Module dxt

Expand description

Decoding of DXT (S3TC) compression

DXT is an image format that supports lossy compression

Note: this module only implements bare DXT encoding/decoding, it does not parse formats that can contain DXT files like .dds

Structs§

DxtVariant 🔒: What version of DXT compression are we using? Note that DXT2 and DXT4 are left away as they’re just DXT3 and DXT5 with premultiplied alpha

alpha_table_dxt5 🔒: Constructs the DXT5 alpha lookup table from the two alpha entries if alpha0 > alpha1, constructs a table of [a0, a1, 6 linearly interpolated values from a0 to a1] if alpha0 <= alpha1, constructs a table of [a0, a1, 4 linearly interpolated values from a0 to a1, 0, 0xFF]
decode_dxt1_block 🔒: Decodes a 8-byte bock of dxt5 data to a 16xRGB block
decode_dxt1_row 🔒: Decode a row of DXT1 data to four rows of RGB data. source.len() should be a multiple of 8, otherwise this panics.
decode_dxt3_block 🔒: Decodes a 16-byte bock of dxt3 data to a 16xRGBA block
decode_dxt3_row 🔒: Decode a row of DXT3 data to four rows of RGBA data. source.len() should be a multiple of 16, otherwise this panics.
decode_dxt5_block 🔒: Decodes a 16-byte bock of dxt5 data to a 16xRGBA block
decode_dxt5_row 🔒: Decode a row of DXT5 data to four rows of RGBA data. source.len() should be a multiple of 16, otherwise this panics.
decode_dxt_colors 🔒: decodes an 8-byte dxt color block into the RGB channels of a 16xRGB or 16xRGBA block. source should have a length of 8, dest a length of 48 (RGB) or 64 (RGBA)
enc565_decode 🔒: decodes a 5-bit R, 6-bit G, 5-bit B 16-bit packed color value into 8-bit RGB mapping is done so min/max range values are preserved. So for 5-bit values 0x00 -> 0x00 and 0x1F -> 0xFF