From 726bb9ea134fbf90df24e8a2e4dd94453c86aa23 Mon Sep 17 00:00:00 2001
From: Kim Woelders <kim@woelders.dk>
Date: Tue, 27 Apr 2021 11:06:19 +0200
Subject: [PATCH] FX: Fix clipping with compositing enabled

---
 src/ecompmgr.c | 24 ++++++++++++++++++------
 src/ecompmgr.h |  6 ++++--
 src/fx.c       |  6 +++---
 src/x.c        |  6 ++++++
 src/xwin.h     |  1 +
 5 files changed, 32 insertions(+), 11 deletions(-)

diff --git a/src/ecompmgr.c b/src/ecompmgr.c
index 5753c69c..43ee7b3b 100644
--- a/src/ecompmgr.c
+++ b/src/ecompmgr.c
@@ -256,17 +256,29 @@ static int          ECompMgrDetermineOrder(EObj * const *lst, int num,
 #define REGION_DESTROY(rgn) \
    if (rgn != NoXID) { ERegionDestroy(rgn); rgn = NoXID; }
 
-void
-ECompMgrWinClipToGC(EObj * eo, GC gc)
+EX_SrvRegion
+ECompMgrChildClipRegion(void)
 {
+   EObj               *const *lst, *eoi;
+   int                 i, num;
    EX_SrvRegion        rgn = Mode_compmgr.rgn_tmp2;
 
-   if (!eo || !eo->cmhook)
-      return;
+   if (!Mode_compmgr.active)
+      return NoXID;
 
    ERegionCopy(rgn, Mode_compmgr.rgn_screen);
-   ERegionSubtract(rgn, eo->cmhook->clip);
-   XFixesSetGCClipRegion(disp, gc, 0, 0, rgn);
+
+   lst = EobjListStackGet(&num);
+   for (i = 0; i < num; i++)
+     {
+	eoi = lst[i];
+	if (eoi->cmhook && eoi->cmhook->shape &&
+	    (eoi->type == EOBJ_TYPE_EWIN || eoi->type == EOBJ_TYPE_BUTTON ||
+	     eoi->type == EOBJ_TYPE_MISC))
+	   ERegionSubtract(rgn, eoi->cmhook->shape);
+     }
+
+   return rgn;
 }
 
 #if !USE_BG_WIN_ON_ALL_DESKS
diff --git a/src/ecompmgr.h b/src/ecompmgr.h
index f840f15a..0a94c0fd 100644
--- a/src/ecompmgr.h
+++ b/src/ecompmgr.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2004-2014 Kim Woelders
+ * Copyright (C) 2004-2021 Kim Woelders
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to
@@ -27,6 +27,7 @@
 
 #include "eobj.h"
 #include "etypes.h"
+#include "xtypes.h"
 
 typedef struct {
    char                enable;
@@ -60,7 +61,6 @@ void                ECompMgrWinChangeOpacity(EObj * eo, unsigned int opacity);
 void                ECompMgrWinChangeShadow(EObj * eo, int shadow);
 EX_Pixmap           ECompMgrWinGetPixmap(const EObj * eo);
 EX_Picture          ECompMgrWinGetAlphaPict(const EObj * eo);
-void                ECompMgrWinClipToGC(EObj * eo, GC gc);
 
 void                ECompMgrConfigGet(cfg_composite * cfg);
 void                ECompMgrConfigSet(const cfg_composite * cfg);
@@ -70,6 +70,8 @@ int                 ECompMgrRender(int dt);
 
 EX_Window           ECompMgrRootWin(void);
 
+EX_SrvRegion        ECompMgrChildClipRegion(void);
+
 #else
 
 #define ECompMgrIsActive()          0
diff --git a/src/fx.c b/src/fx.c
index bb5a81fe..e9a39887 100644
--- a/src/fx.c
+++ b/src/fx.c
@@ -67,10 +67,10 @@ _FxSetup(FXData * d, unsigned int height)
 {
    EObj               *bgeo;
 
-   bgeo = DeskGetBackgroundObj(DesksGetCurrent());
-
    if (!d->above)
      {
+	bgeo = DeskGetBackgroundObj(DesksGetCurrent());
+
 	d->win = EobjGetWin(bgeo);
 #if USE_COMPOSITE
 	if (ECompMgrIsActive() && !Mode.wm.window)
@@ -89,7 +89,7 @@ _FxSetup(FXData * d, unsigned int height)
 
 #if USE_COMPOSITE
    /* As of composite 0.4 we need to set the clip region */
-   ECompMgrWinClipToGC(bgeo, d->gc1);
+   EGCSetClip(d->gc1, ECompMgrChildClipRegion());
 #endif
 }
 
diff --git a/src/x.c b/src/x.c
index 8f0b40c3..b20d7187 100644
--- a/src/x.c
+++ b/src/x.c
@@ -2171,6 +2171,12 @@ EPictureFillRect(EX_Picture pict, int x, int y, int w, int h,
 
 #if USE_COMPOSITE
 
+void
+EGCSetClip(GC gc, EX_SrvRegion clip)
+{
+   XFixesSetGCClipRegion(disp, gc, 0, 0, clip);
+}
+
 void
 EPictureSetClip(EX_Picture pict, EX_SrvRegion clip)
 {
diff --git a/src/xwin.h b/src/xwin.h
index e1357439..5422287f 100644
--- a/src/xwin.h
+++ b/src/xwin.h
@@ -352,6 +352,7 @@ int                 ERegionIsEmpty(EX_SrvRegion rgn);
 void                ERegionShow(const char *txt, EX_SrvRegion rgn,
 				void (*prf)(const char *fmt, ...));
 
+void                EGCSetClip(GC gc, EX_SrvRegion clip);
 void                EPictureSetClip(EX_Picture pict, EX_SrvRegion clip);
 
 EX_Pixmap           EWindowGetPixmap(const Win win);