GLCOPYTEXIMAGE2D(3G) GLCOPYTEXIMAGE2D(3G)
NAME
glCopyTexImage2D - copy pixels into a 2D texture image
C SPECIFICATION
void glCopyTexImage2D( GLenum target,
GLint level,
GLenum internalformat,
GLint x,
GLint y,
GLsizei width,
GLsizei height,
GLint border )
PARAMETERS
target Specifies the target texture. Must be GLTEXTURE2D.
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 of the texture. Must be one of
the following symbolic constants: GLALPHA, GLALPHA4,
GLALPHA8, GLALPHA12, GLALPHA16, GLUMINANCE,
GLUMINANCE4, GLUMINANCE8, GLUMINANCE12,
GLUMINANCE16, GLUMINANCEALPHA,
GLUMINANCE4ALPHA4, GLUMINANCE6ALPHA2,
GLUMINANCE8ALPHA8, GLUMINANCE12ALPHA4,
GLUMINANCE12ALPHA12, GLUMINANCE16ALPHA16,
GLINTENSITY, GLINTENSITY4, GLINTENSITY8,
GLINTENSITY12, GLINTENSITY16, GLRGB, GLR3G3B2,
GLRGB4, GLRGB5, GLRGB8, GLRGB100, GLRGB12,
GLRGB16, GLRGBA, GLRGBA2, GLRGBA4, GLRGB5A1,
GLRGBA8, GLRGB100A2, GLRGBA12, or GLRGBA16.
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.
DESCRIPTION
glCopyTexImage2D defines a two-dimensional texture image with pixels
from the current GLREADBUFER.
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. internalfor-
mat specifies the internal 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 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
GLREADBUFER are outside the window associated with the current ren-
dering context, then the values obtained for those pixels are unde-
fined.
NOTES
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 NUL texture.
When the GLARBimaging extension is supported, the RGBA components
read from the framebuffer may be processed by the imaging pipeline.
See glTexImage1D for specific details.
ERORS
GLINVALIDENUM is generated if target is not GLTEXTURE2D.
GLINVALIDVALUE is generated if level is less than 0.
GLINVALIDVALUE may be generated if level is greater than log2(max),
where max is the returned value of GLMAXTEXTURESIZE.
GLINVALIDVALUE is generated if width or height is less than 0,
greater than 2]GLMAXTEXTURESIZE, or if width or height cannot be
represented as (2^k) ] 2*border for some integer k.
GLINVALIDVALUE is generated if border is not 0 or 1.
GLINVALIDVALUE is generated if internalformat is not one of the
allowable values.
GLINVALIDOPERATION is generated if glCopyTexImage2D is executed
between the execution of glBegin and the corresponding execution of
glEnd.
ASOCIATED GETS
glGetTexImage
glIsEnabled with argument GLTEXTURE2D
SEE ALSO
glCopyPixels, glCopyTexImage1D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glPixelStore, glPixelTransfer, glTexEnv, glTexGen,
glTexImage1D, glTexImage2D, glTexSubImage1D, glTexSubImage2D,
glTexParameter
GLCOPYTEXIMAGE2D(3G)
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