/*
 * Copyright (C) Volition, Inc. 1999.  All rights reserved.
 *
 * All source code herein is the property of Volition, Inc. You may not sell 
 * or otherwise commercially exploit the source or things you created based on the 
 * source.
 *
*/ 



#include <cstdlib>

#include "cfile/cfile.h"
#include "freespace.h"
#include "gamesequence/gamesequence.h"
#include "gamesnd/eventmusic.h"	/* for Master_event_music_volume */
#include "gamesnd/gamesnd.h"
#include "globalincs/alphacolors.h"
#include "graphics/font.h"
#include "io/key.h"
#include "io/timer.h"
#include "localization/localize.h"
#include "menuui/credits.h"
#include "missionui/missionscreencommon.h"
#include "parse/parselo.h"
#include "playerman/player.h"
#include "sound/audiostr.h"
#include "ui/ui.h"

#include <lua.h>


// This is the fs2_open credit list, please only add yourself if you have actually contributed code
// Rules!
const char *fs2_open_credit_text =
"SOURCE CODE PROJECT STAFF:\n"
	"\n"
	"\n"
	"Project Leader:\n"
	"\n"
	"Tyler \"DahBlount\" Blount\n"
	"\n"
	"Senior Advisors:\n"
	"\n"
	"Ian \"Goober5000\" Warfield\n"
	"Fabian \"The E\" Woltermann\n"
	"Cliff \"chief1983\" Gordon\n"
	"Taylor Richards\n"
	"Michael \"Zacam\" LaFleur\n"
	"Edward \"Inquisitor\" Gardner\n"
	"\n"
	"Programmers:\n"
	"\n"
	"Mike \"Bobboau\" Abegg\n"
	"Hassan \"Karajorma\" Kazmi\n"
	"Derek \"Kazan\" Meek\n"
	"Nick \"phreak\" Iannetta\n"
	"Zoe \"EatThePath\" Gibson\n"
	"Mike \"MjnMixael\" Nelson\n"
	"argv[-1], Backslash, Baezon\n"
	"CommanderDJ, Cyborg, DTP\n"
	"Echelon9, EdrickV, Eternal1\n"
	"Flaming_Sword, Fry_Day, FUBAR\n"
	"Hery, Iss Mneur, jg18\n"
	"Kiloku, Lafiel, m!m\n"
	"MageKing17, mrduckman, naomimyselfandi\n"
	"niffiwan, penguin, Phantom Hoover\n"
	"portej05, qazwsxal, RandomTiger\n"
	"Righteous1, Sesquipedalian, Shade\n"
	"Sticks, Sushi, Swifty\n"
	"UnknownPlayer, Valathil, Wanderer\n"
	"WMCoolmon, wookieejedi, Yarn\n"
	"z64555, zookeeper\n"
	"\n"
	"\n"
	"Web Support:\n"
	"\n"
	"https://www.hard-light.net/\n"
	"https://scp.indiegames.us/\n"
	"\n"
	"\n"
	"Special thanks to:\n"
	"\n"
	"Fury\n"
	"kasperl\n"
	"QuantumDelta\n"
	"redmenace\n"
	"\n"
	"\n"
	"Linux and OSX version with the support of\n"
	"the icculus.org FreeSpace2 project:\n"
	"Steven \"relnev\" Fuller\n"
	"Ryan Gordon\n"
	"Charles Mason\n"
	"Dan Olson\n"
	"Taylor Richards\n"
	"\"tigital\"\n"
	"\n"
	"\n"
	"Very special thanks to:\n"
	"\n"
	"Volition for making FS2 such a great game\n"
	"Dave Baranec for giving us the code and keeping us sanity checked\n"
	"\n"
	"\n"
	"FS2_Open makes use of the following technologies:\n"
	"\n"
	"Ogg Vorbis - (C) 2005, Xiph.Org Foundation\n"
	"JPEG - Independent JPEG Group, (C) 1991-1998, Thomas G. Lane\n"
	"libpng - Copyright (C) 1998-2010 Glenn Randers-Pehrson\n"
	"liblua (" LUA_RELEASE ") - " LUA_COPYRIGHT "\n"
	"zlib - Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler\n"
	"FXAA - Copyright (c) 2010 NVIDIA Corporation. All rights reserved.\n"
	"libpcp - Copyright (c) 2013 by Cisco Systems, Inc.\n"
	"This software uses libraries from the FFmpeg project under the LGPLv2.1\n"
	"Dear ImGui by Omar Cornut and contributors\n"
	"dkjson.lua - Copyright (C) 2010-2014 David Heiko Kolf"
	"\n"
	"\n"
	"\n";

