Texture array in HLSL

Texture array in HLSL

• sfleck

  is there a way to index into the sampler array using a variable it seems to work fine if i do
  
  int i = 2; sampler[ i ];
  
  but if i try to pass a variable from the vertex shader and use that as an index it gives me
  
  error X3512: sampler array index must be a literal expression
  
  maybe i'm doing something wrong if i set the index to a variable instead of a number like 1 it gives me this error, is there any way to do it
  
  

• Chris Knight

  Correct - DX9 doesn't have the concept of an "array" of textures, there's just a bunch of separate textures and samplers. You could put them all in a 3D texture as different 2D slices, but they're kinda slow as well. Try both!
  
  

• AntonioCanaveral

  In an effect (.fx) I tryed to do:
  
  shared sampler2D textures [ 8 ];
  
  and got the following compiler error message:
  
  shared.fxh(182): ID3DXEffectCompiler: Arrays must be either numeric, structure, string or shader
  shared.fxh(182): ID3DXEffectCompiler: Error initializing variable type
  shared.fxh(199): ID3DXEffectCompiler: State 'TEXTURE' cannot be assigned an array or structure
  ID3DXEffectCompiler: There was an error initializing the compiler
  
  So I bet YOU CAN'T used texture arrays in HLSL, sorry !!!
  
  

• harrier_coder

  In ps_2_0 you can have an array of samplers and index into the sampler array. (In ps_1_1 you can have the array but you have to use the elements in order. ) I think you may still have to hard-associate each element of the sampler array with an individual texture, but that's probably OK.

  sampler Samplers[3] = {
  sampler_state
  {
  texture = <TextureX>;
  magfilter = LINEAR;
  minfilter = LINEAR;
  mipfilter = LINEAR;
  AddressU = mirror;
  AddressV = mirror;
  },

  sampler_state
  {
  texture = <TextureY>;
  magfilter = LINEAR;
  minfilter = LINEAR;
  mipfilter = LINEAR;
  AddressU = mirror;
  AddressV = mirror;
  },

  sampler_state
  {
  texture = <TextureZ>;
  magfilter = LINEAR;
  minfilter = LINEAR;
  mipfilter = LINEAR;
  AddressU = mirror;
  AddressV = mirror;
  },
  };
  

  And then you can do stuff like this:

  int x = 1;
  float4 color = tex2D(Samplers[x], coord);

  
  
• Texture array in HLSL