proper use of buildTextureTransform()

[Arcoroc]

I am struggling to properly implement uv transformation.

I have setup an orthographic camera, and i am calling the below method within a class that holds a planar quad node. Its purpose is to set the uv on the node so that only a source rectangle from the texture will map into the quad.

Here is how it is used:

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MyQuadNode.setTextureAndUV( "myTexture.png", rect<s32>(0,0,100,100) ) ;     

which takes a rectangle 100 pixel square and map it with proper pixel size to the quad rendered to screen.
It should be simple enough, and in fact works great with tex rect coordinates starting at (0,0) as above.

It does not work anymore if i pass, say,

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MyQuadNode.setTextureAndUV( "myTexture.png", rect<s32>(10,10,100,100) ) ;

Node that source rect is no longer (0,0) based. I can't seem to find what i am missing.
Here is the source code for the uv method:

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void MyQuadNode::setTextureAndUV(  const video::ITexture* texture, const RenderMan::rect<s32>& sourceTexRect )
	{
		
	dimension2du		texsize = texture->getSize() ;
	dimension2df		uvScaleFactor( sourceTexRect.getWidth()/texsize.Width, sourceTexRect.getHeight()/texsize.Height )  ;
	position2d		rectCenter =  sourceTexRect.getCenter(); 
	vector2df		translation0 = vector2df( (1.f*rectCenter.X)/texsize.Width, (1.f*rectCenter.Y)/texsize.Height )/vector2df( uvScaleFactor.Width, uvScaleFactor.Height ) ;
	vector2df		translation = translation0 - vector2df(0.5f, 0.5f); 
		
		getMaterial().setTexture(0, texture ); 
		getMaterial().getTextureMatrix( 0 ).buildTextureTransform( 0*DEGTORAD64,
																   vector2df(0.f, 0.f),    
																   translation ,
																  uvScaleFactor );
	}

Thanks for any suggestion.

[Arcoroc]

If you thought that the translation calculation code above might have something to do with the extra beer, you would be entirely right.
The below should work much better.

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void MyQuadNode::setTextureAndUV(  const video::ITexture* texture, const RenderMan::rect<s32>& sourceTexRect ) 
   { 
       
   dimension2du      texsize = texture->getSize() ; 
   dimension2df		uvScaleFactor( (f32)sourceTexRect.getWidth()/texsize.Width, (f32)sourceTexRect.getHeight()/texsize.Height )  ;
   vector2df		translation ( (f32)sourceTexRect.UpperLeftCorner.X/texsize.Width, (f32)sourceTexRect.UpperLeftCorner.Y/texsize.Height ) ;
      
      getMaterial().setTexture(0, texture ); 
      getMaterial().getTextureMatrix( 0 ).buildTextureTransform( 0*DEGTORAD64, 
                                                   vector2df(0.f, 0.f),    
                                                   translation , 
                                                  uvScaleFactor ); 
   }