const char *unmodified_credits = "ORIGINAL VOLITION STAFF:\n\n\n";
const char *mod_check = "Design:";

#define NUM_BUTTONS				5
#define DEFAULT_NUM_IMAGES		46

#define TECH_DATABASE_BUTTON	0
#define SIMULATOR_BUTTON		1
#define CUTSCENES_BUTTON		2
#define CREDITS_BUTTON			3
#define EXIT_BUTTON				4

// inidicies for coordinates
#define CREDITS_X_COORD 0
#define CREDITS_Y_COORD 1
#define CREDITS_W_COORD 2
#define CREDITS_H_COORD 3

static const char* Credits_bitmap_fname[GR_NUM_RESOLUTIONS] = {
	"Credits",			// GR_640
	"2_Credits"
};

static const char* Credits_bitmap_mask_fname[GR_NUM_RESOLUTIONS] = {
	"Credits-M",			// GR_640
	"2_Credits-M"
};

int Credits_image_coords[GR_NUM_RESOLUTIONS][4] = {
	{
		219, 15, 394, 286			// GR_640
	},
	{
		351, 25, 629, 455			// GR_1024
	}
};

// x, y, w, h
int Credits_text_coords[GR_NUM_RESOLUTIONS][4] = {
	{
		26, 316, 482, 157			// GR_640
	},
	{
		144, 507, 568, 249			// GR_640
	}
};

struct credits_screen_buttons {
	const char *filename;
	int x, y, xt, yt;
	int hotspot;
	UI_BUTTON button;  // because we have a class inside this struct, we need the constructor below..

	credits_screen_buttons(const char *name, int x1, int y1, int xt1, int yt1, int h) : filename(name), x(x1), y(y1), xt(xt1), yt(yt1), hotspot(h) {}
};

static int Background_bitmap;
static UI_WINDOW Ui_window;

static credits_screen_buttons Buttons[NUM_BUTTONS][GR_NUM_RESOLUTIONS] = {
//XSTR:OFF
	{
			credits_screen_buttons("TDB_00", 7, 3, 37, 7, 0),			// GR_640
			credits_screen_buttons("2_TDB_00", 12, 5, 59, 12, 0)			// GR_1024
	},
	{
			credits_screen_buttons("TDB_01", 7, 18, 37, 23,	1),		// GR_640
			credits_screen_buttons("2_TDB_01", 12, 31, 59, 37, 1)		// GR_1024
	},
	{
			credits_screen_buttons("TDB_02", 7, 34, 37, 38, 2),		// GR_640
			credits_screen_buttons("2_TDB_02", 12, 56, 59, 62, 2)		// GR_1024
	},
	{
			credits_screen_buttons("TDB_03", 7, 49, 37, 54,	3),		// GR_640
			credits_screen_buttons("2_TDB_03", 12, 81, 59, 88, 3)		// GR_1024
	},
	{
			credits_screen_buttons("CRB_04", 571, 425, 588, 413, 4),	// GR_640
			credits_screen_buttons("2_CRB_04", 914, 681, 953, 668, 4)	// GR_1024
	}
//XSTR:ON
};

char Credits_music_name[NAME_LENGTH] = "Cinema";
char Credits_substitute_music_name[NAME_LENGTH] = "";

static int	Credits_music_handle = -1;
static UI_TIMESTAMP	Credits_music_begin_timestamp;

static int	Credits_frametime;		// frametime of credits_do_frame() loop in ms
static int	Credits_last_time;		// timestamp used to calc frametime (in ms)
static float Credits_counter;

int Credits_num_images = DEFAULT_NUM_IMAGES;
int Credits_artwork_index = -1;
static SCP_vector<int> Credits_bmps;

