Hello,

I am trying to get a shader to give an effect over sprites I draw. Currently I don't have the shader altering the sprites, I'm just trying to test that it works/compiles.

Here is my TestShader.fx:

// World * View * Projection matrix
float4x4 g_mWorldViewProjection : WORLDVIEWPROJECTION;
float4x4 g_mWorld : WORLD;

texture g_SpriteTexture; //What Sprite('s Texture) to use

sampler SpriteSampler = 
sampler_state
{
    Texture = <g_SpriteTexture>;
    MipFilter = WRAP;
    MinFilter = WRAP;
    MagFilter = WRAP;
};

float4 PixelShaderFunction(float2 texCoord : TEXCOORD0) : COLOR
{  
    //return float4(1, 0, 0, 1);  Turn every pixel red
	float4 color = tex2D(SpriteSampler, texCoord);  
	//color.gb = color.r; //make texture GreyScale
	return color;  
}  
  
technique DefaultTechnique //Renders The current Sprite as is
{  
    pass Pass1  
    {  
        PixelShader = compile ps_2_0 PixelShaderFunction();  
    }  
}  

Then I create it like so:

	//==== Load in our shader:
	LPD3DXBUFFER pErrors = NULL;
	wchar_t *str1 = L"TestShader.fx";
	DWORD dwShaderFlags = 0;
	//Create The First Shader
	if (FAILED(D3DXCreateEffectFromFile( g_pd3dDevice, str1, NULL, NULL, dwShaderFlags, NULL, &g_pTestShader, &pErrors ) ))
	{
		if (pErrors != NULL)
		{
			char *errorString = (char*)pErrors->GetBufferPointer();
			printf(errorString);
			MessageBox( NULL, L"Could not Create Test Shader", L"Textures1.exe", MB_OK );
            //return E_FAIL;
		}
	 
		//return E_FAIL;
	}	

Then I try to set it's Matrix, but it crashes my program. I get an error:

Unhandled exception at 0x76fc15de in Sprites.exe: 0xC0000005: Access violation reading location 0x00000000.

g_pTestShader->SetMatrix( "g_mWorldViewProjection", &Cam.GetWorldViewProj());

The above line is the only code that tries to use my shader object and it crashes it.

Any ideas why?

Thanks

g_pTestShader is a NULL pointer, or Cam is a NULL reference.

Yeah, g_pTestShader is a NULL pointer.

I think the problem is my file directory ("TestShader.fx"), but I have the shader file in my root directory and in the cpp files location (just in case). But it still doesn't seem to load the file correctly

Call D3DXCreateEffectFromFile() with the debug flag and see what error message is being produced.

DWORD dwShaderFlags = D3DXSHADER_DEBUG;
if (FAILED(D3DXCreateEffectFromFile( g_pd3dDevice, str1, NULL, NULL, dwShaderFlags, NULL, &g_pTestShader, &pErrors ) ))
{
	if (pErrors != NULL)
	{
		char *errorString = (char*)pErrors->GetBufferPointer();
	}
}

It says:

You were right to change it to LINEAR (WRAP is wrong for the filters). You said in a previous post you copied the effect to different locations to try getting it to work. Are you sure you changed the right copy?

Oh god, yeah I forgot about that.

Thanks heaps, it's compiling now