The right one is this dear
Procedure Matrix_to_Win; var model, proj, Winx,Winy,Winz : PGLdouble; Matrixx,Matrixy,Matrixz : real; view : PGLint; begin {view := 0; model := GL_MODELVIEW; proj := GL_PROJECTION;} Winx := 0; Winy := 0; Winz := 0; Matrixx := 0; Matrixy := 0; Matrixz := 0; glGetDoublev(GL_MODELVIEW_MATRIX, model); glGetDoublev(GL_PROJECTION_MATRIX, proj); glGetIntegerv(GL_VIEWPORT, view); gluProject(Matrixx, Matrixy, Matrixz, model, proj, view, Winx, Winy, Winz); end;