//
// 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 automap code
//

#include "deh_main.h"
#include "doomdef.h"
#include "doomkeys.h"
#include "i_system.h"
#include "m_cheat.h"
#include "m_controls.h"
#include "m_misc.h"
#include "p_local.h"
#include "st_stuff.h"
#include "w_wad.h"
#include "z_zone.h"

#include <stdio.h>

// Needs access to LFB.
#include "v_video.h"

// State.
#include "doomstat.h"
#include "r_state.h"

// Data.
#include "am_map.h"
#include "dstrings.h"

// For use if I do walls with outsides/insides
#define REDS (256 - 5 * 16)
#define REDRANGE 16
#define BLUES (256 - 4 * 16 + 8)
#define BLUERANGE 8
#define GREENS (7 * 16)
#define GREENRANGE 16
#define GRAYS (6 * 16)
#define GRAYSRANGE 16
#define BROWNS (4 * 16)
#define BROWNRANGE 16
#define YELLOWS (256 - 32 + 7)
#define YELLOWRANGE 1
#define BLACK 0
#define WHITE (256 - 47)

// Automap colors
#define BACKGROUND BLACK
#define YOURCOLORS WHITE
#define YOURRANGE 0
#define WALLCOLORS REDS
#define WALLRANGE REDRANGE
#define TSWALLCOLORS GRAYS
#define TSWALLRANGE GRAYSRANGE
#define FDWALLCOLORS BROWNS
#define FDWALLRANGE BROWNRANGE
#define CDWALLCOLORS YELLOWS
#define CDWALLRANGE YELLOWRANGE
#define THINGCOLORS GREENS
#define THINGRANGE GREENRANGE
#define SECRETWALLCOLORS WALLCOLORS
#define SECRETWALLRANGE WALLRANGE
#define GRIDCOLORS (GRAYS + GRAYSRANGE / 2)
#define GRIDRANGE 0
#define XHAIRCOLORS GRAYS

// drawing stuff

#define AM_NUMMARKPOINTS 10

// scale on entry
#define INITSCALEMTOF (.2 * FRACUNIT)
// how much the automap moves window per tic in frame-buffer coordinates
// moves 140 pixels in 1 second
#define F_PANINC 4
// how much zoom-in per tic
// goes to 2x in 1 second
#define M_ZOOMIN ((int) (1.02 * FRACUNIT))
// how much zoom-out per tic
// pulls out to 0.5x in 1 second
#define M_ZOOMOUT ((int) (FRACUNIT / 1.02))

// translates between frame-buffer and map distances
#define FTOM(x) FixedMul(((x) << 16), scale_ftom)
#define MTOF(x) (FixedMul((x), scale_mtof) >> 16)
// translates between frame-buffer and map coordinates
#define CXMTOF(x) (f_x + MTOF((x) -m_x))
#define CYMTOF(y) (f_y + (f_h - MTOF((y) -m_y)))

// the following is crap
#define LINE_NEVERSEE ML_DONTDRAW

typedef struct {
    int x, y;
} fpoint_t;

typedef struct {
    fpoint_t a, b;
} fline_t;

typedef struct {
    fixed_t x, y;
} mpoint_t;

typedef struct {
    mpoint_t a, b;
} mline_t;

typedef struct {
    fixed_t slp, islp;
} islope_t;

//
// The vector graphics for the automap.
//  A line drawing of the player pointing right,
//   starting from the middle.
//
#define R ((8 * PLAYERRADIUS) / 7)
mline_t player_arrow[] = {{{-R + R / 8, 0}, {R, 0}},                                     // -----
    {{R, 0}, {R - R / 2, R / 4}},                                                        // ----->
    {{R, 0}, {R - R / 2, -R / 4}}, {{-R + R / 8, 0}, {-R - R / 8, R / 4}},               // >---->
    {{-R + R / 8, 0}, {-R - R / 8, -R / 4}}, {{-R + 3 * R / 8, 0}, {-R + R / 8, R / 4}}, // >>--->
    {{-R + 3 * R / 8, 0}, {-R + R / 8, -R / 4}}};
#undef R

