3D graphics questions that do not deserve their own thread (OpenGL / Dx10)

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > 3D graphics questions that do not deserve their own thread (OpenGL / Dx10)

Seat Safety Switch: May 27, 2008; MY RELIGION IS THE SMALL BLOCK V8 AND COMMANDMENTS ONE THROUGH TEN ARE NEVER LIFT.; Pillbug

I'm using SlimDX with Direct3D 10.1 and I created a 2D 32x32 texture of format A8_UNorm set up for usage as a shader resource and flagged for write access. When I map the texture to get at a stream to write into it (using WriteDiscard and mip level 0), the stream's stated Length is 2048 bytes long which doesn't make any sense to me (assuming that the 8 in A8_UNorm means 8 bits, 32 * 32 * 1 = 1024).

The DataRectangle that I get from the mapping says that the pitch is 64 as well. It does the same thing if I use R8_UNorm. R32_Float says 4 bytes per texel, which is correct.

Any idea why the stream seems to be twice as long as it should be when I'm using one of the *8_UNorm formats? I'm relatively new to SlimDX (and D3D in general) so perhaps I've made some bad decisions here.

code:

Texture2DDescription textureDescription = new Texture2DDescription
{
  Width = 32,
  Height = 32,
  Format = SlimDX.DXGI.Format.A8_UNorm,
  MipLevels = 1,
  ArraySize = 1,
  SampleDescription = new SlimDX.DXGI.SampleDescription(1, 0),
  Usage = ResourceUsage.Dynamic,
  CpuAccessFlags = CpuAccessFlags.Write,
  BindFlags = BindFlags.ShaderResource,
  OptionFlags = ResourceOptionFlags.None
};
_texture = new Texture2D(_device, textureDescription);

code:

textureStream = _texture.Map(0, MapMode.WriteDiscard, MapFlags.None).Data;

# ¿ Dec 15, 2011 00:30

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# ¿ Apr 26, 2024 01:06

Seat Safety Switch: May 27, 2008; MY RELIGION IS THE SMALL BLOCK V8 AND COMMANDMENTS ONE THROUGH TEN ARE NEVER LIFT.; Pillbug

I tried the identical code on my ATI card at home as opposed to my Quadro at work, and it returns a stream of the proper size and pitch. I'm really confused, so I'm just using R32_Float for now. Thanks anyway

# ¿ Dec 17, 2011 04:27

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Cavern of COBOL > 3D graphics questions that do not deserve their own thread (OpenGL / Dx10)