Wolfenstein 3-D!

This is a port of Wolf4SDL, which is derived from the original id
software source release. The port runs on top of the SDL plugin
runtime and is loaded as an overlay.

Licensing of the game code is not an issue, as discussed below
(essentially, the Debian project treats Wolf4SDL as GPLv2, with an
email from John Carmack backing it up):

  http://forums.rockbox.org/index.php?topic=52872

Included is a copy of MAME's Yamaha OPL sound chip emulator
(fmopl_gpl.c).  This file was not part of the original Wolf4SDL source
(which includes a non-GPL'd version), but was rather rebased from from
a later MAME source which had been relicensed to GPLv2.

Change-Id: I64c2ba035e0be7e2f49252f40640641416613439

1 files changed, 1366 insertions, 0 deletions

diff --git a/apps/plugins/sdl/progs/wolf3d/wl_play.c b/apps/plugins/sdl/progs/wolf3d/wl_play.c
new file mode 100644
index 0000000000..79efcefe50
--- /dev/null
+++ b/apps/plugins/sdl/progs/wolf3d/wl_play.c
@@ -0,0 +1,1366 @@
+// WL_PLAY.C
+
+#include "wl_def.h"
+#pragma hdrstop
+
+#include "wl_cloudsky.h"
+#include "wl_shade.h"
+
+/*
+=============================================================================
+
+                                                 LOCAL CONSTANTS
+
+=============================================================================
+*/
+
+#define sc_Question     0x35
+
+/*
+=============================================================================
+
+                                                 GLOBAL VARIABLES
+
+=============================================================================
+*/
+
+boolean madenoise;              // true when shooting or screaming
+
+exit_t playstate;
+
+static musicnames lastmusicchunk = (musicnames) 0;
+
+static int DebugOk;
+
+objtype objlist[MAXACTORS];
+objtype *newobj, *obj, *player, *lastobj, *objfreelist, *killerobj;
+
+boolean noclip, ammocheat;
+int godmode, singlestep, extravbls = 0;
+
+byte tilemap[MAPSIZE][MAPSIZE]; // wall values only
+byte spotvis[MAPSIZE][MAPSIZE];
+objtype *actorat[MAPSIZE][MAPSIZE];
+
+//
+// replacing refresh manager
+//
+unsigned tics;
+
+//
+// control info
+//
+boolean mouseenabled, joystickenabled;
+int dirscan[4] = { sc_UpArrow, sc_RightArrow, sc_DownArrow, sc_LeftArrow };
+
+int buttonscan[NUMBUTTONS] = { sc_Return, sc_Alt, sc_LShift, sc_UpArrow, sc_1, sc_2, sc_3, sc_4,
+                               sc_DownArrow, 0, 0, 0, sc_A, sc_D };
+int buttonmouse[4] = { bt_attack, bt_strafe, bt_use, bt_nobutton };
+int buttonjoy[32] = {
+#ifdef _arch_dreamcast
+    bt_attack, bt_strafe, bt_use, bt_run, bt_esc, bt_prevweapon, bt_nobutton, bt_nextweapon,
+    bt_pause, bt_strafeleft, bt_straferight, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton,
+#else
+    bt_attack, bt_strafe, bt_use, bt_run, bt_strafeleft, bt_straferight, bt_esc, bt_pause,
+    bt_prevweapon, bt_nextweapon, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton,
+#endif
+    bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton,
+    bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton, bt_nobutton
+};
+
+int viewsize;
+
+boolean buttonheld[NUMBUTTONS];
+
+boolean demorecord, demoplayback;
+int8_t *demoptr, *lastdemoptr;
+memptr demobuffer;
+
+//
+// current user input
+//
+int controlx, controly;         // range from -100 to 100 per tic
+boolean buttonstate[NUMBUTTONS];
+
+int lastgamemusicoffset = 0;
+
+
