- copy a one-dimensional texture subimage
C SPECIFICATION
PARAMETERS
_param1 Specifies the target texture. Must be
GL_TEXTURE_1D.
_param2 Specifies the level-of-detail number. Level 0 is
the base image level. Level n is the nth mipmap
reduction image.
_param3 Specifies the texel offset within the texture
array.
_param4, _param5
Specify the window coordinates of the left corner
of the row of pixels to be copied.
_param6 Specifies the width of the texture subimage.
DESCRIPTION
glCopyTexSubImage1D replaces a portion of a one-dimen-
sional 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
(_param4, _param5), and with length _param6 replaces the
portion of the texture array with x indices _param3
through _eqnparam3+_eqnparam6-1, inclusive. The destina-
tion in the texture array may not include any texels out-
side the texture 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 compo-
nent values are clamped to the range [0, 1] and then con-
verted 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 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 val-
ues outside the specified subregion.
ERRORS
GL_INVALID_ENUM is generated if _param1 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 _param2 is less than 0.
GL_INVALID_VALUE may be generated if _param2>log2 max,
where max is the returned value of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if _param5<-b or if
_param6<-b, where b is the border width of the texture
array.
GL_INVALID_VALUE is generated if _eqnparam3<-b, or
(_eqnparam3+_eqnparam6)>(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, glCopyTexImage1D, glCopyTexImage2D,
glCopyTexSubImage2D, glCopyTexSubImage3D, glPixelStore,
glPixelTransfer, glReadBuffer, glTexEnv, glTexGen,
glTexImage1D, glTexImage2D, glTexImage3D, glTexParameter,
glTexSubImage1D, glTexSubImage2D, glTexSubImage3D
1