- Method
glCopyTexSubImage1D
void glCopyTexSubImage1D(int target, int level, int xoffset, int x, int y, int width)
- Description
glCopyTexSubImage1D replaces a portion of a one-dimensional
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 (x,\ y), and with
length width replaces the portion of the
texture array with x indices xoffset through "xoffset" ~+~ "width" ~-~ 1,
inclusive. The destination in the texture array may not
include any texels outside 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 component values are clamped to the range [0,\ 1]
and then converted to the texture's internal format 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 values outside the specified subregion.
- Parameter target
Specifies the target texture.
Must be GL_TEXTURE_1D .
- Parameter level
Specifies the level-of-detail number.
Level 0 is the base image level.
Level n is the nth mipmap reduction image.
- Parameter xoffset
Specifies the texel offset within the texture array.
- Parameter x
Specify the window coordinates of the left corner
of the row of pixels to be copied.
- Parameter width
Specifies the width of the texture subimage.
- Throws
GL_INVALID_ENUM is generated if target 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 level is less than 0.
.P
GL_INVALID_VALUE may be generated if level>log sub 2 max,
where max is the returned value of GL_MAX_TEXTURE_SIZE .
GL_INVALID_VALUE is generated if y ~<~ ~-b
or if width ~<~ ~-b, where b
is the border width of the texture array.
GL_INVALID_VALUE is generated if "xoffset" ~<~ ~-b, or
("xoffset"~+~"width") ~>~ (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.
GL.glCopyTexImage2D()