+//===========================================================================
+
+
+void CenterWindow (word w, word h);
+void InitObjList (void);
+void RemoveObj (objtype * gone);
+void PollControls (void);
+int StopMusic (void);
+void StartMusic (void);
+void ContinueMusic (int offs);
+void PlayLoop (void);
+
+/*
+=============================================================================
+
+                                                 LOCAL VARIABLES
+
+=============================================================================
+*/
+
+
+objtype dummyobj;
+
+//
+// LIST OF SONGS FOR EACH VERSION
+//
+int songs[] = {
+#ifndef SPEAR
+    //
+    // Episode One
+    //
+    GETTHEM_MUS,
+    SEARCHN_MUS,
+    POW_MUS,
+    SUSPENSE_MUS,
+    GETTHEM_MUS,
+    SEARCHN_MUS,
+    POW_MUS,
+    SUSPENSE_MUS,
+
+    WARMARCH_MUS,               // Boss level
+    CORNER_MUS,                 // Secret level
+
+    //
+    // Episode Two
+    //
+    NAZI_OMI_MUS,
+    PREGNANT_MUS,
+    GOINGAFT_MUS,
+    HEADACHE_MUS,
+    NAZI_OMI_MUS,
+    PREGNANT_MUS,
+    HEADACHE_MUS,
+    GOINGAFT_MUS,
+
+    WARMARCH_MUS,               // Boss level
+    DUNGEON_MUS,                // Secret level
+
+    //
+    // Episode Three
+    //
+    INTROCW3_MUS,
+    NAZI_RAP_MUS,
+    TWELFTH_MUS,
+    ZEROHOUR_MUS,
+    INTROCW3_MUS,
+    NAZI_RAP_MUS,
+    TWELFTH_MUS,
+    ZEROHOUR_MUS,
+
+    ULTIMATE_MUS,               // Boss level
+    PACMAN_MUS,                 // Secret level
+
+    //
+    // Episode Four
+    //
+    GETTHEM_MUS,
+    SEARCHN_MUS,
+    POW_MUS,
+    SUSPENSE_MUS,
+    GETTHEM_MUS,
+    SEARCHN_MUS,
+    POW_MUS,
+    SUSPENSE_MUS,
+
+    WARMARCH_MUS,               // Boss level
+    CORNER_MUS,                 // Secret level
+
+    //
+    // Episode Five
+    //
+    NAZI_OMI_MUS,
+    PREGNANT_MUS,
+    GOINGAFT_MUS,
+    HEADACHE_MUS,
+    NAZI_OMI_MUS,
+    PREGNANT_MUS,
+    HEADACHE_MUS,
+    GOINGAFT_MUS,
+
+    WARMARCH_MUS,               // Boss level
+    DUNGEON_MUS,                // Secret level
+
+    //
+    // Episode Six
+    //
+    INTROCW3_MUS,
+    NAZI_RAP_MUS,
+    TWELFTH_MUS,
+    ZEROHOUR_MUS,
+    INTROCW3_MUS,
+    NAZI_RAP_MUS,
+    TWELFTH_MUS,
+    ZEROHOUR_MUS,
+
+    ULTIMATE_MUS,               // Boss level
+    FUNKYOU_MUS                 // Secret level
+#else
+
+    //////////////////////////////////////////////////////////////
+    //
+    // SPEAR OF DESTINY TRACKS
+    //
+    //////////////////////////////////////////////////////////////
+    XTIPTOE_MUS,
+    XFUNKIE_MUS,
+    XDEATH_MUS,
+    XGETYOU_MUS,                // DON'T KNOW
+    ULTIMATE_MUS,               // Trans Gr”sse
+
+    DUNGEON_MUS,
+    GOINGAFT_MUS,
+    POW_MUS,
+    TWELFTH_MUS,
+    ULTIMATE_MUS,               // Barnacle Wilhelm BOSS
+
+    NAZI_OMI_MUS,
+    GETTHEM_MUS,
+    SUSPENSE_MUS,
+    SEARCHN_MUS,
+    ZEROHOUR_MUS,
+    ULTIMATE_MUS,               // Super Mutant BOSS
+
+    XPUTIT_MUS,
+    ULTIMATE_MUS,               // Death Knight BOSS
+
+    XJAZNAZI_MUS,               // Secret level
+    XFUNKIE_MUS,                // Secret level (DON'T KNOW)
+
+    XEVIL_MUS                   // Angel of Death BOSS
+#endif
+};
+
+
+/*
+=============================================================================
+
+                               USER CONTROL
+
+=============================================================================
+*/
+
+/*
+===================
