Strange access violation problem

Graphics and GPU Programming Programming

Started by Rasenger July 14, 2007 08:58 AM

10 comments, last by Rasenger 16 years, 9 months ago

122

Author

July 14, 2007 08:58 AM

I'm trying to use shaders with C++ / DX9. Creating vertex shader works but creating pixel shader doesn't. I get "access violation reading ... 0x000000 blaa blaa"-error here:


d3ddev->CreatePixelShader((DWORD*)code2->GetBufferPointer(), &pixelShader);

Here's some code from my terrain class:


LPDIRECT3DVERTEXDECLARATION9 vertexDeclaration;
LPDIRECT3DVERTEXSHADER9 vertexShader;
LPD3DXCONSTANTTABLE constantTable;
LPDIRECT3DPIXELSHADER9 pixelShader;

...

// Now were're in constructor

vertexDeclaration = NULL;
vertexShader = NULL;
pixelShader = NULL;
constantTable = NULL;

...

/* Vertex declaration */

D3DVERTEXELEMENT9 decl[] = {
	{0, 0, D3DDECLTYPE_FLOAT3, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_POSITION, 0},
    {0, 12, D3DDECLTYPE_FLOAT2, D3DDECLMETHOD_DEFAULT, D3DDECLUSAGE_TEXCOORD, 0},
    D3DDECL_END()};

d3ddev->CreateVertexDeclaration(decl, &vertexDeclaration);

/* Load shaders */

HRESULT result1 = NULL;
HRESULT result2 = NULL;
LPD3DXBUFFER code1 = NULL;
LPD3DXBUFFER code2 = NULL;

//set up Vertex Shader
result1 = D3DXCompileShaderFromFile(L"TerrainVertex.fx",
                                   NULL,
                                   NULL,
                                   "vs_main",
                                   "vs_1_1",
                                   0,
                                   &code1,
                                   NULL,
                                   &constantTable);

d3ddev->CreateVertexShader((DWORD*)code1->GetBufferPointer(), &vertexShader);
code1->Release();

//set up Pixel Shader
result2 = D3DXCompileShaderFromFile(L"TerrainPixel.fx",
                                   NULL,     
                                   NULL,
                                   "ps_main",
                                   "ps_1_1",
                                   0,
                                   &code2,
                                   NULL,
                                   NULL);

/* ||||||  NEXT LINE PRODUCES ACCESS VIOLATION ERROR |||||| */
d3ddev->CreatePixelShader((DWORD*)code2->GetBufferPointer(), &pixelShader);
code2->Release();

SiCrane

11,840

July 14, 2007 09:06 AM

Are you sure the return values from all the previous functions indicate success? You don't seem to be doing any checking in your code.

Gage64

1,235

July 14, 2007 09:06 AM

Try adding:

if (FAILED(result2))    // ...

EDIT: Too slow...

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Rasenger

122

Author

July 14, 2007 09:18 AM

Well I added assertions there (should've done it earlier -__-) and it seems there's something wrong with this:

//set up Pixel Shaderresult2 = D3DXCompileShaderFromFile(L"TerrainPixel.fx",                                   NULL,                                        NULL,                                   "ps_main",                                   "ps_1_1",                                   0,                                   &code2,                                   NULL,                                   NULL);

I've checked that the filename is correct, also the HLSL file _should_ be OK. Hmm..

SiCrane

11,840

July 14, 2007 09:30 AM

Well, which error did it give? It should be one of D3DERR_INVALIDCALL, D3DXERR_INVALIDDATA, or E_OUTOFMEMORY.

Rasenger

122

Author

July 14, 2007 09:54 AM

How would I know? :DDDDD Yes, I'm so fucking noob I shouldn't exist but I do and please bear with it. :D

SiCrane

11,840

July 14, 2007 09:57 AM

There are lots of ways. You can set a breakpoint on the line in the debugger and examine the value directly after the call. You can print the value to a file. You can display the value with a MessageBox call.

Rasenger

122

Author

July 14, 2007 10:13 AM

Yes but where is the value? I can't just print result2 as it is..

SiCrane

11,840

July 14, 2007 10:33 AM

You can use DXGetErrorDescription()/DXGetErrorString() in dxerr.h in your code.

jollyjeffers

1,571

July 14, 2007 10:47 AM

Quote:Original post by Rasenger

//set up Pixel Shaderresult2 = D3DXCompileShaderFromFile(L"TerrainPixel.fx",                                   NULL,                                        NULL,                                   "ps_main",                                   "ps_1_1",                                   0,                                   &code2,                                   NULL,                                   NULL);

I've checked that the filename is correct, also the HLSL file _should_ be OK. Hmm..

Well "should be ok" is nice to say, but evidence would suggest you are wrong [wink]

Running FX files against fxc.exe on the command line or creating a custom build step in VS is a convenient way of checking this. You can get VS to compile each FX file when you compile the rest of your app and it'll catch the errors the same as with any other code...

Alternatively, just refer to your documentation and set your penultimate 'NULL' parameter to be a LPD3DXBUFFER and pass it to OutputDebugStringA() and you'll get a list of the errors during compilation. This should be as standard as checking the return codes.

hth
Jack

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Strange access violation problem

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