Skip to content

Implement support for ASTC compressed KTX textures #37

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
Erik-White wants to merge 10 commits into
base: main
Choose a base branch
from
Open

Implement support for ASTC compressed KTX textures #37

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
10 commits
Select commit Hold shift + click to select a range
6577b4c
Add ASTC decoding support
Erik-White Feb 27, 2026
6e58d6f
Integrate AstcSharp ASTC decoder
Erik-White Feb 27, 2026
0aba876
Use existing test utils for Astc tests
Erik-White Feb 27, 2026
44599c8
Add HDR support
Erik-White Feb 27, 2026
724bd61
Fix overflow issue
Erik-White Feb 27, 2026
abd3b4c
Move KTX1 test images to subdirectories
Erik-White Feb 27, 2026
86ff81a
Remove unused AstcSharp reference
Erik-White Mar 6, 2026
94d0f72
Small fixes and variable naming
Erik-White Mar 6, 2026
e7ce5fa
Astc files are little endian
Erik-White Mar 6, 2026
1d3acec
Update shared infra
Erik-White Mar 6, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
The table of contents is too big for display.
Diff view
Diff view
  •  
  •  
  •  
1 change: 1 addition & 0 deletions .gitattributes
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -126,6 +126,7 @@
*.dds filter=lfs diff=lfs merge=lfs -text
*.ktx filter=lfs diff=lfs merge=lfs -text
*.ktx2 filter=lfs diff=lfs merge=lfs -text
*.astc filter=lfs diff=lfs merge=lfs -text
Copy link
Contributor Author

@Erik-White Erik-White Feb 27, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This keeps getting overwritten by a target that copies gitattributes from the shared project, so I will need to update it there as well

Copy link
Member

@JimBobSquarePants JimBobSquarePants Mar 6, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Here's the repo that manages that. It's loaded as a sub repository

https://github.com/SixLabors/SharedInfrastructure

Copy link
Contributor Author

@Erik-White Erik-White Mar 6, 2026

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I opened a PR there to upstream the change SixLabors/SharedInfrastructure#56

