glCopyTexImage2D - copy pixels into a	2D texture image

glCopyTexImage2D
	glCopyTexImage2D(target, level, internalFormat, x, y, width, height, border) -> None

void glCopyTexImage2D( GLenum	target,
                       GLint level,
                       GLenum	internalFormat,
                       GLint x,
                       GLint y,
                       GLsizei width,
                       GLsizei height,
                       GLint border )

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.

internalFormat  Specifies the	internal format	of the
                texture.  Must be one	of the following
                symbolic constants:  GL_ALPHA, GL_ALPHA4,
                GL_ALPHA8, GL_ALPHA12, GL_ALPHA16,
                GL_LUMINANCE,	GL_LUMINANCE4, GL_LUMINANCE8,
                GL_LUMINANCE12, GL_LUMINANCE16,
                GL_LUMINANCE_ALPHA, GL_LUMINANCE4_ALPHA4,
                GL_LUMINANCE6_ALPHA2,	GL_LUMINANCE8_ALPHA8,
                GL_LUMINANCE12_ALPHA4,
                GL_LUMINANCE12_ALPHA12,
                GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
                GL_INTENSITY4, GL_INTENSITY8,
                GL_INTENSITY12, GL_INTENSITY16, GL_RGB,
                GL_R3_G3_B2, GL_RGB4,	GL_RGB5, GL_RGB8,
                GL_RGB10, GL_RGB12, GL_RGB16,	GL_RGBA,
                GL_RGBA2, GL_RGBA4, GL_RGB5_A1, GL_RGBA8,
                GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.

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 image.
                Must be 0 or 2**n + 2*border for some
                integer n.

height	  Specifies the	height of the texture image.
                Must be 0 or 2**m + 2*border for some
                integer m.

border	  Specifies the	width of the border.  Must be
                either 0 or 1.

glCopyTexImage2D defines a two-dimensional texture image
with pixels from the current GL_READ_BUFFER.

The screen-aligned pixel rectangle with lower	left corner at
(x, y) and with a width of width + 2 * border	and a height
of height + 2	* border defines the texture array at the
mipmap level specified by level.  internalFormat specifies
the internal format of the texture array.

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 format	for storage in the texel
array.

Pixel	ordering is such that lower x and y screen coordinates
correspond to	lower s	and t texture coordinates.

If any of the	pixels within the specified rectangle of the
current GL_READ_BUFFER are outside the window	associated
with the current rendering context, then the values obtained
for those pixels are undefined.

glCopyTexImage2D is available	only if	the GL version is 1.1
or greater.

Texturing has	no effect in color index mode.

1, 2,	3, and 4 are not accepted values for internalFormat.

An image with	height or width	of 0 indicates a NULL texture.

GL_INVALID_ENUM is generated if target is not	GL_TEXTURE_2D.

GL_INVALID_VALUE is generated	if level is less than 0.

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

GL_INVALID_VALUE is generated	if width or height is less
than 0, greater than 2 + GL_MAX_TEXTURE_SIZE,	or if width or
height cannot	be represented as 2**k + 2 * border for	some
integer k.

GL_INVALID_VALUE is generated	if border is not 0 or 1.

GL_INVALID_VALUE is generated	if internalFormat is not one
of the allowable values.

GL_INVALID_OPERATION is generated if glCopyTexImage2D	is
executed between the execution of glBegin and	the
corresponding	execution of glEnd.

glGetTexImage
glIsEnabled with argument GL_TEXTURE_2D

glCopyPixels,	glCopyTexImage1D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glPixelStore, glPixelTransfer,
glTexEnv, glTexGen, glTexImage1D, glTexImage2D,
glTexSubImage1D, glTexSubImage2D,
glTexParameter