+=
+= PollKeyboardButtons
+=
+===================
+*/
+
+void PollKeyboardButtons (void)
+{
+    int i;
+
+    //LOGF("button state: ");
+    for (i = 0; i < NUMBUTTONS; i++)
+    {
+        if (Keyboard[buttonscan[i]])
+        {
+            buttonstate[i] = true;
+            LOGF("enabling bit %d in buttonstate");
+        }
+        //LOGF("%d ", buttonstate[i]);
+    }
+    //LOGF("\n");
+}
+
+
+/*
+===================
+=
+= PollMouseButtons
+=
+===================
+*/
+
+void PollMouseButtons (void)
+{
+    int buttons = IN_MouseButtons ();
+
+    if (buttons & 1)
+        buttonstate[buttonmouse[0]] = true;
+    if (buttons & 2)
+        buttonstate[buttonmouse[1]] = true;
+    if (buttons & 4)
+        buttonstate[buttonmouse[2]] = true;
+}
+
+
+
+/*
+===================
+=
+= PollJoystickButtons
+=
+===================
+*/
+
+void PollJoystickButtons (void)
+{
+    int buttons = IN_JoyButtons();
+
+    for(int i = 0, val = 1; i < JoyNumButtons; i++, val <<= 1)
+    {
+        if(buttons & val)
+            buttonstate[buttonjoy[i]] = true;
+    }
+}
+
+
+/*
+===================
+=
+= PollKeyboardMove
+=
+===================
+*/
+
+void PollKeyboardMove (void)
+{
+    int delta = buttonstate[bt_run] ? RUNMOVE * tics : BASEMOVE * tics;
+
+    if (Keyboard[dirscan[di_north]])
+        controly -= delta;
+    if (Keyboard[dirscan[di_south]])
+        controly += delta;
+    if (Keyboard[dirscan[di_west]])
+        controlx -= delta;
+    if (Keyboard[dirscan[di_east]])
+        controlx += delta;
+}
+
+
+/*
+===================
+=
+= PollMouseMove
+=
+===================
+*/
+
+void PollMouseMove (void)
+{
+    int mousexmove, mouseymove;
+
+    SDL_GetMouseState(&mousexmove, &mouseymove);
+    if(IN_IsInputGrabbed())
+        IN_CenterMouse();
+
+    mousexmove -= screenWidth / 2;
+    mouseymove -= screenHeight / 2;
+
+    controlx += mousexmove * 10 / (13 - mouseadjustment);
+    controly += mouseymove * 20 / (13 - mouseadjustment);
+}
+
+
+/*
+===================
+=
+= PollJoystickMove
+=
+===================
+*/
+
+void PollJoystickMove (void)
+{
+    int joyx, joyy;
+
+    IN_GetJoyDelta (&joyx, &joyy);
+
+    int delta = buttonstate[bt_run] ? RUNMOVE * tics : BASEMOVE * tics;
+
+    if (joyx > 64 || buttonstate[bt_turnright])
+        controlx += delta;
+    else if (joyx < -64  || buttonstate[bt_turnleft])
+        controlx -= delta;
+    if (joyy > 64 || buttonstate[bt_movebackward])
+        controly += delta;
+    else if (joyy < -64 || buttonstate[bt_moveforward])
+        controly -= delta;
+}
+
+/*
+===================
+=
+= PollControls
+=
+= Gets user or demo input, call once each frame
+=
+= controlx              set between -100 and 100 per tic
+= controly
+= buttonheld[]  the state of the buttons LAST frame
+= buttonstate[] the state of the buttons THIS frame
+=
+===================
+*/
+
+void PollControls (void)
+{
+    int max, min, i;
+    byte buttonbits;
+
+    IN_ProcessEvents();
+
+//
+// get timing info for last frame
+//
+    if (demoplayback || demorecord)   // demo recording and playback needs to be constant
+    {
+        // wait up to DEMOTICS Wolf tics
+        uint32_t curtime = SDL_GetTicks();
+        lasttimecount += DEMOTICS;
+        int32_t timediff = (lasttimecount * 100) / 7 - curtime;
+        if(timediff > 0)
+            SDL_Delay(timediff);
+
+        if(timediff < -2 * DEMOTICS)       // more than 2-times DEMOTICS behind?
