From a88d0927d8c64044ea417eea4376c475ec7ecf1c Mon Sep 17 00:00:00 2001
From: Daniel Cousens <github@dcousens.com>
Date: Mon, 24 Apr 2017 13:01:46 +1000
Subject: [PATCH] center windows if useless gaps occur

---
 dwm.c | 37 +++++++++++++++++++++++++++++++++++--
 1 file changed, 35 insertions(+), 2 deletions(-)

diff --git a/dwm.c b/dwm.c
index b452ed7..9baf58b 100644
--- a/dwm.c
+++ b/dwm.c
@@ -1266,6 +1266,22 @@ resize(Client *c, int x, int y, int w, int h, int interact)
 }
 
 void
+dummyresizeclient(Client *c, int x, int y, int w, int h)
+{
+	c->x = x;
+	c->y = y;
+	c->w = w;
+	c->h = h;
+}
+
+void
+dummyresize(Client *c, int x, int y, int w, int h, int interact)
+{
+	if (applysizehints(c, &x, &y, &w, &h, interact))
+		dummyresizeclient(c, x, y, w, h);
+}
+
+void
 resizeclient(Client *c, int x, int y, int w, int h)
 {
 	XWindowChanges wc;
@@ -1667,6 +1683,7 @@ void
 tile(Monitor *m)
 {
 	unsigned int i, n, h, mw, my, ty;
+	unsigned int dx = 0;
 	Client *c;
 
 	for (n = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), n++);
@@ -1677,14 +1694,30 @@ tile(Monitor *m)
 		mw = m->nmaster ? m->ww * m->mfact : 0;
 	else
 		mw = m->ww;
+
+	/* dummy tile, for size hints only */
 	for (i = my = ty = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)
 		if (i < m->nmaster) {
 			h = (m->wh - my) / (MIN(n, m->nmaster) - i);
-			resize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
+			dummyresize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
 			my += HEIGHT(c);
 		} else {
 			h = (m->wh - ty) / (n - i);
-			resize(c, m->wx + mw, m->wy + ty, m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
+			dummyresize(c, m->wx + mw, m->wy + ty, m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
+			ty += HEIGHT(c);
+		}
+
+	my = (m->wh - my) / 2;
+	ty = (m->wh - ty) / 2;
+
+	for (i = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)
+		if (i < m->nmaster) {
+			dx = ((mw - (2*c->bw)) - WIDTH(c)) / 2;
+			resize(c, m->wx + dx, m->wy + my, WIDTH(c), HEIGHT(c), 0);
+			my += HEIGHT(c);
+		} else {
+			dx = ((m->ww - mw - (2*c->bw)) - WIDTH(c)) / 2;
+			resize(c, m->wx + mw + dx, m->wy + ty, WIDTH(c), HEIGHT(c), 0);
 			ty += HEIGHT(c);
 		}
 }
-- 
2.12.2