// Positions for credits...
float Credit_start_pos, Credit_stop_pos, Credit_position = 0.0f;

static int Credits_music_delay				= 2000;
float Credits_scroll_rate					= 15.0f;
float Credits_artwork_display_time			= 9.0f;
float Credits_artwork_fade_time				= 1.0f;

SCP_string credits_complete;

SCP_vector<SCP_string> Credit_text_parts;

static bool Credits_parsed;

static bool Split_credits_lines = true;

enum CreditsPosition
{
	START,
	END
};

static CreditsPosition SCP_credits_position	= START;

void credits_stop_music(bool fade)
{
	if ( Credits_music_handle != -1 ) {
		audiostream_close_file(Credits_music_handle, fade);
		Credits_music_handle = -1;
	}
}

void credits_load_music(const char* fname)
{
	if ( Credits_music_handle != -1 ){
		return;
	}

	if ( fname && *fname ){
		Credits_music_handle = audiostream_open( fname, ASF_MENUMUSIC );
	}
}

void credits_start_music()
{
	if (Credits_music_handle != -1) {
		if ( !audiostream_is_playing(Credits_music_handle) ){
			audiostream_play(Credits_music_handle, Master_event_music_volume, 1);
		}
	} else {
		nprintf(("Warning", "Cannot play credits music\n"));
	}
}

const char* credits_get_music_filename(const char* music)
{
	int credits_spooled_music_index = event_music_get_spooled_music_index(music);
	if (credits_spooled_music_index != -1) {
		return Spooled_music[credits_spooled_music_index].filename;
	}
	return nullptr;
}

int credits_screen_button_pressed(int n)
{
	switch (n) {
	case TECH_DATABASE_BUTTON:
		gamesnd_play_iface(InterfaceSounds::SWITCH_SCREENS);
		gameseq_post_event(GS_EVENT_TECH_MENU);
		return 1;

	case SIMULATOR_BUTTON:
		gamesnd_play_iface(InterfaceSounds::SWITCH_SCREENS);
		gameseq_post_event(GS_EVENT_SIMULATOR_ROOM);
		return 1;

	case CUTSCENES_BUTTON:
		gamesnd_play_iface(InterfaceSounds::SWITCH_SCREENS);
		gameseq_post_event(GS_EVENT_GOTO_VIEW_CUTSCENES_SCREEN);
		return 1;

	case EXIT_BUTTON:
		gamesnd_play_iface(InterfaceSounds::COMMIT_PRESSED);
		gameseq_post_event(GS_EVENT_MAIN_MENU);
		game_flush();
		break;
	}

	return 0;
}

void credits_parse_table(const char* filename)
{	
	try
	{
		read_file_text(filename, CF_TYPE_TABLES);
		reset_parse();

		// any metadata?
		if (optional_string("$Music:"))
		{
			stuff_string(Credits_music_name, F_NAME, NAME_LENGTH);
		}
		if (optional_string("$Substitute Music:"))
		{
			stuff_string(Credits_substitute_music_name, F_NAME, NAME_LENGTH);
		}
		if (optional_string("$Number of Images:"))
		{
			int temp;
			stuff_int(&temp);
			if (temp > 0) 
				Credits_num_images = temp;
		}
		if (optional_string("$Start Image Index:"))
		{
			stuff_int(&Credits_artwork_index);

