static bool printNextDebugMessage() {
	if (!hasPendingDebugMessage()) {
		return false;
	}

	GLint msgLen = 0;
	glGetIntegerv(GL_DEBUG_NEXT_LOGGED_MESSAGE_LENGTH_ARB, &msgLen);

	SCP_vector<GLchar> msg;
	msg.resize(msgLen + 1); // Includes null character, needs to be removed later

	GLenum source;
	GLenum type;
	GLenum severity;
	GLuint id;
	GLsizei length;

	GLuint numFound = glGetDebugMessageLogARB(1, static_cast<GLsizei>(msg.size()), &source, &type, &id, &severity, &length, &msg[0]);

	if (numFound < 1) {
		return false;
	}

	debug_callback(source, type, id, severity, length, msg.data(), nullptr);

	return true;
}
static void cache_program_binary(GLuint program, const SCP_string& hash) {
	if (!do_shader_caching()) {
		return;
	}
	
	GR_DEBUG_SCOPE("Saving shader binary");

	GLint size;
	glGetProgramiv(program, GL_PROGRAM_BINARY_LENGTH, &size);

	if (size <= 0) {
		// No binary available (I'm looking at you Mesa...)
		return;
	}

	SCP_vector<uint8_t> binary;
	binary.resize((size_t) size);
	GLenum binary_fmt;
	GLsizei length;
	glGetProgramBinary(program, (GLsizei) binary.size(), &length, &binary_fmt, binary.data());
	if (length == 0) {
		return;
	}

	auto base_filename = SCP_string("ogl_shader-") + hash;

	auto metadata_name = base_filename + ".json";
	auto binary_name = base_filename + ".bin";

	auto metadata_fp = cfopen(metadata_name.c_str(), "wb", CFILE_NORMAL, CF_TYPE_CACHE, false,
	                          CF_LOCATION_ROOT_USER | CF_LOCATION_ROOT_GAME | CF_LOCATION_TYPE_ROOT);
	if (!metadata_fp) {
		mprintf(("Could not open shader cache metadata file!\n"));
		return;
	}

	auto metadata = json_pack("{sI}", "format", (json_int_t)binary_fmt);
	if (json_dump_callback(metadata, json_write_callback, metadata_fp, 0) != 0) {
		mprintf(("Failed to write shader cache metadata file!\n"));
		cfclose(metadata_fp);
		return;
	}
	cfclose(metadata_fp);
	json_decref(metadata);

	auto binary_fp = cfopen(binary_name.c_str(), "wb", CFILE_NORMAL, CF_TYPE_CACHE, false,
	                        CF_LOCATION_ROOT_USER | CF_LOCATION_ROOT_GAME | CF_LOCATION_TYPE_ROOT);
	if (!binary_fp) {
		mprintf(("Could not open shader cache binary file!\n"));
		return;
	}
	cfwrite(binary.data(), 1, (int) binary.size(), binary_fp);
	cfclose(binary_fp);
}
static bool load_cached_shader_binary(opengl::ShaderProgram* program, const SCP_string& hash) {
	if (!do_shader_caching()) {
		return false;
	}

	auto base_filename = SCP_string("ogl_shader-") + hash;

	auto metadata = base_filename + ".json";
	auto binary = base_filename + ".bin";

	auto metadata_fp = cfopen(metadata.c_str(), "rb", CFILE_NORMAL, CF_TYPE_CACHE, false,
	                          CF_LOCATION_ROOT_USER | CF_LOCATION_ROOT_GAME | CF_LOCATION_TYPE_ROOT);
	if (!metadata_fp) {
		nprintf(("ShaderCache", "Metadata file does not exist.\n"));
		return false;
	}

	auto size = cfilelength(metadata_fp);
	SCP_string metadata_content;
	metadata_content.resize((size_t) size);
	cfread(&metadata_content[0], 1, size, metadata_fp);

	cfclose(metadata_fp);

	auto metadata_root = json_loads(metadata_content.c_str(), 0, nullptr);
	if (!metadata_root) {
		mprintf(("Loading of cache metadata failed! Falling back to GLSL shader...\n"));
		return false;
	}

	json_int_t format;
	if (json_unpack(metadata_root, "{sI}", "format", &format) != 0) {
		mprintf(("Failed to unpack values from metadata JSON! Falling back to GLSL shader...\n"));
		return false;
	}
	auto binary_format = (GLenum) format;
	json_decref(metadata_root);

	bool supported = false;
	for (auto supported_fmt : GL_binary_formats) {
		if ((GLenum)supported_fmt == binary_format) {
			supported = true;
			break;
		}
	}

	if (!supported) {
		// This can happen in case an implementation stops supporting a particular binary format
		nprintf(("ShaderCache", "Unsupported binary format %d encountered in shader cache.\n", binary_format));
		return false;
	}

	auto binary_fp = cfopen(binary.c_str(), "rb", CFILE_NORMAL, CF_TYPE_CACHE, false,
	                        CF_LOCATION_ROOT_USER | CF_LOCATION_ROOT_GAME | CF_LOCATION_TYPE_ROOT);
	if (!binary_fp) {
		nprintf(("ShaderCache", "Binary file does not exist.\n"));
		return false;
	}
	