#define R ((8 * PLAYERRADIUS) / 7)
mline_t cheat_player_arrow[] = {{{-R + R / 8, 0}, {R, 0}},                               // -----
    {{R, 0}, {R - R / 2, R / 6}},                                                        // ----->
    {{R, 0}, {R - R / 2, -R / 6}}, {{-R + R / 8, 0}, {-R - R / 8, R / 6}},               // >----->
    {{-R + R / 8, 0}, {-R - R / 8, -R / 6}}, {{-R + 3 * R / 8, 0}, {-R + R / 8, R / 6}}, // >>----->
    {{-R + 3 * R / 8, 0}, {-R + R / 8, -R / 6}}, {{-R / 2, 0}, {-R / 2, -R / 6}},        // >>-d--->
    {{-R / 2, -R / 6}, {-R / 2 + R / 6, -R / 6}},
    {{-R / 2 + R / 6, -R / 6}, {-R / 2 + R / 6, R / 4}}, {{-R / 6, 0}, {-R / 6, -R / 6}}, // >>-dd-->
    {{-R / 6, -R / 6}, {0, -R / 6}}, {{0, -R / 6}, {0, R / 4}}, {{R / 6, R / 4}, {R / 6, -R / 7}}, // >>-ddt->
    {{R / 6, -R / 7}, {R / 6 + R / 32, -R / 7 - R / 32}},
    {{R / 6 + R / 32, -R / 7 - R / 32}, {R / 6 + R / 10, -R / 7}}};
#undef R

#define R (FRACUNIT)
mline_t triangle_guy[] = {
    {{(fixed_t)(-.867 * R), (fixed_t)(-.5 * R)}, {(fixed_t)(.867 * R), (fixed_t)(-.5 * R)}},
    {{(fixed_t)(.867 * R), (fixed_t)(-.5 * R)}, {(fixed_t)(0), (fixed_t)(R)}},
    {{(fixed_t)(0), (fixed_t)(R)}, {(fixed_t)(-.867 * R), (fixed_t)(-.5 * R)}}};
#undef R

#define R (FRACUNIT)
mline_t thintriangle_guy[] = {{{(fixed_t)(-.5 * R), (fixed_t)(-.7 * R)}, {(fixed_t)(R), (fixed_t)(0)}},
    {{(fixed_t)(R), (fixed_t)(0)}, {(fixed_t)(-.5 * R), (fixed_t)(.7 * R)}},
    {{(fixed_t)(-.5 * R), (fixed_t)(.7 * R)}, {(fixed_t)(-.5 * R), (fixed_t)(-.7 * R)}}};
#undef R

static int cheating = 0;
static int grid = 0;

static int leveljuststarted = 1; // kluge until AM_LevelInit() is called

boolean automapactive = false;
static int finit_width = SCREENWIDTH;
static int finit_height = SCREENHEIGHT - 32;

// location of window on screen
static int f_x;
static int f_y;

// size of window on screen
static int f_w;
static int f_h;

static int lightlev; // used for funky strobing effect
static byte* fb;     // pseudo-frame buffer
static int amclock;

static mpoint_t m_paninc;    // how far the window pans each tic (map coords)
static fixed_t mtof_zoommul; // how far the window zooms in each tic (map coords)
static fixed_t ftom_zoommul; // how far the window zooms in each tic (fb coords)

static fixed_t m_x, m_y;   // LL x,y where the window is on the map (map coords)
static fixed_t m_x2, m_y2; // UR x,y where the window is on the map (map coords)

//
// width/height of window on map (map coords)
//
static fixed_t m_w;
static fixed_t m_h;

// based on level size
static fixed_t min_x;
static fixed_t min_y;
static fixed_t max_x;
static fixed_t max_y;

static fixed_t max_w; // max_x-min_x,
static fixed_t max_h; // max_y-min_y

// based on player size
static fixed_t min_w;
static fixed_t min_h;

static fixed_t min_scale_mtof; // used to tell when to stop zooming out
static fixed_t max_scale_mtof; // used to tell when to stop zooming in

// old stuff for recovery later
static fixed_t old_m_w, old_m_h;
static fixed_t old_m_x, old_m_y;

