s_sound.v

@[translated]
module main

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Simple basic typedefs, isolated here to make it easier
//	 separating modules.
//
// #define macros to provide functions missing in Windows.
// Outside Windows, we use strings.h for str[n]casecmp.
//
// The packed attribute forces structures to be packed into the minimum
// space necessary.  If this is not done, the compiler may align structure
// fields differently to optimize memory access, inflating the overall
// structure size.  It is important to use the packed attribute on certain
// structures where alignment is important, particularly data read/written
// to disk.
//
// C99 integer types; with gcc we just use this.  Other compilers
// should add conditional statements that define the C99 types.
// What is really wanted here is stdint.h; however, some old versions
// of Solaris don't have stdint.h and only have inttypes.h (the
// pre-standardisation version).  inttypes.h is also in the C99
// standard and defined to include stdint.h, so include this.
// Use builtin bool type with C++.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	The not so system specific sound interface.
//
// so that the individual game logic and sound driver code agree
//
// SoundFX struct.
//
//
// MusicInfo struct.
//
// Interface for sound modules
@[c: 'I_ShutdownSound']
fn i_shutdown_sound()

@[c: 'I_GetSfxLumpNum']
fn i_get_sfx_lump_num(sfxinfo &Sfxinfo_t) int

@[c: 'I_UpdateSound']
fn i_update_sound()

@[c: 'I_UpdateSoundParams']
fn i_update_sound_params(channel int, vol int, sep int)

@[c: 'I_StartSound']
fn i_start_sound(sfxinfo &Sfxinfo_t, channel int, vol int, sep int, pitch int) int

@[c: 'I_StopSound']
fn i_stop_sound(channel int)

@[c: 'I_SoundIsPlaying']
fn i_sound_is_playing(channel int) bool

@[c: 'I_PrecacheSounds']
fn i_precache_sounds(sounds &Sfxinfo_t, num_sounds int)

// Interface for music modules
@[c: 'I_ShutdownMusic']
fn i_shutdown_music()

@[c: 'I_SetMusicVolume']
fn i_set_music_volume(volume int)

@[c: 'I_PauseSong']
fn i_pause_song()

@[c: 'I_ResumeSong']
fn i_resume_song()

@[c: 'I_RegisterSong']
fn i_register_song(data voidptr, len int) voidptr

@[c: 'I_UnRegisterSong']
fn i_un_register_song(handle voidptr)

@[c: 'I_PlaySong']
fn i_play_song(handle voidptr, looping bool)

@[c: 'I_StopSong']
fn i_stop_song()

@[c: 'I_MusicIsPlaying']
fn i_music_is_playing() bool

// DMX version to emulate for OPL emulation:
@[c: 'I_SetOPLDriverVer']
fn i_set_opld_river_ver(ver Opl_driver_ver_t)

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 1993-2008 Raven Software
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	System specific interface stuff.
//
// The data sampled per tick (single player)
// and transmitted to other peers (multiplayer).
// Mainly movements/button commands per game tick,
// plus a checksum for internal state consistency.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//
//
//
// Event handling.
//
// Input event types.
// Event structure.
//
// Button/action code definitions.
//
// villsa [STRIFE] Strife specific buttons
// TODO - not finished
// Called by IO functions when input is detected.
// Read an event from the event queue
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	System specific interface stuff.
//
// Called by DoomMain.
// Called by startup code
// to get the ammount of memory to malloc
// for the zone management.
// Asynchronous interrupt functions should maintain private queues
// that are read by the synchronous functions
// to be converted into events.
// Either returns a null ticcmd,
// or calls a loadable driver to build it.
// This ticcmd will then be modified by the gameloop
// for normal input.
// Called by M_Responder when quit is selected.
// Clean exit, displays sell blurb.
@[c: 'I_Error']
@[c2v_variadic]
fn i_error(error ...&i8)

// Schedule a function to be called when the program exits.
// If run_if_error is true, the function is called if the exit
// is due to an error (I_Error)
@[c: 'I_AtExit']
fn i_at_exit(func Atexit_func_t, run_if_error bool)

// Add all system-specific config file variable bindings.
// Print startup banner copyright message.
// Print a centered text banner displaying the given string.
// Print a dividing line for startup banners.
//
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
//
// Dehacked string replacements
//
// Used to do dehacked text substitutions throughout the program
@[c: 'DEH_String']
fn deh_string(s &i8) &i8

// Static macro versions of the functions above
// #ifndef DEH_STR_H
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//      System-specific timer interface
//
// Called by D_DoomLoop,
// returns current time in tics.
// returns current time in ms
// Pause for a specified number of ms
// Initialize timer
// Wait for vertical retrace or pause a bit.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//   Functions and definitions relating to the game type and operational
//   mode.
//
// The "mission" controls what game we are playing.
// The "mode" allows more accurate specification of the game mode we are
// in: eg. shareware vs. registered.  So doom1.wad and doom.wad are the
// same mission, but a different mode.
// What version are we emulating?
// What IWAD variant are we using?
// Skill level.
// #ifndef __D_MODE__
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Internally used data structures for virtually everything,
//   lots of other stuff.
//
//
// Global parameters/defines.
//
// DOOM version
// Version code for cph's longtics hack ("v1.91")
// If rangecheck is undefined,
// most parameter validation debugging code will not be compiled
// The maximum number of players, multiplayer/networking.
// The current state of the game: whether we are
// playing, gazing at the intermission screen,
// the game final animation, or a demo.
//
// Difficulty/skill settings/filters.
//
// Skill flags.
// Deaf monsters/do not react to sound.
//
// Key cards.
//
// The defined weapons,
//  including a marker indicating
//  user has not changed weapon.
// Ammunition types defined.
// Power up artifacts.
//
// Power up durations,
//  how many seconds till expiration,
//  assuming TICRATE is 35 ticks/second.
//
// __DOOMDEF__
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  all external data is defined here
//  most of the data is loaded into different structures at run time
//  some internal structures shared by many modules are here
//
// The most basic types we use, portability.
// Some global defines, that configure the game.
//
// Map level types.
// The following data structures define the persistent format
// used in the lumps of the WAD files.
//
// Lump order in a map WAD: each map needs a couple of lumps
// to provide a complete scene geometry description.


