Provided by: opengl-4-man-doc_1.0~svn33624-1_all 
NAME
glCopyTexSubImage2D, glCopyTextureSubImage2D - copy a two-dimensional texture subimage
C SPECIFICATION
void glCopyTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset,
GLint x, GLint y, GLsizei width, GLsizei height);
void glCopyTextureSubImage2D(GLuint texture, GLint level, GLint xoffset, GLint yoffset,
GLint x, GLint y, GLsizei width, GLsizei height);
PARAMETERS
target
Specifies the target to which the texture object is bound for glCopyTexSubImage2D
function. Must be GL_TEXTURE_1D_ARRAY, GL_TEXTURE_2D, GL_TEXTURE_CUBE_MAP_POSITIVE_X,
GL_TEXTURE_CUBE_MAP_NEGATIVE_X, GL_TEXTURE_CUBE_MAP_POSITIVE_Y,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Y, GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, or GL_TEXTURE_RECTANGLE.
texture
Specifies the texture object name for glCopyTextureSubImage2D function.
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.
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.
DESCRIPTION
glCopyTexSubImage2D and glCopyTextureSubImage2D replace a rectangular portion of a
two-dimensional texture image, cube-map texture image, rectangular image, or a linear
portion of a number of slices of a one-dimensional array texture 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 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 + height - 1,
inclusive, 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 $[0,1]$ 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.
When target is GL_TEXTURE_1D_ARRAY then the y coordinate and height are treated as the
start slice and number of slices to modify.
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.
NOTES
glPixelStore() modes affect texture images.
ERRORS
GL_INVALID_ENUM is generated if target is not GL_TEXTURE_2D,
GL_TEXTURE_CUBE_MAP_POSITIVE_X, GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
GL_TEXTURE_CUBE_MAP_POSITIVE_Y, GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
GL_TEXTURE_CUBE_MAP_POSITIVE_Z, GL_TEXTURE_CUBE_MAP_NEGATIVE_Z, GL_TEXTURE_1D_ARRAY, or
GL_RECTANGLE.
GL_INVALID_FRAMEBUFFER_OPERATION is generated if the object bound to
GL_READ_FRAMEBUFFER_BINDING is not framebuffer complete.
GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous
glTexImage2D(), glTexStorage2D() or glCopyTexImage2D() operation.
GL_INVALID_OPERATION is generated by glCopyTextureSubImage2D if texture is not the name of
an existing texture object.
GL_INVALID_OPERATION is generated by glCopyTextureSubImage2D if the effective target of
texture does not correspond to one of the texture targets supported by the function.
GL_INVALID_VALUE is generated if level is less than 0.
GL_INVALID_VALUE is generated if the effective target is GL_TEXTURE_RECTANGLE and level is
not zero.
GL_INVALID_VALUE may be generated if level > log 2 max, where max is the returned value
of GL_MAX_TEXTURE_SIZE.
GL_INVALID_VALUE is generated if xoffset < 0, xoffset + width > w, yoffset < 0, or yoffset
+ height > 0,, where w is the GL_TEXTURE_WIDTH, h is the GL_TEXTURE_HEIGHT and of the
texture image being modified.
GL_INVALID_OPERATION is generated if:
• the read buffer is GL_NONE, or
• the value of GL_READ_FRAMEBUFFER_BINDING is non-zero, and:
• the read buffer selects an attachment that has no image attached, or
• the effective value of GL_SAMPLE_BUFFERS for the read framebuffer is one.
ASSOCIATED GETS
glGetTexImage()
VERSION SUPPORT
┌────────────────────────┬───────────────────────────────────────────────────────────────────────┐
│ │ OpenGL Version │
├────────────────────────┼─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┬─────┤
│Function │ 2.0 │ 2.1 │ 3.0 │ 3.1 │ 3.2 │ 3.3 │ 4.0 │ 4.1 │ 4.2 │ 4.3 │ 4.4 │ 4.5 │
│/ │ │ │ │ │ │ │ │ │ │ │ │ │
│Feature │ │ │ │ │ │ │ │ │ │ │ │ │
│Name │ │ │ │ │ │ │ │ │ │ │ │ │
├────────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│glCopyTexSubImage2D │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │ ✔ │
├────────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
│glCopyTextureSubImage2D │ - │ - │ - │ - │ - │ - │ - │ - │ - │ - │ - │ ✔ │
└────────────────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘
SEE ALSO
glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage1D(), glCopyTexSubImage3D(),
glPixelStore(), glReadBuffer(), glTexImage1D(), glTexImage2D(), glTexImage3D(),
glTexParameter(), glTexSubImage1D(), glTexSubImage2D(), glTexSubImage3D()
COPYRIGHT
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2012-2014 Khronos Group. This
document is licensed under the SGI Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.
COPYRIGHT
Copyright © 2014 Khronos Group
[FIXME: source] 01/03/2018 GLCOPYTEXSUBIMAGE2D(3G)