// old location used by the Follower routine
static mpoint_t f_oldloc;

// used by MTOF to scale from map-to-frame-buffer coords
static fixed_t scale_mtof = (fixed_t) INITSCALEMTOF;
// used by FTOM to scale from frame-buffer-to-map coords (=1/scale_mtof)
static fixed_t scale_ftom;

static player_t* plr; // the player represented by an arrow

static patch_t* marknums[10];                 // numbers used for marking by the automap
static mpoint_t markpoints[AM_NUMMARKPOINTS]; // where the points are
static int markpointnum = 0;                  // next point to be assigned

static int followplayer = 1; // specifies whether to follow the player around

cheatseq_t cheat_amap = CHEAT("iddt", 0);

static boolean stopped = true;

// Calculates the slope and slope according to the x-axis of a line
// segment in map coordinates (with the upright y-axis n' all) so
// that it can be used with the brain-dead drawing stuff.

void AM_getIslope(mline_t* ml, islope_t* is) {
    int dx, dy;

    dy = ml->a.y - ml->b.y;
    dx = ml->b.x - ml->a.x;
    if (!dy)
        is->islp = (dx < 0 ? -INT_MAX : INT_MAX);
    else
        is->islp = FixedDiv(dx, dy);
    if (!dx)
        is->slp = (dy < 0 ? -INT_MAX : INT_MAX);
    else
        is->slp = FixedDiv(dy, dx);
}

//
//
//
void AM_activateNewScale(void) {
    m_x += m_w / 2;
    m_y += m_h / 2;
    m_w = FTOM(f_w);
    m_h = FTOM(f_h);
    m_x -= m_w / 2;
    m_y -= m_h / 2;
    m_x2 = m_x + m_w;
    m_y2 = m_y + m_h;
}

//
//
//
void AM_saveScaleAndLoc(void) {
    old_m_x = m_x;
    old_m_y = m_y;
    old_m_w = m_w;
    old_m_h = m_h;
}

//
//
//
void AM_restoreScaleAndLoc(void) {
    m_w = old_m_w;
    m_h = old_m_h;
    if (!followplayer) {
        m_x = old_m_x;
        m_y = old_m_y;
    } else {
        m_x = plr->mo->x - m_w / 2;
        m_y = plr->mo->y - m_h / 2;
    }
    m_x2 = m_x + m_w;
    m_y2 = m_y + m_h;

    // Change the scaling multipliers
    scale_mtof = FixedDiv(f_w << FRACBITS, m_w);
    scale_ftom = FixedDiv(FRACUNIT, scale_mtof);
}

//
// adds a marker at the current location
//
void AM_addMark(void) {
    markpoints[markpointnum].x = m_x + m_w / 2;
    markpoints[markpointnum].y = m_y + m_h / 2;
    markpointnum = (markpointnum + 1) % AM_NUMMARKPOINTS;
}

//
// Determines bounding box of all vertices,
// sets global variables controlling zoom range.
//
void AM_findMinMaxBoundaries(void) {
    int i;
    fixed_t a;
    fixed_t b;

    min_x = min_y = INT_MAX;
    max_x = max_y = -INT_MAX;

    for (i = 0; i < numvertexes; i++) {
        if (vertexes[i].x < min_x)
            min_x = vertexes[i].x;
        else if (vertexes[i].x > max_x)
            max_x = vertexes[i].x;

        if (vertexes[i].y < min_y)
            min_y = vertexes[i].y;
        else if (vertexes[i].y > max_y)
            max_y = vertexes[i].y;
    }

    max_w = max_x - min_x;
    max_h = max_y - min_y;

    min_w = 2 * PLAYERRADIUS; // const? never changed?
    min_h = 2 * PLAYERRADIUS;

    a = FixedDiv(f_w << FRACBITS, max_w);
    b = FixedDiv(f_h << FRACBITS, max_h);

    min_scale_mtof = a < b ? a : b;
    max_scale_mtof = FixedDiv(f_h << FRACBITS, 2 * PLAYERRADIUS);
}

