Index for Section 3G

Alphabetical listing for G

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glCopyTexSubImage2D(3G)
NAME
  glCopyTexSubImage2D - copy a two-dimensional texture subimage

SYNOPSIS
  void glCopyTexSubImage2D(
	  GLenum target,
	  GLint level,
	  GLint xoffset,
	  GLint yoffset,
	  GLint x,
	  GLint y,
	  GLsizei width,
	  GLsizei height );

PARAMETERS
  target
      Specifies the target texture. Must be GL_TEXTURE_2D.

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

  xoffset
      Specifies a texel offset in the x direction within the texture array.

  yoffset
      Specifies a texel offset in the y direction within the texture array.

  x, y
      Specify the window coordinates of the lower left corner of the
      rectangular region of pixels to be copied.

  width
      Specifies the width of the texture subimage.

  height
      Specifies the height of the texture subimage.

DESCRIPTION
  glCopyTexSubImage2D() replaces a rectangular portion of a two-dimensional
  texture image with pixels from the current GL_READ_BUFFER (rather than from
  main memory, as is the case for glTexSubImage2D()).

  The screen-aligned pixel rectangle with lower left corner at (x, y) and
  with width width and height height replaces the portion of the texture
  array with x indices xoffset through xoffset+width-1, inclusive, and y
  indices yoffset through yoffset+height-1, inclusive, at the mipmap level
  specified by level.

  The pixels in the rectangle 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.

  The destination rectangle in the texture array may not include any texels
  outside the texture array as it was originally specified. It is not an
  error to specify a subtexture with zero width or height, but such a
  specification has no effect.

  If any of the pixels within the specified rectangle 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, height, or border
  parameters of the specified texture array or to texel values outside the
  specified subregion.

NOTES
  glCopyTexSubImage2D() 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 read
  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_2D.

  GL_INVALID_OPERATION is generated if the texture array has not been defined
  by a previous glTexImage2D() or glCopyTexImage2D() operation.

  GL_INVALID_VALUE is generated if level is less than 0.

  GL_INVALID_VALUE may be generated if level is greater than log[2] max,
  where max is the returned value of GL_MAX_TEXTURE_SIZE.

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

  GL_INVALID_VALUE is generated if xoffset < -b, (xoffset+width)>(w -b),
  yoffset< -b, or (yoffset+height)>(h -b), where w is the GL_TEXTURE_WIDTH, h
  is the GL_TEXTURE_HEIGHT, and b is the GL_TEXTURE_BORDER of the texture
  image being modified. Note that w and h include twice the border width.

  GL_INVALID_OPERATION is generated if glCopyTexSubImage2D() is executed
  between the execution of glBegin() and the corresponding execution of
  glEnd().

ASSOCIATED GETS
       glGetTexImage()
       glIsEnabled() with argument GL_TEXTURE_2D

SEE ALSO
  glCopyPixels(3), glCopyTexImage1D(3), glCopyTexImage2D(3),
  glCopyTexSubImage1D(3), glCopyTexSubImage3D(3), glPixelStore(3),
  glPixelTransfer(3), glReadBuffer(3), glTexEnv(3), glTexGen(3),
  glTexImage1D(3), glTexImage2D(3), glTexImage3D(3), glTexParameter(3),
  glTexSubImage1D(3), glTexSubImage2D(3), glTexSubImage3D(3)

Index for Section 3G

Alphabetical listing for G

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