From 2372127c0f81b247945acf9075630a37bbcb5ae2 Mon Sep 17 00:00:00 2001
From: Yuxuan Shui <yshuiv7@gmail.com>
Date: Tue, 31 Mar 2020 06:07:09 +0100
Subject: [PATCH] core: query glx extension in session_init

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 src/backend/gl/glx.c | 4 +---
 src/opengl.c         | 8 ++------
 src/picom.c          | 9 +++++++++
 3 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/src/backend/gl/glx.c b/src/backend/gl/glx.c
index 9303a986..ac066199 100644
--- a/src/backend/gl/glx.c
+++ b/src/backend/gl/glx.c
@@ -45,8 +45,6 @@ struct _glx_data {
 	Display *display;
 	int screen;
 	xcb_window_t target_win;
-	int glx_event;
-	int glx_error;
 	GLXContext ctx;
 };
 
@@ -246,7 +244,7 @@ static backend_t *glx_init(session_t *ps) {
 	XVisualInfo *pvis = NULL;
 
 	// Check for GLX extension
-	if (!glXQueryExtension(ps->dpy, &gd->glx_event, &gd->glx_error)) {
+	if (!ps->glx_exists) {
 		log_error("No GLX extension.");
 		goto end;
 	}
diff --git a/src/opengl.c b/src/opengl.c
index 0a80c6d3..1e956be4 100644
--- a/src/opengl.c
+++ b/src/opengl.c
@@ -51,12 +51,8 @@ bool glx_init(session_t *ps, bool need_render) {
 
 	// Check for GLX extension
 	if (!ps->glx_exists) {
-		if (glXQueryExtension(ps->dpy, &ps->glx_event, &ps->glx_error))
-			ps->glx_exists = true;
-		else {
-			log_error("No GLX extension.");
-			goto glx_init_end;
-		}
+		log_error("No GLX extension.");
+		goto glx_init_end;
 	}
 
 	// Get XVisualInfo
diff --git a/src/picom.c b/src/picom.c
index 80c3d769..fd84081a 100644
--- a/src/picom.c
+++ b/src/picom.c
@@ -19,6 +19,7 @@
 #include <string.h>
 #include <xcb/composite.h>
 #include <xcb/damage.h>
+#include <xcb/glx.h>
 #include <xcb/present.h>
 #include <xcb/randr.h>
 #include <xcb/render.h>
@@ -1721,6 +1722,7 @@ static session_t *session_init(int argc, char **argv, Display *dpy,
 	xcb_prefetch_extension_data(ps->c, &xcb_xinerama_id);
 	xcb_prefetch_extension_data(ps->c, &xcb_present_id);
 	xcb_prefetch_extension_data(ps->c, &xcb_sync_id);
+	xcb_prefetch_extension_data(ps->c, &xcb_glx_id);
 
 	ext_info = xcb_get_extension_data(ps->c, &xcb_render_id);
 	if (!ext_info || !ext_info->present) {
@@ -1776,6 +1778,13 @@ static session_t *session_init(int argc, char **argv, Display *dpy,
 	                                                  XCB_XFIXES_MINOR_VERSION)
 	                             .sequence);
 
+	ext_info = xcb_get_extension_data(ps->c, &xcb_glx_id);
+	if (ext_info && ext_info->present) {
+		ps->glx_exists = true;
+		ps->glx_error = ext_info->first_error;
+		ps->glx_event = ext_info->first_event;
+	}
+
 	// Parse configuration file
 	win_option_mask_t winopt_mask[NUM_WINTYPES] = {{0}};
 	bool shadow_enabled = false, fading_enable = false, hasneg = false;