+            lasttimecount = (curtime * 7) / 100;    // yes, set to current timecount
+
+        tics = DEMOTICS;
+    }
+    else
+        CalcTics ();
+
+    controlx = 0;
+    controly = 0;
+    memcpy (buttonheld, buttonstate, sizeof (buttonstate));
+    memset (buttonstate, 0, sizeof (buttonstate));
+
+    if (demoplayback)
+    {
+        //
+        // read commands from demo buffer
+        //
+        buttonbits = *demoptr++;
+        for (i = 0; i < NUMBUTTONS; i++)
+        {
+            buttonstate[i] = buttonbits & 1;
+            buttonbits >>= 1;
+        }
+
+        controlx = *demoptr++;
+        controly = *demoptr++;
+        LOGF("%d %d %d", buttonbits, controlx, controly);
+
+        if (demoptr == lastdemoptr)
+            playstate = ex_completed;   // demo is done
+
+        controlx *= (int) tics;
+        controly *= (int) tics;
+
+        return;
+    }
+
+
+//
+// get button states
+//
+    PollKeyboardButtons ();
+
+//    if (mouseenabled && IN_IsInputGrabbed())
+//        PollMouseButtons ();
+
+    if (joystickenabled)
+        PollJoystickButtons ();
+
+//
+// get movements
+//
+    PollKeyboardMove ();
+
+//    if (mouseenabled && IN_IsInputGrabbed())
+//        PollMouseMove ();
+
+    if (joystickenabled)
+        PollJoystickMove ();
+
+//
+// bound movement to a maximum
+//
+    max = 100 * tics;
+    min = -max;
+    if (controlx > max)
+        controlx = max;
+    else if (controlx < min)
+        controlx = min;
+
+    if (controly > max)
+        controly = max;
+    else if (controly < min)
+        controly = min;
+
+    if (demorecord)
+    {
+        //
+        // save info out to demo buffer
+        //
+        controlx /= (int) tics;
+        controly /= (int) tics;
+
+        buttonbits = 0;
+
+        // TODO: Support 32-bit buttonbits
+        for (i = NUMBUTTONS - 1; i >= 0; i--)
+        {
+            buttonbits <<= 1;
+            if (buttonstate[i])
+                buttonbits |= 1;
+        }
+
+        *demoptr++ = buttonbits;
+        *demoptr++ = controlx;
+        *demoptr++ = controly;
+
+        if (demoptr >= lastdemoptr - 8)
+            playstate = ex_completed;
+        else
+        {
+            controlx *= (int) tics;
+            controly *= (int) tics;
+        }
+    }
+}
+
+
+
+//==========================================================================
+
+
+
+///////////////////////////////////////////////////////////////////////////
+//
+//      CenterWindow() - Generates a window of a given width & height in the
+//              middle of the screen
+//
+///////////////////////////////////////////////////////////////////////////
+#define MAXX    320
+#define MAXY    160
+
+void CenterWindow (word w, word h)
+{
+    US_DrawWindow (((MAXX / 8) - w) / 2, ((MAXY / 8) - h) / 2, w, h);
+}
+
+//===========================================================================
+
+
+/*
+=====================
+=
+= CheckKeys
+=
+=====================
+*/
+
+void CheckKeys (void)
+{
+    ScanCode scan;
+
+
+    if (screenfaded || demoplayback)    // don't do anything with a faded screen
+        return;
+
+    scan = LastScan;
+
+
+#ifdef SPEAR
+    //
+    // SECRET CHEAT CODE: TAB-G-F10
+    //
+    if (Keyboard[sc_Tab] && Keyboard[sc_G] && Keyboard[sc_F10])
+    {
+        WindowH = 160;
+        if (godmode)
+        {
+            Message ("God mode OFF");
+            SD_PlaySound (NOBONUSSND);
+        }
+        else
+        {
+            Message ("God mode ON");
+            SD_PlaySound (ENDBONUS2SND);
+        }
+
+        IN_Ack ();
+        godmode ^= 1;
+        DrawPlayBorderSides ();
+        IN_ClearKeysDown ();
+        return;
+    }
+#endif
+
+
+    //
+    // SECRET CHEAT CODE: 'MLI'
+    //
+    if (Keyboard[sc_M] && Keyboard[sc_L] && Keyboard[sc_I])
+    {
+        gamestate.health = 100;
+        gamestate.ammo = 99;
+        gamestate.keys = 3;
+        gamestate.score = 0;
+        gamestate.TimeCount += 42000L;
+        GiveWeapon (wp_chaingun);
+        DrawWeapon ();
+        DrawHealth ();
+        DrawKeys ();
+        DrawAmmo ();
+        DrawScore ();
+
+        ClearMemory ();
+        CA_CacheGrChunk (STARTFONT + 1);
+        ClearSplitVWB ();
+
+        Message (STR_CHEATER1 "\n"
+                 STR_CHEATER2 "\n\n" STR_CHEATER3 "\n" STR_CHEATER4 "\n" STR_CHEATER5);
+
+        UNCACHEGRCHUNK (STARTFONT + 1);
+        IN_ClearKeysDown ();
+        IN_Ack ();
+
+        if (viewsize < 17)
+            DrawPlayBorder ();
+    }
+
+    //
+    // OPEN UP DEBUG KEYS
+    //
+#ifdef DEBUGKEYS
+    if (Keyboard[sc_BackSpace] && Keyboard[sc_LShift] && Keyboard[sc_Alt] && param_debugmode)
+    {
+        ClearMemory ();
+        CA_CacheGrChunk (STARTFONT + 1);
+        ClearSplitVWB ();
+
+        Message ("Debugging keys are\nnow available!");
+        UNCACHEGRCHUNK (STARTFONT + 1);
+        IN_ClearKeysDown ();
+        IN_Ack ();
+
+        DrawPlayBorderSides ();
+        DebugOk = 1;
+    }
+#endif
+
+    //
+    // TRYING THE KEEN CHEAT CODE!
