Convert a homography matrix to a gl 4x4 matrix to apply the homography to a gl texture

gistfile1.cpp

		/* calculate a new homography matrix if the src or dst quads have changed */
		if(x->changed)
		{
			// cvFindHomography(x,x,x); // can also use this, it is supposedly more accurate, but requires some unnessesary copies and i didn't see a difference
			cvWarpPerspectiveQMatrix( x->cvsrc, x->cvdst, x->homographyMatrix );  // calculate homography
			x->changed = 0;	
		}
		
		// output the transformation matrix	(format it as a 4x4 matrix that works with opengl)	
		  
		// x->homographyMatrix->data.fl;
		// is a 3 X 3 homography matrix.  we need a 4 x 4 transformation matrix.  they are related!
	
		float *data = x->homographyMatrix->data.fl;
		
		op2 = out2_bp;
		
		// WE NEED A 4x4 GLMATRIX that we can glPushMatrix()
		// 0 [ 0 0 0 0 ]
		// 1 [ 0 0 0 0 ]
		// 2 [ 0 0 0 0 ]
		// 3 [ 0 0 0 0 ]

  

// [data[0], data[1], 0, data[2]]
// [data[3], data[4], 0, data[5]]
// [      0,       0, 1,       0]
// [data[5], data[7], 0,       1]


		// first row
		op2 = out2_bp + 0*out2_minfo.dimstride[0];
		*op2++ = data[0];
		*op2++ = data[1];
		*op2++ = 0;
		*op2++ = data[2];

		
		// second row
		op2 = out2_bp + 1*out2_minfo.dimstride[0];
		*op2++ = data[3];
		*op2++ = data[4];
		*op2++ = 0;
		*op2++ = data[5];
		
		// third row
		op2 = out2_bp + 2*out2_minfo.dimstride[0];
		*op2++ = 0;
		*op2++ = 0;
		*op2++ = 1;
		*op2++ = 0;
		
		// fourth row
		op2 = out2_bp + 3*out2_minfo.dimstride[0];
		*op2++ = data[6];
		*op2++ = data[7];
		*op2++ = 0;
		*op2++ = 1;