements are being queried, and pMemoryRequirements is an output structure that receives the results.

VkMemoryRequirements contains three fields: size, alignment, and memoryTypeBits. size is the total number of bytes required for the image’s memory block. alignment specifies the byte alignment required for the image’s memory. memoryTypeBits is a bitmask where each set bit i indicates that memory type i on the physical device is compatible with the image. Determining a suitable memory type typically involves querying the physical device’s memory properties and selecting a type that satisfies both the bitmask and desired property flags (for example VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT).

Usage notes: After creating an image, call vkGetImageMemoryRequirements to obtain the memory requirements. Allocate memory with vkAllocateMemory using a type that satisfies the requirements, then bind the memory to the image with vkBindImageMemory. The reported size and alignment must be respected, and the chosen memory type must be compatible with the memoryTypeBits.

Variants: For extended scenarios, vkGetImageMemoryRequirements2 (and variant VK_KHR_get_image_memory_requirements2) provides a more flexible querying mechanism using VkImageMemoryRequirementsInfo2 and VkMemoryRequirements2, while preserving the same underlying concepts.

See also: Vulkan memory management, vkAllocateMemory, vkBindImageMemory, VkMemoryRequirements.