// A single Vertex.
// A separator, name, ExMx or MAPxx
// Monsters, items..
// LineDefs, from editing                   // A single Vertex.
// SideDefs, from editing                   typedef PACKED_STRUCT (
// Vertices, edited and BSP splits generated{
// LineSegs, from LineDefs split by BSP       short		x;
// SubSectors, list of LineSegs               short		y;
// BSP nodes                                }) mapvertex_t;
// Sectors, from editing
// LUT, sector-sector visibility	
// LUT, motion clipping, walls/grid element // A SideDef, defining the visual appearance of a wall,
// by setting textures and offsets.
// A LineDef, as used for editing, and as input
// to the BSP builder.
//
// LineDef attributes.
//
// Solid, is an obstacle.
// Blocks monsters only.
// Backside will not be present at all
//  if not two sided.
// If a texture is pegged, the texture will have
// the end exposed to air held constant at the
// top or bottom of the texture (stairs or pulled
// down things) and will move with a height change
// of one of the neighbor sectors.
// Unpegged textures allways have the first row of
// the texture at the top pixel of the line for both
// top and bottom textures (use next to windows).
// upper texture unpegged
// lower texture unpegged
// In AutoMap: don't map as two sided: IT'S A SECRET!
// Sound rendering: don't let sound cross two of these.
// Don't draw on the automap at all.
// Set if already seen, thus drawn in automap.
// Sector definition, from editing.
// SubSector, as generated by BSP.
// LineSeg, generated by splitting LineDefs
// using partition lines selected by BSP builder.
// BSP node structure.
// Indicate a leaf.
// Thing definition, position, orientation and type,
// plus skill/visibility flags and attributes.
// __DOOMDATA__
//
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//     SHA-1 digest.
//
// #ifndef __SHA1_H__
//
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//     Definitions for use in networking code.
//
// Absolute maximum number of "nodes" in the game.  This is different to
// NET_MAXPLAYERS, as there may be observers that are not participating
// (eg. left/right monitors)
// The maximum number of players, multiplayer/networking.
// This is the maximum supported by the networking code; individual games
// have their own values for MAXPLAYERS that can be smaller.
// Maximum length of a player's name.
// Networking and tick handling related.
// net_addr_t
// Magic number sent when connecting to check this is a valid client
// Old magic number used by Chocolate Doom versions before v3.0:
// header field value indicating that the packet is a reliable packet
// Supported protocols. If you're developing a fork of Chocolate
// Doom, you can add your own entry to this list while maintaining
// compatibility with Chocolate Doom servers. Higher-numbered enum values
// will be preferred when negotiating a protocol for the client and server
// to use, so the order matters.
// NOTE: The values in this enum do not have any special value outside of
// the program they're compiled in. What matters is the string representation.
// packet types
// Settings specified when the client connects to the server.
// Game settings sent by client to server when initiating game start,
// and received from the server by clients when the game starts.
// Complete set of ticcmds from all players
// Data sent in response to server queries
// Data sent by the server while waiting for the game to start.
// #ifndef NET_DEFS_H
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Main loop stuff.
//
// Callback function invoked while waiting for the netgame to start.
// The callback is invoked when new players are ready. The callback
// should return true, or return false to abort startup.
// Register callback functions for the main loop code to use.
// Create any new ticcmds and broadcast to other players.
// Broadcasts special packets to other players
//  to notify of game exit
//? how many ticks to run?
// Called at start of game loop to initialize timers
// Initialize networking code and connect to server.
// Start game with specified settings. The structure will be updated
// with the actual settings for the game.
// Check if it is permitted to record a demo with a non-vanilla feature.
// Check if it is permitted to play back a demo with a non-vanilla feature.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Items: key cards, artifacts, weapon, ammunition.
//
// Weapon info: sprite frames, ammunition use.
// skipping global dup "weaponinfo"
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Fixed point arithemtics, implementation.
//
//
// Fixed point, 32bit as 16.16.
//
@[c: 'FixedMul']
fn fixed_mul(a int, b int) int

