I'm pulling my hair off with one specific hardware. This is an Acer Iconia w3-810 tablet, with Windows 8, Intel Atom Z2760, and GMA "GPU".

Newest driver pack has been installed.

I'm developing with DirectX9 and HLSL. Some objects I render with DirectX 9 pipeline but some objects requiring advanced coloring render with HLSL vertex and pixel shaders. The problem is coordinate conversion in the HLSL, from object space to screen coords. I suspect this must be some kind of floating point accuracy thing.

In vertex shader, this works with all other computers:

vout.Pos_ps = mul(position, WorldViewProjection); //WorldViewProjection has all transformations

[attachment=18188:amd.jpg]

It's taken with AMD GPU, this is all OK.

But compare it to Atom's screenshot:

[attachment=18189:spectrogram_iconia.jpg]

All other objects are in place, but not the one I render with HLSL, the colorful spectrogram surface.

If I convert the coordinates in CPU side with WorldViewProjection matrix, and don't convert it all in GPU side, it renders OK with Atom too. But the matrix multiplication has to be done as follows:

Vector3 TransformCoordinate( Vector3 coord, Matrix transform )
   {
   Vector4 vector;


   vector.X = (((coord.X * transform.M11) + (coord.Y * transform.M21)) + (coord.Z * transform.M31)) + transform.M41;
   vector.Y = (((coord.X * transform.M12) + (coord.Y * transform.M22)) + (coord.Z * transform.M32)) + transform.M42;
   vector.Z = (((coord.X * transform.M13) + (coord.Y * transform.M23)) + (coord.Z * transform.M33)) + transform.M43;
   vector.W = 1.0f / ((((coord.X * transform.M14) + (coord.Y * transform.M24)) + (coord.Z * transform.M34)) + transform.M44);


            Vector3 v3 = new Vector3(vector.X * vector.W, vector.Y * vector.W, vector.Z * vector.W );
            return v3; 
   }

Then I tried to implement the similar coordinate conversion in HLSL:

vout.Pos_ps = TransformCoord(position);



float4 TransformCoord(float4 pos)
{
float4 tr; 


tr.x = (((pos.x * WorldViewProjection._11) + (pos.y * WorldViewProjection._21)) + (pos.z * WorldViewProjection._31)) + WorldViewProjection._41;
tr.y = (((pos.x * WorldViewProjection._12) + (pos.y * WorldViewProjection._22)) + (pos.z * WorldViewProjection._32)) + WorldViewProjection._42;
tr.z = (((pos.x * WorldViewProjection._13) + (pos.y * WorldViewProjection._23)) + (pos.z * WorldViewProjection._33)) + WorldViewProjection._43;
tr.w = 1.0f / ((((pos.x * WorldViewProjection._14) + (pos.y * WorldViewProjection._24)) + (pos.z * WorldViewProjection._34)) + WorldViewProjection._44);


return float4 (tr.x * tr.w, tr.y * tr.w, tr.z * tr.w, 1.0f); 
}

It renders correctly with the reference rasterizer. HLSL transformations all work correctly. But not with hardware driver.

I'm contacting Intel.

Have you tried creating the device with D3DCREATE_SOFTWARE_VERTEXPROCESSING instead of D3DCREATE_HARDWARE_VERTEXPROCESSING? I remember some Intel cards having problems with the latter.

A quick search says this isn't really an Intel GPU at all. It's a Power VR SGX545.

What are the actual values in the WorldViewProjection matrix?

Have you tried passing w through as normal out of the vertex shader like this?

float4 TransformCoord(float4 pos)
{
float4 tr; 

tr.x = (((pos.x * WorldViewProjection._11) + (pos.y * WorldViewProjection._21)) + (pos.z * WorldViewProjection._31)) + WorldViewProjection._41;
tr.y = (((pos.x * WorldViewProjection._12) + (pos.y * WorldViewProjection._22)) + (pos.z * WorldViewProjection._32)) + WorldViewProjection._42;
tr.z = (((pos.x * WorldViewProjection._13) + (pos.y * WorldViewProjection._23)) + (pos.z * WorldViewProjection._33)) + WorldViewProjection._43;
tr.w = (((pos.x * WorldViewProjection._14) + (pos.y * WorldViewProjection._24)) + (pos.z * WorldViewProjection._34)) + WorldViewProjection._44;

return tr;
}

Have you tried creating the device with D3DCREATE_SOFTWARE_VERTEXPROCESSING instead of D3DCREATE_HARDWARE_VERTEXPROCESSING? I remember some Intel cards having problems with the latter.

this, since early atom CPUs had old IGPs...

It renders correctly with the reference rasterizer. HLSL transformations all work correctly. But not with hardware driver.

I'm contacting Intel.

Try also to disable the driver optimization in the intel graphic control panel

Thanks for trying to help me.

Setting software vertex processing instead of hardware vertex processing doesn't help.

This Intel graphics control panel doesn't allow changing any settings, it just shows info. This clearly a stripped-down version of the intel grahics control panel found in laptops.

[attachment=18245:intel_settings.png]

A quick search says this isn't really an Intel GPU at all. It's a Power VR SGX545.

GPU-Z shows "Intel(R) Grpahics Media Accelerator" as the name of the GPU. It may be Power VR inside, but is Intel GMA to the DirectX and to me.

[attachment=18244:GPUZ.png]