raze/source/core/console/c_console.cpp

/*
** c_console.cpp
** Implements the console itself
**
**---------------------------------------------------------------------------
** Copyright 1998-2006 Randy Heit
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/

#include <string>

#include "templates.h"
#include "version.h"
#include "c_bind.h"
#include "c_console.h"
#include "c_cvars.h"
#include "c_dispatch.h"
#include "gamestate.h"
#include "v_text.h"
#include "filesystem.h"
#include "d_gui.h"
#include "cmdlib.h"
#include "d_event.h"
#include "c_consolebuffer.h"
#include "utf8.h"
#include "v_2ddrawer.h"
#include "v_draw.h"
#include "v_font.h"
#include "printf.h"
#include "inputstate.h"
#include "i_time.h"
#include "gamecvars.h"
#include "baselayer.h"
#include "i_system.h"
#include "s_soundinternal.h"
#include "engineerrors.h"

#define LEFTMARGIN 8
#define RIGHTMARGIN 8
#define BOTTOMARGIN 12

extern bool hud_toggled;
void D_ToggleHud();


CUSTOM_CVAR(Int, con_buffersize, -1, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
{
	// ensure a minimum size
	if (self >= 0 && self < 128) self = 128;
}

FConsoleBuffer *conbuffer;

static void C_TabComplete (bool goForward);
static bool C_TabCompleteList ();
static bool TabbedLast;		// True if last key pressed was tab
static bool TabbedList;		// True if tab list was shown
CVAR(Bool, con_notablist, false, CVAR_ARCHIVE)


static FTexture* conback;
static uint32_t conshade;
static bool conline;

extern int		gametic;
extern bool		automapactive;	// in AM_map.c
extern bool		advancedemo;

extern FBaseCVar *CVars;
extern FConsoleCommand *Commands[FConsoleCommand::HASH_SIZE];

unsigned	ConCols;
int			ConWidth;
bool		vidactive = false;
bool		cursoron = false;
int			ConBottom, ConScroll, RowAdjust;
uint64_t	CursorTicker;
constate_e	ConsoleState = c_up;


static int TopLine, InsertLine;

static void ClearConsole ();

struct GameAtExit
{
	GameAtExit(FString str) : Command(str) {}

	GameAtExit *Next;
	FString Command;
};

static GameAtExit *ExitCmdList;

#define SCROLLUP 1
#define SCROLLDN 2
#define SCROLLNO 0

// Buffer for AddToConsole()
static char *work = NULL;
static int worklen = 0;

CVAR(Float, con_notifytime, 3.f, CVAR_ARCHIVE)
CVAR(Bool, con_centernotify, false, CVAR_ARCHIVE)
CUSTOM_CVAR(Int, con_scaletext, 2, CVAR_ARCHIVE|CVAR_GLOBALCONFIG)		// Scale notify text at high resolutions?
{
	if (self < 0) self = 0;
}

CUSTOM_CVAR(Int, con_scale, 0, CVAR_ARCHIVE)
{
	if (self < 0) self = 0;
}

CUSTOM_CVAR(Float, con_alpha, 0.75f, CVAR_ARCHIVE)
{
	if (self < 0.f) self = 0.f;
	if (self > 1.f) self = 1.f;
}

// Command to run when Ctrl-D is pressed at start of line
CVAR(String, con_ctrl_d, "", CVAR_ARCHIVE | CVAR_GLOBALCONFIG)

CVAR(Int, developer, 0, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)

EXTERN_CVAR(Int, uiscale);


bool generic_ui = true;


struct History
{
	struct History *Older;
	struct History *Newer;
	FString String;
};

struct FCommandBuffer
{
private:
	std::u32string Text;
	unsigned CursorPos = 0;
	unsigned StartPos = 0;	// First character to display
	unsigned CursorPosCells = 0;
	unsigned StartPosCells = 0;

	std::u32string YankBuffer;	// Deleted text buffer

public:
	bool AppendToYankBuffer = false;	// Append consecutive deletes to buffer

	FCommandBuffer() = default;

	FCommandBuffer(const FCommandBuffer &o)
	{
		Text = o.Text;
		CursorPos = o.CursorPos;
		StartPos = o.StartPos;
	}

	FString GetText() const
	{
		FString build;
		for (auto chr : Text) build.AppendCharacter(chr);
		return build;
	}

	size_t TextLength() const
	{
		return Text.length();
	}

	void Draw(int x, int y, int scale, bool cursor)
	{
		if (scale == 1)
		{
			DrawChar(twod, CurrentConsoleFont, CR_ORANGE, x, y, '\x1c', TAG_DONE);
			DrawText(twod, CurrentConsoleFont, CR_ORANGE, x + CurrentConsoleFont->CharWidth(0x1c), y,
				&Text[StartPos], TAG_DONE);

			if (cursor)
			{
				DrawChar(twod, CurrentConsoleFont, CR_YELLOW,
					x + CurrentConsoleFont->CharWidth(0x1c) + (CursorPosCells - StartPosCells) * CurrentConsoleFont->CharWidth(0xb),
					y, '\xb', TAG_DONE);
			}
		}
		else
		{
			DrawChar(twod, CurrentConsoleFont, CR_ORANGE, x, y, '\x1c',
				DTA_VirtualWidth, screen->GetWidth() / scale,
				DTA_VirtualHeight, screen->GetHeight() / scale,
				DTA_KeepRatio, true, TAG_DONE);

			DrawText(twod, CurrentConsoleFont, CR_ORANGE, x + CurrentConsoleFont->CharWidth(0x1c), y,
				&Text[StartPos],
				DTA_VirtualWidth, screen->GetWidth() / scale,
				DTA_VirtualHeight, screen->GetHeight() / scale,
				DTA_KeepRatio, true, TAG_DONE);

			if (cursor)
			{
				DrawChar(twod, CurrentConsoleFont, CR_YELLOW,
					x + CurrentConsoleFont->CharWidth(0x1c) + (CursorPosCells - StartPosCells) * CurrentConsoleFont->CharWidth(0xb),
					y, '\xb',
					DTA_VirtualWidth, screen->GetWidth() / scale,
					DTA_VirtualHeight, screen->GetHeight() / scale,
					DTA_KeepRatio, true, TAG_DONE);
			}
		}
	}

	unsigned CalcCellSize(unsigned length)
	{
		unsigned cellcount = 0;
		for (unsigned i = 0; i < length; i++)
		{
			int w;
			NewConsoleFont->GetChar(Text[i], CR_UNTRANSLATED, &w);
			cellcount += w / 9;
		}
		return cellcount;