+    //
+    if (Keyboard[sc_B] && Keyboard[sc_A] && Keyboard[sc_T])
+    {
+        ClearMemory ();
+        CA_CacheGrChunk (STARTFONT + 1);
+        ClearSplitVWB ();
+
+        Message ("Commander Keen is also\n"
+                 "available from Apogee, but\n"
+                 "then, you already know\n" "that - right, Cheatmeister?!");
+
+        UNCACHEGRCHUNK (STARTFONT + 1);
+        IN_ClearKeysDown ();
+        IN_Ack ();
+
+        if (viewsize < 18)
+            DrawPlayBorder ();
+    }
+
+//
+// pause key weirdness can't be checked as a scan code
+//
+    if(buttonstate[bt_pause]) Paused = true;
+    if(Paused)
+    {
+        int lastoffs = StopMusic();
+        LatchDrawPic (20 - 4, 80 - 2 * 8, PAUSEDPIC);
+        VH_UpdateScreen();
+        IN_Ack ();
+        Paused = false;
+        ContinueMusic(lastoffs);
+        if (MousePresent && IN_IsInputGrabbed())
+            IN_CenterMouse();     // Clear accumulated mouse movement
+        lasttimecount = GetTimeCount();
+        return;
+    }
+
+//
+// F1-F7/ESC to enter control panel
+//
+    if (
+#ifndef DEBCHECK
+           scan == sc_F10 ||
+#endif
+           scan == sc_F9 || scan == sc_F7 || scan == sc_F8)     // pop up quit dialog
+    {
+        short oldmapon = gamestate.mapon;
+        short oldepisode = gamestate.episode;
+        ClearMemory ();
+        ClearSplitVWB ();
+        US_ControlPanel (scan);
+
+        DrawPlayBorderSides ();
+
+        SETFONTCOLOR (0, 15);
+        IN_ClearKeysDown ();
+        return;
+    }
+
+    if ((scan >= sc_F1 && scan <= sc_F9) || scan == sc_Escape || buttonstate[bt_esc])
+    {
+        int lastoffs = StopMusic ();
+        ClearMemory ();
+        VW_FadeOut ();
+
+        US_ControlPanel (buttonstate[bt_esc] ? sc_Escape : scan);
+
+        SETFONTCOLOR (0, 15);
+        IN_ClearKeysDown ();
+        VW_FadeOut();
+        if(viewsize != 21)
+            DrawPlayScreen ();
+        if (!startgame && !loadedgame)
+            ContinueMusic (lastoffs);
+        if (loadedgame)
+            playstate = ex_abort;
+        lasttimecount = GetTimeCount();
+        if (MousePresent && IN_IsInputGrabbed())
+            IN_CenterMouse();     // Clear accumulated mouse movement
+        return;
+    }
+
+//
+// TAB-? debug keys
+//
+#ifdef DEBUGKEYS
+    if (Keyboard[sc_Tab] && DebugOk)
+    {
+        CA_CacheGrChunk (STARTFONT);
+        fontnumber = 0;
+        SETFONTCOLOR (0, 15);
+        if (DebugKeys () && viewsize < 20)
+            DrawPlayBorder ();       // dont let the blue borders flash
+
+        if (MousePresent && IN_IsInputGrabbed())
+            IN_CenterMouse();     // Clear accumulated mouse movement
+
+        lasttimecount = GetTimeCount();
+        return;
+    }
+#endif
+}
+
+
+//===========================================================================
+
+/*
+#############################################################################
+
+                                  The objlist data structure
+
+#############################################################################
+
+objlist containt structures for every actor currently playing.  The structure
+is accessed as a linked list starting at *player, ending when ob->next ==
+NULL.  GetNewObj inserts a new object at the end of the list, meaning that
+if an actor spawn another actor, the new one WILL get to think and react the
+same frame.  RemoveObj unlinks the given object and returns it to the free
+list, but does not damage the objects ->next pointer, so if the current object
+removes itself, a linked list following loop can still safely get to the
+next element.
