glViewport - set the viewport
void glViewport( GLint x, GLint y, GLsizei width, GLsizei height )
x, y Specify the lower left corner of the viewport rectangle, in pixels.
The default is (0,0).
width, height
Specify the width and height, respectively, 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 , y ) be normalized
nd nd
device coordinates. Then the window coordinates x , y ) are computed as
follows: w w
width
x = (x +1)----- + x
w nd 2
height
y = (y +1)------ + y
w nd 2
Viewport width and height are silently clamped to a range that depends on
the implementation. This range is queried by calling glGet with argument
GL_MAX_VIEWPORT_DIMS.
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
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Last Edited: Fri, May 26, 1995