//
//
//
void AM_changeWindowLoc(void) {
    if (m_paninc.x || m_paninc.y) {
        followplayer = 0;
        f_oldloc.x = INT_MAX;
    }

    m_x += m_paninc.x;
    m_y += m_paninc.y;

    if (m_x + m_w / 2 > max_x)
        m_x = max_x - m_w / 2;
    else if (m_x + m_w / 2 < min_x)
        m_x = min_x - m_w / 2;

    if (m_y + m_h / 2 > max_y)
        m_y = max_y - m_h / 2;
    else if (m_y + m_h / 2 < min_y)
        m_y = min_y - m_h / 2;

    m_x2 = m_x + m_w;
    m_y2 = m_y + m_h;
}

//
//
//
void AM_initVariables(void) {
    int pnum;
    static event_t st_notify = {ev_keyup, AM_MSGENTERED, 0, 0, 0};

    automapactive = true;
    fb = I_VideoBuffer;

    f_oldloc.x = INT_MAX;
    amclock = 0;
    lightlev = 0;

    m_paninc.x = m_paninc.y = 0;
    ftom_zoommul = FRACUNIT;
    mtof_zoommul = FRACUNIT;

    m_w = FTOM(f_w);
    m_h = FTOM(f_h);

    // find player to center on initially
    if (playeringame[consoleplayer]) {
        plr = &players[consoleplayer];
    } else {
        plr = &players[0];

        for (pnum = 0; pnum < MAXPLAYERS; pnum++) {
            if (playeringame[pnum]) {
                plr = &players[pnum];
                break;
            }
        }
    }

    m_x = plr->mo->x - m_w / 2;
    m_y = plr->mo->y - m_h / 2;
    AM_changeWindowLoc();

    // for saving & restoring
    old_m_x = m_x;
    old_m_y = m_y;
    old_m_w = m_w;
    old_m_h = m_h;

    // inform the status bar of the change
    ST_Responder(&st_notify);
}

//
//
//
void AM_loadPics(void) {
    int i;
    char namebuf[9];

    for (i = 0; i < 10; i++) {
        DEH_snprintf(namebuf, 9, "AMMNUM%d", i);
        marknums[i] = W_CacheLumpName(namebuf, PU_STATIC);
    }
}

void AM_unloadPics(void) {
    int i;
    char namebuf[9];

    for (i = 0; i < 10; i++) {
        DEH_snprintf(namebuf, 9, "AMMNUM%d", i);
        W_ReleaseLumpName(namebuf);
    }
}

void AM_clearMarks(void) {
    int i;

    for (i = 0; i < AM_NUMMARKPOINTS; i++)
        markpoints[i].x = -1; // means empty
    markpointnum = 0;
}

//
// should be called at the start of every level
// right now, i figure it out myself
//
void AM_LevelInit(void) {
    leveljuststarted = 0;

    f_x = f_y = 0;
    f_w = finit_width;
    f_h = finit_height;

    AM_clearMarks();

    AM_findMinMaxBoundaries();
    scale_mtof = FixedDiv(min_scale_mtof, (int) (0.7 * FRACUNIT));
    if (scale_mtof > max_scale_mtof)
        scale_mtof = min_scale_mtof;
    scale_ftom = FixedDiv(FRACUNIT, scale_mtof);
}

//
//
//
void AM_Stop(void) {
    static event_t st_notify = {0, ev_keyup, AM_MSGEXITED, 0, 0};

    AM_unloadPics();
    automapactive = false;
    ST_Responder(&st_notify);
    stopped = true;
}

//
//
//
void AM_Start(void) {
    static int lastlevel = -1, lastepisode = -1;

    if (!stopped)
        AM_Stop();
    stopped = false;
    if (lastlevel != gamemap || lastepisode != gameepisode) {
        AM_LevelInit();
        lastlevel = gamemap;
        lastepisode = gameepisode;
    }
    AM_initVariables();
    AM_loadPics();
}

//
// set the window scale to the maximum size
//
void AM_minOutWindowScale(void) {
    scale_mtof = min_scale_mtof;
    scale_ftom = FixedDiv(FRACUNIT, scale_mtof);
    AM_activateNewScale();
}

