GL_EXT_texture_view
http://www.opengl.org/registry/specs/EXT/texture_view.txt
GL_EXT_texture_view

	GL_TEXTURE_VIEW_MIN_LEVEL_EXT 0x82DB
	GL_TEXTURE_VIEW_NUM_LEVELS_EXT 0x82DC
	GL_TEXTURE_VIEW_MIN_LAYER_EXT 0x82DD
	GL_TEXTURE_VIEW_NUM_LAYERS_EXT 0x82DE
	GL_TEXTURE_IMMUTABLE_LEVELS 0x82DF
	void glTextureViewEXT (GLuint texture, GLenum target, GLuint origtexture, GLenum internalformat, GLuint minlevel, GLuint numlevels, GLuint minlayer, GLuint numlayers)
