A pure Rust texture compression suite

This library started out as squish-rs, a pure rust port of Simon Brown's libsquish but was forked and renamed to avoid confusion as the API and format support is expanded beyond the original C++ library.

Crates in This Workspace

• lib: texpresso - The library itself
• cli: texpresso_cli - A command-line utility for compressing and decompressing textures, also serves as a usage example for the library. Note that the actual executable is also called 'texpresso'.

Roadmap

Library

S3 Texture Compression formats

• DXT1 aka BC1: 8bpc RGB with optional binary alpha
• DXT3 aka BC2: 8bpc RGB with paletted alpha
• DXT5 aka BC3: 8bpc RGB with interpolated alpha

3Dc variants / RGTC (Red-Green Texture Compression)

• ATI1 aka RGTC1 aka BC4: 8-bit grayscale
• ATI2 aka RGTC2 aka BC5: two 8-bit channels

Direct3D 11 additions / BPTC (Block-Partition Texture Compression?)

• BPTC_ALPHA aka BC6h: 16-bit HDR RGB
• BPTC aka BC7: 8-bit RGB with optional alpha

Ericsson Texture Compression (common in mobile chips)

• R11_EAC: 11-bit grayscale
• RG11_EAC: two 11-bit channels
• ETC2: 8bpc RGB
• ETC2_EAC: 8bpc RGB + 11-bit alpha
• PUNCHTHROUGH_ALPHA1_ETC2: 8bpc RGB with punchthrough alpha

Adaptable Scalable Texture Compression (common in modern mobile chips)

• the texture compression format to end all texture compression formats
• needs further investigating due to vast complexity and e.g. supporting non-square blocks
• ASTC_LDR
• ASTC_HDR

Compatibility / ease of use

• no_std
• support compiling for GPU targets via rust-gpu
• Support 1-4 input channels without requiring padding in the calling code

CLI

non-texture formats

• Read PNG
• Read JPG
• Write PNG

Containers for compressed textures

• Read DDS
• Write DDS
• Read KTX
• Write KTX
• Read KTX2
• Write KTX2

Target platforms

• Support encoding on GPU via Vulkan

Maintenance

• Migrate to clap 3