NAME

       glCopyTexSubImage1D, glCopyTextureSubImage1D - copy a one-dimensional texture subimage

C SPECIFICATION

       void glCopyTexSubImage1D(GLenum target, GLint level, GLint xoffset, GLint x, GLint y, GLsizei width);

       void glCopyTextureSubImage1D(GLuint texture, GLint level, GLint xoffset, GLint x, GLint y,
                                    GLsizei width);

PARAMETERS

       target
           Specifies the target to which the texture object is bound for glCopyTexSubImage1D function. Must be
           GL_TEXTURE_1D.

       texture
           Specifies the texture object name for glCopyTextureSubImage1D 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 the texel offset within the texture array.

       x, y
           Specify the window coordinates of the left corner of the row of pixels to be copied.

       width
           Specifies the width of the texture subimage.

DESCRIPTION

       glCopyTexSubImage1D and glCopyTextureSubImage1D replace 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()). For glCopyTexSubImage1D, the texture object that is bound to target will be used for
       the process. For glCopyTextureSubImage1D, texture tells which texture object should be used for the
       purpose of the call.

       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 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.

       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 or width parameters of the specified texture array or to texel
       values outside the specified subregion.

NOTES

       The glPixelStore() mode affects texture images.

ERRORS

       GL_INVALID_ENUM is generated by glCopyTexSubImage1D if target is not GL_TEXTURE_1D.

       GL_INVALID_FRAMEBUFFER_OPERATION is generated if the object bound to GL_READ_FRAMEBUFFER_BINDING is not
       framebuffer complete.

       GL_INVALID_OPERATION is generated by glCopyTextureSubImage1D if texture is not the name of an existing
       texture object, or if the effective target of texture is not GL_TEXTURE_1D.

       GL_INVALID_OPERATION is generated if the texture array has not been defined by a previous glTexImage1D(),
       glCopyTexImage1D(), or glTexStorage1D() operation.

       GL_INVALID_VALUE is generated if level is less than 0.

       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, or xoffset + width > w, where w is the GL_TEXTURE_WIDTH 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                    │     │     │     │     │     │     │     │     │     │     │     │     │
       ├─────────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
       │ glCopyTexSubImage1D     │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │  ✔  │
       ├─────────────────────────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┼─────┤
       │ glCopyTextureSubImage1D │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  -  │  ✔  │
       └─────────────────────────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┴─────┘

SEE ALSO

       glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage2D(), 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                            GLCOPYTEXSUBIMAGE1D(3G)