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 or width 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 < 0, or xoffset + width > w, where w is the
       GL_TEXTURE_WIDTH of the texture image being modified.

ASSOCIATED GETS

       glGetTexImage()

SEE ALSO

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

COPYRIGHT

       Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2012-2013 Khronos Group. This
       document is licensed under the SGI Free Software B License. For details, see
       http://oss.sgi.com/projects/FreeB/.

AUTHORS

       opengl.org