View source for High-Level Shader Language

{{short description|Shading language}}
{{Use American English|date=February 2023}}
{{Use mdy dates|date=February 2023}}
{{Infobox programming language
| name = Cg/HLSL
| logo =       <!-- (filename) -->
| logo caption = 
| screenshot = File:HLSL-Examples-1.PNG
| screenshot caption = A scene containing several different 2D HLSL shaders. [[Distortion]] of the statue is achieved purely physically, while the texture of the rectangular frame beside it is based on color intensity. The square in the background has been [[linear transformation|transformed]] and [[rotation|rotated]]. The partial [[Transparency (graphic)|transparency]] and [[reflection (computer graphics)|reflection]] of the water in the foreground are added by a shader applied finally to the entire scene.
| paradigm =   <!-- or: | paradigms = -->
| family = [[shading language]]
| designer =   <!-- or: | designers = -->
| developer = nVIDIA, Microsoft
| dialects = Cg, HLSL, Playstation Shading Language, ReShadeFX, Slang
| influenced by = [[C (programming language)|C]], [[RenderMan Shading Language]]
| influenced = [[GLSL]]
}}

The '''High-Level Shader Language'''<ref>{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-writing-shaders-9 |title=Writing HLSL Shaders in Direct3D 9 |website=[[Microsoft Docs]] |access-date=February 22, 2021}}</ref> or '''High-Level Shading Language'''<ref>{{cite web |title=High-level shader language (HLSL) |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl |website=[[Microsoft Docs]] |accessdate=February 22, 2021}}</ref> ('''HLSL''') is a proprietary [[shading language]] developed by [[Microsoft]] for the [[Direct3D]] 9 [[API]] to augment the [[Shading language#DirectX Shader Assembly Language|shader assembly]] language, and went on to become the required shading language for the unified shader model of Direct3D 10 and higher. It was developed alongside the '''Cg''' (short for ''C for Graphics'') shading language from Nvidia. Early versions of the two languages were considered identical, only marketed differently.<ref>{{cite web|url=http://www.fusionindustries.com/default.asp?page=cg-hlsl-faq|archive-url=https://web.archive.org/web/20120824051248/http://www.fusionindustries.com/default.asp?page=cg-hlsl-faq|url-status=dead|archive-date=August 24, 2012|title=Fusion Industries :: Cg and HLSL FAQ ::|date=August 24, 2012|publisher=}}</ref>

Although Cg and HLSL share the same core syntax, some features of C were modified and new data types were added to make Cg/HLSL more suitable for programming [[graphics processing unit]]s.<ref>{{cite web|url=http://www.fusionindustries.com/default.asp?page=cg-hlsl-faq|archive-url=https://web.archive.org/web/20120824051248/http://www.fusionindustries.com/default.asp?page=cg-hlsl-faq|url-status=dead|archive-date=24 August 2012|title=Fusion Industries :: Cg and HLSL FAQ ::|date=24 August 2012}}</ref><ref>{{cite web |title=The Cg Tutorial - Chapter 1. Introduction |url=https://developer.download.nvidia.cn/CgTutorial/cg_tutorial_chapter01.html |website=developer.download.nvidia.cn}}</ref>

Two main branches of the Cg/HLSL language exist: the Nvidia Cg compiler (cgc) which outputs [[DirectX]] or [[OpenGL]] and the Microsoft HLSL which outputs DirectX shaders in bytecode format.<ref>{{cite web|url=https://msdn.microsoft.com/en-us/library/windows/desktop/bb944006.aspx|title=Writing HLSL Shaders in Direct3D 9 (Windows)|website=msdn.microsoft.com|date=24 May 2021 }}</ref><ref>{{cite web|title=Cg FAQ|url=https://developer.nvidia.com/cg-faq|website=NVIDIA DesignWorks|date=8 March 2011|access-date=25 May 2017}}</ref> Nvidia's cgc was [[Deprecation|deprecated]] in 2012, with no additional development or support available.<ref>{{cite web|url=https://developer.nvidia.com/cg-toolkit|title=Cg Toolkit &#124; NVIDIA Developer|date=8 March 2011}}</ref>

