diff --git a/apps/trimeshinfo/defs.h b/apps/trimeshinfo/defs.h
index cb59ad23..1122dc4f 100644
--- a/apps/trimeshinfo/defs.h
+++ b/apps/trimeshinfo/defs.h
@@ -1,18 +1,48 @@
+// -----------------------------------------------------------------------------------------------
 #ifndef _DEFS_H
 #define _DEFS_H
 // -----------------------------------------------------------------------------------------------
 
+// command line parameters
+#define CMD_LINE_ARG_HIST                           'H'
+#define CMD_LINE_ARG_VERTEX_SAMPLE                  'V'
+#define CMD_LINE_ARG_EDGE_SAMPLE                    'E'
+#define CMD_LINE_ARG_FACE_SAMPLE                    'F'
+#define CMD_LINE_ARG_SAMPLE_TYPE                    'S'
+#define CMD_LINE_ARG_MONTECARLO_SAMPLING            'M'
+#define CMD_LINE_ARG_SUBDIVISION_SAMPLING           'S'
+#define CMD_LINE_ARG_SIMILAR_TRIANGLES_SAMPLING     'T'
+#define CMD_LINE_ARG_N_SAMPLES                      'N'
+#define CMD_LINE_ARG_SAMPLES_PER_AREA_UNIT          'A'
+#define CMD_LINE_ARG_SAVE_DISPLACEMENT              'O'
+#define CMD_LINE_ARG_SAVE_ERROR_AS_COLOUR           'C'
+
+
 // error messages
-#define MSG_ERR_N_ARGS                  \
-  "\nUsage:  "\
-  "trimeshinfo filename [opt]\n"\
-  "where opt can be:\n"\
-  "     -x[y|n]  Enable or not XML info dumping (default no)\n"\
-	"     -a[y|n]  Enable or not ascii info dumping (default yes)\n"\
-  "     -o<filename.ext>  Save the input mesh in the specified format\n"
-			
+#define MSG_ERR_N_ARGS                  "\nUsage:  "\
+                                        "trimeshinfo filename \n"
+
 #define MSG_ERR_MESH_LOAD               "error loading the input meshes.\n"
 #define MSG_ERR_INVALID_OPTION          "unable to parse option '%s'\n"
+#define MSG_ERR_FILE_OPEN               "unable to open the output file.'n"
+#define MSG_ERR_UNKNOWN_FORMAT          "unknown file format '%s'.\n"
 
+// global constants
+#define NO_SAMPLES_PER_FACE             10
+#define N_SAMPLES_EDGE_TO_FACE_RATIO    0.1
+#define BBOX_FACTOR                     0.1
+#define INFLATE_PERCENTAGE			    0.02
+#define MIN_SIZE					    125		/* 125 = 5^3 */
+#define N_HIST_BINS                     256
+#define PRINT_EVERY_N_ELEMENTS          1000
+#define FILE_EXT_SMF                    "smf"
+#define FILE_EXT_PLY                    "ply"
+
+// strings
+#define STR_HIST_FILENAME_DEFAULT       "hist.txt"
+#define STR_NEW_MESH_FILENAME_DEFAULT   "error.ply"
+#define STR_NEW_MESH_FILENAME_DEFAULT_2 "error_colour.ply"
+
+// -----------------------------------------------------------------------------------------------
 #endif
 // -----------------------------------------------------------------------------------------------