//
// set the window scale to the minimum size
//
void AM_maxOutWindowScale(void) {
    scale_mtof = max_scale_mtof;
    scale_ftom = FixedDiv(FRACUNIT, scale_mtof);
    AM_activateNewScale();
}

//
// Handle events (user inputs) in automap mode
//
boolean AM_Responder(event_t* ev) {
    int rc;
    static int bigstate = 0;
    static char buffer[20];
    int key;

    rc = false;

    if (!automapactive) {
        if (ev->type == ev_keydown && ev->data1 == key_map_toggle) {
            AM_Start();
            viewactive = false;
            rc = true;
        }
    } else if (ev->type == ev_keydown) {
        rc = true;
        key = ev->data1;

        if (key == key_map_east) // pan right
        {
            if (!followplayer)
                m_paninc.x = FTOM(F_PANINC);
            else
                rc = false;
        } else if (key == key_map_west) // pan left
        {
            if (!followplayer)
                m_paninc.x = -FTOM(F_PANINC);
            else
                rc = false;
        } else if (key == key_map_north) // pan up
        {
            if (!followplayer)
                m_paninc.y = FTOM(F_PANINC);
            else
                rc = false;
        } else if (key == key_map_south) // pan down
        {
            if (!followplayer)
                m_paninc.y = -FTOM(F_PANINC);
            else
                rc = false;
        } else if (key == key_map_zoomout) // zoom out
        {
            mtof_zoommul = M_ZOOMOUT;
            ftom_zoommul = M_ZOOMIN;
        } else if (key == key_map_zoomin) // zoom in
        {
            mtof_zoommul = M_ZOOMIN;
            ftom_zoommul = M_ZOOMOUT;
        } else if (key == key_map_toggle) {
            bigstate = 0;
            viewactive = true;
            AM_Stop();
        } else if (key == key_map_maxzoom) {
            bigstate = !bigstate;
            if (bigstate) {
                AM_saveScaleAndLoc();
                AM_minOutWindowScale();
            } else
                AM_restoreScaleAndLoc();
        } else if (key == key_map_follow) {
            followplayer = !followplayer;
            f_oldloc.x = INT_MAX;
            if (followplayer)
                plr->message = DEH_String(AMSTR_FOLLOWON);
            else
                plr->message = DEH_String(AMSTR_FOLLOWOFF);
        } else if (key == key_map_grid) {
            grid = !grid;
            if (grid)
                plr->message = DEH_String(AMSTR_GRIDON);
            else
                plr->message = DEH_String(AMSTR_GRIDOFF);
        } else if (key == key_map_mark) {
            M_snprintf(buffer, sizeof(buffer), "%s %d", DEH_String(AMSTR_MARKEDSPOT), markpointnum);
            plr->message = buffer;
            AM_addMark();
        } else if (key == key_map_clearmark) {
            AM_clearMarks();
            plr->message = DEH_String(AMSTR_MARKSCLEARED);
        } else {
            rc = false;
        }

        if (!deathmatch && cht_CheckCheat(&cheat_amap, ev->data2)) {
            rc = false;
            cheating = (cheating + 1) % 3;
        }
    } else if (ev->type == ev_keyup) {
        rc = false;
        key = ev->data1;

        if (key == key_map_east) {
            if (!followplayer)
                m_paninc.x = 0;
        } else if (key == key_map_west) {
            if (!followplayer)
                m_paninc.x = 0;
        } else if (key == key_map_north) {
            if (!followplayer)
                m_paninc.y = 0;
        } else if (key == key_map_south) {
            if (!followplayer)
                m_paninc.y = 0;
        } else if (key == key_map_zoomout || key == key_map_zoomin) {
            mtof_zoommul = FRACUNIT;
            ftom_zoommul = FRACUNIT;
        }
    }

    return rc;
}

//
// Zooming
//
void AM_changeWindowScale(void) {
    // Change the scaling multipliers
    scale_mtof = FixedMul(scale_mtof, mtof_zoommul);
    scale_ftom = FixedDiv(FRACUNIT, scale_mtof);

    if (scale_mtof < min_scale_mtof)
        AM_minOutWindowScale();
    else if (scale_mtof > max_scale_mtof)
        AM_maxOutWindowScale();
    else
        AM_activateNewScale();
}

