From 9dff55540fc2f984c25f7cc8d6c14c3f071d2b03 Mon Sep 17 00:00:00 2001
From: Uli Schlachter <psychon@znc.in>
Date: Sat, 29 Sep 2018 11:46:29 +0200
Subject: [PATCH] Convert Xinerama usage to xcb

Signed-off-by: Uli Schlachter <psychon@znc.in>
---
 Makefile      |  2 +-
 src/common.h  | 10 +++++-----
 src/compton.c | 31 +++++++++++++++++++------------
 src/compton.h | 13 ++++++++++---
 4 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/Makefile b/Makefile
index 1dc8d2c..e90212c 100644
--- a/Makefile
+++ b/Makefile
@@ -26,7 +26,7 @@ endif
 # Enables support for --xinerama-shadow-crop
 ifeq "$(NO_XINERAMA)" ""
   CFG += -DCONFIG_XINERAMA
-  PACKAGES += xinerama
+  PACKAGES += xcb-xinerama
 endif
 
 # ==== libconfig ====
diff --git a/src/common.h b/src/common.h
index 8b21ad1..dad6a7e 100644
--- a/src/common.h
+++ b/src/common.h
@@ -88,16 +88,16 @@
 #include <X11/extensions/sync.h>
 #endif
 
-#ifdef CONFIG_XINERAMA
-#include <X11/extensions/Xinerama.h>
-#endif
-
 #include <xcb/composite.h>
 #include <xcb/render.h>
 #include <xcb/damage.h>
 #include <xcb/randr.h>
 #include <xcb/shape.h>
 
+#ifdef CONFIG_XINERAMA
+#include <xcb/xinerama.h>
+#endif
+
 // Workarounds for missing definitions in very old versions of X headers,
 // thanks to consolers for reporting
 #ifndef PictOpDifference
@@ -977,7 +977,7 @@ typedef struct session {
   /// Whether X Xinerama extension exists.
   bool xinerama_exists;
   /// Xinerama screen info.
-  XineramaScreenInfo *xinerama_scrs;
+  xcb_xinerama_query_screens_reply_t *xinerama_scrs;
   /// Xinerama screen regions.
   XserverRegion *xinerama_scr_regs;
   /// Number of Xinerama screens.
diff --git a/src/compton.c b/src/compton.c
index 35a619d..5ffaba0 100644
--- a/src/compton.c
+++ b/src/compton.c
@@ -5110,21 +5110,28 @@ cxinerama_upd_scrs(session_t *ps) {
 
   if (!ps->o.xinerama_shadow_crop || !ps->xinerama_exists) return;
 
-  if (!XineramaIsActive(ps->dpy)) return;
-
-  ps->xinerama_scrs = XineramaQueryScreens(ps->dpy, &ps->xinerama_nscrs);
-
-  // Just in case the shit hits the fan...
-  if (!ps->xinerama_nscrs) {
-    cxfree(ps->xinerama_scrs);
-    ps->xinerama_scrs = NULL;
+  xcb_connection_t *c = XGetXCBConnection(ps->dpy);
+  xcb_xinerama_is_active_reply_t *active =
+    xcb_xinerama_is_active_reply(c,
+        xcb_xinerama_is_active(c), NULL);
+  if (!active || !active->state) {
+    free(active);
     return;
   }
+  free(active);
+
+  ps->xinerama_scrs = xcb_xinerama_query_screens_reply(c,
+      xcb_xinerama_query_screens(c), NULL);
+  if (!ps->xinerama_scrs)
+    return;
+
+  xcb_xinerama_screen_info_t *scrs = xcb_xinerama_query_screens_screen_info(ps->xinerama_scrs);
+  ps->xinerama_nscrs = xcb_xinerama_query_screens_screen_info_length(ps->xinerama_scrs);
 
   ps->xinerama_scr_regs = allocchk(malloc(sizeof(XserverRegion *)
         * ps->xinerama_nscrs));
   for (int i = 0; i < ps->xinerama_nscrs; ++i) {
-    const XineramaScreenInfo * const s = &ps->xinerama_scrs[i];
+    const xcb_xinerama_screen_info_t * const s = &scrs[i];
     XRectangle r = { .x = s->x_org, .y = s->y_org,
       .width = s->width, .height = s->height };
     ps->xinerama_scr_regs[i] = XFixesCreateRegion(ps->dpy, &r, 1);
@@ -5385,6 +5392,7 @@ session_init(session_t *ps_old, int argc, char **argv) {
   xcb_prefetch_extension_data(c, &xcb_damage_id);
   xcb_prefetch_extension_data(c, &xcb_shape_id);
   xcb_prefetch_extension_data(c, &xcb_randr_id);
+  xcb_prefetch_extension_data(c, &xcb_xinerama_id);
 
   ext_info = xcb_get_extension_data(c, &xcb_render_id);
   if (!ext_info || !ext_info->present) {
@@ -5515,9 +5523,8 @@ session_init(session_t *ps_old, int argc, char **argv) {
   // Query X Xinerama extension
   if (ps->o.xinerama_shadow_crop) {
 #ifdef CONFIG_XINERAMA
-    int xinerama_event = 0, xinerama_error = 0;
-    if (XineramaQueryExtension(ps->dpy, &xinerama_event, &xinerama_error))
-      ps->xinerama_exists = true;
+    ext_info = xcb_get_extension_data(c, &xcb_xinerama_id);
+    ps->xinerama_exists = ext_info && ext_info->present;
 #else
     printf_errf("(): Xinerama support not compiled in.");
 #endif
diff --git a/src/compton.h b/src/compton.h
index 37628bd..bb755c6 100644
--- a/src/compton.h
+++ b/src/compton.h
@@ -650,14 +650,21 @@ static inline void
 cxinerama_win_upd_scr(session_t *ps, win *w) {
 #ifdef CONFIG_XINERAMA
   w->xinerama_scr = -1;
-  for (XineramaScreenInfo *s = ps->xinerama_scrs;
-      s < ps->xinerama_scrs + ps->xinerama_nscrs; ++s)
+
+  if (!ps->xinerama_scrs)
+    return;
+
+  xcb_xinerama_screen_info_t *scrs = xcb_xinerama_query_screens_screen_info(ps->xinerama_scrs);
+  int length = xcb_xinerama_query_screens_screen_info_length(ps->xinerama_scrs);
+  for (int i = 0; i < length; i++) {
+    xcb_xinerama_screen_info_t *s = &scrs[i];
     if (s->x_org <= w->g.x && s->y_org <= w->g.y
         && s->x_org + s->width >= w->g.x + w->widthb
         && s->y_org + s->height >= w->g.y + w->heightb) {
-      w->xinerama_scr = s - ps->xinerama_scrs;
+      w->xinerama_scr = i;
       return;
     }
+  }
 #endif
 }