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GL
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Method GL.glViewport()
- Method
glViewport
void glViewport(int x, int y, int width, int height)
- Description
glViewport specifies the affine transformation of x and y from
normalized device coordinates to window coordinates.
Let (x sub nd, y sub nd) be normalized device coordinates.
Then the window coordinates (x sub w, y sub w) are computed as follows:
.sp
.ce
.EQ
x sub w ~=~ ( x sub nd + 1 ) left ( "width" over 2 right ) ~+~ "x"
.EN
.sp
.ce
.EQ
y sub w ~=~ ( y sub nd + 1 ) left ( "height" over 2 right ) ~+~ "y"
.EN
.RE
Viewport width and height are silently clamped
to a range that depends on the implementation.
To query this range, call glGet with argument
GL_MAX_VIEWPORT_DIMS .
- Parameter x
Specify the lower left corner of the viewport rectangle,
in pixels. The initial value is (0,0).
- Parameter width
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.
- Throws
GL_INVALID_VALUE is generated if either width or height is negative.
GL_INVALID_OPERATION is generated if glViewport
is executed between the execution of glBegin
and the corresponding execution of glEnd .
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