Hook up a basic cairo surface to the pixmap.

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

1 files changed, 32 insertions, 0 deletions

diff --git a/multitouch.c b/multitouch.c
index 981b81d..ec95eac 100644
--- a/multitouch.c
+++ b/multitouch.c
@@ -9,6 +9,9 @@
 #include <signal.h>
 #include <poll.h>
 
+#include <cairo.h>
+#include <cairo-xlib.h>
+
 #include <X11/Xlib.h>
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
@@ -25,6 +28,8 @@ struct multitouch {
 
     int width;
     int height;
+
+    cairo_t *cr;
 };
 
 static int error(const char *fmt, ...)
@@ -147,6 +152,29 @@ static void print_event(struct multitouch *mt, XIDeviceEvent* event)
     msg("\ttouchid: %d\n", event->detail);
 }
 
+static int init_cairo(struct multitouch *mt)
+{
+    cairo_surface_t *surface;
+    cairo_t *cr;
+
+    surface = cairo_xlib_surface_create_for_bitmap(mt->dpy, mt->pixmap,
+                                                   mt->screen, mt->width, mt->height);
+    if (!surface)
+        return error("Failed to create cairo surface\n");
+
+    cr = cairo_create(surface);
+    if (!cr)
+        return error("Failed to create cairo context\n");
+
+    cairo_set_line_width(cr, 1);
+    cairo_set_source_rgb(cr, 0, 0, 0);
+    cairo_rectangle(cr, 0, 0, 1, 1);
+    cairo_fill(cr);
+
+    mt->cr = cr;
+
+    return EXIT_SUCCESS;
+}
 
 static int main_loop(struct multitouch *mt)
 {
@@ -189,6 +217,10 @@ int main(int argc, char **argv)
     if (rc != EXIT_SUCCESS)
         return rc;
 
+    rc = init_cairo(&mt);
+    if (rc != EXIT_SUCCESS)
+        return rc;
+
     signal(SIGINT, sighandler);
 
     main_loop(&mt);