glCopyTexSubImage2D: copy a two-dimensional texture subimage.
C Specification |
Associated Gets |
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
- Specifies the target texture. Must be GL_TEXTURE_2D
- Specifies the level-of-detail number. Level 0 is the base image level.
Level n is the nth mipmap reduction image.
- Specifies a texel offset in the X direction within the texture array.
- 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.
- Specifies the width of the texture subimage.
- Specifies the height of the texture subimage.
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 +
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 format 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
No change is made to the internalformat,
width, height, or border
parameters of the specified texture array or to texel values outside the
glCopyTexSubImage2D is available only if the GL version is 1.1 or
Texturing has no effect in color index mode.
glPixelStore and glPixelTransfer modes affect texture
images in exactly the way they affect glDrawPixels.
- GL_INVALID_ENUM is generated if target is
- 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 log2
max, where max is the returned value of
- GL_INVALID_VALUE is generated if x
< b or if
y < b, where b is the border width of the texture
- 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
glIsEnabled with argument