Need help with transformed vertex from OpenGL matrix

[CharlieB]

From the OpenGL FAQ:

How do I find the coordinates of a vertex transformed only by the ModelView
matrix?

It's often useful to obtain the eye coordinate space value of a vertex
(i.e., the object space vertex transformed by the ModelView matrix). You
can obtain this by retrieving the current ModelView matrix and performing
simple vector / matrix multiplication.

This is exactly what I need. However I cannot figure out how to multiply the
vertex by the returned ModelView matrix. (It may be simple to them but not
me :-) )

Here is what I had in mind but it doesn't look right:

/* Transforms the points array in p1 to p2 by multipling by OpenGL matrix
glmatrix */
void multi_glmatrix_vertex (GLfloat *glmatrix, POINT *p1, POINT *p2,
int num_points)
{
int i;
for (i = 0; i < num_points; i++)
{
p2[i].x = (p1[i].x * glmatrix[0]) + (p1[i].y * glmatrix[4]) +
(p1[i].z * glmatrix[8]) + glmatrix[12];
p2[i].y = (p1[i].x * glmatrix[1]) + (p1[i].y * glmatrix[5]) +
(p1[i].z * glmatrix[9]) + glmatrix[13];
p2[i].z = (p1[i].x * glmatrix[2]) + (p1[i].y * glmatrix[6]) +
(p1[i].z * glmatrix[10]) + glmatrix[14];
}
}

Thanks in advance,
Charlie

[fungus]

CharlieB wrote:
>
> Here is what I had in mind but it doesn't look right:
>

It looks right to me.

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[CharlieB]

fungus wrote:

> CharlieB wrote:
>>
>> Here is what I had in mind but it doesn't look right:
>>
>
> It looks right to me.
>
>

Oh. I'll start using it. Thanks.