fgluProject(3G) OpenGL Reference fgluProject(3G)NAMEfgluProject - map object coordinates to window coordinates
FORTRAN SPECIFICATION
INTEGER*4 fgluProject( REAL*4 objX,
REAL*4 objY,
REAL*4 objZ,
CHARACTER*8 model,
CHARACTER*8 proj,
CHARACTER*8 view,
CHARACTER*8 winX,
CHARACTER*8 winY,
CHARACTER*8 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.
DESCRIPTIONfgluProject 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 fgluProject 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) and
'x' represents matrix multiplication.
The window coordinates are then computed as follows:
winX = view(0) + view(2) * (v'(0) + 1) / 2
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fgluProject(3G) OpenGL Reference fgluProject(3G)
winY = view(1) + view(3) * (v'(1) + 1) / 2
winZ = (v'(2) + 1) / 2
SEE ALSO
glGet, fgluUnProject
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