			// bounds check
			if (Credits_artwork_index < 0)
			{
				Credits_artwork_index = 0;
			}
			else if (Credits_artwork_index >= Credits_num_images)
			{
				Credits_artwork_index = Credits_num_images - 1;
			}
		}
		if (optional_string("$Text scroll rate:"))
		{
			stuff_float(&Credits_scroll_rate);
			if (Credits_scroll_rate < 0.01f)
				Credits_scroll_rate = 0.01f;
		}
		if (optional_string("$Artworks display time:"))
		{
			stuff_float(&Credits_artwork_display_time);
			if (Credits_artwork_display_time < 0.01f) {
				Credits_artwork_display_time = 0.01f;
			}
		}
		if (optional_string("$Artworks fade time:"))
		{
			stuff_float(&Credits_artwork_fade_time);
			if (Credits_artwork_fade_time < 0.01f)
				Credits_artwork_fade_time = 0.01f;
		}
		if (optional_string("$SCP Credits position:"))
		{
			char mode[NAME_LENGTH];

			stuff_string(mode, F_NAME, NAME_LENGTH);

			if (!stricmp(mode, "Start"))
				SCP_credits_position = START;
			else if (!stricmp(mode, "End"))
				SCP_credits_position = END;
			else
				Warning(LOCATION, "Unknown credits position mode \"%s\".", mode);
		}

		ignore_white_space();

		SCP_string credits_text;
		SCP_string line;

		SCP_vector<int> charNum;
		SCP_vector<const char*> lines;
		int numLines = -1;

		bool first_run = true;
		while (!check_for_eof_raw() && !check_for_string_raw("#end"))
		{
			// Read in a line of text			
			stuff_string_line(line);

			// This is a bit odd but it means if a total conversion uses different credits the 
			// Volition credit won't happen
			// Also don't append the default credits anymore when there was already a parsed table
			if (first_run && !Credits_parsed && line == mod_check)
			{
				credits_text.append(unmodified_credits);
			}

			first_run = false;

			if (line.empty())
			{
				// If the line is empty then just append a newline, don't bother with splitting it first
				credits_text.append("\n");
			}
			else
			{
				// optionally split lines. This is default behavior but SCPUI doesn't use it
				if (Split_credits_lines) {

					// split_str doesn't take care of this.
					charNum.clear();

					// Split the string into multiple lines if it's too long
					numLines = split_str(line.c_str(), Credits_text_coords[gr_screen.res][2], charNum, lines);

					// Make sure that we have valid data
					Assertion(lines.size() == (size_t)numLines,
						"split_str reported %d lines but vector contains " SIZE_T_ARG " entries!",
						numLines,
						lines.size());

					Assertion(lines.size() <= charNum.size(),
						"Something has gone wrong while splitting strings. Got " SIZE_T_ARG
						" lines but only " SIZE_T_ARG " chacter lengths.",
						lines.size(),
						charNum.size());
				} else {
					lines.push_back(line.c_str());
					charNum.push_back((int)line.length());
					numLines = 1;
				}

				// Now add all splitted lines to the credit text and append a newline to the end
				for (int i = 0; i < numLines; i++)
				{
					credits_text.append(SCP_string(lines[i], charNum[i]));
					credits_text.append("\n");
				}

				// clear vectors for the next round
				lines.clear();
				charNum.clear();
			}
		}

		Credit_text_parts.push_back(std::move(credits_text));

		Credits_parsed = true;
	}
	catch (const parse::ParseException& e)
	{
		mprintf(("TABLES: Unable to parse '%s'!  Error message = %s.\n", filename, e.what()));
		return;
	}
}

void credits_scp_position()
{
	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;
	}
}

void credits_parse(bool split_lines)
{

	Split_credits_lines = split_lines;

	// Parse main table
	credits_parse_table("credits.tbl");

	// Parse modular tables
	parse_modular_table("*-crd.tbm", credits_parse_table);
}

void credits_init()
{
	int i;
	credits_screen_buttons *b;

	// 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 = Random::next(Credits_num_images);
	}

	const char *credits_wavfile_name = nullptr;

	// try substitute music first
	if (*Credits_substitute_music_name)
		credits_wavfile_name = credits_get_music_filename(Credits_substitute_music_name);

	// fall back to regular music
	if (!credits_wavfile_name)
		credits_wavfile_name = credits_get_music_filename(Credits_music_name);