	}

	unsigned CharsForCells(unsigned cellin, bool *overflow)
	{
		unsigned chars = 0;
		int cells = cellin;
		while (cells > 0)
		{
			int w;
			NewConsoleFont->GetChar(Text[chars++], CR_UNTRANSLATED, &w);
			cells -= w / 9;
		}
		*overflow = (cells < 0);
		return chars;
	}


	void MakeStartPosGood()
	{
		// Make sure both values point to something valid.
		if (CursorPos > Text.length()) CursorPos = (unsigned)Text.length();
		if (StartPos > Text.length()) StartPos = (unsigned)Text.length();

		CursorPosCells = CalcCellSize(CursorPos);
		StartPosCells = CalcCellSize(StartPos);
		unsigned LengthCells = CalcCellSize((unsigned)Text.length());

		int n = StartPosCells;
		unsigned cols = ConCols / active_con_scale();

		if (StartPosCells >= LengthCells)
		{ // Start of visible line is beyond end of line
			n = CursorPosCells - cols + 2;
		}
		if ((CursorPosCells - StartPosCells) >= cols - 2)
		{ // The cursor is beyond the visible part of the line
			n = CursorPosCells - cols + 2;
		}
		if (StartPosCells > CursorPosCells)
		{ // The cursor is in front of the visible part of the line
			n = CursorPosCells;
		}
		StartPosCells = std::max(0, n);
		bool overflow;
		StartPos = CharsForCells(StartPosCells, &overflow);
		if (overflow)
		{
			// We ended up in the middle of a double cell character, so set the start to the following character.
			StartPosCells++;
			StartPos = CharsForCells(StartPosCells, &overflow);
		}
	}

	void CursorStart()
	{
		CursorPos = 0;
		StartPos = 0;
		CursorPosCells = 0;
		StartPosCells = 0;
	}

	void CursorEnd()
	{
		CursorPos = (unsigned)Text.length();
		MakeStartPosGood();
	}

private:
	void MoveCursorLeft()
	{
		CursorPos--;
	}

	void MoveCursorRight()
	{
		CursorPos++;
	}

public:
	void CursorLeft()
	{
		if (CursorPos > 0)
		{
			MoveCursorLeft();
			MakeStartPosGood();
		}
	}

	void CursorRight()
	{
		if (CursorPos < Text.length())
		{
			MoveCursorRight();
			MakeStartPosGood();
		}
	}

	void CursorWordLeft()
	{
		if (CursorPos > 0)
		{
			do MoveCursorLeft();
			while (CursorPos > 0 && Text[CursorPos - 1] != ' ');
			MakeStartPosGood();
		}
	}

	void CursorWordRight()
	{
		if (CursorPos < Text.length())
		{
			do MoveCursorRight();
			while (CursorPos < Text.length() && Text[CursorPos] != ' ');
			MakeStartPosGood();
		}
	}

	void DeleteLeft()
	{
		if (CursorPos > 0)
		{
			MoveCursorLeft();
			Text.erase(CursorPos, 1);
			MakeStartPosGood();
		}
	}

	void DeleteRight()
	{
		if (CursorPos < Text.length())
		{
			Text.erase(CursorPos, 1);
			MakeStartPosGood();
		}
	}

	void DeleteWordLeft()
	{
		if (CursorPos > 0)
		{
			auto now = CursorPos;

			CursorWordLeft();

			if (AppendToYankBuffer) {
				YankBuffer = Text.substr(CursorPos, now - CursorPos) + YankBuffer;
			} else {
				YankBuffer = Text.substr(CursorPos, now - CursorPos);
			}
			Text.erase(CursorPos, now - CursorPos);
			MakeStartPosGood();
		}
	}

	void DeleteLineLeft()
	{
		if (CursorPos > 0)
		{
			if (AppendToYankBuffer) {
				YankBuffer = Text.substr(0, CursorPos) + YankBuffer;
			} else {
				YankBuffer = Text.substr(0, CursorPos);
			}
			Text.erase(0, CursorPos);
			CursorStart();
		}
	}

	void DeleteLineRight()
	{
		if (CursorPos < Text.length())
		{
			if (AppendToYankBuffer) {
				YankBuffer += Text.substr(CursorPos, Text.length() - CursorPos);
			} else {
				YankBuffer = Text.substr(CursorPos, Text.length() - CursorPos);
			}
			Text.resize(CursorPos);
			CursorEnd();
		}
	}

	void AddChar(int character)
	{
		if (Text.length() == 0)
		{
			Text += character;
		}
		else
		{
			Text.insert(CursorPos, 1, character);
		}
		CursorPos++;
		MakeStartPosGood();
	}

	void AddString(FString clip)
	{
		if (clip.IsNotEmpty())
		{
			// Only paste the first line.
			long brk = clip.IndexOfAny("\r\n\b");
			std::u32string build;
			if (brk >= 0)
			{
				clip.Truncate(brk);
			}
			auto strp = (const uint8_t*)clip.GetChars();
			while (auto chr = GetCharFromString(strp)) build += chr;
			
			if (Text.length() == 0)
			{
				Text = build;
			}
			else
			{
				Text.insert(CursorPos, build);
			}
			CursorPos += (unsigned)build.length();
			MakeStartPosGood();
		}
	}

	void SetString(const FString &str)
	{
		Text.clear();
		auto strp = (const uint8_t*)str.GetChars();
		while (auto chr = GetCharFromString(strp)) Text += chr;

		CursorEnd();
		MakeStartPosGood();
	}

	void AddYankBuffer()
	{
		if (YankBuffer.length() > 0)
		{
			if (Text.length() == 0)
			{
				Text = YankBuffer;
			}
			else
			{
				Text.insert(CursorPos, YankBuffer);
			}
			CursorPos += (unsigned)YankBuffer.length();
			MakeStartPosGood();
		}
	}
};
static FCommandBuffer CmdLine;

#define MAXHISTSIZE 50
static struct History *HistHead = NULL, *HistTail = NULL, *HistPos = NULL;
static int HistSize;

#define NUMNOTIFIES 4
#define NOTIFYFADETIME 6

struct FNotifyText
{
	int TimeOut;
	int Ticker;
	int PrintLevel;
	FString Text;
};

struct FNotifyBuffer
{
public:
	FNotifyBuffer();
	void AddString(int printlevel, FString source);
	void Shift(int maxlines);
	void Clear() { Text.Clear(); }
	void Tick();
	void Draw();

private:
	TArray<FNotifyText> Text;
	int Top;
	int TopGoal;
	enum { NEWLINE, APPENDLINE, REPLACELINE } AddType;
};
static FNotifyBuffer NotifyStrings;

