In Unity, shader programs are written in a variant of HLSL language (also called Cg but for most practical uses the two are the same).
Currently, for maximum portability between different platforms, writing in DX9-style HLSL (e.g. use DX9 style sampler2D
and tex2D
for texture sampling instead of DX10 style Texture2D
, SamplerState
and tex.Sample
).
Internally, different shader compilers are used for shader program compilation:
In case you really need to identify which compiler is being used (to use HLSL syntax only supported by one compiler, or to work around a compiler bug), predefined shader macros can be used. For example, UNITY_COMPILER_HLSL
is set when compiling with HLSL compiler (for D3D or GLCore/GLES3 platforms); and UNITY_COMPILER_HLSL2GLSL
when compiling via hlsl2glsl.