HLSL shaders can enable many [[special effects]] in both 2D and 3D [[computer graphics]].
* The Cg/HLSL language originally only included support for [[vertex shader]]s and [[pixel shader]]s ("fragment" in GLSL).  A vertex shader is executed for each vertex that is submitted by the application, and is primarily responsible for transforming the vertex from object space to view space, generating texture coordinates, and calculating lighting coefficients such as the vertex's normal, tangent, and bitangent vectors. When a group of vertices (normally 3, to form a triangle) come through the vertex shader, their output position is interpolated to form pixels within its area; this process is known as [[rasterization]].
* DirectX 10 (Shader Model 4) and Cg 2.0 introduced [[geometry shader]]s.<ref>{{Cite web |date=January 2008 |title=Cg 2.0 Release Notes |url=https://developer.download.nvidia.com/cg/Cg_2.0/2.0.0012/Cg-2.0_Jan2008_ReleaseNotes.pdf |website=nvidia.com}}</ref> This shader takes as its input some vertices of a primitive (triangle/line/point) and uses this data to generate/degenerate (or [[Tessellation (computer graphics)|tessellate]]) additional primitives or to change the type of primitives, which are each then sent to the rasterizer.
* DirectX 11 (Shader Model 5) introduced [[compute shader]]s ([[GPGPU]]) and [[tessellation shader]]s (hull and domain). The latter is present in Cg 3.1.
* DirectX 12 (Shader Model 6.3) introduced [[Ray tracing (graphics)|ray tracing]] shaders (ray generation, intersection, any hit / closest hit / miss).

D3D11.3 and D3D12 introduced Shader Model 5.1<ref>{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/shader-model-5-1-objects |title=Shader Model 5.1 Objects |website=[[Microsoft Docs]] |access-date=February 22, 2021}}</ref> and later 6.0.<ref>{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/hlsl-shader-model-6-0-features-for-direct3d-12 |title=HLSL Shader Model 6.0 |website=[[Microsoft Docs]] |access-date=February 22, 2021}}</ref>

==Background==
Due to technical advances in graphics hardware, some areas of 3D graphics programming have become quite complex. To simplify the process, new features were added to graphics cards, including the ability to modify their rendering pipelines using vertex and pixel shaders.

In the beginning, vertex and pixel shaders were programmed at a very low level with only the assembly language of the graphics processing unit. Although using the assembly language gave the programmer complete control over code and flexibility, it was fairly hard to use. A portable, higher level language for programming the GPU was needed, so Cg was created to overcome these problems and make shader development easier.

Some of the benefits of using Cg/HLSL over assembly are:
* High level code is easier to learn, program, read, and maintain than assembly code.
* Cg/HLSL code is portable to a wide range of hardware and platforms, unlike assembly code, which usually depends on hardware and the platforms it's written for.
* The Cg/HLSL compiler can optimize code and do lower level tasks automatically, which are hard to do and error-prone in assembly.

==Language==

===Data types===
Cg/HLSL has six basic data types. Some of them are the same as in C, while others are especially added for GPU programming. These types are:
* [[IEEE floating point|float]] - a 32bit floating point number
* [[Half-precision floating-point format|half]] - a 16bit floating point number
* [[Integer (computer science)|int]] - a 32bit integer
* [[Fixed-point arithmetic|fixed]] - a 12bit fixed point number
* [[Boolean data type|bool]] - a Boolean variable
* sampler* - represents a texture object

Cg also features vector and matrix data types that are based on the basic data types, such as float3 and float4x4. Such data types are quite common when dealing with 3D graphics programming. Cg also has struct and [[array data type]]s, which work in a similar way to their C equivalents.

===Operators===
Cg supports a wide range of operators, including the common arithmetic operators from C, the equivalent arithmetic operators for vector and matrix data types, and the common [[logical operator]]s.

===Functions and control structures===
Cg shares the basic control structures with C, like if/else, while, and for. It also has a similar way of defining functions.

=== Semantics ===
<!-- Variable Syntax -->

=== Preprocessor ===
Cg implements many [[C preprocessor]] directives and its macro expansion system. It implements {{code|#include}}.<ref name=2p>[[Mark Kilgard|Mark J. Kilgard]], [https://arxiv.org/abs/cs/0302013 ''Cg in Two Pages''], 2003.</ref>

=== HLSL features ===
* Namespace
* Annotation

== Environment ==

Cg programs are built for different ''shader profiles'' that stand for GPUs with different capabilities.<ref name=cgp>{{cite web |title=Cg Profile Documentation |url=http://developer.download.nvidia.com/cg/index_profiles.html |website=Nvidia developer}}</ref> These profiles decide, among others, how many instructions can be in each shader, how many registers are available, and what kind of resources a shader can use. Even if a program is correct, it might be too complex to work on a profile.<ref name=2p/>