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 1993-2008 Raven Software
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Lookup tables.
//	Do not try to look them up :-).
//	In the order of appearance:
//
//	int finetangent[4096]	- Tangens LUT.
//	 Should work with BAM fairly well (12 of 16bit,
//      effectively, by shifting).
//
//	int finesine[10240]		- Sine lookup.
//	 Guess what, serves as cosine, too.
//	 Remarkable thing is, how to use BAMs with this?
//
//	int tantoangle[2049]	- ArcTan LUT,
//	  maps tan(angle) to angle fast. Gotta search.	
//
// 0x100000000 to 0x2000
// Effective size is 10240.
// Re-use data, is just PI/2 pahse shift.
// Effective size is 4096.
// Gamma correction tables.
// Binary Angle Measument, BAM.
// Heretic code uses this definition as though it represents one
// degree, but it is not!  This is actually ~1.40 degrees.
// Effective size is 2049;
// The +1 size is to handle the case when x==y
//  without additional checking.
// Utility function,
//  called by R_PointToAngle.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  MapObj data. Map Objects or mobjs are actors, entities,
//  thinker, take-your-pick... anything that moves, acts, or
//  suffers state changes of more or less violent nature.
//
//
// Experimental stuff.
// To compile this as "ANSI C with classes"
//  we will need to handle the various
//  action functions cleanly.
//
// Historically, "think_t" is yet another
//  function pointer to a routine to handle
//  an actor.
// Doubly linked list of actors.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Thing frame/state LUT,
//	generated by multigen utilitiy.
//	This one is the original DOOM version, preserved.
//
// Needed for action function pointer handling.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Sprite animation.
//
// Basic data types.
// Needs fixed point, and BAM angles.
//
// Needs to include the precompiled
//  sprite animation tables.
// Header generated by multigen utility.
// This includes all the data for thing animation,
// i.e. the Thing Atrributes table
// and the Frame Sequence table.
//
// Frame flags:
// handles maximum brightness (torches, muzzle flare, light sources)
//
// flag in thing->frame
//
// Overlay psprites are scaled shapes
// drawn directly on the view screen,
// coordinates are given for a 320*200 view screen.
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Map Objects, MObj, definition and handling.
//
// Basics.
// We need the thinker_t stuff.
// We need the WAD data structure for Map things,
// from the THINGS lump.
// States are tied to finite states are
//  tied to animation frames.
// Needs precompiled tables/data structures.
//
// NOTES: mobj_t
//
// mobj_ts are used to tell the refresh where to draw an image,
// tell the world simulation when objects are contacted,
// and tell the sound driver how to position a sound.
//
// The refresh uses the next and prev links to follow
// lists of things in sectors as they are being drawn.
// The sprite, frame, and angle elements determine which patch_t
// is used to draw the sprite if it is visible.
// The sprite and frame values are allmost allways set
// from state_t structures.
// The statescr.exe utility generates the states.h and states.c
// files that contain the sprite/frame numbers from the
// statescr.txt source file.
// The xyz origin point represents a point at the bottom middle
// of the sprite (between the feet of a biped).
// This is the default origin position for patch_ts grabbed
// with lumpy.exe.
// A walking creature will have its z equal to the floor
// it is standing on.
//
// The sound code uses the x,y, and subsector fields
// to do stereo positioning of any sound effited by the mobj_t.
//
// The play simulation uses the blocklinks, x,y,z, radius, height
// to determine when mobj_ts are touching each other,
// touching lines in the map, or hit by trace lines (gunshots,
// lines of sight, etc).
// The mobj_t->flags element has various bit flags
// used by the simulation.
//
// Every mobj_t is linked into a single sector
// based on its origin coordinates.
// The subsector_t is found with R_PointInSubsector(x,y),
// and the sector_t can be found with subsector->sector.
// The sector links are only used by the rendering code,
// the play simulation does not care about them at all.
//
// Any mobj_t that needs to be acted upon by something else
// in the play world (block movement, be shot, etc) will also
// need to be linked into the blockmap.
// If the thing has the MF_NOBLOCK flag set, it will not use
// the block links. It can still interact with other things,
// but only as the instigator (missiles will run into other
// things, but nothing can run into a missile).
// Each block in the grid is 128*128 units, and knows about
// every line_t that it contains a piece of, and every
// interactable mobj_t that has its origin contained.
//
// A valid mobj_t is a mobj_t that has the proper subsector_t
// filled in for its xy coordinates and is linked into the
// sector from which the subsector was made, or has the
// MF_NOSECTOR flag set (the subsector_t needs to be valid
// even if MF_NOSECTOR is set), and is linked into a blockmap
// block or has the MF_NOBLOCKMAP flag set.
// Links should only be modified by the P_[Un]SetThingPosition()
// functions.
// Do not change the MF_NO? flags while a thing is valid.
//
// Any questions?
//
//
// Misc. mobj flags
//
// Map Object definition.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//
//
// The player data structure depends on a number
// of other structs: items (internal inventory),
// animation states (closely tied to the sprites
// used to represent them, unfortunately).
// In addition, the player is just a special
// case of the generic moving object/actor.
// Finally, for odd reasons, the player input
// is buffered within the player data struct,
// as commands per game tick.
//
// Player states.
//
//
// Player internal flags, for cheats and debug.
//
//
// Extended player object info: player_t
//
//
// INTERMISSION
// Structure passed e.g. to WI_Start(wb)
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//   All the global variables that store the internal state.
//   Theoretically speaking, the internal state of the engine
//    should be found by looking at the variables collected
//    here, and every relevant module will have to include
//    this header file.
//   In practice, things are a bit messy.
//
// We need globally shared data structures,
//  for defining the global state variables.
// We need the playr data structure as well.
// Game mode/mission
// ------------------------
// Command line parameters.
//
// skipping global dup "nomonsters"
// checkparm of -nomonsters
// skipping global dup "respawnparm"
// checkparm of -respawn
// skipping global dup "fastparm"
// checkparm of -fast
// skipping global dup "devparm"
// DEBUG: launched with -devparm
// -----------------------------------------------------
// Game Mode - identify IWAD as shareware, retail etc.
//
// Convenience macro.
// 'gamemission' can be equal to pack_chex or pack_hacx, but these are
// just modified versions of doom and doom2, and should be interpreted
// as the same most of the time.
//
//#define logical_gamemission                             \
//    (gamemission == pack_chex ? doom :                  \
//     gamemission == pack_hacx ? doom2 : gamemission)
//
// Set if homebrew PWAD stuff has been added.
// -------------------------------------------
// Selected skill type, map etc.
//
// Defaults for menu, methinks.
// skipping global dup "startskill"
// skipping global dup "startepisode"
// skipping global dup "startmap"
// Savegame slot to load on startup.  This is the value provided to
// the -loadgame option.  If this has not been provided, this is -1.
// skipping global dup "startloadgame"
// skipping global dup "autostart"
// Selected by user.
// skipping global dup "gameskill"
// skipping global dup "gameepisode"
// skipping global dup "gamemap"
// If non-zero, exit the level after this number of minutes
// skipping global dup "timelimit"
// Nightmare mode flag, single player.
// skipping global dup "respawnmonsters"
// Netgame? Only true if >1 player.
// skipping global dup "netgame"
// 0=Cooperative; 1=Deathmatch; 2=Altdeath
// skipping global dup "deathmatch"
// -------------------------
// Internal parameters for sound rendering.
// These have been taken from the DOS version,
//  but are not (yet) supported with Linux
//  (e.g. no sound volume adjustment with menu.
// From m_menu.c:
//  Sound FX volume has default, 0 - 15
//  Music volume has default, 0 - 15
// These are multiplied by 8.
// skipped extern global sfxVolume
// skipped extern global musicVolume
// Current music/sfx card - index useless
//  w/o a reference LUT in a sound module.
// Ideally, this would use indices found
//  in: /usr/include/linux/soundcard.h
// Config file? Same disclaimer as above.
// -------------------------
// Status flags for refresh.
//
// Depending on view size - no status bar?
// Note that there is no way to disable the
//  status bar explicitely.
// skipping global dup "automapactive"
// In AutoMap mode?
// skipping global dup "menuactive"
// Menu overlayed?
// skipping global dup "paused"
// Game Pause?
// skipping global dup "viewactive"
// skipping global dup "nodrawers"
// skipping global dup "testcontrols"
// skipping global dup "testcontrols_mousespeed"
// This one is related to the 3-screen display mode.
// ANG90 = left side, ANG270 = right
// Player taking events, and displaying.
// skipping global dup "consoleplayer"
// skipping global dup "displayplayer"
// -------------------------------------
// Scores, rating.
// Statistics on a given map, for intermission.
//
// skipping global dup "totalkills"
// skipping global dup "totalitems"
// skipping global dup "totalsecret"
// Timer, for scores.
// skipping global dup "levelstarttic"
// gametic at level start
// skipping global dup "leveltime"
// tics in game play for par
// --------------------------------------
// DEMO playback/recording related stuff.
// No demo, there is a human player in charge?
// Disable save/end game?
// skipping global dup "usergame"
//?
// skipping global dup "demoplayback"
// skipping global dup "demorecording"
// Round angleturn in ticcmds to the nearest 256.  This is used when
// recording Vanilla demos in netgames.
// skipping global dup "lowres_turn"
// Quit after playing a demo from cmdline.
// skipping global dup "singledemo"
//?
// skipping global dup "gamestate"
//-----------------------------
// Internal parameters, fixed.
// These are set by the engine, and not changed
//  according to user inputs. Partly load from
//  WAD, partly set at startup time.
// Bookkeeping on players - state.
// skipping global dup "players"
// Alive? Disconnected?
// skipping global dup "playeringame"
// Player spawn spots for deathmatch.
// skipping global dup "deathmatchstarts"
// skipping global dup "deathmatch_p"
// Player spawn spots.
// skipping global dup "playerstarts"
// skipping global dup "playerstartsingame"
// Intermission stats.
// Parameters for world map / intermission.
// skipping global dup "wminfo"
//-----------------------------------------
// Internal parameters, used for engine.
//
// File handling stuff.
// skipping global dup "savegamedir"
// if true, load all graphics at level load
// skipping global dup "precache"
// wipegamestate can be set to -1
//  to force a wipe on the next draw
// skipping global dup "wipegamestate"
// skipping global dup "mouseSensitivity"
// skipping global dup "bodyqueslot"
// Needed to store the number of the dummy sky flat.
// Used for rendering,
//  as well as tracking projectiles etc.
// skipping global dup "skyflatnum"
// Netgame stuff (buffers and pointers, i.e. indices).
// skipping global dup "rndindex"
// skipping global dup "netcmds"
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Created by the sound utility written by Dave Taylor.
//	Kept as a sample, DOOM2  sounds. Frozen.
//
// the complete set of sound effects
// skipping global dup "S_sfx"
// the complete set of music
// skipping global dup "S_music"
//
// Identifiers for all music in game.
//
//
// Identifiers for all sfx in game.
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	The not so system specific sound interface.
//
//
// Initializes sound stuff, including volume
// Sets channels, SFX and music volume,
//  allocates channel buffer, sets S_sfx lookup.
//
@[c: 'S_Init']
fn s_init(sfx_volume int, music_volume int)