+
+<backwardly linked free list>
+
+#############################################################################
+*/
+
+
+/*
+=========================
+=
+= InitActorList
+=
+= Call to clear out the actor object lists returning them all to the free
+= list.  Allocates a special spot for the player.
+=
+=========================
+*/
+
+int objcount;
+
+void InitActorList (void)
+{
+    int i;
+
+//
+// init the actor lists
+//
+    for (i = 0; i < MAXACTORS; i++)
+    {
+        objlist[i].prev = &objlist[i + 1];
+        objlist[i].next = NULL;
+    }
+
+    objlist[MAXACTORS - 1].prev = NULL;
+
+    objfreelist = &objlist[0];
+    lastobj = NULL;
+
+    objcount = 0;
+
+//
+// give the player the first free spots
+//
+    GetNewActor ();
+    player = newobj;
+
+}
+
+//===========================================================================
+
+/*
+=========================
+=
+= GetNewActor
+=
+= Sets the global variable new to point to a free spot in objlist.
+= The free spot is inserted at the end of the liked list
+=
+= When the object list is full, the caller can either have it bomb out ot
+= return a dummy object pointer that will never get used
+=
+=========================
+*/
+
+void GetNewActor (void)
+{
+    if (!objfreelist)
+        Quit ("GetNewActor: No free spots in objlist!");
+
+    newobj = objfreelist;
+    objfreelist = newobj->prev;
+    memset (newobj, 0, sizeof (*newobj));
+
+    if (lastobj)
+        lastobj->next = newobj;
+    newobj->prev = lastobj;     // new->next is allready NULL from memset
+
+    newobj->active = ac_no;
+    lastobj = newobj;
+
+    objcount++;
+}
+
+//===========================================================================
+
+/*
+=========================
+=
+= RemoveObj
+=
+= Add the given object back into the free list, and unlink it from it's
+= neighbors
+=
+=========================
+*/
+
+void RemoveObj (objtype * gone)
+{
+    if (gone == player)
+        Quit ("RemoveObj: Tried to remove the player!");
+
+    gone->state = NULL;
+
+//
+// fix the next object's back link
+//
+    if (gone == lastobj)
+        lastobj = (objtype *) gone->prev;
+    else
+        gone->next->prev = gone->prev;
+
+//
+// fix the previous object's forward link
+//
+    gone->prev->next = gone->next;
+
+//
+// add it back in to the free list
+//
+    gone->prev = objfreelist;
+    objfreelist = gone;
+
+    objcount--;
+}
+
+/*
+=============================================================================
+
+                                                MUSIC STUFF
+
+=============================================================================
+*/
+
+
+/*
+=================
+=
+= StopMusic
+=
+=================
+*/
+int StopMusic (void)
+{
+    int lastoffs = SD_MusicOff ();
+
+    UNCACHEAUDIOCHUNK (STARTMUSIC + lastmusicchunk);
+
+    return lastoffs;
+}
+
+//==========================================================================
+
+
+/*
+=================
+=
+= StartMusic
+=
+=================
+*/
+
+void StartMusic ()
+{
+    SD_MusicOff ();
+    lastmusicchunk = (musicnames) songs[gamestate.mapon + gamestate.episode * 10];
+    SD_StartMusic(STARTMUSIC + lastmusicchunk);
+}
+
+void ContinueMusic (int offs)
+{
+    SD_MusicOff ();
+    lastmusicchunk = (musicnames) songs[gamestate.mapon + gamestate.episode * 10];
+    SD_ContinueMusic(STARTMUSIC + lastmusicchunk, offs);
+}
+
+/*
+=============================================================================
+
+                                        PALETTE SHIFTING STUFF
+
+=============================================================================
+*/
+
+#define NUMREDSHIFTS    6
+#define REDSTEPS        8
+
+#define NUMWHITESHIFTS  3
+#define WHITESTEPS      20
+#define WHITETICS       6
+
+
+SDL_Color redshifts[NUMREDSHIFTS][256];