CUSTOM_CVAR(Int, con_notifylines, NUMNOTIFIES, CVAR_GLOBALCONFIG | CVAR_ARCHIVE)
{
	NotifyStrings.Shift(self);
}


int PrintColors[PRINTLEVELS+2] = { CR_RED, CR_GOLD, CR_GRAY, CR_GREEN, CR_GREEN, CR_GOLD };

static void setmsgcolor (int index, int color);

FILE *Logfile = NULL;


FIntCVar msglevel ("msg", 0, CVAR_ARCHIVE);

CUSTOM_CVAR (Int, msg0color, 6, CVAR_ARCHIVE)
{
	setmsgcolor (0, self);
}

CUSTOM_CVAR (Int, msg1color, 5, CVAR_ARCHIVE)
{
	setmsgcolor (1, self);
}

CUSTOM_CVAR (Int, msg2color, 2, CVAR_ARCHIVE)
{
	setmsgcolor (2, self);
}

CUSTOM_CVAR (Int, msg3color, 3, CVAR_ARCHIVE)
{
	setmsgcolor (3, self);
}

CUSTOM_CVAR (Int, msg4color, 3, CVAR_ARCHIVE)
{
	setmsgcolor (4, self);
}

CUSTOM_CVAR (Int, msgmidcolor, 5, CVAR_ARCHIVE)
{
	setmsgcolor (PRINTLEVELS, self);
}

CUSTOM_CVAR (Int, msgmidcolor2, 4, CVAR_ARCHIVE)
{
	setmsgcolor (PRINTLEVELS+1, self);
}

void C_InitConback()
{
#if 0
	conback = TexMan.CheckForTexture ("CONBACK", ETextureType::MiscPatch);

	if (!conback.isValid())
	{
		conback = TexMan.GetTextureID (gameinfo.TitlePage, ETextureType::MiscPatch);
		conshade = MAKEARGB(175,0,0,0);
		conline = true;
	}
	else
	{
		conshade = 0;
		conline = false;
	}
#else
	conshade = MAKEARGB(175, 0, 0, 0);
	conline = true;
#endif
}

void C_InitConsole (int width, int height, bool ingame)
{
	int cwidth, cheight;

	vidactive = ingame;
	if (CurrentConsoleFont != NULL)
	{
		cwidth = CurrentConsoleFont->CharWidth ('M');
		cheight = CurrentConsoleFont->GetHeight();
	}
	else
	{
		cwidth = cheight = 8;
	}
	ConWidth = (width - LEFTMARGIN - RIGHTMARGIN);
	ConCols = ConWidth / cwidth;

	if (conbuffer == NULL) conbuffer = new FConsoleBuffer;

	timerSetCallback(C_Ticker);
}

//==========================================================================
//
// CCMD atexit
//
//==========================================================================

UNSAFE_CCMD (atexit)
{
	if (argv.argc() == 1)
	{
		Printf ("Registered atexit commands:\n");
		GameAtExit *record = ExitCmdList;
		while (record != NULL)
		{
			Printf ("%s\n", record->Command.GetChars());
			record = record->Next;
		}
		return;
	}
	for (int i = 1; i < argv.argc(); ++i)
	{
		GameAtExit *record = new GameAtExit(argv[i]);
		record->Next = ExitCmdList;
		ExitCmdList = record;
	}
}

//==========================================================================
//
// C_DeinitConsole
//
// Executes the contents of the atexit cvar, if any, at quit time.
// Then releases all of the console's memory.
//
//==========================================================================

void C_DeinitConsole ()
{
	GameAtExit *cmd = ExitCmdList;

	while (cmd != NULL)
	{
		GameAtExit *next = cmd->Next;
		AddCommandString (cmd->Command);
		delete cmd;
		cmd = next;
	}

	// Free command history
	History *hist = HistTail;

	while (hist != NULL)
	{
		History *next = hist->Newer;
		delete hist;
		hist = next;
	}
	HistTail = HistHead = HistPos = NULL;

	// Free cvars allocated at runtime
	FBaseCVar *var, *next, **nextp;
	for (var = CVars, nextp = &CVars; var != NULL; var = next)
	{
		next = var->m_Next;
		if (var->GetFlags() & CVAR_UNSETTABLE)
		{
			delete var;
			*nextp = next;
		}
		else
		{
			nextp = &var->m_Next;
		}
	}

	// Free alias commands. (i.e. The "commands" that can be allocated
	// at runtime.)
	for (size_t i = 0; i < countof(Commands); ++i)
	{
		FConsoleCommand *cmd = Commands[i];

		while (cmd != NULL)
		{
			FConsoleCommand *next = cmd->m_Next;
			if (cmd->IsAlias())
			{
				delete cmd;
			}
			cmd = next;
		}
	}

	// Make sure all tab commands are cleared before the memory for
	// their names is deallocated.
	C_ClearTabCommands ();
	C_ClearDynCCmds();

	// Free AddToConsole()'s work buffer
	if (work != NULL)
	{
		free (work);
		work = NULL;
		worklen = 0;
	}

	if (conbuffer != NULL)
	{
		delete conbuffer;
		conbuffer = NULL;
	}
}

static void ClearConsole ()
{
	if (conbuffer != NULL)
	{
		conbuffer->Clear();
	}
	TopLine = InsertLine = 0;
}

static void setmsgcolor (int index, int color)
{
	if ((unsigned)color >= (unsigned)NUM_TEXT_COLORS)
		color = 0;
	PrintColors[index] = color;
}

FNotifyBuffer::FNotifyBuffer()
{
	Top = TopGoal = 0;
	AddType = NEWLINE;
}

void FNotifyBuffer::Shift(int maxlines)
{
	if (maxlines >= 0 && Text.Size() > (unsigned)maxlines)
	{
		Text.Delete(0, Text.Size() - maxlines);
	}
}

void FNotifyBuffer::AddString(int printlevel, FString source)
{
	TArray<FBrokenLines> lines;
	int width;

	if (hud_messages != 2 ||
		source.IsEmpty() ||
		//gamestate == GS_FULLCONSOLE ||
		//gamestate == GS_DEMOSCREEN ||
		con_notifylines == 0)
		return;

	width = screen->GetWidth() / active_con_scaletext(generic_ui);

	FFont *font = generic_ui ? NewSmallFont : AlternativeSmallFont;
	if (font == nullptr) return;	// Without an initialized font we cannot handle the message (this is for those which come here before the font system is ready.)