// Shut down sound
@[c: 'S_Shutdown']
fn s_shutdown()

//
// Per level startup code.
// Kills playing sounds at start of level,
//  determines music if any, changes music.
//
@[c: 'S_Start']
fn s_start()

//
// Start sound for thing at <origin>
//  using <sound_id> from sounds.h
//
@[c: 'S_StartSound']
fn s_start_sound(origin voidptr, sound_id int)

// Stop sound for thing at <origin>
@[c: 'S_StopSound']
fn s_stop_sound(origin &Mobj_t)

// Start music using <music_id> from sounds.h
@[c: 'S_StartMusic']
fn s_start_music(music_id int)

// Start music using <music_id> from sounds.h,
//  and set whether looping
@[c: 'S_ChangeMusic']
fn s_change_music(music_id int, looping int)

// query if music is playing
@[c: 'S_MusicPlaying']
fn s_music_playing() bool

// Stops the music fer sure.
@[c: 'S_StopMusic']
fn s_stop_music()

// Stop and resume music, during game PAUSE.
@[c: 'S_PauseSound']
fn s_pause_sound()

@[c: 'S_ResumeSound']
fn s_resume_sound()

//
// Updates music & sounds
//
@[c: 'S_UpdateSounds']
fn s_update_sounds(listener &Mobj_t)

@[c: 'S_SetMusicVolume']
fn s_set_music_volume(volume int)

@[c: 'S_SetSfxVolume']
fn s_set_sfx_volume(volume int)

// skipped extern global snd_channels
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//      Miscellaneous.
//
@[c: 'M_snprintf']
@[c2v_variadic]
fn m_snprintf(buf &i8, buf_len usize, s ...&i8) int

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//
//
// Returns a number from 0 to 255,
// from a lookup table.
@[c: 'M_Random']
fn m_random() int