As the number of profile and shader types cropped up, Microsoft has switched to use the term "Shader Model" to group a set of profiles found in a generation of GPUs.<ref>{{cite web |title=Shader Models vs Shader Profiles - Win32 apps |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-models |website=docs.microsoft.com |date=30 June 2021 |language=en-us}}</ref> Cg supports some of the newer profiles up to Shader Model 5.0 as well as translation to glsl or hlsl.<ref name=cgp/>

GPUs listed are the hardware that first supported the given specifications. Manufacturers generally support all lower shader models through drivers. Note that games may claim to require a certain DirectX version, but don't necessarily require a GPU conforming to the full specification of that version, as developers can use a higher DirectX API version to target lower-Direct3D-spec hardware; for instance DirectX 9 exposes features of DirectX7-level hardware that DirectX7 did not, targeting their fixed-function T&L pipeline.
===Pixel shader comparison===
{| class="wikitable"
! Pixel shader version
!1.0
!1.1
!1.2
1.3<ref name="PS1-3">{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx9-graphics-reference-asm-ps-differences |title=Pixel Shader Differences |work=[[Microsoft Docs]] |date=August 19, 2020 |access-date=February 22, 2021}}</ref>      
!1.4<ref name="PS1-3"/>      !!2.0<ref name="PS1-3"/><ref name=SM2>{{cite web |url=https://docs.microsoft.com/en-us/previous-versions/ms810449(v=msdn.10) |title=Introduction to the DirectX 9 High-Level Shader Language |last1=Peeper |first1=Craig |last2=Mitchell |first2=Jason L. |date=July 2003 |work=[[Microsoft Docs]] |access-date=February 22, 2021}}</ref>!!2.0a<ref name="PS1-3"/><ref name=SM2/><ref name="VS2.0a">{{cite web |url=https://www.anandtech.com/show/1034/4 |archive-url=https://web.archive.org/web/20130610035912/http://www.anandtech.com/show/1034/4 |url-status=dead |archive-date=June 10, 2013 |title=NVIDIA Introduces GeForce FX (NV30) |last=Shimpi |first=Anand Lal |author-link=Anand Lal Shimpi |work=[[AnandTech]] |access-date=February 22, 2021}}</ref>!!2.0b<ref name="PS1-3"/><ref name=SM2/><ref name="PS2.0b">{{cite web |url=https://www.anandtech.com/show/1314/4 |archive-url=https://web.archive.org/web/20120928192354/http://www.anandtech.com/show/1314/4 |url-status=dead |archive-date=September 28, 2012 |title=ATI Radeon X800 Pro and XT Platinum Edition: R420 Arrives |first=Derek |last=Wilson |work=[[AnandTech]] |access-date=February 22, 2021}}</ref>!!3.0<ref name="PS1-3"/><ref name=SM3>Shader Model 3.0, Ashu Rege, NVIDIA Developer Technology Group, 2004.</ref>!!4.0<ref name=D3D10>The Direct3D 10 System, David Blythe, Microsoft Corporation, 2006.</ref> 4.1<ref name="SM4.1">{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-sm4-registers-ps-4-1 |title=Registers - ps_4_1 |website=[[Microsoft Docs]] |date=August 23, 2019 |access-date=February 22, 2021}}</ref>
5.0<ref name="SM5">{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/registers---ps-5-0 |title=Registers - ps_5_0 |website=[[Microsoft Docs]] |date=August 23, 2019 |access-date=February 22, 2021}}</ref>
|-
!Dependent texture limit
|4
|4           
|4||6           || 8           ||Unlimited    ||8           ||Unlimited   ||Unlimited
|-
!Texture instruction limit
|4
|4           
|4||6 * 2           ||32          ||Unlimited   ||Unlimited   ||Unlimited   ||Unlimited
|-
!Arithmetic instruction limit
|8
|8
|8
|8 * 2
|64
|Unlimited
|Unlimited
|Unlimited
|Unlimited
|-
!Position register
|{{No}}
|{{No}}         
|{{No}}|| {{No}}           || {{No}}         || {{No}}         || {{No}}         || {{Yes}}        || {{Yes}}
|-
!Instruction slots
|8
|8 + 4         
|8 + 4||(8 + 6) * 2           ||64 + 32     ||512         ||512        ||≥ 512    ||≥ 65536
|-
!Executed instructions
|8
|8 + 4         
|8 + 4||(8 + 6) * 2           ||64 + 32     ||512         ||512         ||65536   ||Unlimited
|-
!Texture indirections
|4
|4           
|4||4           ||4           ||Unlimited    ||4           ||Unlimited     ||Unlimited
|-
!Interpolated registers
|2 + 4
|2 + 4       
|2 + 4||2 + 6           ||2 + 8       ||2 + 8       ||2 + 8       ||10          ||32
|-
!Instruction predication
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{Yes}}         || {{No}}          || {{Yes}}         || {{No}}
|-
!Index input registers
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{No}}          || {{No}}          || {{Yes}}         || {{Yes}}
|-
!Temp registers
|2
|2 + 4           
|3 + 4||6           ||12 to 32          ||22          ||32          ||32          ||4096
|-
!Constant registers
|8
|8           
|8||8           ||32          ||32          ||32          ||224         ||16×4096
|-
!Arbitrary [[Swizzling (computer graphics)|swizzling]]
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{Yes}}         || {{No}}          || {{Yes}}         || {{Yes}}
|-
!Gradient instructions
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{Yes}}         || {{No}}          || {{Yes}}         || {{Yes}}
|-
!Loop count register
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{No}}          || {{No}}          || {{Yes}}         || {{Yes}}
|-
!Face register (2-sided lighting)
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{No}}          || {{Yes}}          || {{Yes}}         || {{Yes}}
|-
!Dynamic flow control
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{No}}          || {{No}}          || {{Yes}} (24)          || {{Yes}} (64)
|-
!Bitwise Operators
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{No}}          || {{No}}          || {{No}}          || {{Yes}}
|-
!Native Integers
|{{No}}
|{{No}}          
|{{No}}|| {{No}}           || {{No}}          || {{No}}          || {{No}}          || {{No}}          || {{Yes}}
|}

