glCopyTexSubImage2D — copy a two-dimensional texture subimage
Specifies the target texture. Must be
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.
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.
glCopyTexSubImage2D replaces a rectangular portion of a two-dimensional texture image or cube-map texture image with pixels from the current
GL_READ_BUFFER (rather than from main memory, as is the case for glTexSubImage2D).
The screen-aligned pixel rectangle with lower left corner at and with width
width and height
height replaces the portion of the texture array with x indices
xoffset through , inclusive, and y indices
yoffset through , inclusive, at the mipmap level specified by
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 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 undefined.
No change is made to the internalformat, width or height parameters of the specified texture array or to texel values outside the specified subregion.
glPixelStore modes affect texture images.
GL_INVALID_ENUM is generated if
target is not
GL_INVALID_VALUE is generated if
level is less than 0.
GL_INVALID_VALUE may be generated if , where is the returned value of
GL_INVALID_VALUE is generated if , , , or , where is the
GL_TEXTURE_WIDTH, and is the
GL_TEXTURE_HEIGHT of the texture image being modified.
glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage3D, 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/.