// As M_Random, but used only by the play simulation.
// Fix randoms for demos.
// Defined version of P_Random() - P_Random()
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Nil.
//
//
// MISC
//
// Returns the position of the given parameter
// in the arg list (0 if not found).
// Same as M_CheckParm, but checks that num_args arguments are available
// following the specified argument.
// Parameter has been specified?
// Get name of executable used to run this program:
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	System specific interface stuff.
//
// Screen width and height.
// Screen height used when aspect_ratio_correct=true.
// Called by D_DoomMain,
// determines the hardware configuration
// and sets up the video mode
// Takes full 8 bit values.
// Called before processing any tics in a frame (just after displaying a frame).
// Time consuming syncronous operations are performed here (joystick reading).
// Called before processing each tic in a frame.
// Quick syncronous operations are performed here.
// Enable the loading disk image displayed when reading from disk.
// Joystic/gamepad hysteresis
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//      Refresh/rendering module, shared data struct definitions.
//
// Screenwidth.
// Some more or less basic data types
// we depend on.
// We rely on the thinker data struct
// to handle sound origins in sectors.
// SECTORS do store MObjs anyway.
// Silhouette, needed for clipping Segs (mainly)
// and sprites representing things.
//
// INTERNAL MAP TYPES
//  used by play and refresh
//
//
// Your plain vanilla vertex.
// Note: transformed values not buffered locally,
//  like some DOOM-alikes ("wt", "WebView") did.
//
// Forward of LineDefs, for Sectors.
// Each sector has a degenmobj_t in its center
//  for sound origin purposes.
// I suppose this does not handle sound from
//  moving objects (doppler), because
//  position is prolly just buffered, not
//  updated.
//
// The SECTORS record, at runtime.
// Stores things/mobjs.
//
//
// The SideDef.
//
//
// Move clipping aid for LineDefs.
//
//
// A SubSector.
// References a Sector.
// Basically, this is a list of LineSegs,
//  indicating the visible walls that define
//  (all or some) sides of a convex BSP leaf.
//
//
// The LineSeg.
//
//
// BSP node.
//
// PC direct to screen pointers
// B UNUSED - keep till detailshift in r_draw.c resolved
// extern byte*	destview;
// extern byte*	destscreen;
//
// OTHER TYPES
//
// This could be wider for >8 bit display.
// Indeed, true color support is posibble
//  precalculating 24bpp lightmap/colormap LUT.
//  from darkening PLAYPAL to all black.
// Could even us emore than 32 levels.
// typedef pixel_t		lighttable_t;
// XTODO  alias to alias
//
// ?
//
// A vissprite_t is a thing
//  that will be drawn during a refresh.
// I.e. a sprite object that is partly visible.
//	
// Sprites are patches with a special naming convention
//  so they can be recognized by R_InitSprites.
// The base name is NNNNFx or NNNNFxFx, with
//  x indicating the rotation, x = 0, 1-7.
// The sprite and frame specified by a thing_t
//  is range checked at run time.
// A sprite is a patch_t that is assumed to represent
//  a three dimensional object and may have multiple
//  rotations pre drawn.
// Horizontal flipping is used to save space,
//  thus NNNNF2F5 defines a mirrored patch.
// Some sprites will only have one picture used
// for all views: NNNNF0
//
//
// A sprite definition:
//  a number of animation frames.
//
//
// Now what is a visplane, anyway?
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Refresh/render internal state variables (global).
//
// Need data structure definitions.
//
// Refresh internal data structures,
//  for rendering.
//
// needed for texture pegging
// skipping global dup "textureheight"
// needed for pre rendering (fracs)
// skipping global dup "spritewidth"
// skipping global dup "spriteoffset"
// skipping global dup "spritetopoffset"
// skipping global dup "colormaps"
// skipping global dup "firstflat"
// for global animation
// skipping global dup "flattranslation"
// skipping global dup "texturetranslation"
// Sprite....
// skipping global dup "firstspritelump"
// skipping global dup "lastspritelump"
// skipping global dup "numspritelumps"
//
// Lookup tables for map data.
//
// skipping global dup "numsprites"
// skipping global dup "sprites"
// skipping global dup "numvertexes"
// skipping global dup "vertexes"
// skipping global dup "numsegs"
// skipping global dup "segs"
// skipping global dup "numsectors"
// skipping global dup "sectors"
// skipping global dup "numsubsectors"
// skipping global dup "subsectors"
// skipping global dup "numnodes"
// skipping global dup "nodes"
// skipping global dup "numlines"
// skipping global dup "lines"
// skipping global dup "numsides"
// skipping global dup "sides"
//
// POV data.
//
// ?
// extern fixed_t		finetangent[FINEANGLES/2];
// skipping global dup "rw_distance"
// skipping global dup "rw_normalangle"
// angle to line origin
// skipping global dup "rw_angle1"
// Segs count?
// skipping global dup "floorplane"
// skipping global dup "ceilingplane"
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//  Refresh module, data I/O, caching, retrieval of graphics
//  by name.
//
// Retrieve column data for span blitting.
// I/O, setting up the stuff.
// Retrieval.
// Floor/ceiling opaque texture tiles,
// lookup by name. For animation?
// Called by P_Ticker for switches and animations,
// returns the texture number for the texture name.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	System specific interface stuff.
//
//
// POV related.
//
//
// Lighting LUT.
// Used for z-depth cuing per column/row,
//  and other lighting effects (sector ambient, flash).
//
// Lighting constants.
// Now why not 32 levels here?
// Number of diminishing brightness levels.
// There a 0-31, i.e. 32 LUT in the COLORMAP lump.
// Blocky/low detail mode.
// B remove this?
//  0 = high, 1 = low
//
// Function pointers to switch refresh/drawing functions.
// Used to select shadow mode etc.
//
// No shadow effects on floors.
//
// Utility functions.
@[c: 'R_PointToAngle2']
fn r_point_to_angle2(x1 int, y1 int, x2 int, y2 int) Angle_t