//
//
//
void AM_doFollowPlayer(void) {
    if (f_oldloc.x != plr->mo->x || f_oldloc.y != plr->mo->y) {
        m_x = FTOM(MTOF(plr->mo->x)) - m_w / 2;
        m_y = FTOM(MTOF(plr->mo->y)) - m_h / 2;
        m_x2 = m_x + m_w;
        m_y2 = m_y + m_h;
        f_oldloc.x = plr->mo->x;
        f_oldloc.y = plr->mo->y;

        //  m_x = FTOM(MTOF(plr->mo->x - m_w/2));
        //  m_y = FTOM(MTOF(plr->mo->y - m_h/2));
        //  m_x = plr->mo->x - m_w/2;
        //  m_y = plr->mo->y - m_h/2;
    }
}

//
//
//
void AM_updateLightLev(void) {
    static int nexttic = 0;
    // static int litelevels[] = { 0, 3, 5, 6, 6, 7, 7, 7 };
    static int litelevels[] = {0, 4, 7, 10, 12, 14, 15, 15};
    static int litelevelscnt = 0;

    // Change light level
    if (amclock > nexttic) {
        lightlev = litelevels[litelevelscnt++];
        if (litelevelscnt == arrlen(litelevels))
            litelevelscnt = 0;
        nexttic = amclock + 6 - (amclock % 6);
    }
}

//
// Updates on Game Tick
//
void AM_Ticker(void) {
    if (!automapactive)
        return;

    amclock++;

    if (followplayer)
        AM_doFollowPlayer();

    // Change the zoom if necessary
    if (ftom_zoommul != FRACUNIT)
        AM_changeWindowScale();

    // Change x,y location
    if (m_paninc.x || m_paninc.y)
        AM_changeWindowLoc();

    // Update light level
    // AM_updateLightLev();
}

//
// Clear automap frame buffer.
//
void AM_clearFB(int color) {
    memset(fb, color, f_w * f_h);
}

//
// Automap clipping of lines.
//
// Based on Cohen-Sutherland clipping algorithm but with a slightly
// faster reject and precalculated slopes.  If the speed is needed,
// use a hash algorithm to handle  the common cases.
//
boolean AM_clipMline(mline_t* ml, fline_t* fl) {
    enum { LEFT = 1, RIGHT = 2, BOTTOM = 4, TOP = 8 };

    register int outcode1 = 0;
    register int outcode2 = 0;
    register int outside;

    fpoint_t tmp;
    int dx;
    int dy;

#define DOOUTCODE(oc, mx, my)                                                                      \
    (oc) = 0;                                                                                      \
    if ((my) < 0)                                                                                  \
        (oc) |= TOP;                                                                               \
    else if ((my) >= f_h)                                                                          \
        (oc) |= BOTTOM;                                                                            \
    if ((mx) < 0)                                                                                  \
        (oc) |= LEFT;                                                                              \
    else if ((mx) >= f_w)                                                                          \
        (oc) |= RIGHT;

    // do trivial rejects and outcodes
    if (ml->a.y > m_y2)
        outcode1 = TOP;
    else if (ml->a.y < m_y)
        outcode1 = BOTTOM;

    if (ml->b.y > m_y2)
        outcode2 = TOP;
    else if (ml->b.y < m_y)
        outcode2 = BOTTOM;

    if (outcode1 & outcode2)
        return false; // trivially outside

    if (ml->a.x < m_x)
        outcode1 |= LEFT;
    else if (ml->a.x > m_x2)
        outcode1 |= RIGHT;

    if (ml->b.x < m_x)
        outcode2 |= LEFT;
    else if (ml->b.x > m_x2)
        outcode2 |= RIGHT;

    if (outcode1 & outcode2)
        return false; // trivially outside

    // transform to frame-buffer coordinates.
    fl->a.x = CXMTOF(ml->a.x);
    fl->a.y = CYMTOF(ml->a.y);
    fl->b.x = CXMTOF(ml->b.x);
    fl->b.y = CYMTOF(ml->b.y);