	GR_DEBUG_SCOPE("Loading cached shader");
	
	SCP_vector<uint8_t> buffer;
	int length = cfilelength(binary_fp);
	buffer.resize((size_t) length);
	cfread(&buffer[0], 1, length, binary_fp);

	cfclose(binary_fp);

	// Load the data!
	glProgramBinary(program->getShaderHandle(), binary_format, buffer.data(), (GLsizei) buffer.size());

	// Check the status...
	GLint status;
	glGetProgramiv(program->getShaderHandle(), GL_LINK_STATUS, &status);

	return status == GL_TRUE;
}
void credits_init()
{
	int i;
	credits_screen_buttons *b;

	// pre-initialize
	Credits_num_images = DEFAULT_NUM_IMAGES;
	Credits_artwork_index = -1;

	// this is moved up here so we can override it if desired
	strcpy_s(Credits_music_name, "Cinema");

	// parse credits early so as to set up any overrides (for music and such)
	Credits_parsed = false;
	credits_parse();

	// we could conceivably have specified a number of images but not an index,
	// so if that's the case, set the value here
	if (Credits_artwork_index < 0) {
		Credits_artwork_index = rand() % Credits_num_images;
	}

	int credits_spooled_music_index = event_music_get_spooled_music_index(Credits_music_name);	
	if(credits_spooled_music_index != -1){
		char *credits_wavfile_name = Spooled_music[credits_spooled_music_index].filename;		
		if(credits_wavfile_name != NULL){
			credits_load_music(credits_wavfile_name);
		}
	}

	// Use this id to trigger the start of music playing on the briefing screen
	Credits_music_begin_timestamp = timestamp(Credits_music_delay);

	Credits_frametime = 0;
	Credits_last_time = timer_get_milliseconds();
	
	if (!Credits_parsed)
	{
		Credit_text_parts.push_back(SCP_string("No credits available.\n"));
	}
	else
	{
		switch (SCP_credits_position)
		{
			case START:
				Credit_text_parts.insert(Credit_text_parts.begin(), fs2_open_credit_text);
				break;

			case END:
				Credit_text_parts.push_back(fs2_open_credit_text);
				break;

			default:
				Error(LOCATION, "Unimplemented credits position %d. Get a coder!", (int) SCP_credits_position);
				break;
		}
	}

	int ch;
	SCP_vector<SCP_string>::iterator iter;

	for (iter = Credit_text_parts.begin(); iter != Credit_text_parts.end(); ++iter)
	{
		for (SCP_string::iterator ii = iter->begin(); ii != iter->end(); ++ii)
		{
			ch = *ii;
			switch (ch)
			{
				case -4:
					ch = 129;
					break;

				case -28:
					ch = 132;
					break;

				case -10:
					ch = 148;
					break;

				case -23:
					ch = 130;
					break;

				case -30:
					ch = 131;
					break;

				case -25:
					ch = 135;
					break;

				case -21:
					ch = 137;
					break;

				case -24:
					ch = 138;
					break;

				case -17:
					ch = 139;
					break;

				case -18:
					ch = 140;
					break;

				case -60:
					ch = 142;
					break;

				case -55:
					ch = 144;
					break;

				case -12:
					ch = 147;
					break;

				case -14:
					ch = 149;
					break;

				case -5:
					ch = 150;
					break;

				case -7:
					ch = 151;
					break;

				case -42:
					ch = 153;
					break;

				case -36:
					ch = 154;
					break;

				case -31:
					ch = 160;
					break;

				case -19:
					ch = 161;
					break;

				case -13:
					ch = 162;
					break;

				case -6:
					ch = 163;
					break;

				case -32:
					ch = 133;
					break;

				case -22:
					ch = 136;
					break;

				case -20:
					ch = 141;
					break;
			}

			*ii = (char) ch;
		}
	}

	int temp_h;
	int h = 0;

	for (iter = Credit_text_parts.begin(); iter != Credit_text_parts.end(); ++iter)
	{
		gr_get_string_size(NULL, &temp_h, iter->c_str(), (int)iter->length());

		h = h + temp_h;
	}

	Credit_start_pos = i2fl(Credits_text_coords[gr_screen.res][CREDITS_H_COORD]);
	Credit_stop_pos = -i2fl(h);
	Credit_position = Credit_start_pos;

