VkImageCompressionFixedRateFlagBitsEXT

Bits which can be set in VkImageCompressionControlEXT::pFixedRateFlags, specifying allowed compression rates for an image plane, are:

typedef enum VkImageCompressionFixedRateFlagBitsEXT {
    VK_IMAGE_COMPRESSION_FIXED_RATE_NONE_EXT = 0,
    VK_IMAGE_COMPRESSION_FIXED_RATE_1BPC_BIT_EXT = 0x00000001,
    VK_IMAGE_COMPRESSION_FIXED_RATE_2BPC_BIT_EXT = 0x00000002,
    VK_IMAGE_COMPRESSION_FIXED_RATE_3BPC_BIT_EXT = 0x00000004,
    VK_IMAGE_COMPRESSION_FIXED_RATE_4BPC_BIT_EXT = 0x00000008,
    VK_IMAGE_COMPRESSION_FIXED_RATE_5BPC_BIT_EXT = 0x00000010,
    VK_IMAGE_COMPRESSION_FIXED_RATE_6BPC_BIT_EXT = 0x00000020,
    VK_IMAGE_COMPRESSION_FIXED_RATE_7BPC_BIT_EXT = 0x00000040,
    VK_IMAGE_COMPRESSION_FIXED_RATE_8BPC_BIT_EXT = 0x00000080,
    VK_IMAGE_COMPRESSION_FIXED_RATE_9BPC_BIT_EXT = 0x00000100,
    VK_IMAGE_COMPRESSION_FIXED_RATE_10BPC_BIT_EXT = 0x00000200,
    VK_IMAGE_COMPRESSION_FIXED_RATE_11BPC_BIT_EXT = 0x00000400,
    VK_IMAGE_COMPRESSION_FIXED_RATE_12BPC_BIT_EXT = 0x00000800,
    VK_IMAGE_COMPRESSION_FIXED_RATE_13BPC_BIT_EXT = 0x00001000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_14BPC_BIT_EXT = 0x00002000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_15BPC_BIT_EXT = 0x00004000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_16BPC_BIT_EXT = 0x00008000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_17BPC_BIT_EXT = 0x00010000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_18BPC_BIT_EXT = 0x00020000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_19BPC_BIT_EXT = 0x00040000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_20BPC_BIT_EXT = 0x00080000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_21BPC_BIT_EXT = 0x00100000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_22BPC_BIT_EXT = 0x00200000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_23BPC_BIT_EXT = 0x00400000,
    VK_IMAGE_COMPRESSION_FIXED_RATE_24BPC_BIT_EXT = 0x00800000,
} VkImageCompressionFixedRateFlagBitsEXT;

• VK_IMAGE_COMPRESSION_FIXED_RATE_NONE_EXT specifies that fixed-rate compression must not be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_1BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [1,2) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_2BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [2,3) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_3BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [3,4) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_4BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [4,5) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_5BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [5,6) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_6BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [6,7) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_7BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [7,8) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_8BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [8,9) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_9BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [9,10) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_10BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [10,11) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_11BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of [11,12) bits per component may be used.
• VK_IMAGE_COMPRESSION_FIXED_RATE_12BPC_BIT_EXT specifies that fixed-rate compression with a bitrate of at least 12 bits per component may be used.

If the format has a different bit rate for different components, VkImageCompressionControlEXT::pFixedRateFlags describes the rate of the component with the largest number of bits assigned to it, scaled pro rata. For example, to request that a VK_FORMAT_A2R10G10B10_UNORM_PACK32 format be stored at a rate of 8 bits per pixel, use VK_IMAGE_COMPRESSION_FIXED_RATE_2BPC_BIT_EXT (10 bits for the largest component, stored at quarter the original size, 2.5 bits, rounded down).

If flags includes VK_IMAGE_COMPRESSION_FIXED_RATE_EXPLICIT_EXT, and multiple bits are set in VkImageCompressionControlEXT::pFixedRateFlags for a plane, implementations should apply the lowest allowed bitrate that is supported.