GL_ARB_copy_image http://www.opengl.org/registry/specs/gl/ARB/copy_image.txt GL_ARB_copy_image void glCopyImageSubData (GLuint srcName, GLenum srcTarget, GLint srcLevel, GLint srcX, GLint srcY, GLint srcZ, GLuint dstName, GLenum dstTarget, GLint dstLevel, GLint dstX, GLint dstY, GLint dstZ, GLsizei srcWidth, GLsizei srcHeight, GLsizei srcDepth)