	if (AddType == APPENDLINE && Text.Size() > 0 && Text[Text.Size() - 1].PrintLevel == printlevel)
	{
		FString str = Text[Text.Size() - 1].Text + source;
		lines = V_BreakLines (font, width, str);
	}
	else
	{
		lines = V_BreakLines (font, width, source);
		if (AddType == APPENDLINE)
		{
			AddType = NEWLINE;
		}
	}

	if (lines.Size() == 0)
		return;

	for (auto &line : lines)
	{
		FNotifyText newline;

		newline.Text = line.Text;
		newline.TimeOut = int(con_notifytime * GameTicRate);
		newline.Ticker = 0;
		newline.PrintLevel = printlevel;
		if (AddType == NEWLINE || Text.Size() == 0)
		{
			if (con_notifylines > 0)
			{
				Shift(con_notifylines - 1);
			}
			Text.Push(newline);
		}
		else
		{
			Text[Text.Size() - 1] = newline;
		}
		AddType = NEWLINE;
	}

	switch (source[source.Len()-1])
	{
	case '\r':	AddType = REPLACELINE;	break;
	case '\n':	AddType = NEWLINE;		break;
	default:	AddType = APPENDLINE;	break;
	}

	TopGoal = 0;
}

void AddToConsole (int printlevel, const char *text)
{
	conbuffer->AddText(printlevel, MakeUTF8(text));
}

//==========================================================================
//
//
//
//==========================================================================

void WriteLineToLog(FILE *LogFile, const char *outline)
{
	// Strip out any color escape sequences before writing to the log file
	TArray<char> copy(strlen(outline) + 1);
	const char * srcp = outline;
	char * dstp = copy.Data();

	while (*srcp != 0)
	{

		if (*srcp != TEXTCOLOR_ESCAPE)
		{
			*dstp++ = *srcp++;
		}
		else if (srcp[1] == '[')
		{
			srcp += 2;
			while (*srcp != ']' && *srcp != 0) srcp++;
			if (*srcp == ']') srcp++;
		}
		else
		{
			if (srcp[1] != 0) srcp += 2;
			else break;
		}
	}
	*dstp = 0;

	fputs(copy.Data(), LogFile);
	fflush(LogFile);
}

extern bool gameisdead;

int PrintString (int iprintlevel, const char *outline)
{
	if (gameisdead)
		return 0;

	if (!conbuffer) return 0;	// when called too early
	int printlevel = iprintlevel & PRINT_TYPES;
	if (printlevel < msglevel || *outline == '\0')
	{
		return 0;
	}
	if (printlevel != PRINT_LOG || Logfile != nullptr)
	{
		// Convert everything coming through here to UTF-8 so that all console text is in a consistent format
		int count;
		outline = MakeUTF8(outline, &count);

		if (printlevel != PRINT_LOG)
		{
			I_PrintStr(outline);

			conbuffer->AddText(printlevel, outline);
			if (vidactive && (iprintlevel & PRINT_NOTIFY))
			{
				NotifyStrings.AddString(printlevel, outline);
			}
		}
		if (Logfile != nullptr && !(iprintlevel & PRINT_NOLOG))
		{
			WriteLineToLog(Logfile, outline);
		}
		return count;
	}
	return 0;	// Don't waste time on calculating this if nothing at all was printed...
}

int VPrintf (int printlevel, const char *format, va_list parms)
{
	FString outline;
	outline.VFormat (format, parms);
	return PrintString (printlevel, outline.GetChars());
}

int Printf (int printlevel, const char *format, ...)
{
	va_list argptr;
	int count;

	va_start (argptr, format);
	count = VPrintf (printlevel, format, argptr);
	va_end (argptr);

	return count;
}

int Printf (const char *format, ...)
{
	va_list argptr;
	int count;

	va_start (argptr, format);
	count = VPrintf (PRINT_HIGH, format, argptr);
	va_end (argptr);

	return count;
}

int DPrintf (int level, const char *format, ...)
{
	va_list argptr;
	int count;

	if (developer >= level)
	{
		va_start (argptr, format);
		count = VPrintf (PRINT_HIGH, format, argptr);
		va_end (argptr);
		return count;
	}
	else
	{
		return 0;
	}
}

void C_FlushDisplay ()
{
	NotifyStrings.Clear();
}

void C_AdjustBottom ()
{
	/*if (gamestate == GS_FULLCONSOLE || gamestate == GS_STARTUP)
		ConBottom = screen->GetHeight();
	else*/ if (ConBottom > screen->GetHeight() / 2 || ConsoleState == c_down)
		ConBottom = screen->GetHeight() / 2;
}

void C_NewModeAdjust ()
{
	C_InitConsole (screen->GetWidth(), screen->GetHeight(), true);
	C_FlushDisplay ();
	C_AdjustBottom ();
}

int consoletic = 0;
void C_Ticker()
{
	// The engine timer ticks at 120 fps which is 4x too fast for this.
	static int delay = 0;
	if (++delay < 4) return;
	delay = 0;

	static int lasttic = 0;
	consoletic++;

	if (lasttic == 0)
		lasttic = consoletic - 1;

	if (con_buffersize > 0)
	{
		conbuffer->ResizeBuffer(con_buffersize);
	}

	if (ConsoleState != c_up)
	{
		if (ConsoleState == c_falling)
		{
			ConBottom += (consoletic - lasttic) * (screen->GetHeight() * 2 / 25);
			if (ConBottom >= screen->GetHeight() / 2)
			{
				GSnd->SetSfxPaused(true, PAUSESFX_CONSOLE);
				ConBottom = screen->GetHeight() / 2;
				ConsoleState = c_down;
			}
		}
		else if (ConsoleState == c_rising)
		{
			ConBottom -= (consoletic - lasttic) * (screen->GetHeight() * 2 / 25);
			if (ConBottom <= 0)
			{
				GSnd->SetSfxPaused(false, PAUSESFX_CONSOLE);
				ConsoleState = c_up;
				ConBottom = 0;
			}
		}
	}

	lasttic = consoletic;
	NotifyStrings.Tick();
	if (ConsoleState == c_down)
	{
		D_ProcessEvents();
	}
}

void FNotifyBuffer::Tick()
{
	if (TopGoal > Top)
	{
		Top++;
	}
	else if (TopGoal < Top)
	{
		Top--;
	}

	// Remove lines from the beginning that have expired.
	unsigned i;
	for (i = 0; i < Text.Size(); ++i)
	{
		Text[i].Ticker++;
	}
	
	for (i = 0; i < Text.Size(); ++i)
	{
		if (Text[i].TimeOut != 0 && Text[i].TimeOut > Text[i].Ticker)
			break;
	}
	if (i > 0)
	{
		Text.Delete(0, i);
		FFont* font = generic_ui ? NewSmallFont : AlternativeSmallFont;
		Top += font->GetHeight();
	}
}

void FNotifyBuffer::Draw()
{
	bool center = (con_centernotify != 0.f);
	int line, lineadv, color, j;
	bool canskip;
	
