Страницы справочника OS X

Эта страница руководства является частью версии 5.0 Инструментов XCode

Читать страницы руководства

GLSCISSOR(3G)                                    OpenGL 3.3                                    GLSCISSOR(3G)



NAME
       glScissor - define the scissor box

C SPECIFICATION
       void glScissor(GLint x, GLint y, GLsizei width, GLsizei height);

PARAMETERS
       x, y
           Specify the lower left corner of the scissor box. Initially (0, 0).

       width, height
           Specify the width and height of the scissor box. When a GL context is first attached to a window,
           width and height are set to the dimensions of that window.

DESCRIPTION
       glScissor defines a rectangle, called the scissor box, in window coordinates. The first two
       arguments, x and y, specify the lower left corner of the box.  width and height specify the width and
       height of the box.

       To enable and disable the scissor test, call glEnable() and glDisable() with argument
       GL_SCISSOR_TEST. The test is initially disabled. While the test is enabled, only pixels that lie
       within the scissor box can be modified by drawing commands. Window coordinates have integer values at
       the shared corners of frame buffer pixels.  glScissor(0,0,1,1) allows modification of only the lower
       left pixel in the window, and glScissor(0,0,0,0) doesn't allow modification of any pixels in the
       window.

       When the scissor test is disabled, it is as though the scissor box includes the entire window.

ERRORS
       GL_INVALID_VALUE is generated if either width or height is negative.

ASSOCIATED GETS
       glGet() with argument GL_SCISSOR_BOX


       glIsEnabled() with argument GL_SCISSOR_TEST

SEE ALSO
       glEnable(), glViewport()


COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software
       B License. For details, see http://oss.sgi.com/projects/FreeB/.



OpenGL 3.3                                       03/08/2011                                    GLSCISSOR(3G)