Load X11 dynamically

The loaders have been generated through hpvb's dynload-wrapper, although
they had to be heavily handpatched to workaround some already reported
issues with it. I added a note to each generated file to account for
that.

As GLAD uses X11 stuff directly, I had to define the GLAD_GLX_NO_X11
macro to not let do it that, and handle myself the display loading and
screen handling part myself, which wasn't that hard but it's still
something worth saying.

I plan to improve greatly the X11 backend (including this aspect) but,
as the release isn't that far and I'm also working on the Wayland
backend, this will do for now, I hope.

platform/linuxbsd/detect.py

@@ -184,13 +184,14 @@ def configure(env: "Environment"):
     ## Dependencies
 
     if env["x11"]:
-        env.ParseConfig("pkg-config x11 --cflags --libs")
-        env.ParseConfig("pkg-config xcursor --cflags --libs")
-        env.ParseConfig("pkg-config xinerama --cflags --libs")
-        env.ParseConfig("pkg-config xext --cflags --libs")
-        env.ParseConfig("pkg-config xrandr --cflags --libs")
-        env.ParseConfig("pkg-config xrender --cflags --libs")
-        env.ParseConfig("pkg-config xi --cflags --libs")
+        # Only cflags, we dlopen the libraries.
+        env.ParseConfig("pkg-config x11 --cflags")
+        env.ParseConfig("pkg-config xcursor --cflags")
+        env.ParseConfig("pkg-config xinerama --cflags")
+        env.ParseConfig("pkg-config xext --cflags")
+        env.ParseConfig("pkg-config xrandr --cflags")
+        env.ParseConfig("pkg-config xrender --cflags")
+        env.ParseConfig("pkg-config xi --cflags")
 
     if env["touch"]:
         env.Append(CPPDEFINES=["TOUCH_ENABLED"])

platform/linuxbsd/x11/SCsub

@@ -5,12 +5,20 @@ Import("env")
 source_files = [
     "display_server_x11.cpp",
     "key_mapping_x11.cpp",
+    "dynwrappers/xlib-so_wrap.c",
+    "dynwrappers/xcursor-so_wrap.c",
+    "dynwrappers/xinerama-so_wrap.c",
+    "dynwrappers/xinput2-so_wrap.c",
+    "dynwrappers/xrandr-so_wrap.c",
+    "dynwrappers/xrender-so_wrap.c",
+    "dynwrappers/xext-so_wrap.c",
 ]
 
 if env["vulkan"]:
     source_files.append("vulkan_context_x11.cpp")
 
 if env["opengl3"]:
+    env.Append(CPPDEFINES=["GLAD_GLX_NO_X11"])
     source_files.append(["gl_manager_x11.cpp", "detect_prime_x11.cpp", "#thirdparty/glad/glx.c"])
 
 objects = []

platform/linuxbsd/x11/detect_prime_x11.cpp

@@ -41,8 +41,7 @@
 #include "thirdparty/glad/glad/gl.h"
 #include "thirdparty/glad/glad/glx.h"
 
-#include <X11/Xlib.h>
-#include <X11/Xutil.h>
+#include "dynwrappers/xlib-so_wrap.h"
 
 #include <cstring>
 
@@ -89,6 +88,10 @@ void create_context() {
 		None
 	};
 
+	if (gladLoaderLoadGLX(x11_display, XScreenNumberOfScreen(XDefaultScreenOfDisplay(x11_display))) == 0) {
+		print_verbose("Unable to load GLX, GPU detection skipped.");
+		quick_exit(1);
+	}
 	int fbcount;
 	GLXFBConfig fbconfig = nullptr;
 	XVisualInfo *vi = nullptr;
@@ -189,11 +192,6 @@ int detect_prime() {
 				setenv("DRI_PRIME", "1", 1);
 			}
 
-			if (gladLoaderLoadGLX(NULL, 0) == 0) {
-				print_verbose("Unable to load GLX, GPU detection skipped.");
-				quick_exit(1);
-			}
-
 			create_context();
 
 			PFNGLGETSTRINGPROC glGetString = (PFNGLGETSTRINGPROC)glXGetProcAddressARB((GLubyte *)"glGetString");

platform/linuxbsd/x11/display_server_x11.cpp

@@ -58,11 +58,6 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-#include <X11/Xatom.h>
-#include <X11/Xutil.h>
-#include <X11/extensions/Xinerama.h>
-#include <X11/extensions/shape.h>
-
 // ICCCM
 #define WM_NormalState 1L // window normal state
 #define WM_IconicState 3L // window minimized
@@ -4710,6 +4705,46 @@ DisplayServerX11::WindowID DisplayServerX11::_create_window(WindowMode p_mode, V
 }
 
 DisplayServerX11::DisplayServerX11(const String &p_rendering_driver, WindowMode p_mode, VSyncMode p_vsync_mode, uint32_t p_flags, const Vector2i *p_position, const Vector2i &p_resolution, Error &r_error) {
+#ifdef DEBUG_ENABLED
+	int dylibloader_verbose = 1;
+#else
+	int dylibloader_verbose = 0;
+#endif
+	if (initialize_xlib(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load Xlib dynamically.");
+	}
+
+	if (initialize_xcursor(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load XCursor dynamically.");
+	}
+
+	if (initialize_xext(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load Xext dynamically.");
+	}
+
+	if (initialize_xinerama(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load Xinerama dynamically.");
+	}
+
+	if (initialize_xrandr(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load Xrandr dynamically.");
+	}
+
+	if (initialize_xrender(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load Xrender dynamically.");
+	}
+
+	if (initialize_xinput2(dylibloader_verbose) != 0) {
+		r_error = ERR_UNAVAILABLE;
+		ERR_FAIL_MSG("Can't load Xinput2 dynamically.");
+	}
+
 	Input::get_singleton()->set_event_dispatch_function(_dispatch_input_events);
 
 	r_error = OK;
@@ -4910,7 +4945,7 @@ DisplayServerX11::DisplayServerX11(const String &p_rendering_driver, WindowMode
 
 		gl_manager = memnew(GLManager_X11(p_resolution, opengl_api_type));
 
-		if (gl_manager->initialize() != OK) {
+		if (gl_manager->initialize(x11_display) != OK) {
 			memdelete(gl_manager);
 			gl_manager = nullptr;
 			r_error = ERR_UNAVAILABLE;

platform/linuxbsd/x11/display_server_x11.h

@@ -64,12 +64,20 @@
 #include "../freedesktop_screensaver.h"
 #endif
 
-#include <X11/Xcursor/Xcursor.h>
+#include <X11/Xatom.h>
 #include <X11/Xlib.h>
-#include <X11/extensions/XInput2.h>
-#include <X11/extensions/Xrandr.h>
+#include <X11/Xutil.h>
 #include <X11/keysym.h>
 
+#include "dynwrappers/xlib-so_wrap.h"
+
+#include "dynwrappers/xcursor-so_wrap.h"
+#include "dynwrappers/xext-so_wrap.h"
+#include "dynwrappers/xinerama-so_wrap.h"
+#include "dynwrappers/xinput2-so_wrap.h"
+#include "dynwrappers/xrandr-so_wrap.h"
+#include "dynwrappers/xrender-so_wrap.h"
+
 typedef struct _xrr_monitor_info {
 	Atom name;
 	Bool primary = false;