glCopyTexSubImage3D — 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 or GL_TEXTURE_2D_ARRAY.
                
levelSpecifies the level-of-detail number. Level 0 is the base image level. Level n is the nth mipmap reduction image.
xoffsetSpecifies a texel offset in the x direction within the texture array.
yoffsetSpecifies a texel offset in the y direction within the texture array.
zoffsetSpecifies a texel offset in the z direction within the texture array.
x, ySpecify the window coordinates of the lower left corner of the rectangular region of pixels to be copied.
widthSpecifies the width of the texture subimage.
heightSpecifies the height of the texture subimage.
            glCopyTexSubImage3D replaces a rectangular portion of a three-dimensional
            or two-dimensional array 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
            glReadPixels 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, or depth parameters of the specified texture array or to texel values outside the specified subregion.
            GL_INVALID_ENUM is generated if target is not GL_TEXTURE_3D or GL_TEXTURE_2D_ARRAY.
        
            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 if target
            is GL_TEXTURE_3D or the returned value of GL_MAX_ARRAY_TEXTURE_LAYERS
            if target is GL_TEXTURE_2D_ARRAY.
        
            GL_INVALID_VALUE is generated if 
            GL_TEXTURE_WIDTH,
            GL_TEXTURE_HEIGHT, and
            GL_TEXTURE_DEPTH
            of the texture image being modified.
        
glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glPixelStore, glReadBuffer, 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/.