1 files changed, 55 insertions, 1 deletions

diff --git a/src/mgl.c b/src/mgl.c
index 5b87134..2a5325e 100644
--- a/src/mgl.c
+++ b/src/mgl.c
@@ -1,6 +1,10 @@
 #include "../include/mgl/mgl.h"
 #include <X11/Xutil.h>
 #include <X11/XKBlib.h>
+#include <X11/extensions/Xrender.h>
+#include <X11/extensions/Xrandr.h>
+#include <stdbool.h>
+#include <string.h>
 #include <stdio.h>
 #ifndef NDEBUG
 #include <stdlib.h>
@@ -22,9 +26,39 @@ static int ignore_xioerror(Display *display) {
     return 0;
 }
 
+static bool xrender_is_supported(Display *display, int *event_base, int *error_base) {
+    *event_base = 0;
+    *error_base = 0;
+    if(!XRenderQueryExtension(display, event_base, error_base))
+        return false;
+
+    int major_version = 0;
+    int minor_version = 0;
+    if(!XRenderQueryVersion(display, &major_version, &minor_version))
+        return false;
+
+    return major_version > 0 || (major_version == 0 && minor_version >= 7);
+}
+
+static bool xrandr_is_supported(Display *display, int *event_base, int *error_base) {
+    *event_base = 0;
+    *error_base = 0;
+    if(!XRRQueryExtension(display, event_base, error_base))
+        return false;
+
+    int major_version = 0;
+    int minor_version = 0;
+    if(!XRRQueryVersion(display, &major_version, &minor_version))
+        return false;
+
+    return major_version > 1 || (major_version == 1 && minor_version >= 2);
+}
+
 int mgl_init(void) {
     ++init_count;
     if(init_count == 1) {
+        memset(&context, 0, sizeof(context));
+
         context.connection = XOpenDisplay(NULL);
         if(!context.connection) {
             fprintf(stderr, "mgl error: XOpenDisplay failed\n");
@@ -34,6 +68,22 @@ int mgl_init(void) {
 
         prev_xerror = XSetErrorHandler(ignore_xerror);
         prev_xioerror = XSetIOErrorHandler(ignore_xioerror);
+
+        if(!xrender_is_supported(context.connection, &context.render_event_base, &context.render_error_base)) {
+            fprintf(stderr, "mgl error: x11 render extension is not supported by your X server\n");
+            mgl_deinit();
+            return -1;
+        }
+
+        if(!xrandr_is_supported(context.connection, &context.randr_event_base, &context.randr_error_base)) {
+            fprintf(stderr, "mgl error: x11 randr extension is not supported by your X server\n");
+            mgl_deinit();
+            return -1;
+        }
+
+        fprintf(stderr, "randr event base: %d\n", context.randr_event_base);
+        XRRSelectInput(context.connection, DefaultRootWindow(context.connection), RRScreenChangeNotifyMask | RRCrtcChangeNotifyMask | RROutputChangeNotifyMask);
+
         XInitThreads();
         XkbSetDetectableAutoRepeat(context.connection, True, NULL);
 
@@ -51,13 +101,17 @@ int mgl_init(void) {
 
 void mgl_deinit(void) {
     if(init_count == 1) {
-        if(context.connection) {
+        if(prev_xioerror) {
             XSetIOErrorHandler(prev_xioerror);
             prev_xioerror = NULL;
+        }
 
+        if(prev_xerror) {
             XSetErrorHandler(prev_xerror);
             prev_xerror = NULL;
+        }
 
+        if(context.connection) {
             XCloseDisplay(context.connection);
             context.connection = NULL;