*'''PS 1.0''' — Unreleased [[3dfx]] Rampage, DirectX 8
*'''PS 1.1''' — [[GeForce 3]], DirectX 8
*'''PS 1.2''' — [[3Dlabs]] Wildcat VP, DirectX 8.1
*'''PS 1.3''' — [[GeForce 4 Ti]], DirectX 8.1
*'''PS 1.4''' — [[ATI Radeon R200 series|Radeon 8500–9250]], [[Matrox Parhelia]], DirectX 8.1
*'''Shader Model 2.0''' — [[ATi Radeon R300 Series|Radeon 9500–9800/X300–X600]], DirectX 9
*'''Shader Model 2.0a''' — [[GeForce FX|GeForce FX/PCX]]-optimized model, DirectX 9.0a
*'''Shader Model 2.0b''' — [[Radeon R420|Radeon X700–X850]] shader model, DirectX 9.0b
*'''Shader Model 3.0''' — [[Radeon X1000]] and [[GeForce 6]], DirectX 9.0c
*'''Shader Model 4.0''' — [[Radeon HD 2000]] and [[GeForce 8]], DirectX 10
*'''Shader Model 4.1''' — [[Radeon HD 3000]] and [[GeForce 200]], DirectX 10.1
*'''Shader Model 5.0''' — [[Radeon HD 5000 series|Radeon HD 5000]] and [[GeForce 400]], DirectX 11
*'''Shader Model 5.1''' — [[Graphics Core Next#first|GCN 1+]], Fermi+, DirectX 12 (11_0+) with WDDM 2.0
*'''Shader Model 6.0''' — GCN 1+, Kepler+, DirectX 12 (11_0+) with WDDM 2.1
*'''Shader Model 6.1''' — GCN 1+, Kepler+, DirectX 12 (11_0+) with WDDM 2.3
*'''Shader Model 6.2''' — GCN 1+, Kepler+, DirectX 12 (11_0+) with WDDM 2.4
*'''Shader Model 6.3''' — GCN 1+, Kepler+, DirectX 12 (11_0+) with WDDM 2.5
*'''Shader Model 6.4''' — GCN 1+, Kepler+, Skylake+, DirectX 12 (11_0+) with WDDM 2.6
*'''Shader Model 6.5''' — GCN 1+, Kepler+, Skylake+, DirectX 12 (11_0+) with WDDM 2.7
*'''Shader Model 6.6''' — GCN 4+, Maxwell+, DirectX 12 (11_0+) with WDDM 3.0
*'''Shader Model 6.7''' — GCN 4+, Maxwell+, DirectX 12 (12_0+) with WDDM 3.1
*'''Shader Model 6.8''' — RDNA 1+, Maxwell 2+, DirectX 12 (12_0+) with WDDM 3.1 / 3.2 with Agility SDK


"32 + 64" for ''Executed Instructions'' means "32 texture instructions and 64 arithmetic instructions."

