glCopyTexSubImage2D(3G)


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]                   07/22/2015           GLCOPYTEXSUBIMAGE2D(3G)





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