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GLCOPYTEXSUBIMAGE1D(3G)                                                              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  cur-rent current
       rent 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 + xwidth - 1, inclusive. The  destination
       in the texture array may not include any texels outside the texture array as it was originally speci-fied. specified.
       fied.

       The pixels in the row are processed exactly as if glCopyPixels 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  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 win-dow window
       dow 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
       glCopyTexSubImage1D is available only if the GL version is 1.1 or greater.

       Texturing has no effect in color index mode.

       glPixelStore and glPixelTransfer  modes  affect  texture  images  in  exactly  the  way  they  affect
       glDrawPixels.

       When  the  GL_ARB_imaging extension is supported, the RGBA components copied from the framebuffer may
       be processed by the imaging pipeline.  See glTexImage1D for specific details.

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  >  log2(  max),  where  max is the returned value of
       GL_MAX_TEXTURE_SIZE.

       GL_INVALID_VALUE is generated if y < -b or if width <  -b, where b is the border width of the texture
       array.

       GL_INVALID_VALUE  is  generated  if  xoffset  <  -b,  or  (f2xoffset+f2width) > (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
       glIsEnabled with argument GL_TEXTURE_1D

SEE ALSO
       glCopyPixels(3G),    glCopyTexImage1D(3G),    glCopyTexImage2D(3G),   glCopyTexSubImage2D(3G),   glCopyTexSubImage3D(3G),
       glPixelStore(3G),  glPixelTransfer(3G),  glReadBuffer(3G),  glTexEnv(3G),   glTexGen(3G),   glTexImage1D(3G),   glTexImage2D(3G),
       glTexImage3D(3G), glTexParameter(3G), glTexSubImage1D(3G), glTexSubImage2D(3G), glTexSubImage3D(3G)




                                                                                     GLCOPYTEXSUBIMAGE1D(3G)