//
// REFRESH - the actual rendering functions.
//
// Called by G_Drawer.
// Called by startup code.
// Called by M_Responder.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Refresh module, BSP traversal and handling.
//
// skipping global dup "curline"
// skipping global dup "sidedef"
// skipping global dup "linedef"
// skipping global dup "frontsector"
// skipping global dup "backsector"
// skipping global dup "rw_x"
// skipping global dup "rw_stopx"
// skipping global dup "segtextured"
// false if the back side is the same plane
// skipping global dup "markfloor"
// skipping global dup "markceiling"
// skipping global dup "drawsegs"
// skipping global dup "ds_p"
// BSP?
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Refresh module, drawing LineSegs from BSP.
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Refresh, visplane stuff (floor, ceilings).
//
// Visplane related.
// skipping global dup "lastopening"
// skipping global dup "floorfunc"
// skipping global dup "floorclip"
// skipping global dup "ceilingclip"
// skipping global dup "yslope"
// skipping global dup "distscale"
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Rendering of moving objects, sprites.
//
// skipping global dup "vissprites"
// skipping global dup "vissprite_p"
// skipping global dup "vsprsortedhead"
// Constant arrays used for psprite clipping
//  and initializing clipping.
// skipping global dup "negonearray"
// skipping global dup "screenheightarray"
// vars for R_DrawMaskedColumn
// skipping global dup "mfloorclip"
// skipping global dup "mceilingclip"
// skipping global dup "spryscale"
// skipping global dup "sprtopscreen"
// skipping global dup "pspritescale"
// skipping global dup "pspriteiscale"
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	System specific interface stuff.
//
// first pixel in a column
// The span blitting interface.
// Hook in assembler or system specific BLT
//  here.
// The Spectre/Invisibility effect.
// Draw with color translation tables,
//  for player sprite rendering,
//  Green/Red/Blue/Indigo shirts.
// start of a 64*64 tile image
// Span blitting for rows, floor/ceiling.
// No Sepctre effect needed.
// Low resolution mode, 160x200?
// Initialize color translation tables,
//  for player rendering etc.
// Rendering function.
// If the view size is not full screen, draws a border around it.
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	Play functions, animation, global header.
//
// mapblocks are used to check movement
// against lines and things
// player radius for movement checking
// MAXRADIUS is for precalculated sector block boxes
// the spider demon is larger,
// but we do not have any moving sectors nearby
// follow a player exlusively for 3 seconds
//
// P_TICK
//
// both the head and tail of the thinker list
// skipping global dup "thinkercap"
//
// P_PSPR
//
//
// P_USER
//
//
// P_MOBJ
//
// Time interval for item respawning.
// skipping global dup "itemrespawnque"
// skipping global dup "itemrespawntime"
// skipping global dup "iquehead"
// skipping global dup "iquetail"
//
// P_ENEMY
//
//
// P_MAPUTL
//
// Extended MAXINTERCEPTS, to allow for intercepts overrun emulation.
//
// P_MAP
//
// If "floatok" true, move would be ok
// if within "tmfloorz - tmceilingz".
// skipping global dup "floatok"
// skipping global dup "tmfloorz"
// skipping global dup "tmceilingz"
// skipping global dup "ceilingline"
// fraggle: I have increased the size of this buffer.  In the original Doom,
// overrunning past this limit caused other bits of memory to be overwritten,
// affecting demo playback.  However, in doing so, the limit was still
// exceeded.  So we have to support more than 8 specials.
//
// We keep the original limit, to detect what variables in memory were
// overwritten (see SpechitOverrun())
// skipping global dup "spechit"
// skipping global dup "numspechit"
// skipping global dup "linetarget"
// who got hit (or NULL)
//
// P_SETUP
//
// skipping global dup "rejectmatrix"
// for fast sight rejection
// skipping global dup "blockmaplump"
// offsets in blockmap are from here
// skipping global dup "blockmap"
// skipping global dup "bmapwidth"
// skipping global dup "bmapheight"
// in mapblocks
// skipping global dup "bmaporgx"
// skipping global dup "bmaporgy"
// origin of block map
// skipping global dup "blocklinks"
// for thing chains
//
// P_INTER
//
// skipping global dup "maxammo"
// skipping global dup "clipammo"
//
// P_SPEC
//
// __P_LOCAL__
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:  none
//	Implements special effects:
//	Texture animation, height or lighting changes
//	 according to adjacent sectors, respective
//	 utility functions, etc.
//
//
// End-level timer (-TIMER option)
//
// skipping global dup "levelTimer"
// skipping global dup "levelTimeCount"
//      Define values for map objects
// at game start
// at map load
// every tic
// when needed
//
// SPECIAL
//
//
// P_LIGHTS
//
//
// P_SWITCH
//
// max # of wall switches in a level
// 4 players, 4 buttons each at once, max.
// 1 second, in ticks.
// skipping global dup "buttonlist"
//
// P_PLATS
//
// skipping global dup "activeplats"
//
// P_DOORS
//
// UNUSED
//
//      Sliding doors...
//
// how many frames of animation
// how many diff. types of anims
//
// P_CEILNG
//
// skipping global dup "activeceilings"
//
// P_FLOOR
//
//
// P_TELEPT
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	WAD I/O functions.
//
// Open the specified file. Returns a pointer to a new wad_file_t
// handle for the WAD file, or NULL if it could not be opened.
// Close the specified WAD file.
// Read data from the specified file into the provided buffer.  The
// data is read from the specified offset from the start of the file.
// Returns the number of bytes read.
// #ifndef __W_FILE__
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//	WAD I/O functions.
//
//
// TYPES
//
//
// WADFILE I/O related stuff.
//
@[c: 'W_CheckNumForName']
fn w_check_num_for_name(name &i8) Lumpindex_t

@[c: 'W_GetNumForName']
fn w_get_num_for_name(name &i8) Lumpindex_t

@[c: 'W_LumpLength']
fn w_lump_length(lump Lumpindex_t) int

@[c: 'W_CacheLumpNum']
fn w_cache_lump_num(lump Lumpindex_t, tag int) voidptr

@[c: 'W_ReleaseLumpNum']
fn w_release_lump_num(lump Lumpindex_t)

//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//      Zone Memory Allocation, perhaps NeXT ObjectiveC inspired.
//	Remark: this was the only stuff that, according
//	 to John Carmack, might have been useful for
//	 Quake.
//
//
// ZONE MEMORY
// PU - purge tags.
// static entire execution time
// static while playing
// static while playing
// a free block
// static until level exited
// a special thinker in a level
// Tags >= PU_PURGELEVEL are purgable whenever needed.
// Total number of different tag types
@[c: 'Z_Malloc']
fn z_malloc(size int, tag int, ptr voidptr) voidptr

//
// This is used to get the local FILE:LINE info from CPP
// prior to really call the function in question.
//
//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:  none
//
// when to clip out sounds
// Does not fit the large outdoor areas.
// Distance tp origin when sounds should be maxed out.
// This should relate to movement clipping resolution
// (see BLOCKMAP handling).
// In the source code release: (160*FRACUNIT).  Changed back to the
// Vanilla value of 200 (why was this changed?)
// The range over which sound attenuates
// Stereo separation
struct Channel_t {
	// sound information (if null, channel avail.)
	sfxinfo &Sfxinfo_t
	// origin of sound
	origin &Mobj_t
	// handle of the sound being played
	handle int
	pitch  int
}

// The set of channels available
// Maximum volume of a sound effect.
// Internal default is max out of 0-15.
// Maximum volume of music.
// Internal volume level, ranging from 0-127
// Whether songs are mus_paused
// Music currently being played
// Number of channels to use
//
// Initializes sound stuff, including volume
// Sets channels, SFX and music volume,
//  allocates channel buffer, sets S_sfx lookup.
//
@[c: 'S_Init']
fn s_init(sfx_volume int, music_volume int) {
	i := 0
	if gameversion == GameVersion_t.exe_doom_1_666 {
		if GameMission_t.doom == GameMission_t.doom {
			i_set_opld_river_ver(Opl_driver_ver_t.opl_doom1_1_666)
		} else {
			i_set_opld_river_ver(Opl_driver_ver_t.opl_doom2_1_666)
		}
	} else {
		i_set_opld_river_ver(Opl_driver_ver_t.opl_doom_1_9)
	}
	i_precache_sounds(S_sfx, Sfxenum_t.numsfx)
	s_set_sfx_volume(sfxVolume)
	s_set_music_volume(musicVolume)
	// Allocating the internal channels for mixing
	// (the maximum numer of sounds rendered
	// simultaneously) within zone memory.
	channels = z_malloc(snd_channels * sizeof(Channel_t), 1, 0)
	// Free all channels for use
	for i = 0; i < snd_channels; i++ {
		channels[i].sfxinfo = 0
	}
	// no sounds are playing, and they are not mus_paused
	mus_paused = 0
	// Note that sounds have not been cached (yet).
	for i = 1; i < Sfxenum_t.numsfx; i++ {
		S_sfx[i].lumpnum = -1
		S_sfx[i].usefulness = S_sfx[i].lumpnum
	}
	// Doom defaults to pitch-shifting off.
	if snd_pitchshift == -1 {
		snd_pitchshift = 0
	}
	i_at_exit(s_shutdown, true)
}