	// if we have something, play it
	if (credits_wavfile_name)
		credits_load_music(credits_wavfile_name);

	// Use this id to trigger the start of music playing on the credits screen
	Credits_music_begin_timestamp = ui_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
	{
		credits_scp_position();
	}

	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(nullptr, &temp_h, iter->c_str(), 1.0f, 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;
	}
}

void credits_close()
{	
	int i;

	for (i=0; i<Credits_num_images; i++) {
		if (Credits_bmps[i] >= 0){
			bm_release(Credits_bmps[i]);
		}
	}	
	Credits_bmps.clear();

	Credit_text_parts.clear();

	if (Background_bitmap){
		bm_release(Background_bitmap);
	}

	Ui_window.destroy();
	common_free_interface_palette();		// restore game palette


	// non-UI stuff
	credits_stop_music(true);
}

void credits_do_frame(float  /*frametime*/)
{
	GR_DEBUG_SCOPE("Credits do frame");

	int i, k, next, percent, bm1, bm2;
	int bx1, by1, bw1, bh1;
	int bx2, by2, bw2, bh2;

	// Use this id to trigger the start of music playing on the credits screen
	if ( ui_timestamp_elapsed(Credits_music_begin_timestamp) ) {
		Credits_music_begin_timestamp = UI_TIMESTAMP::invalid();
		credits_start_music();
	}

	k = Ui_window.process();
	switch (k) {
	case KEY_ESC:
		gameseq_post_event(GS_EVENT_MAIN_MENU);
		key_flush();
		break;

	case KEY_CTRLED | KEY_UP:
	case KEY_SHIFTED | KEY_TAB:
		if ( !(Player->flags & PLAYER_FLAGS_IS_MULTI) ) {
			credits_screen_button_pressed(CUTSCENES_BUTTON);
			break;
		}
		// else, react like tab key.
		FALLTHROUGH;

	case KEY_CTRLED | KEY_DOWN:
	case KEY_TAB:
		credits_screen_button_pressed(TECH_DATABASE_BUTTON);
		break;

	default:
		break;
	} // end switch

	for (i=0; i<NUM_BUTTONS; i++){
		if (Buttons[i][gr_screen.res].button.pressed()){
			if (credits_screen_button_pressed(i)){
				return;
			}
		}
	}

	gr_reset_clip();	
	GR_MAYBE_CLEAR_RES(Background_bitmap);
	if (Background_bitmap >= 0) {
		gr_set_bitmap(Background_bitmap);
		gr_bitmap(0, 0, GR_RESIZE_MENU);
	} 

	percent = (int) (100.0f - (Credits_artwork_display_time - Credits_counter) * 100.0f / Credits_artwork_fade_time);
	if (percent < 0){
		percent = 0;
	}

	next = Credits_artwork_index + 1;
	if (next >= Credits_num_images){
		next = 0;
	}

	if (Credits_bmps[Credits_artwork_index] < 0) {
		char buf[40];

		if (gr_screen.res == GR_1024) {
			sprintf(buf, NOX("2_CrIm%.2d"), Credits_artwork_index);
		} else {
			sprintf(buf, NOX("CrIm%.2d"), Credits_artwork_index);
		}
		Credits_bmps[Credits_artwork_index] = bm_load(buf);
	}

	if (Credits_bmps[next] < 0) {
		char buf[40];

		if (gr_screen.res == GR_1024) {
			sprintf(buf, NOX("2_CrIm%.2d"), next);
		} else {
			sprintf(buf, NOX("CrIm%.2d"), next);
		}
		Credits_bmps[next] = bm_load(buf);
	}

	bm1 = Credits_bmps[Credits_artwork_index];
	bm2 = Credits_bmps[next];

	if((bm1 != -1) && (bm2 != -1)){
		GR_DEBUG_SCOPE("Render credits bitmap");

		Assert(percent >= 0 && percent <= 100);

		// get width and height
		bm_get_info(bm1, &bw1, &bh1, NULL, NULL, NULL);	
		bm_get_info(bm2, &bw2, &bh2, NULL, NULL, NULL);	
	