+SDL_Color whiteshifts[NUMWHITESHIFTS][256];
+
+int damagecount, bonuscount;
+boolean palshifted;
+
+/*
+=====================
+=
+= InitRedShifts
+=
+=====================
+*/
+
+void InitRedShifts (void)
+{
+    SDL_Color *workptr, *baseptr;
+    int i, j, delta;
+
+
+//
+// fade through intermediate frames
+//
+    for (i = 1; i <= NUMREDSHIFTS; i++)
+    {
+        workptr = redshifts[i - 1];
+        baseptr = gamepal;
+
+        for (j = 0; j <= 255; j++)
+        {
+            delta = 256 - baseptr->r;
+            workptr->r = baseptr->r + delta * i / REDSTEPS;
+            delta = -baseptr->g;
+            workptr->g = baseptr->g + delta * i / REDSTEPS;
+            delta = -baseptr->b;
+            workptr->b = baseptr->b + delta * i / REDSTEPS;
+            baseptr++;
+            workptr++;
+        }
+        rb->yield();
+    }
+
+    for (i = 1; i <= NUMWHITESHIFTS; i++)
+    {
+        workptr = whiteshifts[i - 1];
+        baseptr = gamepal;
+
+        for (j = 0; j <= 255; j++)
+        {
+            delta = 256 - baseptr->r;
+            workptr->r = baseptr->r + delta * i / WHITESTEPS;
+            delta = 248 - baseptr->g;
+            workptr->g = baseptr->g + delta * i / WHITESTEPS;
+            delta = 0-baseptr->b;
+            workptr->b = baseptr->b + delta * i / WHITESTEPS;
+            baseptr++;
+            workptr++;
+        }
+        rb->yield();
+    }
+}
+
+
+/*
+=====================
+=
+= ClearPaletteShifts
+=
+=====================
+*/
+
+void ClearPaletteShifts (void)
+{
+    bonuscount = damagecount = 0;
+    palshifted = false;
+}
+
+
+/*
+=====================
+=
+= StartBonusFlash
+=
+=====================
+*/
+
+void StartBonusFlash (void)
+{
+    bonuscount = NUMWHITESHIFTS * WHITETICS;    // white shift palette
+}
+
+
+/*
+=====================
+=
+= StartDamageFlash
+=
+=====================
+*/
+
+void StartDamageFlash (int damage)
+{
+    damagecount += damage;
+}
+
+
+/*
+=====================
+=
+= UpdatePaletteShifts
+=
+=====================
+*/
+
+void UpdatePaletteShifts (void)
+{
+    int red, white;
+
+    if (bonuscount)
+    {
+        white = bonuscount / WHITETICS + 1;
+        if (white > NUMWHITESHIFTS)
+            white = NUMWHITESHIFTS;
+        bonuscount -= tics;
+        if (bonuscount < 0)
+            bonuscount = 0;
+    }
+    else
+        white = 0;
+
+
+    if (damagecount)
+    {
+        red = damagecount / 10 + 1;
+        if (red > NUMREDSHIFTS)
+            red = NUMREDSHIFTS;
+
+        damagecount -= tics;
+        if (damagecount < 0)
+            damagecount = 0;
+    }
+    else
+        red = 0;
+
+    if (red)
+    {
+        VL_SetPalette (redshifts[red - 1], false);
+        palshifted = true;
+    }
+    else if (white)
+    {
+        VL_SetPalette (whiteshifts[white - 1], false);
+        palshifted = true;
+    }
+    else if (palshifted)
+    {
+        VL_SetPalette (gamepal, false);        // back to normal
+        palshifted = false;
+    }
+}
+
+
+/*
+=====================
+=
+= FinishPaletteShifts
+=
+= Resets palette to normal if needed
+=
+=====================
+*/
+
+void FinishPaletteShifts (void)
+{
+    if (palshifted)
+    {
+        palshifted = 0;
+        VL_SetPalette (gamepal, true);
+    }
+}
+
+
+/*
+=============================================================================
+
+                                                CORE PLAYLOOP
+
+=============================================================================
+*/
+
+
+/*
+=====================
+=
+= DoActor
+=
+=====================
+*/
+
+void DoActor (objtype * ob)
+{
+    void (*think) (objtype *);
+
+    if (!ob->active && !areabyplayer[ob->areanumber])
+        return;
+
+    if (!(ob->flags & (FL_NONMARK | FL_NEVERMARK)))