=== Vertex shader comparison ===
{| class="wikitable"
! Vertex shader version
!1.0
!1.1<ref name="VS1-3">{{cite web |url=https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx9-graphics-reference-asm-vs-differences |title=Vertex Shader Differences |work=[[Microsoft Docs]] |date=August 19, 2020 |access-date=February 22, 2021}}</ref>
      !2.0<ref name="SM2" /><ref name="VS1-3" /><ref name="VS2.0a" />      !!2.0a<ref name="SM2" /><ref name="VS1-3" /><ref name="VS2.0a" />      !!3.0<ref name="SM3" /><ref name="VS1-3" />    !!4.0<ref name="D3D10" /> <br>4.1<ref name="SM4.1" /> <br>5.0<ref name="SM5" />
|-
!# of instruction slots
|128
|128         ||256         ||256         ||≥ 512     ||≥ 65536
|-
!Max # of instructions executed
|128
|128         ||1024         ||65536       ||65536     ||Unlimited
|-
![[Branch predication|Instruction predication]]
|{{No}}|| {{No}}         || {{No}}         || {{Yes}}        || {{Yes}}      || {{Yes}}
|-
!Temp registers
|12
|12          ||12          ||16          ||32        ||4096
|-
!# constant registers
|≥ 96
|≥ 96       ||≥ 256       ||256       ||≥ 256     ||16×4096
|-
!Address register
|{{No}}
|{{Yes}}
|{{Yes}}
|{{Yes}}
|{{Yes}}
|{{Yes}}
|-
!Static flow control
|{{No}}|| {{No}}        || {{Yes}}        || {{Yes}}        || {{Yes}}      || {{Yes}}
|-
!Dynamic flow control
|{{No}}|| {{No}}         || {{No}}         || {{Yes}}        || {{Yes}}      || {{Yes}}
|-
!Dynamic flow control depth
|{{N/A}}|| {{N/A}}          || {{N/A}}          || 24          || 24        || 64
|-
!Vertex texture fetch
|{{No}}|| {{No}}          || {{No}}          || {{No}}          || {{Yes}}       || {{Yes}}
|-
!# of texture samplers
| {{N/A}}|| {{N/A}}         || {{N/A}}         || {{N/A}}         || 4         ||128
|-
![[Geometry instancing]] support
|{{No}}|| {{No}}          || {{No}}          || {{No}}          || {{Yes}}       || {{Yes}}
|-
!Bitwise operators
|{{No}}|| {{No}}          || {{No}}          || {{No}}          || {{No}}        || {{Yes}}
|-
!Native integers
|{{No}}|| {{No}}          || {{No}}          || {{No}}          || {{No}}        || {{Yes}}
|}

===The standard library===
As in C, Cg/HLSL features a set of functions for common tasks in GPU programming.  Some of the functions have equivalents in C, like the mathematical functions abs and sin, while others are specialized in GPU programming tasks, like the [[texture mapping]] functions tex1D and tex2D.

===The Cg/HLSL runtime library===
Cg/HLSL programs are merely vertex and pixel shaders, and they need supporting programs that handle the rest of the rendering process.  Cg can be used with two graphics [[API]]s: [[OpenGL]] or [[DirectX]].  Each has its own set of Cg functions to communicate with the Cg program, like setting the current Cg shader, passing parameters, and such tasks. (HLSL only targets DirectX.)

In addition to being able to compile Cg source to assembly code, the Cg runtime also has the ability to compile shaders during execution of the supporting program.  This allows the runtime to compile the shader using the latest optimizations available for hardware that the program is currently executing on. However, this technique requires that the source code for the shader be available in plain text to the compiler, allowing the user of the program to access the source-code for the shader. Some developers view this as a major drawback of this technique.