@[c: 'S_Shutdown']
fn s_shutdown() {
	i_shutdown_sound()
	i_shutdown_music()
}

@[c: 'S_StopChannel']
fn s_stop_channel(cnum int) {
	i := 0
	c := &Channel_t(0)
	c = &channels[cnum]
	if c.sfxinfo {
		// stop the sound playing
		if i_sound_is_playing(c.handle) {
			i_stop_sound(c.handle)
		}
		// check to see if other channels are playing the sound
		for i = 0; i < snd_channels; i++ {
			if cnum != i && c.sfxinfo == channels[i].sfxinfo {
				break
			}
		}
		// degrade usefulness of sound data
		c.sfxinfo.usefulness--
		c.sfxinfo = (unsafe { nil })
		c.origin = (unsafe { nil })
	}
}

//
// Per level startup code.
// Kills playing sounds at start of level,
//  determines music if any, changes music.
//
@[c: 'S_Start']
fn s_start() {
	cnum := 0
	mnum := 0
	// kill all playing sounds at start of level
	//  (trust me - a good idea)
	for cnum = 0; cnum < snd_channels; cnum++ {
		if channels[cnum].sfxinfo {
			s_stop_channel(cnum)
		}
	}
	// start new music for the level
	mus_paused = 0
	if gamemode == GameMode_t.commercial {
		mnum = Musicenum_t.mus_runnin + gamemap - 1
	} else {
		spmus := [// Song - Who? - Where?
			Musicenum_t.mus_e3m4, // American     e4m1
			Musicenum_t.mus_e3m2, // Romero       e4m2
			Musicenum_t.mus_e3m3, // Shawn        e4m3
			Musicenum_t.mus_e1m5, // American     e4m4
			Musicenum_t.mus_e2m7, // Tim          e4m5
			Musicenum_t.mus_e2m4, // Romero       e4m6
			Musicenum_t.mus_e2m6, // J.Anderson   e4m7 CHIRON.WAD
			Musicenum_t.mus_e2m5, // Shawn        e4m8
			Musicenum_t.mus_e1m9, // Tim          e4m9
		]!

		if gameepisode < 4 {
			mnum = Musicenum_t.mus_e1m1 + (gameepisode - 1) * 9 + gamemap - 1
		} else {
			mnum = spmus[gamemap - 1]
		}
	}
	s_change_music(mnum, true)
}

@[c: 'S_StopSound']
fn s_stop_sound(origin &Mobj_t) {
	cnum := 0
	for cnum = 0; cnum < snd_channels; cnum++ {
		if channels[cnum].sfxinfo && channels[cnum].origin == origin {
			s_stop_channel(cnum)
			break
		}
	}
}

//
// S_GetChannel :
//   If none available, return -1.  Otherwise channel #.
//
@[c: 'S_GetChannel']
fn s_get_channel(origin &Mobj_t, sfxinfo &Sfxinfo_t) int {
	// channel number to use
	cnum := 0
	c := &Channel_t(0)
	// Find an open channel
	for cnum = 0; cnum < snd_channels; cnum++ {
		if !channels[cnum].sfxinfo {
			break
		} else if origin && channels[cnum].origin == origin {
			s_stop_channel(cnum)
			break
		}
	}
	// None available
	if cnum == snd_channels {
		// Look for lower priority
		for cnum = 0; cnum < snd_channels; cnum++ {
			if channels[cnum].sfxinfo.priority >= sfxinfo.priority {
				break
			}
		}
		if cnum == snd_channels {
			// FUCK!  No lower priority.  Sorry, Charlie.
			return -1
		} else {
			// Otherwise, kick out lower priority.
			s_stop_channel(cnum)
		}
	}
	c = &channels[cnum]
	// channel is decided to be cnum.
	c.sfxinfo = sfxinfo
	c.origin = origin
	return cnum
}

//
// Changes volume and stereo-separation variables
//  from the norm of a sound effect to be played.
// If the sound is not audible, returns a 0.
// Otherwise, modifies parameters and returns 1.
//
@[c: 'S_AdjustSoundParams']
fn s_adjust_sound_params(listener &Mobj_t, source &Mobj_t, vol &int, sep &int) int {
	approx_dist := 0
	adx := 0
	ady := 0
	angle := u32(0)
	// calculate the distance to sound origin
	//  and clip it if necessary
	adx = C.abs(listener.x - source.x)
	ady = C.abs(listener.y - source.y)
	// From _GG1_ p.428. Appox. eucledian distance fast.
	approx_dist = adx + ady - ((if adx < ady { adx } else { ady }) >> 1)
	if gamemap != 8 && approx_dist > (1200 * (1 << 16)) {
		return 0
	}
	// angle of source to listener
	angle = r_point_to_angle2(listener.x, listener.y, source.x, source.y)
	if angle > listener.angle {
		angle = angle - listener.angle
	} else {
		angle = angle + (4294967295 - listener.angle)
	}
	angle >>= 19
	// stereo separation
	*sep = 128 - (fixed_mul((96 * (1 << 16)), finesine[angle]) >> 16)
	// volume calculation
	if approx_dist < (200 * (1 << 16)) {
		*vol = snd_SfxVolume
	} else if gamemap == 8 {
		if approx_dist > (1200 * (1 << 16)) {
			approx_dist = (1200 * (1 << 16))
		}
		*vol = 15 +((snd_SfxVolume - 15) * (((1200 * (1 << 16)) - approx_dist) >> 16)) / (((1200 * (1 << 16)) - (200 * (1 << 16))) >> 16)
	} else {
		// distance effect
		*vol = (snd_SfxVolume * (((1200 * (1 << 16)) - approx_dist) >> 16)) / (((1200 * (1 << 16)) - (200 * (1 << 16))) >> 16)
	}
	return *vol > 0
}

// clamp supplied integer to the range 0 <= x <= 255.
@[c: 'Clamp']
fn clamp(x int) int {
	if x < 0 {
		return 0
	} else if x > 255 {
		return 255
	}
	return x
}

