glCopyTexSubImage3D â copy a three-dimensional texture subimage
void glCopyTexSubImage3D( | GLenum  | target, |
|  | GLint  | level, |
|  | GLint  | xoffset, |
|  | GLint  | yoffset, |
|  | GLint  | zoffset, |
|  | GLint  | x, |
|  | GLint  | y, |
|  | GLsizei  | width, |
|  | GLsizei  | height); |
+
target
+ Specifies the target texture.
+ Must be GL_TEXTURE_3D
+
level+ Specifies the level-of-detail number. + Level 0 is the base image level. + Level n is the nth mipmap reduction image. +
xoffset+ Specifies a texel offset in the x direction within the texture array. +
yoffset+ Specifies a texel offset in the y direction within the texture array. +
zoffset+ Specifies a texel offset in the z 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. +
width+ Specifies the width of the texture subimage. +
height+ Specifies the height of the texture subimage. +
+ glCopyTexSubImage3D replaces a rectangular portion of a three-dimensional
+ texture image with pixels from the current GL_READ_BUFFER (rather
+ than from main memory, as is the case for glTexSubImage3D).
+
+ 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
+ yoffset through
+ zoffset and 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
+
+ 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 undefined.
+
+ No change is made to the internalformat, width, + height, depth, or border parameters of the specified texture + array or to texel values outside the specified subregion. +
+ glCopyTexSubImage3D is available only if the GL version is 1.2 or greater.
+
+ Texturing has no effect in color index mode. +
+ glPixelStore and glPixelTransfer modes affect texture images + in exactly the way they affect glDrawPixels. +
+ When the ARB_imaging extension is supported, the RGBA components
+ copied from the framebuffer may be processed by the imaging pipeline, as
+ if they were a two-dimensional texture. See glTexImage2D for
+ specific details.
+
+ GL_INVALID_ENUM is generated if /target is not GL_TEXTURE_3D.
+
+ GL_INVALID_OPERATION is generated if the texture array has not
+ been defined by a previous glTexImage3D operation.
+
+ GL_INVALID_VALUE is generated if level is less than 0.
+
+ GL_INVALID_VALUE may be generated if
+ GL_MAX_3D_TEXTURE_SIZE.
+
+ GL_INVALID_VALUE is generated if
+ GL_TEXTURE_WIDTH,
+ GL_TEXTURE_HEIGHT,
+ GL_TEXTURE_DEPTH,
+ and
+ GL_TEXTURE_BORDER
+ of the texture image being modified.
+ Note that
+
+ GL_INVALID_OPERATION is generated if glCopyTexSubImage3D is executed
+ between the execution of glBegin and the corresponding
+ execution of glEnd.
+
+ glCopyPixels, + glCopyTexImage1D, + glCopyTexImage2D, + glCopyTexSubImage1D, + glCopyTexSubImage2D, + glPixelStore, + glPixelTransfer, + glReadBuffer, + glTexEnv, + glTexGen, + glTexImage1D, + glTexImage2D, + glTexImage3D, + glTexParameter, + glTexSubImage1D, + glTexSubImage2D, + glTexSubImage3D +
+ Copyright © 1991-2006 + Silicon Graphics, Inc. This document is licensed under the SGI + Free Software B License. For details, see + http://oss.sgi.com/projects/FreeB/. +