To avoid exposing the source code of the shader, and still maintain some of the hardware specific optimizations, the concept of profiles was developed. Shaders can be compiled to suit different graphics hardware platforms (according to profiles).  When executing the supporting program, the best/most optimized shader is loaded according to its profile. For instance there might be a profile for a graphics card that supports complex pixel shaders, and another profile for one that supports only minimal pixel shaders. By creating a pixel shader for each of these profiles a supporting program enlarges the number of supported hardware platforms without sacrificing picture quality on powerful systems.'

== Compilers and dialects ==
The Cg dialect has only ever had one compiler, in the form of Nvidia's Cg toolkit.

Microsoft has released two compilers for HLSL. The original compiler was the closed-source FXC (Effect Compiler), supported until 2015. It was deprecated in favor of the open-source [[LLVM]]-based DXC (DirectXShaderCompiler) with support for newer HLSL features.<ref>{{cite web |title=Porting from FXC to DXC |url=https://github.com/microsoft/DirectXShaderCompiler/wiki/Porting-shaders-from-FXC-to-DXC |website=GitHub |language=en}}</ref> Both compilers generate bytecode: while the older FXC used DXBC, DXC now uses DXIL. DXC can also emit [[SPIR-V]] bytecode.<ref>{{cite web |title=microsoft/DirectXShaderCompiler: This repo hosts the source for the DirectX Shader Compiler which is based on LLVM/Clang. |url=https://github.com/microsoft/DirectXShaderCompiler |publisher=Microsoft |date=21 October 2020}}</ref>

The [[Khronos Group]] has also written a LLVM-based HLSL compiler, in the form of a frontend for ''glslang'', their GLSL-to-SPIR_V compiler. Support for SPIR-V means that the shaders can be cross-platform, no longer limiting them to a DirectX stack.<ref>{{cite web |title=glslang: Khronos-reference front end for GLSL/ESSL, partial front end for HLSL, and a SPIR-V generator. |url=https://github.com/KhronosGroup/glslang |publisher=The Khronos Group |date=21 October 2020}}</ref> This task was previously performed by source-level converters like [[HLSL2GLSL]], but the resulting code is often bloated.<ref>Matt Turner. {{YouTube|3C96NJeYAy4}}.</ref>

=== Derived languages ===
The [[PlayStation Shader Language]] (PSSL) is based on Cg/HLSL.<ref>{{cite web |last1=Stenson |first1=Richard |last2=Ho |first2=Chris |title=PlayStation Shading Language for PS4 |url=https://www.gdcvault.com/play/1019252/PlayStation-Shading-Language-for |website=GDC Europe 2013}}</ref>

The ReshadeFX shading language is also based on Cg/HLSL. Shaders written in ReshadeFX are compiled to OpenGL, DX, or Vulkan and injected into games to act as post-processing filters.<ref>{{cite web|url=https://github.com/crosire/reshade-shaders/blob/master/REFERENCE.md|website=GitHub|title=ReShade FX shading language|date=15 February 2022}}</ref>

Khronos has since evolved ''glslang'' into ''slang'', a shading language and compiler that is mostly source-code-compatible with HLSL. Slang can compile to textual shading languages (GLSL, [[Metal (API)|MSL]], CUDA, [[WebGPU Shading Language|WGSL]]), bytecodes (D3D11, D3D12, Vulkan [[SPIR-V]]) as well as the CPU. It also has a GLSL-compatibility mode.<ref>{{cite web |title=shader-slang/slang |url=https://github.com/shader-slang/slang |publisher=The Slang Shading Language |date=8 December 2025}}</ref>

