glViewport
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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 (xnd,ynd) be normalized device coordinates. Then the window coordinates (xw,yw) are computed as follows:

xw=(xnd+1)(
width
2
)+x
yw=(ynd+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

See Also

glDepthRange

Python Sample Code

glViewport

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