Present: add -ext present that prints version & screen capabilities

Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Part-of: <https://gitlab.freedesktop.org/xorg/app/xdpyinfo/-/merge_requests/13>

3 files changed, 108 insertions, 2 deletions

diff --git a/Makefile.am b/Makefile.am
index 4cb8b51..596e5c3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -35,7 +35,8 @@ AM_CFLAGS = \
 	$(DPY_XCOMPOSITE_CFLAGS) \
 	$(DPY_XINERAMA_CFLAGS) \
 	$(DPY_DMX_CFLAGS) \
-	$(DPY_XTST_CFLAGS)
+	$(DPY_XTST_CFLAGS) \
+	$(DPY_XPRESENT_CFLAGS)
 
 xdpyinfo_LDADD = \
 	$(XDPYINFO_LIBS) \
@@ -49,7 +50,9 @@ xdpyinfo_LDADD = \
 	$(DPY_XCOMPOSITE_LIBS) \
 	$(DPY_XINERAMA_LIBS) \
 	$(DPY_DMX_LIBS) \
-	$(DPY_XTST_LIBS)
+	$(DPY_XTST_LIBS) \
+	$(DPY_XPRESENT_LIBS)
+
 
 xdpyinfo_SOURCES =	\
         xdpyinfo.c
diff --git a/configure.ac b/configure.ac
index b09d1d8..c3d3543 100644
--- a/configure.ac
+++ b/configure.ac
@@ -138,6 +138,12 @@ PKG_CHECK_MODULES(DPY_XTST, xtst,
 	AC_CHECK_HEADERS([X11/extensions/record.h],,,[#include <X11/Xlib.h>])
 	CPPFLAGS="$SAVE_CPPFLAGS"],[echo "not found"])
 
+PKG_CHECK_MODULES(DPY_XPRESENT, xpresent,
+	[SAVE_CPPFLAGS="$CPPFLAGS"
+	CPPFLAGS="$CPPFLAGS $DPY_XPRESENT_CFLAGS $DPY_X11_CFLAGS"
+	AC_CHECK_HEADERS([X11/extensions/Xpresent.h],,,[#include <X11/Xlib.h>])
+	CPPFLAGS="$SAVE_CPPFLAGS"],[echo "not found"])
+
 dnl Allow checking code with lint, sparse, etc.
 XORG_WITH_LINT
 
diff --git a/xdpyinfo.c b/xdpyinfo.c
index 630703c..c1173f4 100644
--- a/xdpyinfo.c
+++ b/xdpyinfo.c
@@ -76,6 +76,10 @@ in this Software without prior written authorization from The Open Group.
 #  define DMX
 # endif
 
+# if HAVE_X11_EXTENSIONS_XPRESENT_H
+#  define PRESENT
+# endif
+
 #endif
 
 #ifdef WIN32
@@ -137,6 +141,9 @@ in this Software without prior written authorization from The Open Group.
 #ifdef DMX
 #include <X11/extensions/dmxext.h>
 #endif
+#ifdef PRESENT
+#include <X11/extensions/Xpresent.h>
+#endif
 #include <X11/Xos.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -1348,6 +1355,93 @@ static int print_dmx_info(Display *dpy, const char *extname)
 
 #endif /* DMX */
 
+
+#ifdef PRESENT
+static inline void print_present_capabilities(uint32_t capabilities)
+{
+    if (capabilities == PresentCapabilityNone) {
+        fputs("PresentCapabilityNone", stdout);
+    }
+    else {
+        int count = 0;
+
+        if (capabilities & PresentCapabilityAsync) {
+            fputs("PresentCapabilityAsync", stdout);
+            count++;
+            capabilities &= ~PresentCapabilityAsync;
+        }
+        if (capabilities & PresentCapabilityFence) {
+            if (count)
+                fputs(" | ", stdout);
+            fputs("PresentCapabilityFence", stdout);
+            count++;
+            capabilities &= ~PresentCapabilityFence;
+        }
+        if (capabilities & PresentCapabilityUST) {
+            if (count)
+                fputs(" | ", stdout);
+            fputs("PresentCapabilityUST", stdout);
+            count++;
+            capabilities &= ~PresentCapabilityUST;
+        }
+#ifdef PresentCapabilityAsyncMayTear /* added in xorgproto-2023.1 */
+        if (capabilities & PresentCapabilityAsyncMayTear) {
+            if (count)
+                fputs(" | ", stdout);
+            fputs("PresentCapabilityAsyncMayTear", stdout);
+            count++;
+            capabilities &= ~PresentCapabilityAsyncMayTear;
+        }
+#endif
+#ifdef PresentCapabilitySyncobj /* added in xorgproto-2024.1 */
+        if (capabilities & PresentCapabilitySyncobj) {
+            if (count)
+                fputs(" | ", stdout);
+            fputs("PresentCapabilitySyncobj", stdout);
+            count++;
+            capabilities &= ~PresentCapabilitySyncobj;
+        }
+#endif
+        /* Are there any bits left we didn't recognize? */
+        if (capabilities != 0) {
+            for (unsigned int b = 0; b < 32; b++) {
+                uint32_t m = 1U << b;
+
+                if (capabilities & m) {
+                    if (count)
+                        fputs(" | ", stdout);
+                    printf("PresentCapabilityUnknownBit%d", b);
+                    capabilities &= ~m;
+                }
+            }
+        }
+    }
+}
+
+
+static int print_present_info(Display *dpy, const char *extname)
+{
+    int                  opcode, event_base, error_base;
+    int                  major_version, minor_version;
+
+    if (!XPresentQueryExtension(dpy, &opcode, &event_base, &error_base)
+        || !XPresentQueryVersion(dpy, &major_version, &minor_version))
+        return 0;
+    print_standard_extension_info(dpy, extname, major_version, minor_version);
+
+    for (int i = 0; i < ScreenCount (dpy); i++) {
+        Window screen_root = RootWindow(dpy, i);
+        uint32_t capabilities = XPresentQueryCapabilities(dpy, screen_root);
+
+        printf("  screen #%d capabilities: 0x%x (", i, capabilities);
+        print_present_capabilities(capabilities);
+        puts(")");
+    }
+
+    return 1;
+}
+#endif /* XPRESENT */
+
 /* utilities to manage the list of recognized extensions */
 
 
@@ -1401,6 +1495,9 @@ static ExtensionPrintInfo known_extensions[] =
 #ifdef DMX
     {"DMX", print_dmx_info, False},
 #endif
+#ifdef PRESENT
+    {"Present", print_present_info, False},
+#endif
     /* add new extensions here */
 };