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GLCOPYTEXSUBIMAGE1D(3G)                          OpenGL 3.3                          GLCOPYTEXSUBIMAGE1D(3G)



NAME
       glCopyTexSubImage1D - copy a one-dimensional texture subimage

C SPECIFICATION
       void glCopyTexSubImage1D(GLenum target, GLint level, GLint xoffset, GLint x, GLint y, GLsizei width);


PARAMETERS
       target
           Specifies the target texture. Must be GL_TEXTURE_1D.

       level
           Specifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap
           reduction image.

       xoffset
           Specifies the texel offset within the texture array.

       x, y
           Specify the window coordinates of the left corner of the row of pixels to be copied.

       width
           Specifies the width of the texture subimage.

DESCRIPTION
       glCopyTexSubImage1D replaces a portion of a one-dimensional texture image with pixels from the
       current GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage1D()).

       The screen-aligned pixel row with left corner at (x,\ y), and with length width replaces the portion
       of the texture array with x indices xoffset through xoffset + width - 1, inclusive. The destination
       in the texture array may not include any texels outside the texture array as it was originally
       specified.

       The pixels in the row are processed exactly as if glReadPixels() had been called, but the process
       stops just before final conversion. At this point, all pixel component values are clamped to the
       range 0 1 and then converted to the texture's internal format for storage in the texel array.

       It is not an error to specify a subtexture with zero width, but such a specification has no effect.
       If any of the pixels within the specified row of the current GL_READ_BUFFER are outside the read
       window associated with the current rendering context, then the values obtained for those pixels are
       undefined.

       No change is made to the internalformat, width, or border parameters of the specified texture array
       or to texel values outside the specified subregion.

NOTES
       The glPixelStore() mode affects texture images.

ERRORS
       GL_INVALID_ENUM is generated if /target is not GL_TEXTURE_1D.


       GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous
       glTexImage1D() or glCopyTexImage1D() operation.


       GL_INVALID_VALUE is generated if level is less than 0.


       GL_INVALID_VALUE may be generated if level > log 2 ^, max, where max is the returned value of
       GL_MAX_TEXTURE_SIZE.


       GL_INVALID_VALUE is generated if xoffset < - b, or xoffset + width > w - b, where w is the
       GL_TEXTURE_WIDTH and b is the GL_TEXTURE_BORDER of the texture image being modified. Note that w
       includes twice the border width.


ASSOCIATED GETS
       glGetTexImage()

SEE ALSO
       glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(), glPixelStore(),
       glReadBuffer(), glTexImage1D(), glTexImage2D(), glTexImage3D(), glTexParameter(), glTexSubImage1D(),
       glTexSubImage2D(), glTexSubImage3D()


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                          GLCOPYTEXSUBIMAGE1D(3G)