==Applications and games that use Cg or HLSL==
{{div col start}}
* ''[[Virtools|3DVIA Virtools]]''
* [[Adobe Photoshop]]
* [[Autodesk Maya|Maya]]<ref>{{cite web|url=http://www.nvidia.com/object/MayaCgPlugin.html|title=Maya Cg Plug-in &#124; NVIDIA}}</ref>
* ''[[Battlefield 2]]''
* ''[[Crystal Space]]''
* ''[[Racer (simulator)|Dolphinity Racer]]''
* ''[[Earth's Special Forces]]'' - A Half-Life Mod
* ''[[Enemy Territory: Quake Wars]]''
* ''[[Doom 3 BFG Edition]]''
* ''EON Professional™/Ultra™'' of [[EON Reality]]
* ''[[eyeon Fusion]]''
* ''[[Far Cry]]''
* ''[[Garshasp: The Monster Slayer]]''
* ''[[GLScene]]''
* ''[[Gun Metal]]''
* ''[[Hitman: Blood Money]]''
* ''[[Irrlicht Engine]]''
* ''[[League of Legends]]''
* ''[[Lightfeather 3D Engine]]''
* [[LightWave]] 11.6<ref>{{cite web|url=https://www.lightwave3d.com/11-6_features_overview/|title=LightWave - 11.6 Features Overview}}</ref>
* ''[[muvee Technologies|muvee Reveal]]''
* ''[[OGRE]]''
* ''[[OpenEmu]]''
* ''[[Panda3D]]''
* [[PCSX2]]
* [[PlayStation 3]]
* ''[[RetroArch]]''
* ''[[R.U.S.E.]]''
* ''[[Snes9x]]''
* ''[[Unity (game engine)|Unity game engine]]''<ref>{{cite web|url=http://docs.unity3d.com/Manual/ShadersOverview.html|title=Unity - Manual: Writing Shaders}}</ref>
* ''[[Unreal Engine]]''
{{div col end}}

==See also==
* [[Direct3D]]
* [[DirectX]]
* [[DirectX Raytracing]]
* [[Computer programming]]
* [[Computer graphics]]
* [[Vertex shader|Vertex and pixel shaders]]
* [[GLSL|OpenGL shading language]]
* [[Shader Model]]
* [[OpenGL]]

==References==
{{Reflist}}

==Further reading==
* [http://www.randima.com Randima Fernando], [[Mark Kilgard|Mark J. Kilgard]], ''[http://http.developer.nvidia.com/CgTutorial/cg_tutorial_frontmatter.html The Cg Tutorial]: The Definitive Guide to Programmable Real-Time Graphics'', Addison-Wesley Professional, {{ISBN|0-321-19496-9}}
* [http://www.randima.com Randima Fernando], ''GPU Gems: Programming Techniques, Tips, and Tricks for Real-Time Graphics'', Addison-Wesley Professional, {{ISBN|0-321-22832-4}}
* William R. Mark, R. Steven Glanville, [[Kurt Akeley]], [[Mark Kilgard|Mark J. Kilgard]], ''Cg: A System for Programming Graphics Hardware in a C-like Language'', Proceedings of [[SIGGRAPH]] 2003, {{doi|10.1145/1201775.882362}}

==External links==
* [https://github.com/castano/cgc-opensrc cgc-opensrc] - Mirror for nvidia's open source compiler, 2002
* Some essential materials (e.g. the design paper) are gathered in [http://www.csee.umbc.edu/~olano/s2005c37/ch05.pdf these course notes from Siggraph 2005]
* Nvidia-hosted materials:
** [http://developer.nvidia.com/cg-faq Cg FAQ]
** [https://developer.nvidia.com/cg-toolkit Cg Toolkit]
** Cg [https://developer.download.nvidia.com/cg/ Language Reference and Documentation]
* [https://web.archive.org/web/20081219131420/http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=47 NeHe Cg vertex shader tutorial]
* [https://github.com/Themaister/Emulator-Shader-Pack/blob/master/Cg/README Documentation for the Cg Shader standard used by emulators]
* Aras Pranckevičius,<!-- he is a Unity dev --> [http://aras-p.info/blog/2014/03/28/cross-platform-shaders-in-2014/ Cross Platform Shaders in 2014].
* [https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-pguide Programming guide for HLSL] at [[Microsoft Docs]]
* [https://web.archive.org/web/20100215205220/http://ati.amd.com/developer/ShaderX2_IntroductionToHLSL.pdf Introduction to the DirectX 9 High Level Shading Language], (ATI) AMD developer central
* [http://www.riemers.net/Tutorials/DirectX/Csharp3/index.php Riemer's HLSL Introduction & Tutorial (includes sample code)] {{Webarchive|url=https://web.archive.org/web/20081119034954/http://www.riemers.net/Tutorials/DirectX/Csharp3/index.php |date=November 19, 2008 }}
* [http://www.neatware.com/lbstudio/web/hlsl.html HLSL Introduction]
* [https://github.com/microsoft/DirectXShaderCompiler/blob/master/docs/DXIL.rst DirectX Intermediate Language] (DXIL) specification
{{Nvidia}}

[[Category:C programming language family]]
[[Category:Nvidia software]]
[[Category:Shading languages]]
[[Category:DirectX]]
[[Category:Microsoft application programming interfaces]]