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Manual Reference Pages  - GLVIEWPORT (3G)

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glViewport - set the viewport

CONTENTS

C Specification
Parameters
Description
Errors
Associated Gets
See Also

void glViewport( GLint x,

               GLint y,
               GLsizei width,
               GLsizei height )

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.

 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.

 glGet with argument  GL_VIEWPORT
 glGet with argument  GL_MAX_VIEWPORT_DIMS

 glDepthRange(3G)

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