		// determine where to draw the coords
		bx1 = Credits_image_coords[gr_screen.res][CREDITS_X_COORD] + ((Credits_image_coords[gr_screen.res][CREDITS_W_COORD] - bw1)/2);
		by1 = Credits_image_coords[gr_screen.res][CREDITS_Y_COORD] + ((Credits_image_coords[gr_screen.res][CREDITS_H_COORD] - bh1)/2);
		bx2 = Credits_image_coords[gr_screen.res][CREDITS_X_COORD] + ((Credits_image_coords[gr_screen.res][CREDITS_W_COORD] - bw2)/2);
		by2 = Credits_image_coords[gr_screen.res][CREDITS_Y_COORD] + ((Credits_image_coords[gr_screen.res][CREDITS_H_COORD] - bh2)/2);

		auto alpha = (float)percent / 100.0f;

		gr_set_bitmap(bm1, GR_ALPHABLEND_FILTER, GR_BITBLT_MODE_NORMAL, 1.0f - alpha);
		gr_bitmap(bx1, by1, GR_RESIZE_MENU);

		gr_set_bitmap(bm2, GR_ALPHABLEND_FILTER, GR_BITBLT_MODE_NORMAL, alpha);
		gr_bitmap(bx2, by2, GR_RESIZE_MENU);
	}

	Ui_window.draw();

	for (i=TECH_DATABASE_BUTTON; i<=CREDITS_BUTTON; i++){
		if (Buttons[i][gr_screen.res].button.button_down()){
			break;
		}
	}

	if (i > CREDITS_BUTTON){
		Buttons[CREDITS_BUTTON][gr_screen.res].button.draw_forced(2);
	}

	gr_set_clip(Credits_text_coords[gr_screen.res][CREDITS_X_COORD], Credits_text_coords[gr_screen.res][CREDITS_Y_COORD], Credits_text_coords[gr_screen.res][CREDITS_W_COORD], Credits_text_coords[gr_screen.res][CREDITS_H_COORD], GR_RESIZE_MENU);
	font::set_font(font::FONT1);
	gr_set_color_fast(&Color_normal);
	
	int y_offset = 0;
	for (SCP_vector<SCP_string>::iterator iter = Credit_text_parts.begin(); iter != Credit_text_parts.end(); ++iter)
	{
		size_t currentPos = 0;
		size_t lineEnd;
		do
		{
			int height;
			int width;
			lineEnd = iter->find('\n', currentPos);

			auto length = lineEnd - currentPos;
			if (lineEnd == SCP_string::npos)
			{
				length = std::numeric_limits<size_t>::max();
			}

			gr_get_string_size(&width, &height, iter->c_str() + currentPos, 1.0f, length);
			// Check if the text part is actually visible
			if (Credit_position + y_offset + height > 0.0f)
			{
				int x = (gr_screen.clip_width_unscaled - width) / 2;
				gr_string(i2fl(x), Credit_position + y_offset, iter->c_str() + currentPos, GR_RESIZE_MENU, 1.0f, length);
			}

			y_offset += height;
			currentPos = lineEnd + 1;
		} while (lineEnd < iter->length() && lineEnd != SCP_string::npos);
	}

	int temp_time;
	temp_time = timer_get_milliseconds();

	Credits_frametime = temp_time - Credits_last_time;
	Credits_last_time = temp_time;

	float fl_frametime = i2fl(Credits_frametime) / 1000.f;
	if (key_is_pressed(KEY_LSHIFT)) {
		Credit_position -= fl_frametime * Credits_scroll_rate * 4.0f;
	} else {
		Credit_position -= fl_frametime * Credits_scroll_rate;
	}

	if (Credit_position < Credit_stop_pos){
		Credit_position = Credit_start_pos;
	}

	Credits_counter += fl_frametime;
	while (Credits_counter >= Credits_artwork_display_time) {
		Credits_counter -= Credits_artwork_display_time;
		Credits_artwork_index = next;
	}

	gr_flip();
}