@[c: 'S_StartSound']
fn s_start_sound(origin_p voidptr, sfx_id int) {
	sfx := &Sfxinfo_t(0)
	origin := &Mobj_t(0)
	rc := 0
	sep := 0
	pitch := 0
	cnum := 0
	volume := 0
	origin = &Mobj_t(origin_p)
	volume = snd_SfxVolume
	// check for bogus sound #
	if sfx_id < 1 || sfx_id > Sfxenum_t.numsfx {
		i_error(c'Bad sfx #: %d', sfx_id)
	}
	sfx = &S_sfx[sfx_id]
	// Initialize sound parameters
	pitch = 127
	if sfx.link {
		volume += sfx.volume
		pitch = sfx.pitch
		if volume < 1 {
			return
		}
		if volume > snd_SfxVolume {
			volume = snd_SfxVolume
		}
	}
	// Check to see if it is audible,
	//  and if not, modify the params
	if origin && origin != players[consoleplayer].mo {
		rc = s_adjust_sound_params(players[consoleplayer].mo, origin, &volume, &sep)
		if origin.x == players[consoleplayer].mo.x && origin.y == players[consoleplayer].mo.y {
			sep = 128
		}
		if !rc {
			return
		}
	} else {
		sep = 128
	}
	// hacks to vary the sfx pitches
	if sfx_id >= Sfxenum_t.sfx_sawup && sfx_id <= Sfxenum_t.sfx_sawhit {
		pitch += 8 - (m_random() & 15)
	} else if sfx_id != Sfxenum_t.sfx_itemup && sfx_id != Sfxenum_t.sfx_tink {
		pitch += 16 - (m_random() & 31)
	}
	pitch = clamp(pitch)
	// kill old sound
	s_stop_sound(origin)
	// try to find a channel
	cnum = s_get_channel(origin, sfx)
	if cnum < 0 {
		return
	}
	// increase the usefulness
	if sfx.usefulness++ < 0 {
		sfx.usefulness = 1
	}
	if sfx.lumpnum < 0 {
		sfx.lumpnum = i_get_sfx_lump_num(sfx)
	}
	channels[cnum].pitch = pitch
	channels[cnum].handle = i_start_sound(sfx, cnum, volume, sep, channels[cnum].pitch)
}

//
// Stop and resume music, during game PAUSE.
//
@[c: 'S_PauseSound']
fn s_pause_sound() {
	if mus_playing && !mus_paused {
		i_pause_song()
		mus_paused = true
	}
}

@[c: 'S_ResumeSound']
fn s_resume_sound() {
	if mus_playing && mus_paused {
		i_resume_song()
		mus_paused = false
	}
}

//
// Updates music & sounds
//
@[c: 'S_UpdateSounds']
fn s_update_sounds(listener &Mobj_t) {
	audible := 0
	cnum := 0
	volume := 0
	sep := 0
	sfx := &Sfxinfo_t(0)
	c := &Channel_t(0)
	i_update_sound()
	for cnum = 0; cnum < snd_channels; cnum++ {
		c = &channels[cnum]
		sfx = c.sfxinfo
		if c.sfxinfo {
			if i_sound_is_playing(c.handle) {
				// initialize parameters
				volume = snd_SfxVolume
				sep = 128
				if sfx.link {
					volume += sfx.volume
					if volume < 1 {
						s_stop_channel(cnum)
						continue
					} else if volume > snd_SfxVolume {
						volume = snd_SfxVolume
					}
				}
				// check non-local sounds for distance clipping
				//  or modify their params
				if c.origin && listener != c.origin {
					audible = s_adjust_sound_params(listener, c.origin, &volume, &sep)
					if !audible {
						s_stop_channel(cnum)
					} else {
						i_update_sound_params(c.handle, volume, sep)
					}
				}
			} else {
				// if channel is allocated but sound has stopped,
				//  free it
				s_stop_channel(cnum)
			}
		}
	}
}

@[c: 'S_SetMusicVolume']
fn s_set_music_volume(volume int) {
	if volume < 0 || volume > 127 {
		i_error(c'Attempt to set music volume at %d', volume)
	}
	i_set_music_volume(volume)
}

@[c: 'S_SetSfxVolume']
fn s_set_sfx_volume(volume int) {
	if volume < 0 || volume > 127 {
		i_error(c'Attempt to set sfx volume at %d', volume)
	}
	snd_SfxVolume = volume
}

//
// Starts some music with the music id found in sounds.h.
//
@[c: 'S_StartMusic']
fn s_start_music(m_id int) {
	s_change_music(m_id, false)
}

@[c: 'S_ChangeMusic']
fn s_change_music(musicnum int, looping int) {
	music := &Musicinfo_t(0)
	namebuf := [9]i8{}
	handle := &voidptr(0)
	// The Doom IWAD file has two versions of the intro music: d_intro
	// and d_introa.  The latter is used for OPL playback.
	if musicnum == Musicenum_t.mus_intro && (snd_musicdevice == Snddevice_t.snddevice_adlib
		|| snd_musicdevice == Snddevice_t.snddevice_sb) && w_check_num_for_name(c'D_INTROA') >= 0 {
		musicnum = Musicenum_t.mus_introa
	}
	if musicnum <= Musicenum_t.mus_none || musicnum >= Musicenum_t.nummusic {
		i_error(c'Bad music number %d', musicnum)
	} else {
		music = &S_music[musicnum]
	}
	if mus_playing == music {
		return
	}
	// shutdown old music
	s_stop_music()
	// get lumpnum if neccessary
	if !music.lumpnum {
		m_snprintf(namebuf, sizeof(namebuf), c'd_%s', deh_string(music.name))
		music.lumpnum = w_get_num_for_name(namebuf)
	}
	music.data = w_cache_lump_num(music.lumpnum, 1)
	handle = i_register_song(music.data, w_lump_length(music.lumpnum))
	music.handle = handle
	i_play_song(handle, looping)
	mus_playing = music
}

@[c: 'S_MusicPlaying']
fn s_music_playing() bool {
	return i_music_is_playing()
}

@[c: 'S_StopMusic']
fn s_stop_music() {
	if mus_playing {
		if mus_paused {
			i_resume_song()
		}
		i_stop_song()
		i_un_register_song(mus_playing.handle)
		w_release_lump_num(mus_playing.lumpnum)
		mus_playing.data = (unsafe { nil })
		mus_playing = (unsafe { nil })
	}
}