*.pam filter=lfs diff=lfs merge=lfs -text
*.pbm filter=lfs diff=lfs merge=lfs -text
*.pgm filter=lfs diff=lfs merge=lfs -text
Expand Down
60 changes: 53 additions & 7 deletions ImageSharp.Textures.sln
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -49,35 +49,72 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "workflows", "workflows", "{
.github\workflows\build-and-test.yml = .github\workflows\build-and-test.yml
EndProjectSection
EndProject
Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ImageSharp.Textures.Astc.Reference.Tests", "tests\ImageSharp.Textures.Astc.Reference.Tests\ImageSharp.Textures.Astc.Reference.Tests.csproj", "{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}"
EndProject
Global
GlobalSection(SharedMSBuildProjectFiles) = preSolution
shared-infrastructure\src\SharedInfrastructure\SharedInfrastructure.projitems*{1588f6c4-2186-4a35-9693-e9f296791393}*SharedItemsImports = 5
tests\Images\Images.projitems*{17fcbd4d-d232-45e8-876f-dfbc2fad52cf}*SharedItemsImports = 5
tests\Images\Images.projitems*{18be79b6-6b95-4ed7-a963-ad75f6cb9f3c}*SharedItemsImports = 5
tests\Images\Images.projitems*{68a8cc40-6aed-4e96-b524-31b1158fdeea}*SharedItemsImports = 13
tests\Images\Images.projitems*{b159ffd1-e646-42d0-892c-4abf69103712}*SharedItemsImports = 5
EndGlobalSection
GlobalSection(SolutionConfigurationPlatforms) = preSolution
Debug|Any CPU = Debug|Any CPU
Debug|x64 = Debug|x64
Debug|x86 = Debug|x86
Release|Any CPU = Release|Any CPU
Release|x64 = Release|x64
Release|x86 = Release|x86
EndGlobalSection
GlobalSection(ProjectConfigurationPlatforms) = postSolution
{1588F6C4-2186-4A35-9693-E9F296791393}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Debug|Any CPU.Build.0 = Debug|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Debug|x64.ActiveCfg = Debug|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Debug|x64.Build.0 = Debug|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Debug|x86.ActiveCfg = Debug|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Debug|x86.Build.0 = Debug|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Release|Any CPU.ActiveCfg = Release|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Release|Any CPU.Build.0 = Release|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Release|x64.ActiveCfg = Release|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Release|x64.Build.0 = Release|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Release|x86.ActiveCfg = Release|Any CPU
{1588F6C4-2186-4A35-9693-E9F296791393}.Release|x86.Build.0 = Release|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Debug|Any CPU.Build.0 = Debug|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Debug|x64.ActiveCfg = Debug|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Debug|x64.Build.0 = Debug|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Debug|x86.ActiveCfg = Debug|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Debug|x86.Build.0 = Debug|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Release|Any CPU.ActiveCfg = Release|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Release|Any CPU.Build.0 = Release|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Release|x64.ActiveCfg = Release|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Release|x64.Build.0 = Release|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Release|x86.ActiveCfg = Release|Any CPU
{B159FFD1-E646-42D0-892C-4ABF69103712}.Release|x86.Build.0 = Release|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Debug|Any CPU.Build.0 = Debug|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Debug|x64.ActiveCfg = Debug|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Debug|x64.Build.0 = Debug|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Debug|x86.ActiveCfg = Debug|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Debug|x86.Build.0 = Debug|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Release|Any CPU.ActiveCfg = Release|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Release|Any CPU.Build.0 = Release|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Release|x64.ActiveCfg = Release|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Release|x64.Build.0 = Release|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Release|x86.ActiveCfg = Release|Any CPU
{18BE79B6-6B95-4ED7-A963-AD75F6CB9F3C}.Release|x86.Build.0 = Release|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Debug|Any CPU.Build.0 = Debug|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Debug|x64.ActiveCfg = Debug|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Debug|x64.Build.0 = Debug|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Debug|x86.ActiveCfg = Debug|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Debug|x86.Build.0 = Debug|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Release|Any CPU.ActiveCfg = Release|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Release|Any CPU.Build.0 = Release|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Release|x64.ActiveCfg = Release|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Release|x64.Build.0 = Release|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Release|x86.ActiveCfg = Release|Any CPU
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF}.Release|x86.Build.0 = Release|Any CPU
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}.Debug|x64.ActiveCfg = Debug|Any CPU
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}.Debug|x86.ActiveCfg = Debug|Any CPU
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}.Release|Any CPU.ActiveCfg = Release|Any CPU
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}.Release|x64.ActiveCfg = Release|Any CPU
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720}.Release|x86.ActiveCfg = Release|Any CPU
EndGlobalSection
GlobalSection(SolutionProperties) = preSolution
HideSolutionNode = FALSE
Expand All @@ -90,8 +127,17 @@ Global
{17FCBD4D-D232-45E8-876F-DFBC2FAD52CF} = {6DF92068-B792-4038-8E3F-5FDF2E026BE7}
{E6224AB7-6987-4BA1-B2A6-ECFB7DA281DE} = {9F1F0B0F-704F-4B71-89EF-EE36042A27C9}
{9F19EBB4-32DB-4AFE-A5E4-722EDFAAE04B} = {E6224AB7-6987-4BA1-B2A6-ECFB7DA281DE}
{E15C2E1A-FCD6-42B1-82D2-2C72CC4DC720} = {6DF92068-B792-4038-8E3F-5FDF2E026BE7}
EndGlobalSection
GlobalSection(ExtensibilityGlobals) = postSolution
SolutionGuid = {F1762A0D-74C4-454A-BCB7-C010BB067E58}
EndGlobalSection
GlobalSection(SharedMSBuildProjectFiles) = preSolution
shared-infrastructure\src\SharedInfrastructure\SharedInfrastructure.projitems*{1588f6c4-2186-4a35-9693-e9f296791393}*SharedItemsImports = 5
tests\Images\Images.projitems*{17fcbd4d-d232-45e8-876f-dfbc2fad52cf}*SharedItemsImports = 5
tests\Images\Images.projitems*{18be79b6-6b95-4ed7-a963-ad75f6cb9f3c}*SharedItemsImports = 5
tests\Images\Images.projitems*{68a8cc40-6aed-4e96-b524-31b1158fdeea}*SharedItemsImports = 13
tests\Images\Images.projitems*{b159ffd1-e646-42d0-892c-4abf69103712}*SharedItemsImports = 5
tests\Images\Images.projitems*{e15c2e1a-fcd6-42b1-82d2-2c72cc4dc720}*SharedItemsImports = 5
EndGlobalSection
EndGlobal
3 changes: 2 additions & 1 deletion README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@ SixLabors.ImageSharp.Textures

[![Build Status](https://img.shields.io/github/actions/workflow/status/SixLabors/ImageSharp.Textures/build-and-test.yml?branch=main)](https://github.com/SixLabors/ImageSharp.Textures/actions)
[![Code coverage](https://codecov.io/gh/SixLabors/ImageSharp.Textures/branch/main/graph/badge.svg)](https://codecov.io/gh/SixLabors/ImageSharp)
[![License: Apache 2.0](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
[![License: Six Labors Split](https://img.shields.io/badge/license-Six%20Labors%20Split-%23e30183)](https://github.com/SixLabors/ImageSharp/blob/main/LICENSE)
[![Twitter](https://img.shields.io/twitter/url/http/shields.io.svg?style=flat&logo=twitter)](https://twitter.com/intent/tweet?hashtags=imagesharp,dotnet,oss&text=ImageSharp.+A+new+cross-platform+2D+graphics+API+in+C%23&url=https%3a%2f%2fgithub.com%2fSixLabors%2fImageSharp&via=sixlabors)

</div>
Expand All @@ -33,6 +33,7 @@ with the following compressions:
- BC5
- BC6H
- BC7
- ASTC

Encoding textures is **not** yet supported. PR are of course very welcome.

