glCopyTexSubImage1D(3)

NAME

       glCopyTexSubImage1D - copy a one-dimensional texture subimage

C SPECIFICATION

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

       delim $$

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 destina-
       tion in the texture array may not include any texels outside  the  tex-
       ture array as it was originally specified.

       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 window associ-
       ated 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$>log sub 2$ 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  $("xoff-
       set"~+~"width")  ~>~ (w-b)$, 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
       glIsEnabled with argument GL_TEXTURE_1D

glCopyTexSubImage1D(3)

NAME

C SPECIFICATION

PARAMETERS

DESCRIPTION

NOTES

ERRORS

ASSOCIATED GETS

SEE ALSO