Materials: Support for Opposing Force its SNOW identifer for surfaces in

materials.txt

src/server/footsteps.h

@@ -27,6 +27,7 @@
 #define MATID_METAL		'M'
 #define MATID_SLOSH		'S'
 #define MATID_SNOW		'N'
+#define MATID_SNOW_OP4		'O' /* Gearbox uses a different symbol */
 #define MATID_TILE		'T'
 #define MATID_VENT		'V'
 #define MATID_WOOD		'W'

src/server/footsteps.qc

@@ -119,6 +119,7 @@ Footsteps_HLBSP(base_player target)
 		case MATID_SLOSH:
 			mat_name = "step_slosh";
 			break;
+		case MATID_SNOW_OP4:
 		case MATID_SNOW:
 			mat_name = "step_snow";
 			break;