	//if (gamestate == GS_FULLCONSOLE || gamestate == GS_DEMOSCREEN/* || menuactive != MENU_Off*/)
		//return;

	FFont* font = generic_ui ? NewSmallFont : AlternativeSmallFont;

	line = Top + font->GetDisplacement();
	canskip = true;

	lineadv = font->GetHeight ();

	for (unsigned i = 0; i < Text.Size(); ++ i)
	{
		FNotifyText &notify = Text[i];

		if (notify.TimeOut == 0)
			continue;

		j = notify.TimeOut - notify.Ticker;
		if (j > 0)
		{
			double alpha = (j < NOTIFYFADETIME) ? 1. * j / NOTIFYFADETIME : 1;

			if (notify.PrintLevel >= PRINTLEVELS)
				color = CR_UNTRANSLATED;
			else
				color = PrintColors[notify.PrintLevel];

			int scale = active_con_scaletext(generic_ui);
			if (!center)
				DrawText (twod, font, color, 0, line, notify.Text,
					DTA_VirtualWidth, screen->GetWidth() / scale,
					DTA_VirtualHeight, screen->GetHeight() / scale,
					DTA_KeepRatio, true,
					DTA_Alpha, alpha, TAG_DONE);
			else
				DrawText (twod, font, color, (screen->GetWidth() -
					font->StringWidth (notify.Text) * scale) / 2 / scale,
					line, notify.Text,
					DTA_VirtualWidth, screen->GetWidth() / scale,
					DTA_VirtualHeight, screen->GetHeight() / scale,
					DTA_KeepRatio, true,
					DTA_Alpha, alpha, TAG_DONE);
			line += lineadv;
			canskip = false;
		}
		else
		{
			notify.TimeOut = 0;
		}
	}
	if (canskip)
	{
		Top = TopGoal;
	}
}

void C_DrawConsole ()
{
	static int oldbottom = 0;
	int lines, left, offset;

	int textScale = active_con_scale();

	left = LEFTMARGIN;
	lines = (ConBottom/textScale-CurrentConsoleFont->GetHeight()*2)/CurrentConsoleFont->GetHeight();
	if (-CurrentConsoleFont->GetHeight() + lines*CurrentConsoleFont->GetHeight() > ConBottom/textScale - CurrentConsoleFont->GetHeight()*7/2)
	{
		offset = -CurrentConsoleFont->GetHeight()/2;
		lines--;
	}
	else
	{
		offset = -CurrentConsoleFont->GetHeight();
	}

	oldbottom = ConBottom;

	if (ConsoleState == c_up)
	{
		NotifyStrings.Draw();
		return;
	}
	else if (ConBottom)
	{
		int visheight;

		visheight = ConBottom;

		if (conback)
		{
			DrawTexture (twod, conback, 0, visheight - screen->GetHeight(),
						 DTA_DestWidth, screen->GetWidth(),
						 DTA_DestHeight, screen->GetHeight(),
						 DTA_ColorOverlay, conshade,
						 DTA_Alpha, (/*gamestate != GS_FULLCONSOLE*/true) ? (double)con_alpha : 1.,
						 DTA_Masked, false,
						 TAG_DONE);
		}
		else
		{
			PalEntry pe((uint8_t)(con_alpha * 255), 0, 0, 0);
			twod->AddColorOnlyQuad(0, 0, screen->GetWidth(), visheight, pe);
		}
		if (conline && visheight < screen->GetHeight())
		{
			twod->AddColorOnlyQuad(0, visheight, screen->GetWidth(), visheight+1, 0xff000000);
		}

		if (ConBottom >= 12)
		{
			if (textScale == 1)
				DrawText (twod, CurrentConsoleFont, CR_ORANGE, screen->GetWidth() - 8 -
					CurrentConsoleFont->StringWidth (GetVersionString()),
					ConBottom / textScale - CurrentConsoleFont->GetHeight() - 4,
					GetVersionString(), TAG_DONE);
			else
				DrawText(twod, CurrentConsoleFont, CR_ORANGE, screen->GetWidth() / textScale - 8 -
					CurrentConsoleFont->StringWidth(GetVersionString()),
					ConBottom / textScale - CurrentConsoleFont->GetHeight() - 4,
					GetVersionString(),
					DTA_VirtualWidth, screen->GetWidth() / textScale,
					DTA_VirtualHeight, screen->GetHeight() / textScale,
					DTA_KeepRatio, true, TAG_DONE);

		}

	}

#if 0
	if (menuactive != MENU_Off)
	{
		return;
	}
#endif

	if (lines > 0)
	{
		// No more enqueuing because adding new text to the console won't touch the actual print data.
		conbuffer->FormatText(CurrentConsoleFont, ConWidth / textScale);
		unsigned int consolelines = conbuffer->GetFormattedLineCount();
		FBrokenLines *blines = conbuffer->GetLines();
		FBrokenLines *printline = blines + consolelines - 1 - RowAdjust;

		int bottomline = ConBottom / textScale - CurrentConsoleFont->GetHeight()*2 - 4;

		for(FBrokenLines *p = printline; p >= blines && lines > 0; p--, lines--)
		{
			if (textScale == 1)
			{
				DrawText(twod, CurrentConsoleFont, CR_TAN, LEFTMARGIN, offset + lines * CurrentConsoleFont->GetHeight(), p->Text, TAG_DONE);
			}
			else
			{
				DrawText(twod, CurrentConsoleFont, CR_TAN, LEFTMARGIN, offset + lines * CurrentConsoleFont->GetHeight(), p->Text,
					DTA_VirtualWidth, screen->GetWidth() / textScale,
					DTA_VirtualHeight, screen->GetHeight() / textScale,
					DTA_KeepRatio, true, TAG_DONE);
			}
		}

		if (ConBottom >= 20)
		{
			if (gamestate != GS_STARTUP)
			{
				auto now = I_msTime();
				if (now > CursorTicker)
				{
					CursorTicker = now + 500;
					cursoron = !cursoron;
				}
				CmdLine.Draw(left, bottomline, textScale, cursoron);
			}
			if (RowAdjust && ConBottom >= CurrentConsoleFont->GetHeight()*7/2)
			{
				// Indicate that the view has been scrolled up (10)
				// and if we can scroll no further (12)
				if (textScale == 1)
					DrawChar (twod, CurrentConsoleFont, CR_GREEN, 0, bottomline, RowAdjust == conbuffer->GetFormattedLineCount() ? 12 : 10, TAG_DONE);
				else
					DrawChar(twod, CurrentConsoleFont, CR_GREEN, 0, bottomline, RowAdjust == conbuffer->GetFormattedLineCount() ? 12 : 10,
						DTA_VirtualWidth, screen->GetWidth() / textScale,
						DTA_VirtualHeight, screen->GetHeight() / textScale,
						DTA_KeepRatio, true, TAG_DONE);
			}
		}
	}
}