    DOOUTCODE(outcode1, fl->a.x, fl->a.y);
    DOOUTCODE(outcode2, fl->b.x, fl->b.y);

    if (outcode1 & outcode2)
        return false;

    while (outcode1 | outcode2) {
        // may be partially inside box
        // find an outside point
        if (outcode1)
            outside = outcode1;
        else
            outside = outcode2;

        // clip to each side
        if (outside & TOP) {
            dy = fl->a.y - fl->b.y;
            dx = fl->b.x - fl->a.x;
            tmp.x = fl->a.x + (dx * (fl->a.y)) / dy;
            tmp.y = 0;
        } else if (outside & BOTTOM) {
            dy = fl->a.y - fl->b.y;
            dx = fl->b.x - fl->a.x;
            tmp.x = fl->a.x + (dx * (fl->a.y - f_h)) / dy;
            tmp.y = f_h - 1;
        } else if (outside & RIGHT) {
            dy = fl->b.y - fl->a.y;
            dx = fl->b.x - fl->a.x;
            tmp.y = fl->a.y + (dy * (f_w - 1 - fl->a.x)) / dx;
            tmp.x = f_w - 1;
        } else if (outside & LEFT) {
            dy = fl->b.y - fl->a.y;
            dx = fl->b.x - fl->a.x;
            tmp.y = fl->a.y + (dy * (-fl->a.x)) / dx;
            tmp.x = 0;
        } else {
            tmp.x = 0;
            tmp.y = 0;
        }

        if (outside == outcode1) {
            fl->a = tmp;
            DOOUTCODE(outcode1, fl->a.x, fl->a.y);
        } else {
            fl->b = tmp;
            DOOUTCODE(outcode2, fl->b.x, fl->b.y);
        }

        if (outcode1 & outcode2)
            return false; // trivially outside
    }

    return true;
}
#undef DOOUTCODE

//
// Classic Bresenham w/ whatever optimizations needed for speed
//
void AM_drawFline(fline_t* fl, int color) {
    register int x;
    register int y;
    register int dx;
    register int dy;
    register int sx;
    register int sy;
    register int ax;
    register int ay;
    register int d;

    static int fuck = 0;

    // For debugging only
    if (fl->a.x < 0 || fl->a.x >= f_w || fl->a.y < 0 || fl->a.y >= f_h || fl->b.x < 0
        || fl->b.x >= f_w || fl->b.y < 0 || fl->b.y >= f_h) {
        DEH_fprintf(stderr, "fuck %d \r", fuck++);
        return;
    }

#define PUTDOT(xx, yy, cc) fb[(yy) *f_w + (xx)] = (cc)

    dx = fl->b.x - fl->a.x;
    ax = 2 * (dx < 0 ? -dx : dx);
    sx = dx < 0 ? -1 : 1;

    dy = fl->b.y - fl->a.y;
    ay = 2 * (dy < 0 ? -dy : dy);
    sy = dy < 0 ? -1 : 1;

    x = fl->a.x;
    y = fl->a.y;

    if (ax > ay) {
        d = ay - ax / 2;
        while (1) {
            PUTDOT(x, y, color);
            if (x == fl->b.x)
                return;
            if (d >= 0) {
                y += sy;
                d -= ax;
            }
            x += sx;
            d += ay;
        }
    } else {
        d = ax - ay / 2;
        while (1) {
            PUTDOT(x, y, color);
            if (y == fl->b.y)
                return;
            if (d >= 0) {
                x += sx;
                d -= ay;
            }
            y += sy;
            d += ax;
        }
    }
}

//
// Clip lines, draw visible part sof lines.
//
void AM_drawMline(mline_t* ml, int color) {
    static fline_t fl;

    if (AM_clipMline(ml, &fl))
        AM_drawFline(&fl, color); // draws it on frame buffer using fb coords
}

//
// Draws flat (floor/ceiling tile) aligned grid lines.
//
void AM_drawGrid(int color) {
    fixed_t x, y;
    fixed_t start, end;
    mline_t ml;