	Ui_window.create(0, 0, gr_screen.max_w_unscaled, gr_screen.max_h_unscaled, 0);
	Ui_window.set_mask_bmap(Credits_bitmap_mask_fname[gr_screen.res]);
	common_set_interface_palette("InterfacePalette");  // set the interface palette

	for (i=0; i<NUM_BUTTONS; i++) {
		b = &Buttons[i][gr_screen.res];

		b->button.create(&Ui_window, "", b->x, b->y, 60, 30, (i < 2), 1);
		// set up callback for when a mouse first goes over a button
		b->button.set_highlight_action(common_play_highlight_sound);
		b->button.set_bmaps(b->filename);
		b->button.link_hotspot(b->hotspot);
	}

	// add some text
	Ui_window.add_XSTR("Technical Database", 1055, Buttons[TECH_DATABASE_BUTTON][gr_screen.res].xt,  Buttons[TECH_DATABASE_BUTTON][gr_screen.res].yt, &Buttons[TECH_DATABASE_BUTTON][gr_screen.res].button, UI_XSTR_COLOR_GREEN);
	Ui_window.add_XSTR("Mission Simulator", 1056, Buttons[SIMULATOR_BUTTON][gr_screen.res].xt,  Buttons[SIMULATOR_BUTTON][gr_screen.res].yt, &Buttons[SIMULATOR_BUTTON][gr_screen.res].button, UI_XSTR_COLOR_GREEN);
	Ui_window.add_XSTR("Cutscenes", 1057, Buttons[CUTSCENES_BUTTON][gr_screen.res].xt,  Buttons[CUTSCENES_BUTTON][gr_screen.res].yt, &Buttons[CUTSCENES_BUTTON][gr_screen.res].button, UI_XSTR_COLOR_GREEN);
	Ui_window.add_XSTR("Credits", 1058, Buttons[CREDITS_BUTTON][gr_screen.res].xt,  Buttons[CREDITS_BUTTON][gr_screen.res].yt, &Buttons[CREDITS_BUTTON][gr_screen.res].button, UI_XSTR_COLOR_GREEN);
	Ui_window.add_XSTR("Exit", 1420, Buttons[EXIT_BUTTON][gr_screen.res].xt,  Buttons[EXIT_BUTTON][gr_screen.res].yt, &Buttons[EXIT_BUTTON][gr_screen.res].button, UI_XSTR_COLOR_PINK);

	if (Player->flags & PLAYER_FLAGS_IS_MULTI) {
		Buttons[SIMULATOR_BUTTON][gr_screen.res].button.disable();
		Buttons[CUTSCENES_BUTTON][gr_screen.res].button.disable();
	}

	Buttons[EXIT_BUTTON][gr_screen.res].button.set_hotkey(KEY_CTRLED | KEY_ENTER);

	Background_bitmap = bm_load(Credits_bitmap_fname[gr_screen.res]);

	Credits_bmps.resize(Credits_num_images);
	for (i=0; i<Credits_num_images; i++) {
		Credits_bmps[i] = -1;
	}
}
static bool load_cached_shader_binary(opengl::ShaderProgram* program, SCP_string hash) {
	if (!do_shader_caching()) {
		return false;
	}

	auto base_filename = SCP_string("ogl_shader-") + hash;

	auto metadata = base_filename + ".json";
	auto binary = base_filename + ".bin";

	auto metadata_fp = cfopen(metadata.c_str(), "rb", CFILE_NORMAL, CF_TYPE_CACHE);
	if (!metadata_fp) {
		nprintf(("ShaderCache", "Metadata file does not exist.\n"));
		return false;
	}

	auto size = cfilelength(metadata_fp);
	SCP_string metadata_content;
	metadata_content.resize((size_t) size);
	cfread(&metadata_content[0], 1, size, metadata_fp);

	cfclose(metadata_fp);

	auto metadata_root = json_loads(metadata_content.c_str(), 0, nullptr);
	if (!metadata_root) {
		mprintf(("Loading of cache metadata failed! Falling back to GLSL shader...\n"));
		return false;
	}

	json_int_t format;
	if (json_unpack(metadata_root, "{sI}", "format", &format) != 0) {
		mprintf(("Failed to unpack values from metadata JSON! Falling back to GLSL shader...\n"));
		return false;
	}
	auto binary_format = (GLenum) format;
	json_decref(metadata_root);

	auto binary_fp = cfopen(binary.c_str(), "rb", CFILE_NORMAL, CF_TYPE_CACHE);
	if (!binary_fp) {
		nprintf(("ShaderCache", "Binary file does not exist.\n"));
		return false;
	}
	
	GR_DEBUG_SCOPE("Loading cached shader");
	
	SCP_vector<uint8_t> buffer;
	int length = cfilelength(binary_fp);
	buffer.resize((size_t) length);
	cfread(&buffer[0], 1, length, binary_fp);

	cfclose(binary_fp);

	// Load the data!
	glProgramBinary(program->getShaderHandle(), binary_format, buffer.data(), (GLsizei) buffer.size());

	// Check the status...
	GLint status;
	glGetProgramiv(program->getShaderHandle(), GL_LINK_STATUS, &status);

	return status == GL_TRUE;
}