42/* Set up for C function definitions, even when using C++ */
43#ifdef __cplusplus
44extern"C" {
45#endif
46
47/**
48 * Compares a surface and with reference image data for equality
49 *
50 * \param surface Surface used in comparison
51 * \param referenceSurface Test Surface used in comparison
52 * \param allowable_error Allowable difference (=sum of squared difference for each RGB component) in blending accuracy.
53 *
54 * \returns 0 if comparison succeeded, >0 (=number of pixels for which the comparison failed) if comparison failed, -1 if any of the surfaces were NULL, -2 if the surface sizes differ.