#if 0
void C_FullConsole ()
{
	if (hud_toggled)
		D_ToggleHud();
	if (demoplayback)
		G_CheckDemoStatus ();
	D_QuitNetGame ();
	advancedemo = false;
	ConsoleState = c_down;
	HistPos = NULL;
	TabbedLast = false;
	TabbedList = false;
	if (gamestate != GS_STARTUP)
	{
		gamestate = GS_FULLCONSOLE;
		primaryLevel->Music = "";
		S_Start ();
		S_StartMusic();
		P_FreeLevelData ();
	}
	else
	{
		C_AdjustBottom ();
	}
}
#endif


void C_ToggleConsole ()
{
	/*
	if (gamestate == GS_DEMOSCREEN || demoplayback)
	{
		gameaction = ga_fullconsole;
	}
	else if (!chatmodeon && (ConsoleState == c_up || ConsoleState == c_rising) && menuactive == MENU_Off)*/

	if (ConsoleState == c_up || ConsoleState == c_rising)// && menuactive == MENU_Off)
	{
		ConsoleState = c_falling;
		HistPos = NULL;
		TabbedLast = false;
		TabbedList = false;
		mouseGrabInput(false);
		
	}
	else //if (gamestate != GS_FULLCONSOLE && gamestate != GS_STARTUP)
	{
		ConsoleState = c_rising;
		C_FlushDisplay ();
		mouseGrabInput(true);
	}
}

void C_HideConsole ()
{
	if (gamestate != GS_FULLCONSOLE)
	{
		ConsoleState = c_up;
		ConBottom = 0;
		HistPos = NULL;
	}
}

static bool C_HandleKey (event_t *ev, FCommandBuffer &buffer)
{
	int data1 = ev->data1;
	bool keepappending = false;

	switch (ev->subtype)
	{
	default:
		return false;

	case EV_GUI_Char:
		if (ev->data2)
		{
			// Bash-style shortcuts
			if (data1 == 'b')
			{
				buffer.CursorWordLeft();
				break;
			}
			else if (data1 == 'f')
			{
				buffer.CursorWordRight();
				break;
			}
		}
		// Add keypress to command line
		buffer.AddChar(data1);
		HistPos = NULL;
		TabbedLast = false;
		TabbedList = false;
		break;

	case EV_GUI_WheelUp:
	case EV_GUI_WheelDown:
		if (!(ev->data3 & GKM_SHIFT))
		{
			data1 = GK_PGDN + EV_GUI_WheelDown - ev->subtype;
		}
		else
		{
			data1 = GK_DOWN + EV_GUI_WheelDown - ev->subtype;
		}
		// Intentional fallthrough

	case EV_GUI_KeyDown:
	case EV_GUI_KeyRepeat:
		switch (data1)
		{
		case '\t':
			// Try to do tab-completion
			C_TabComplete ((ev->data3 & GKM_SHIFT) ? false : true);
			break;

		case GK_PGUP:
			if (ev->data3 & (GKM_SHIFT|GKM_CTRL))
			{ // Scroll console buffer up one page
				RowAdjust += (screen->GetHeight()-4)/active_con_scale() /
					((/*gamestate == GS_FULLCONSOLE || gamestate == GS_STARTUP*/false) ? CurrentConsoleFont->GetHeight() : CurrentConsoleFont->GetHeight()*2) - 3;
			}
			else if (RowAdjust < conbuffer->GetFormattedLineCount())
			{ // Scroll console buffer up
				if (ev->subtype == EV_GUI_WheelUp)
				{
					RowAdjust += 3;
				}
				else
				{
					RowAdjust++;
				}
				if (RowAdjust > conbuffer->GetFormattedLineCount())
				{
					RowAdjust = conbuffer->GetFormattedLineCount();
				}
			}
			break;

		case GK_PGDN:
			if (ev->data3 & (GKM_SHIFT|GKM_CTRL))
			{ // Scroll console buffer down one page
				const int scrollamt = (screen->GetHeight()-4)/active_con_scale() /
					((/*gamestate == GS_FULLCONSOLE || gamestate == GS_STARTUP*/false) ? CurrentConsoleFont->GetHeight() : CurrentConsoleFont->GetHeight()*2) - 3;
				if (RowAdjust < scrollamt)
				{
					RowAdjust = 0;
				}
				else
				{
					RowAdjust -= scrollamt;
				}
			}
			else if (RowAdjust > 0)
			{ // Scroll console buffer down
				if (ev->subtype == EV_GUI_WheelDown)
				{
					RowAdjust = std::max (0, RowAdjust - 3);
				}
				else
				{
					RowAdjust--;
				}
			}
			break;

		case GK_HOME:
			if (ev->data3 & GKM_CTRL)
			{ // Move to top of console buffer
				RowAdjust = conbuffer->GetFormattedLineCount();
			}
			else
			{ // Move cursor to start of line
				buffer.CursorStart();
			}
			break;

		case GK_END:
			if (ev->data3 & GKM_CTRL)
			{ // Move to bottom of console buffer
				RowAdjust = 0;
			}
			else
			{ // Move cursor to end of line
				buffer.CursorEnd();
			}
			break;

		case GK_LEFT:
			// Move cursor left one character
			buffer.CursorLeft();
			break;

		case GK_RIGHT:
			// Move cursor right one character
			buffer.CursorRight();
			break;

		case '\b':
			// Erase character to left of cursor
			buffer.DeleteLeft();
			TabbedLast = false;
			TabbedList = false;
			break;

		case GK_DEL:
			// Erase character under cursor
			buffer.DeleteRight();
			TabbedLast = false;
			TabbedList = false;
			break;

		case GK_UP:
			// Move to previous entry in the command history
			if (HistPos == NULL)
			{
				HistPos = HistHead;
			}
			else if (HistPos->Older)
			{
				HistPos = HistPos->Older;
			}

			if (HistPos)
			{
				buffer.SetString(HistPos->String);
			}

			TabbedLast = false;
			TabbedList = false;
			break;

		case GK_DOWN:
			// Move to next entry in the command history
			if (HistPos && HistPos->Newer)
			{
				HistPos = HistPos->Newer;
				buffer.SetString(HistPos->String);
			}
			else
			{
				HistPos = NULL;
				buffer.SetString("");
			}
			TabbedLast = false;
			TabbedList = false;
			break;

		case 'X':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.SetString("");
				TabbedLast = TabbedList = false;
			}
			break;

		case 'D':
			if (ev->data3 & GKM_CTRL && buffer.TextLength() == 0)
			{ // Control-D pressed on an empty line
				if (strlen(con_ctrl_d) == 0)
				{
					break;	// Replacement is empty, so do nothing
				}
				buffer.SetString(*con_ctrl_d);
			}
			else
			{
				break;
			}
			// Intentional fall-through for command(s) added with Ctrl-D

		case '\r':
		{
			// Execute command line (ENTER)
			FString bufferText = buffer.GetText();

			bufferText.StripLeftRight();
			Printf(127, TEXTCOLOR_WHITE "]%s\n", bufferText.GetChars());

			if (bufferText.Len() == 0)
			{
				// Command line is empty, so do nothing to the history
			}
			else if (HistHead && HistHead->String.CompareNoCase(bufferText) == 0)
			{
				// Command line was the same as the previous one,
				// so leave the history list alone
			}
			else
			{
				// Command line is different from last command line,
				// or there is nothing in the history list,
				// so add it to the history list.

