fglViewport(3G) OpenGL Reference fglViewport(3G)NAME
fglViewport - set the viewport
FORTRAN SPECIFICATION
SUBROUTINE fglViewport( INTEGER*4 x,
INTEGER*4 y,
INTEGER*4 width,
INTEGER*4 height )
PARAMETERS
x, y Specify the lower left corner of the viewport rectangle, in pixels.
The initial value is (0,0).
width, height
Specify the width and height of the viewport. When a GL context is
first attached to a window, width and height are set to the
dimensions of that window.
DESCRIPTION
fglViewport specifies the affine transformation of x and y from
normalized device coordinates to window coordinates. Let (x , y ) be
nd nd
normalized device coordinates. Then the window coordinates (x , y ) are
w w
computed as follows:
(_____)
x = (x + 1) + x
w nd ( 2 )
(______)
y = (y + 1) + y
w nd ( 2 )
Viewport width and height are silently clamped to a range that depends on
the implementation. To query this range, call fglGet with argument
GL_MAX_VIEWPORT_DIMS.
ERRORS
GL_INVALID_VALUE is generated if either width or height is negative.
GL_INVALID_OPERATION is generated if fglViewport is executed between the
execution of fglBegin and the corresponding execution of fglEnd.
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fglViewport(3G) OpenGL Reference fglViewport(3G)ASSOCIATED GETS
fglGet with argument GL_VIEWPORT
fglGet with argument GL_MAX_VIEWPORT_DIMS
SEE ALSO
fglDepthRange
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