DirectX implicit truncation of vector type

Question

float3 ParallelLight(SurfaceInfo v, Light L, float3 eyePos)
{
	float3 litColor = float3(0.0f, 0.0f, 0.0f);
 
	// The light vector aims opposite the direction the light rays travel.
	float3 lightVec = -L.dir;
	
	// Add the ambient term.
	litColor += v.diffuse * L.ambient;  //ERROR HERE!!	
	
	// Add diffuse and specular term, provided the surface is in 
	// the line of site of the light.
	
	float diffuseFactor = dot(lightVec, v.normal);
	[branch]
	if( diffuseFactor > 0.0f )
	{
		float specPower  = max(v.spec.a, 1.0f);
		float3 toEye     = normalize(eyePos - v.pos);
		float3 R         = reflect(-lightVec, v.normal);
		float specFactor = pow(max(dot(R, toEye), 0.0f), specPower);
					
		// diffuse and specular terms
		litColor += diffuseFactor * v.diffuse * L.diffuse; //ERROR HERE!
		litColor += specFactor * v.spec * L.spec; //ERROR HERE!!
	}
	
	return litColor;
}

		

You have the name of the error in the title,and I marked where the error appears in the code above.

I just loaded that source code from a book,and I don't even know what that error means.I have a hard time understanding direct x because I haven't started working and making some apps with it.

Answer 1

what book?

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Answer 2

Hi Turda,

Welcome to the MSDN Forum.

According to your description, I suggest you go to DirectX forum for better support and more efficient responses. And here is that forum's link: http://forums.create.msdn.com/forums/?GroupID=7. And this thread will be moved to Off-Topic Posts.

Thanks for your understanding.
Best regards,

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Helen Zhao [MSFT]
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