add some comments to the top

docs/example.Xresources

@@ -56,6 +56,7 @@ spmenu.colorprompt:        1
 spmenu.preselected:        0
 spmenu.type:               1
 spmenu.class:              spmenu
+spmenu.mon:                -1
 spmenu.leftarrow:          <
 spmenu.rightarrow:         >
 spmenu.password:           .

libs/xresources.h

@@ -128,6 +128,7 @@ ResourcePref resources[] = {
     { "generatecache",       INTEGER, &generatecache },
     { "mode",                INTEGER, &mode },
     { "fast",                INTEGER, &fast },
+    { "mon",                 INTEGER, &mon },
     { "pango_item",          INTEGER, &pango_item },
     { "pango_prompt",        INTEGER, &pango_prompt },
     { "pango_input",         INTEGER, &pango_input },

options.h

@@ -7,6 +7,7 @@
 static char class[]                    = "spmenu"; /* Class for spmenu */
 static int fast                        = 0; /* Grab keyboard first */
 static int xresources                  = 1; /* Enable .Xresources support */
+static int mon                         = -1; /* Monitor to run spmenu on */
 
 /* Window options */
 static int alpha                       = 1; /* Enable alpha */

spmenu.c

@@ -1,4 +1,20 @@
-/* See LICENSE file for copyright and license details. */
+/* spmenu - speedie's dmenu fork
+ *
+ * If you're looking for functions used to draw text, see 'libs/draw.c'
+ * If you're looking for wrapper functions used inside the draw functions, see 'libs/sl/draw.c'
+ * If you're looking for functions used to draw images, see 'libs/img.c'
+ * If you're looking for the .Xresources array, see 'libs/xresources.h'
+ *
+ * To disable certain features, pass one or more of the following to the compiler:
+ *
+ * NOXINERAMA, NORTL, NOIMAGE
+ *
+ * You don't need to edit spmenu.c if you aren't making big changes to the software.
+ *
+ * After making changes, run 'make clean install' to install and 'make' to attempt a compilation.
+ * `make man` will generate a man page from 'docs/docs.md', which is a Markdown document. Run this before commiting.
+ *
+ * See LICENSE file for copyright and license details. */
 #include <ctype.h>
 #include <locale.h>
 #include <math.h>
@@ -30,6 +46,13 @@
 #define USEXINERAMA 0
 #endif
 
+/* NOXINERAMA overrides XINERAMA */
+#ifdef NOXINERAMA
+#define USEXINERAMA 0
+#else
+#define USEXINERAMA 1
+#endif
+
 /* include right to left language library */
 #if USERTL
 #include <fribidi.h>
@@ -87,6 +110,7 @@
 #include "libs/schemes.h"
 #include "libs/arg.h"
 #include "libs/mode.h"
+#include "libs/xrdb.h"
 
 static char text[BUFSIZ] = "";
 
@@ -125,15 +149,19 @@ static unsigned int selected = 0;
 static struct item *items = NULL, *backup_items;
 static struct item *matches, *matchend;
 static struct item *prev, *curr, *next, *sel;
-static int mon = -1, screen;
+static int screen;
 static int managed = 0;
 
+/* image globals */
 static int flip = 0;
 static int rotation = 0;
 static int imagew = 0;
 static int imageh = 0;
 static int imageg = 0;
 
+/* set an integer if to 1 if we have right to left language support enabled
+ * doing it this way, because we can reduce the amount of #if and #else lines used.
+ */
 #if USERTL
 static int isrtl = 1;
 #else
@@ -190,13 +218,12 @@ static void readstdin(void);
 static void recalculatenumbers(void);
 static void usage(void);
 
-#include "libs/xrdb.h"
-
 /* user configuration */
 #include "options.h" /* Include main header */
 #include "keybinds.h" /* Include keybinds */
-#include "colors.h" /* Include colors */
-#include "xresources.h" /* Include .Xresources */
+
+#include "libs/xresources.h"
+#include "libs/colors.h"
 
 static char * cistrstr(const char *s, const char *sub);
 static int (*fstrncmp)(const char *, const char *, size_t) = strncasecmp;