add simple (nice) cascading

config.def.h

@@ -102,6 +102,11 @@
  * BEHAVIOR * [Everything in this section is optional unless otherwise noted]
  ***********/
 
+/* If this is at least 2, pretty cascading is enabled, and newly spawned windows
+ * will try to respect it instead of centering */
+
+#define CASCADE_DENSITY 4
+
 /* This sets the size ratio for windows spawned via keyboard or
  * center-snapped; CENTERNUM should be >= 2, so use 2/4 instead of 1/2
  */

dat.h

@@ -198,3 +198,6 @@ extern int kbLaunch;
 
 extern int nmonitors;
 extern XRRMonitorInfo* monitorinfo;
+
+extern int* xstep;
+extern int* ystep;

event.c

@@ -211,10 +211,16 @@ void configurereq(XConfigureRequestEvent* e) {
 
 void mapreq(XMapRequestEvent* e) {
   Client* c;
-  int i;
+  int i, m;
   XRRMonitorInfo monitor;
 
-  monitor = monitorinfo[getmonitorbymouse()];
+#ifdef MONITORFOLLOWSMOUSE
+  m = getmonitorbymouse();
+#else
+  m = getmonitorbyclient(current);
+#endif
+
+  monitor = monitorinfo[m];
 
   curtime = CurrentTime;
   c = getclient(e->window, 0);
@@ -236,7 +242,7 @@ void mapreq(XMapRequestEvent* e) {
     }
   }
 
-  if (kbLaunch) {
+  if (kbLaunch && CASCADE_DENSITY < 2) {
     // usleep(MICROSLEEP_DELAY);
 #ifdef CENTERVMAX
     centerclient(c, monitor, 1);
@@ -244,6 +250,8 @@ void mapreq(XMapRequestEvent* e) {
     centerclient(c, monitor, 0);
 #endif
     kbLaunch = 0;
+  } else if (CASCADE_DENSITY >= 2 && c->trans == None) {
+    getcascadecoords(c->window, m, &(c->x), &(c->y));
   }
   switch (c->state) {
     case WithdrawnState:

fns.h

@@ -130,3 +130,4 @@ void fetchmonitorinfo();
 int getmonitorbyclient(Client*);
 int getmonitorbymouse();
 void wrangle(Client*, XRRMonitorInfo);
+void getcascadecoords(Window, int, int*, int*);

monitor.c

@@ -8,12 +8,58 @@
 
 int nmonitors = 0;
 XRRMonitorInfo* monitorinfo;
+int* xstep;
+int* ystep;
 
 void fetchmonitorinfo() {
   if (monitorinfo)
     XRRFreeMonitors(monitorinfo);
+  if (xstep)
+    free(xstep);
+  if (ystep)
+    free(ystep);
 
   monitorinfo = XRRGetMonitors(dpy, DefaultRootWindow(dpy), 1, &nmonitors);
+  xstep = malloc(nmonitors * sizeof(int));
+  ystep = malloc(nmonitors * sizeof(int));
+  for (int i = 0; i < nmonitors; i++) {
+    xstep[i] = monitorinfo[i].width / CASCADE_DENSITY;
+    ystep[i] = monitorinfo[i].height / CASCADE_DENSITY;
+  }
+}
+
+void getcascadecoords(Window w, int monitor, int* x, int* y) {
+  int mappedclients = 0;
+  Client* c;
+  int ox = monitorinfo[monitor].x;
+  int oy = monitorinfo[monitor].y;
+
+  if (w == 0)
+    return;
+  for (c = clients; c; c = c->next) {
+    if (
+      c->window != w && c->state == NormalState &&
+      getmonitorbyclient(c) == monitor) {
+      mappedclients++;
+    }
+  }
+  for (;;) {
+    if (mappedclients < CASCADE_DENSITY) {
+      *x = ox + mappedclients * xstep[monitor];
+      *y = oy + mappedclients * ystep[monitor];
+      return;
+    } else if (mappedclients < 1.5 * CASCADE_DENSITY) {
+      *x = ox + (mappedclients - CASCADE_DENSITY + 1) * xstep[monitor];
+      *y = oy + (mappedclients - CASCADE_DENSITY) * ystep[monitor];
+      return;
+    } else if (mappedclients < 2 * CASCADE_DENSITY) {
+      *x = ox + (mappedclients - 1.5 * CASCADE_DENSITY) * xstep[monitor];
+      *y = oy + (mappedclients - 1.5 * CASCADE_DENSITY + 1) * ystep[monitor];
+      return;
+    } else {
+      mappedclients -= 2 * CASCADE_DENSITY;
+    }
+  }
 }
 
 int getmonitorbyclient(Client* c) {