Name
glViewport — set the viewport
C Specification
void glViewport
| ( | GLint x
, GLint y
, GLsizei width
, GLsizei height
); |
Python Specification
glViewport
| ( |
x
,
y
,
width
,
height
) →
None
|
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
glViewport specifies the affine transformation of x and
y from normalized device coordinates to window coordinates. Let
x
nd
y
nd
be normalized device coordinates. Then the window coordinates
x
w
y
w
are computed as follows:
x
w
=
x
nd
+
1
width
2
+
x
y
w
=
y
nd
+
1
height
2
+
y
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.
Errors
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.
Associated Gets
glGet with argument GL_VIEWPORT
glGet with argument GL_MAX_VIEWPORT_DIMS