+        actorat[ob->tilex][ob->tiley] = NULL;
+
+//
+// non transitional object
+//
+
+    if (!ob->ticcount)
+    {
+        think = (void (*)(objtype *)) ob->state->think;
+        if (think)
+        {
+            think (ob);
+            if (!ob->state)
+            {
+                RemoveObj (ob);
+                return;
+            }
+        }
+
+        if (ob->flags & FL_NEVERMARK)
+            return;
+
+        if ((ob->flags & FL_NONMARK) && actorat[ob->tilex][ob->tiley])
+            return;
+
+        actorat[ob->tilex][ob->tiley] = ob;
+        return;
+    }
+
+//
+// transitional object
+//
+    ob->ticcount -= (short) tics;
+    while (ob->ticcount <= 0)
+    {
+        think = (void (*)(objtype *)) ob->state->action;        // end of state action
+        if (think)
+        {
+            think (ob);
+            if (!ob->state)
+            {
+                RemoveObj (ob);
+                return;
+            }
+        }
+
+        ob->state = ob->state->next;
+
+        if (!ob->state)
+        {
+            RemoveObj (ob);
+            return;
+        }
+
+        if (!ob->state->tictime)
+        {
+            ob->ticcount = 0;
+            goto think;
+        }
+
+        ob->ticcount += ob->state->tictime;
+    }
+
+think:
+    //
+    // think
+    //
+    think = (void (*)(objtype *)) ob->state->think;
+    if (think)
+    {
+        think (ob);
+        if (!ob->state)
+        {
+            RemoveObj (ob);
+            return;
+        }
+    }
+
+    if (ob->flags & FL_NEVERMARK)
+        return;
+
+    if ((ob->flags & FL_NONMARK) && actorat[ob->tilex][ob->tiley])
+        return;
+
+    actorat[ob->tilex][ob->tiley] = ob;
+}
+
+//==========================================================================
+
+
+/*
+===================
+=
+= PlayLoop
+=
+===================
+*/
+int32_t funnyticount;
+
+
+void PlayLoop (void)
+{
+#if defined(USE_FEATUREFLAGS) && defined(USE_CLOUDSKY)
+    if(GetFeatureFlags() & FF_CLOUDSKY)
+        InitSky();
+#endif
+
+#ifdef USE_SHADING
+    InitLevelShadeTable();
+#endif
+
+    playstate = ex_stillplaying;
+    lasttimecount = GetTimeCount();
+    frameon = 0;
+    anglefrac = 0;
+    facecount = 0;
+    funnyticount = 0;
+    memset (buttonstate, 0, sizeof (buttonstate));
+    ClearPaletteShifts ();
+
+    if (MousePresent && IN_IsInputGrabbed())
+        IN_CenterMouse();         // Clear accumulated mouse movement
+
+    if (demoplayback)
+        IN_StartAck ();
+
+    do
+    {
+        PollControls ();
+
+//
+// actor thinking
+//
+        madenoise = false;
+
+        MoveDoors ();
+        MovePWalls ();
+
+        for (obj = player; obj; obj = obj->next)
+            DoActor (obj);
+
+        UpdatePaletteShifts ();
+
+        ThreeDRefresh ();
+
+        //
+        // MAKE FUNNY FACE IF BJ DOESN'T MOVE FOR AWHILE
+        //
+#ifdef SPEAR
+        funnyticount += tics;
+        if (funnyticount > 30l * 70)
+        {
+            funnyticount = 0;
+            if(viewsize != 21)
+                StatusDrawFace(BJWAITING1PIC + (US_RndT () & 1));
+            facecount = 0;
+        }
+#endif
+
+        gamestate.TimeCount += tics;
+
+        UpdateSoundLoc ();      // JAB
+        if (screenfaded)
+            VW_FadeIn ();
+
+        CheckKeys ();
+
+//
+// debug aids
+//
+        if (singlestep)
+        {
+            VW_WaitVBL (singlestep);
+            lasttimecount = GetTimeCount();
+        }
+        if (extravbls)
+            VW_WaitVBL (extravbls);
+
+        if (demoplayback)
+        {
+            if (IN_CheckAck ())
+            {
+                IN_ClearKeysDown ();
+                playstate = ex_abort;
+            }
+        }
+    }
+    while (!playstate && !startgame);
+
+    if (playstate != ex_died)
+        FinishPaletteShifts ();
+}