Replace Glad usage with newer libobs graphics API

Author: tytan652

cmake/os-linux.cmake

@@ -4,7 +4,7 @@ get_target_property(libdrm_include_directories Libdrm::Libdrm INTERFACE_INCLUDE_
 
 target_include_directories(obs-browser PRIVATE ${libdrm_include_directories})
 
-target_link_libraries(obs-browser PRIVATE CEF::Wrapper CEF::Library X11::X11 OBS::glad)
+target_link_libraries(obs-browser PRIVATE CEF::Wrapper CEF::Library X11::X11)
 set_target_properties(obs-browser PROPERTIES BUILD_RPATH "$ORIGIN/" INSTALL_RPATH "$ORIGIN/")
 
 target_sources(obs-browser PRIVATE drm-format.cpp drm-format.hpp)

obs-browser-plugin.cpp

@@ -56,7 +56,6 @@
 #endif
 
 #if !defined(_WIN32) && !defined(__APPLE__)
-#include <glad/glad.h>
 #include "drm-format.hpp"
 #endif
 
@@ -717,10 +716,12 @@ static void check_hwaccel_support(void)
 	const char *glVersion = NULL;
 
 	obs_enter_graphics();
-	gladLoadGL();
-	glVersion = (const char *)glGetString(GL_VERSION);
+	glVersion = gs_get_driver_version();
 	obs_leave_graphics();
 
+	if (!glVersion)
+		return;
+
 	if (strstr(glVersion, "NVIDIA") != NULL) {
 		hwaccel = false;
 		blog(LOG_INFO,