				History *temp = new History;
				temp->String = bufferText;
				temp->Older = HistHead;
				if (HistHead)
				{
					HistHead->Newer = temp;
				}
				temp->Newer = NULL;
				HistHead = temp;

				if (!HistTail)
				{
					HistTail = temp;
				}

				if (HistSize == MAXHISTSIZE)
				{
					HistTail = HistTail->Newer;
					delete HistTail->Older;
					HistTail->Older = NULL;
				}
				else
				{
					HistSize++;
				}
			}
			HistPos = NULL;
			buffer.SetString("");
			AddCommandString(bufferText);
			TabbedLast = false;
			TabbedList = false;
			break;
		}
		
		case '`':
			// Check to see if we have ` bound to the console before accepting
			// it as a way to close the console.
			if (Bindings.GetBinding(KEY_GRAVE).CompareNoCase("toggleconsole"))
			{
				break;
			}
		case GK_ESCAPE:
			// Close console and clear command line. But if we're in the
			// fullscreen console mode, there's nothing to fall back on
			// if it's closed, so open the main menu instead.
			if (gamestate == GS_STARTUP)
			{
				return false;
			}
			else if (gamestate == GS_FULLCONSOLE)
			{
				C_DoCommand ("menu_main");
			}
			else
			{
				buffer.SetString("");
				HistPos = NULL;
				C_ToggleConsole ();
			}
			break;

		case 'C':
		case 'V':
			TabbedLast = false;
			TabbedList = false;
#ifdef __APPLE__
			if (ev->data3 & GKM_META)
#else // !__APPLE__
			if (ev->data3 & GKM_CTRL)
#endif // __APPLE__
			{
				if (data1 == 'C')
				{ // copy to clipboard
					if (buffer.TextLength() > 0)
					{
						I_PutInClipboard(buffer.GetText());
					}
				}
				else
				{ // paste from clipboard
					buffer.AddString(I_GetFromClipboard(false));
					HistPos = NULL;
				}
				break;
			}
			break;

		// Bash-style shortcuts
		case 'A':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.CursorStart();
			}
			break;
		case 'E':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.CursorEnd();
			}
			break;
		case 'W':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.DeleteWordLeft();
				keepappending = true;
				TabbedLast = false;
				TabbedList = false;
			}
			break;
		case 'U':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.DeleteLineLeft();
				keepappending = true;
				TabbedLast = false;
				TabbedList = false;
			}
			break;
		case 'K':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.DeleteLineRight();
				keepappending = true;
				TabbedLast = false;
				TabbedList = false;
			}
			break;
		case 'Y':
			if (ev->data3 & GKM_CTRL)
			{
				buffer.AddYankBuffer();
				TabbedLast = false;
				TabbedList = false;
				HistPos = NULL;
			}
			break;
		}
		break;

#ifdef __unix__
	case EV_GUI_MButtonDown:
		buffer.AddString(I_GetFromClipboard(true));
		HistPos = NULL;
		break;
#endif
	}

	buffer.AppendToYankBuffer = keepappending;

	// Ensure that the cursor is always visible while typing
	CursorTicker = I_msTime() + 500;
	cursoron = 1;
	return true;
}

bool C_Responder (event_t *ev)
{
	if (ev->type != EV_GUI_Event ||
		ConsoleState == c_up ||
		ConsoleState == c_rising /*||
		menuactive != MENU_Off*/)
	{
		return false;
	}

	return C_HandleKey(ev, CmdLine);
}

CCMD (history)
{
	struct History *hist = HistTail;

	while (hist)
	{
		Printf ("   %s\n", hist->String.GetChars());
		hist = hist->Newer;
	}
}

CCMD (clear)
{
	C_FlushDisplay ();
	ClearConsole ();
}

CCMD (echo)
{
	int last = argv.argc()-1;
	for (int i = 1; i <= last; ++i)
	{
		FString formatted = strbin1 (argv[i]);
		Printf ("%s%s", formatted.GetChars(), i!=last ? " " : "\n");
	}
}

CCMD(toggleconsole)
{
	C_ToggleConsole();
}

#if 0 // The Build engine cannot do this at the moment. Q: Implement and redirect some messages here?
/* Printing in the middle of the screen */

CVAR(Float, con_midtime, 3.f, CVAR_ARCHIVE)

const char *console_bar = "----------------------------------------";

void C_MidPrint (FFont *font, const char *msg, bool bold)
{
	if (StatusBar == nullptr || screen == nullptr)
		return;

	// [MK] allow the status bar to take over MidPrint
	IFVIRTUALPTR(StatusBar, DBaseStatusBar, ProcessMidPrint)
	{
		FString msgstr = msg;
		VMValue params[] = { (DObject*)StatusBar, font, &msgstr, bold };
		int rv;
		VMReturn ret(&rv);
		VMCall(func, params, countof(params), &ret, 1);
		if (!!rv) return;
	}

	if (msg != nullptr)
	{
		auto color = (EColorRange)PrintColors[bold? PRINTLEVELS+1 : PRINTLEVELS];
		Printf(PRINT_HIGH, TEXTCOLOR_ESCAPESTR "%c%s\n%s\n%s\n", color, console_bar, msg, console_bar);

		StatusBar->AttachMessage (Create<DHUDMessage>(font, msg, 1.5f, 0.375f, 0, 0, color, con_midtime), MAKE_ID('C','N','T','R'));
	}
	else
	{
		StatusBar->DetachMessage (MAKE_ID('C','N','T','R'));
	}
}
#endif


/****** Tab completion code ******/

struct TabData
{
	int UseCount;
	FName TabName;

