kmscube: improve the x11 mainloop
authorTomi Valkeinen <tomi.valkeinen@ti.com>
Wed, 20 Apr 2016 09:17:39 +0000 (12:17 +0300)
committerTomi Valkeinen <tomi.valkeinen@ti.com>
Wed, 20 Apr 2016 09:17:39 +0000 (12:17 +0300)
kmscube/cube-x11.cpp

index 795e8f55d3c2214077f56dd572909a7122f51960..9ac64c342926d3369f7d22f59f26f4d2976e1d3b 100644 (file)
@@ -1,5 +1,6 @@
 
 #include <X11/Xlib-xcb.h>
+#include <X11/Xlibint.h>
 
 #include "cube.h"
 #include "cube-egl.h"
@@ -9,9 +10,80 @@
 
 using namespace std;
 
+static void main_loop(Display* dpy, xcb_connection_t *c, xcb_window_t window, uint32_t width, uint32_t height)
+{
+       EglState egl(dpy);
+       EglSurface surface(egl, (void*)(uintptr_t)window);
+       GlScene scene;
+
+       scene.set_viewport(width, height);
+
+       unsigned framenum = 0;
+
+       surface.make_current();
+       surface.swap_buffers();
+
+       bool need_exit = false;
+
+       xcb_generic_event_t *event;
+       while (true) {
+
+               while ((event = xcb_poll_for_event (c))) {
+                       bool handled = false;
+                       uint8_t response_type = event->response_type & ~0x80;
+
+                       switch (response_type) {
+                       case XCB_EXPOSE: {
+                               handled = true;
+                               break;
+                       }
+                       case XCB_KEY_PRESS: {
+                               handled = true;
+
+                               xcb_key_press_event_t *kp = (xcb_key_press_event_t *)event;
+                               if (kp->detail == 24) {
+                                       printf("Exit due to keypress\n");
+                                       need_exit = true;
+                               }
+
+                               break;
+                       }
+                       }
+
+                       if (!handled) {
+                               // Check if a custom XEvent constructor was registered in xlib for this event type, and call it discarding the constructed XEvent if any.
+                               // XESetWireToEvent might be used by libraries to intercept messages from the X server e.g. the OpenGL lib waiting for DRI2 events.
+
+                               XLockDisplay(dpy);
+                               Bool (*proc)(Display*, XEvent*, xEvent*) = XESetWireToEvent(dpy, response_type, NULL);
+                               if (proc) {
+                                       XESetWireToEvent(dpy, response_type, proc);
+                                       XEvent dummy;
+                                       event->sequence = LastKnownRequestProcessed(dpy);
+                                       proc(dpy, &dummy, (xEvent*)event);
+                               }
+                               XUnlockDisplay(dpy);
+                       }
+
+                       free(event);
+               }
+
+               if (s_num_frames && framenum >= s_num_frames)
+                       need_exit = true;
+
+               if (need_exit)
+                       break;
+
+               // this should be in XCB_EXPOSE, but we don't get the event after swaps...
+               scene.draw(framenum++);
+               surface.swap_buffers();
+       }
+}
+
 void main_x11()
 {
        Display* dpy = XOpenDisplay(NULL);
+       FAIL_IF(!dpy, "Failed to connect to the X server");
 
        xcb_connection_t *c = XGetXCBConnection(dpy);
 
@@ -72,48 +144,7 @@ void main_x11()
        xcb_map_window (c, window);
        xcb_flush (c);
 
-       {
-               EglState egl(dpy);
-               EglSurface surface(egl, (void*)(uintptr_t)window);
-               GlScene scene;
-
-               scene.set_viewport(width, height);
-
-               unsigned framenum = 0;
-
-               surface.make_current();
-               surface.swap_buffers();
-
-               bool need_exit = false;
-
-               xcb_generic_event_t *event;
-               while (!need_exit && (event = xcb_wait_for_event (c))) {
-                       switch (event->response_type & ~0x80) {
-                       case XCB_EXPOSE: {
-
-                               break;
-                       }
-                       case XCB_KEY_PRESS: {
-                               xcb_key_press_event_t *kp = (xcb_key_press_event_t *)event;
-                               if (kp->detail == 24) {
-                                       printf("Exit due to keypress\n");
-                                       need_exit = true;
-                               }
-
-                               break;
-                       }
-                       }
-
-                       free(event);
-
-                       if (s_num_frames && framenum >= s_num_frames)
-                               need_exit = true;
-
-                       // this should be in XCB_EXPOSE, but we don't get the event after swaps...
-                       scene.draw(framenum++);
-                       surface.swap_buffers();
-               }
-       }
+       main_loop(dpy, c, window, width, height);
 
        xcb_flush(c);
        xcb_unmap_window(c, window);