gl: print GL version in help

Author: MartinPulec

src/video_display/gl.cpp

@@ -6,7 +6,7 @@
  * @author Martin Pulec     <[email protected]>
  */
 /*
- * Copyright (c) 2010-2024 CESNET, z. s. p. o.
+ * Copyright (c) 2010-2025 CESNET
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -66,7 +66,7 @@
 
 #include "color.h"
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include "config.h"    // for HAVE_SPOUT, HAVE_SYPHON
 #endif
 #include "debug.h"
 #include "gl_context.h"
@@ -347,6 +347,7 @@ static constexpr pair<int64_t, string_view> keybindings[] = {
 };
 
 /* Prototyping */
+static bool check_display_gl_version(bool print_ver);
 static bool display_gl_init_opengl(struct state_gl *s);
 static bool display_gl_putf(void *state, struct video_frame *frame, long long timeout);
 static bool display_gl_process_key(struct state_gl *s, long long int key);
@@ -476,10 +477,6 @@ static constexpr codec_t gl_supp_codecs[] = {
 };
 
 static void gl_print_monitors(bool fullhelp) {
-        if (ref_count_init_once<int>()(glfwInit, glfw_init_count).value_or(GLFW_TRUE) == GLFW_FALSE) {
-                LOG(LOG_LEVEL_ERROR) << "Cannot initialize GLFW!\n";
-                return;
-        }
         printf("\nmonitors:\n");
         int count = 0;
         GLFWmonitor **mon = glfwGetMonitors(&count);
@@ -511,8 +508,6 @@ static void gl_print_monitors(bool fullhelp) {
         if (!fullhelp) {
                 cout << "(use \"fullhelp\" to see modes)\n";
         }
-
-        ref_count_terminate_last()(glfwTerminate, glfw_init_count);
 }
 
 #define FEATURE_PRESENT(x) (strcmp(STRINGIFY(x), "1") == 0 ? "on" : "off")
@@ -580,8 +575,21 @@ static void gl_show_help(bool full) {
                 col() << "\t" << TBOLD(<< keyname <<) << "\t\t" << i.second << "\n";
         }
 
+        if (ref_count_init_once<int>()(glfwInit, glfw_init_count).value_or(GLFW_TRUE) == GLFW_FALSE) {
+                LOG(LOG_LEVEL_ERROR) << "Cannot initialize GLFW!\n";
+                return;
+        }
         gl_print_monitors(full);
-        col() << "\nCompiled " << SBOLD("features: ") << "SPOUT - "
+        color_printf("\n");
+        GLFWwindow *window = glfwCreateWindow(32, 32, DEFAULT_WIN_NAME, nullptr, nullptr);
+        if (window != nullptr) {
+                glfwMakeContextCurrent(window);
+                check_display_gl_version(true);
+                glfwDestroyWindow(window);
+        }
+        ref_count_terminate_last()(glfwTerminate, glfw_init_count);
+
+        col() << "Compiled " << SBOLD("features: ") << "SPOUT - "
               << FEATURE_PRESENT(SPOUT) << ", Syphon - "
               << FEATURE_PRESENT(SYPHON) << ", VDPAU - "
               << FEATURE_PRESENT(HWACC_VDPAU) << "\n";
@@ -1444,7 +1452,9 @@ static void glfw_mouse_callback(GLFWwindow *win, double /* x */, double /* y */)
         }
 }
 
-static bool display_gl_check_gl_version() {
+static bool
+check_display_gl_version(bool print_ver)
+{
         auto version = (const char *) glGetString(GL_VERSION);
         if (!version) {
                 log_msg(LOG_LEVEL_ERROR, MOD_NAME "Unable to get OpenGL version!\n");
@@ -1454,8 +1464,12 @@ static bool display_gl_check_gl_version() {
                 log_msg(LOG_LEVEL_ERROR, MOD_NAME "ERROR: OpenGL 2.0 is not supported, try updating your drivers...\n");
                 return false;
         }
-        log_msg(LOG_LEVEL_INFO, MOD_NAME "OpenGL 2.0 is supported...\n");
-        MSG(VERBOSE, "Supported OpenGL version is %s.\n", version);
+        if (print_ver) { // from help
+                color_printf(TBOLD("OpenGL version:") " %s\n", version);
+        } else {
+                MSG(INFO, "OpenGL 2.0 is supported...\n");
+                MSG(VERBOSE, "Supported OpenGL version is %s.\n", version);
+        }
         return true;
 }
 
@@ -1728,7 +1742,7 @@ static bool display_gl_init_opengl(struct state_gl *s)
                 }
         }
 #endif
-        if (!display_gl_check_gl_version()) {
+        if (!check_display_gl_version(false)) {
                 glfwDestroyWindow(s->window);
                 s->window = nullptr;
                 return false;