xzoom

commit 02455f8f2c282c809f8bea1a00a00b8cda11de57
parent 2efc3a678f4a4694acb57bc368771c5be11c02f3
Author: Phil Carmody <pc+xzoom@asdf.org>
Date:   Thu, 21 Nov 2013 17:38:46 +0200

xzoom: don't redraw the screen when the window's not visible

Most of the CPU usage was in the read/scale/write part, so skip it
if we can.

Signed-off-by: Phil Carmody <pc+xzoom@asdf.org>
Signed-off-by: Christoph Lohmann <20h@r-36.net>

Diffstat:
xzoom.c
 | 
11
++++++++++-

1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/xzoom.c b/xzoom.c
@@ -385,6 +385,7 @@ main(int argc, char **argv) {
 	XSizeHints *sizeh = NULL;
 	XClassHint *ch;
 	int buttonpressed = False;
+	int visible = False;
 	int scroll = 1;
 	char title[80];
 	XGCValues gcv;
@@ -576,6 +577,8 @@ main(int argc, char **argv) {
 	xswa.event_mask = ButtonPressMask|ButtonReleaseMask|ButtonMotionMask;
 	xswa.event_mask |= StructureNotifyMask;	/* resize etc.. */
 	xswa.event_mask |= KeyPressMask|KeyReleaseMask;		/* commands */
+	xswa.event_mask |= VisibilityChangeMask;
+
 	xswa.background_pixel = BlackPixelOfScreen(scr);
 
 	win = XCreateWindow(dpy, RootWindowOfScreen(scr),
@@ -699,6 +702,11 @@ main(int argc, char **argv) {
 			case ReparentNotify:
 				break;	/* what do we do with it? */
 
+			case VisibilityNotify:
+				/* VisibilityUnobscured, VisibilityPartiallyObscured, or VisibilityFullyObscured */
+				visible = (event.xvisibility.state!=VisibilityFullyObscured);
+				break;
+
 			case KeyRelease:
 				switch(XKeycodeToKeysym(dpy, event.xkey.keycode, 0)) {
 				case XK_Control_L:
@@ -901,7 +909,8 @@ main(int argc, char **argv) {
 
 		}
 
-		xzoom(buttonpressed);
+		if(visible)
+			xzoom(buttonpressed);
 
 #ifdef NO_USLEEP
 #define usleep(_t)								\