	TabData()
	: UseCount(0), TabName(NAME_None)
	{
	}

	TabData(const char *name)
	: UseCount(1), TabName(name)
	{
	}

	TabData(const TabData &other) = default;
};

static TArray<TabData> TabCommands (TArray<TabData>::NoInit);
static int TabPos;				// Last TabCommand tabbed to
static int TabStart;			// First char in CmdLine to use for tab completion
static int TabSize;				// Size of tab string

static bool FindTabCommand (const char *name, int *stoppos, int len)
{
	FName aname(name);
	unsigned int i;
	int cval = 1;

	for (i = 0; i < TabCommands.Size(); i++)
	{
		if (TabCommands[i].TabName == aname)
		{
			*stoppos = i;
			return true;
		}
		cval = strnicmp (TabCommands[i].TabName.GetChars(), name, len);
		if (cval >= 0)
			break;
	}

	*stoppos = i;

	return (cval == 0);
}

void C_AddTabCommand (const char *name)
{
	int pos;

	if (FindTabCommand (name, &pos, INT_MAX))
	{
		TabCommands[pos].UseCount++;
	}
	else
	{
		TabData tab(name);
		TabCommands.Insert (pos, tab);
	}
}

void C_RemoveTabCommand (const char *name)
{
	if (TabCommands.Size() == 0)
	{
		// There are no tab commands that can be removed.
		// This is important to skip construction of aname 
		// in case the NameManager has already been destroyed.
		return;
	}

	FName aname(name, true);

	if (aname == NAME_None)
	{
		return;
	}
	for (unsigned int i = 0; i < TabCommands.Size(); ++i)
	{
		if (TabCommands[i].TabName == aname)
		{
			if (--TabCommands[i].UseCount == 0)
			{
				TabCommands.Delete(i);
			}
			break;
		}
	}
}

void C_ClearTabCommands ()
{
	TabCommands.Clear();
}

static int FindDiffPoint (FName name1, const char *str2)
{
	const char *str1 = name1.GetChars();
	int i;

	for (i = 0; tolower(str1[i]) == tolower(str2[i]); i++)
		if (str1[i] == 0 || str2[i] == 0)
			break;

	return i;
}

static void C_TabComplete (bool goForward)
{
	unsigned i;
	int diffpoint;

	auto CmdLineText = CmdLine.GetText();
	if (!TabbedLast)
	{
		bool cancomplete;


		// Skip any spaces at beginning of command line
		for (i = 0; i < CmdLineText.Len(); ++i)
		{
			if (CmdLineText[i] != ' ')
				break;
		}
		if (i == CmdLineText.Len())
		{ // Line was nothing but spaces
			return;
		}
		TabStart = i;

		TabSize = (int)CmdLineText.Len() - TabStart;

		if (!FindTabCommand(&CmdLineText[TabStart], &TabPos, TabSize))
			return;		// No initial matches

		// Show a list of possible completions, if more than one.
		if (TabbedList || con_notablist)
		{
			cancomplete = true;
		}
		else
		{
			cancomplete = C_TabCompleteList ();
			TabbedList = true;
		}

		if (goForward)
		{ // Position just before the list of completions so that when TabPos
		  // gets advanced below, it will be at the first one.
			--TabPos;
		}
		else
		{ // Find the last matching tab, then go one past it.
			while (++TabPos < (int)TabCommands.Size())
			{
				if (FindDiffPoint(TabCommands[TabPos].TabName, &CmdLineText[TabStart]) < TabSize)
				{
					break;
				}
			}
		}
		TabbedLast = true;
		if (!cancomplete)
		{
			return;
		}
	}

	if ((goForward && ++TabPos == (int)TabCommands.Size()) ||
		(!goForward && --TabPos < 0))
	{
		TabbedLast = false;
		CmdLineText.Truncate(TabSize);
	}
	else
	{
		diffpoint = FindDiffPoint(TabCommands[TabPos].TabName, &CmdLineText[TabStart]);

		if (diffpoint < TabSize)
		{
			// No more matches
			TabbedLast = false;
			CmdLineText.Truncate(TabSize - TabStart);
		}
		else
		{
			CmdLineText.Truncate(TabStart);
			CmdLineText << TabCommands[TabPos].TabName.GetChars() << ' ';
		}
	}
	CmdLine.SetString(CmdLineText);
	CmdLine.MakeStartPosGood();
}

static bool C_TabCompleteList ()
{
	int nummatches, i;
	size_t maxwidth;
	int commonsize = INT_MAX;

	nummatches = 0;
	maxwidth = 0;

	auto CmdLineText = CmdLine.GetText();
	for (i = TabPos; i < (int)TabCommands.Size(); ++i)
	{
		if (FindDiffPoint (TabCommands[i].TabName, &CmdLineText[TabStart]) < TabSize)
		{
			break;
		}
		else
		{
			if (i > TabPos)
			{
				// This keeps track of the longest common prefix for all the possible
				// completions, so we can fill in part of the command for the user if
				// the longest common prefix is longer than what the user already typed.
				int diffpt = FindDiffPoint (TabCommands[i-1].TabName, TabCommands[i].TabName.GetChars());
				if (diffpt < commonsize)
				{
					commonsize = diffpt;
				}
			}
			nummatches++;
			maxwidth = std::max (maxwidth, strlen (TabCommands[i].TabName.GetChars()));
		}
	}
	if (nummatches > 1)
	{
		size_t x = 0;
		maxwidth += 3;
		Printf (TEXTCOLOR_BLUE "Completions for %s:\n", CmdLineText.GetChars());
		for (i = TabPos; nummatches > 0; ++i, --nummatches)
		{
			// [Dusk] Print console commands blue, CVars green, aliases red.
			const char* colorcode = "";
			FConsoleCommand* ccmd;
			if (FindCVar (TabCommands[i].TabName.GetChars(), NULL))
				colorcode = TEXTCOLOR_GREEN;
			else if ((ccmd = FConsoleCommand::FindByName (TabCommands[i].TabName.GetChars())) != NULL)
			{
				if (ccmd->IsAlias())
					colorcode = TEXTCOLOR_RED;
				else
					colorcode = TEXTCOLOR_LIGHTBLUE;
			}

			Printf ("%s%-*s", colorcode, int(maxwidth), TabCommands[i].TabName.GetChars());
			x += maxwidth;
			if (x > ConCols / active_con_scale() - maxwidth)
			{
				x = 0;
				Printf ("\n");
			}
		}
		if (x != 0)
		{
			Printf ("\n");
		}
		// Fill in the longest common prefix, if it's longer than what was typed.
		if (TabSize != commonsize)
		{
			TabSize = commonsize;
			CmdLineText.Truncate(TabStart);
			CmdLineText.AppendCStrPart(TabCommands[TabPos].TabName.GetChars(), commonsize);
			CmdLine.SetString(CmdLineText);
		}
		return false;
	}
	return true;
}