Create a backend pixmap for drawing

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 11 insertions, 0 deletions

diff --git a/multitouch.c b/multitouch.c
index f15cbeb..d421c27 100644
--- a/multitouch.c
+++ b/multitouch.c
@@ -20,6 +20,8 @@ struct multitouch {
     Window win;
     int xi_opcode;
 
+    Pixmap pixmap;
+
     int width;
     int height;
 };
@@ -82,6 +84,14 @@ static Window init_window(struct multitouch *mt)
     return win;
 }
 
+static Pixmap init_pixmap(struct multitouch *mt)
+{
+    Pixmap p;
+    p = XCreatePixmap(mt->dpy, mt->win, mt->width, mt->height,
+                      DefaultDepth(mt->dpy, mt->screen));
+    return p;
+}
+
 static int init_x11(struct multitouch *mt, int width, int height)
 {
     Display *dpy;
@@ -107,6 +117,7 @@ static int init_x11(struct multitouch *mt, int width, int height)
     mt->height    = height;
 
     mt->win = init_window(mt);
+    mt->pixmap = init_pixmap(mt);
     if (!mt->win)
         return error("Failed to create window.\n");