Expand Down
2 changes: 1 addition & 1 deletion shared-infrastructure
Open in desktop
Submodule shared-infrastructure updated 2 files
+1 −0 .gitattributes
+1 −1 branding
5 changes: 3 additions & 2 deletions src/Directory.Build.props
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,7 @@
-->

<!-- Import the shared src .props file -->
<Import Project="$(MSBuildThisFileDirectory)..\shared-infrastructure\msbuild\props\SixLabors.Src.props" />
<Import Project="$(MSBuildThisFileDirectory)../shared-infrastructure/msbuild/props/SixLabors.Src.props" />

<!-- Import the solution .props file. -->
<Import Project="$(MSBuildThisFileDirectory)..\Directory.Build.props" />
Expand All @@ -22,9 +22,10 @@
</PropertyGroup>

<ItemGroup>
<InternalsVisibleTo Include="SixLabors.ImageSharp.Textures.Benchmarks" Key="$(SixLaborsPublicKey)" />
<InternalsVisibleTo Include="ImageSharp.Textures.Benchmarks" Key="$(SixLaborsPublicKey)" />
<InternalsVisibleTo Include="SixLabors.ImageSharp.Textures.InteractiveTest" Key="$(SixLaborsPublicKey)" />
<InternalsVisibleTo Include="SixLabors.ImageSharp.Textures.Tests" Key="$(SixLaborsPublicKey)" />
<InternalsVisibleTo Include="SixLabors.ImageSharp.Textures.Astc.Reference.Tests" Key="$(SixLaborsPublicKey)" />
</ItemGroup>

</Project>
69 changes: 43 additions & 26 deletions src/ImageSharp.Textures/Common/Helpers/FloatHelper.cs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using System;
using System.Runtime.CompilerServices;

namespace SixLabors.ImageSharp.Textures.Common.Helpers
Expand All @@ -14,32 +15,31 @@ internal static class FloatHelper
public static uint PackFloatToFloat32(float value) => Unsafe.As<float, uint>(ref value);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float UnpackFloat16ToFloat(uint value)
{
uint result =
((value >> 15) << 31) |
((((value >> 10) & 0x1f) - 15 + 127) << 23) |
((value & 0x3ff) << 13);
return Unsafe.As<uint, float>(ref result);
}
public static float UnpackFloat16ToFloat(uint value) => (float)BitConverter.UInt16BitsToHalf((ushort)value);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint PackFloatToFloat16(float value)
{
uint temp = Unsafe.As<float, uint>(ref value);
return
((temp >> 31) << 15) |
((((temp >> 23) & 0xff) - 127 + 15) << 10) |
((temp & 0x7fffff) >> 13);
}
public static uint PackFloatToFloat16(float value) => BitConverter.HalfToUInt16Bits((Half)value);

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float UnpackFloat10ToFloat(uint value)
public static float UnpackFloat10ToFloat(uint value, uint bias = 10)
{
uint result =
((((value >> 5) & 0x1f) - 10 + 127) << 23) |
((value & 0x1f) << 18);
return Unsafe.As<uint, float>(ref result);
uint e = (value >> 5) & 0x1Fu;
uint m = value & 0x1Fu;

return e switch
{
// Zero
0 when m == 0 => 0f,

// Denormalized
0 => m * BitConverter.UInt32BitsToSingle((128u - bias - 5u) << 23),

// Inf/NaN
31 => BitConverter.UInt32BitsToSingle((0xFFu << 23) | (m << 18)),

// Normalized
_ => BitConverter.UInt32BitsToSingle(((e + 127u - bias) << 23) | (m << 18)),
};
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
Expand All @@ -52,12 +52,29 @@ public static uint PackFloatToFloat10(float value)
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float UnpackFloat11ToFloat(uint value)
public static float UnpackFloat11ToFloat(uint value, uint bias = 11)
{
uint result =
((((value >> 6) & 0x1f) - 11 + 127) << 23) |
((value & 0x3f) << 17);
return Unsafe.As<uint, float>(ref result);
uint e = (value >> 6) & 0x1Fu;
uint m = value & 0x3Fu;

if (e == 0)
{
if (m == 0)
{
return 0f;
}

// Denormalized: m * 2^(1 - bias - 6)
return m * BitConverter.UInt32BitsToSingle((128u - bias - 6u) << 23);
}

if (e == 31)
{
uint ieee = (0xFFu << 23) | (m << 17);
return BitConverter.UInt32BitsToSingle(ieee);
}

return BitConverter.UInt32BitsToSingle(((e + 127u - bias) << 23) | (m << 17));
}

[MethodImpl(MethodImplOptions.AggressiveInlining)]
Expand Down
Loading
Loading