GLUPROJECT(3G)

NAME
gluProject - map object coordinates to window coordinates

C SPECIFICATION
GLint gluProject( GLdouble objX,
	GLdouble objY,
	GLdouble objZ,
	const GLdouble *model,
	const GLdouble *proj,
	const GLint *view,
	GLdouble* winX,
	GLdouble* winY,
	GLdouble* winZ )

PARAMETERS

objX, objY, objZ
    Specify the object coordinates.

model
    Specifies the current modelview matrix (as from a glGetDoublev call).

proj
    Specifies the current projection matrix (as from a glGetDoublev call).

view
    Specifies the current viewport (as from a glGetIntegerv call).

winX, winY, winZ
    Return the computed window coordinates.

DESCRIPTION
gluProject transforms the specified object coordinates into window coordinates using model, proj, and view. The result is stored in winX, winY, and winZ. A return value of GL_TRUE indicates success, a return value of GL_FALSE indicates failure.

To compute the coordinates, let v = (objX, objY, objZ, 1.0) represented as a matrix with 4 rows and 1 column. Then gluProject computes v' as follows:
v' = P X M X v where P is the current projection matrix proj, M is the current modelview matrix model (both represented as 4x4 matrices in column-major order) 'X' represents matrix multiplication.

The window coordinates are then computed as follows: winX = view(0) + view(2) * (v'(0)+1)/2 winY = view(1) + view(3) * (v'(1)+1)/2 winZ = (v'(2) + 1) / 2

SEE ALSO
glGet, gluUnProject