    // Figure out start of vertical gridlines
    start = m_x;
    if ((start - bmaporgx) % (MAPBLOCKUNITS << FRACBITS))
        start += (MAPBLOCKUNITS << FRACBITS) - ((start - bmaporgx) % (MAPBLOCKUNITS << FRACBITS));
    end = m_x + m_w;

    // draw vertical gridlines
    ml.a.y = m_y;
    ml.b.y = m_y + m_h;
    for (x = start; x < end; x += (MAPBLOCKUNITS << FRACBITS)) {
        ml.a.x = x;
        ml.b.x = x;
        AM_drawMline(&ml, color);
    }

    // Figure out start of horizontal gridlines
    start = m_y;
    if ((start - bmaporgy) % (MAPBLOCKUNITS << FRACBITS))
        start += (MAPBLOCKUNITS << FRACBITS) - ((start - bmaporgy) % (MAPBLOCKUNITS << FRACBITS));
    end = m_y + m_h;

    // draw horizontal gridlines
    ml.a.x = m_x;
    ml.b.x = m_x + m_w;
    for (y = start; y < end; y += (MAPBLOCKUNITS << FRACBITS)) {
        ml.a.y = y;
        ml.b.y = y;
        AM_drawMline(&ml, color);
    }
}

//
// Determines visible lines, draws them.
// This is LineDef based, not LineSeg based.
//
void AM_drawWalls(void) {
    int i;
    static mline_t l;

    for (i = 0; i < numlines; i++) {
        l.a.x = lines[i].v1->x;
        l.a.y = lines[i].v1->y;
        l.b.x = lines[i].v2->x;
        l.b.y = lines[i].v2->y;
        if (cheating || (lines[i].flags & ML_MAPPED)) {
            if ((lines[i].flags & LINE_NEVERSEE) && !cheating)
                continue;
            if (!lines[i].backsector) {
                AM_drawMline(&l, WALLCOLORS + lightlev);
            } else {
                if (lines[i].special == 39) { // teleporters
                    AM_drawMline(&l, WALLCOLORS + WALLRANGE / 2);
                } else if (lines[i].flags & ML_SECRET) // secret door
                {
                    if (cheating)
                        AM_drawMline(&l, SECRETWALLCOLORS + lightlev);
                    else
                        AM_drawMline(&l, WALLCOLORS + lightlev);
                } else if (lines[i].backsector->floorheight != lines[i].frontsector->floorheight) {
                    AM_drawMline(&l, FDWALLCOLORS + lightlev); // floor level change
                } else if (lines[i].backsector->ceilingheight != lines[i].frontsector->ceilingheight) {
                    AM_drawMline(&l, CDWALLCOLORS + lightlev); // ceiling level change
                } else if (cheating) {
                    AM_drawMline(&l, TSWALLCOLORS + lightlev);
                }
            }
        } else if (plr->powers[pw_allmap]) {
            if (!(lines[i].flags & LINE_NEVERSEE))
                AM_drawMline(&l, GRAYS + 3);
        }
    }
}

//
// Rotation in 2D.
// Used to rotate player arrow line character.
//
void AM_rotate(fixed_t* x, fixed_t* y, angle_t a) {
    fixed_t tmpx;

    tmpx = FixedMul(*x, finecosine[a >> ANGLETOFINESHIFT]) - FixedMul(*y, finesine[a >> ANGLETOFINESHIFT]);

    *y = FixedMul(*x, finesine[a >> ANGLETOFINESHIFT]) + FixedMul(*y, finecosine[a >> ANGLETOFINESHIFT]);

    *x = tmpx;
}

void AM_drawLineCharacter(mline_t* lineguy, int lineguylines, fixed_t scale, angle_t angle,
    int color, fixed_t x, fixed_t y) {
    int i;
    mline_t l;

    for (i = 0; i < lineguylines; i++) {
        l.a.x = lineguy[i].a.x;
        l.a.y = lineguy[i].a.y;

        if (scale) {
            l.a.x = FixedMul(scale, l.a.x);
            l.a.y = FixedMul(scale, l.a.y);
        }

        if (angle)
            AM_rotate(&l.a.x, &l.a.y, angle);

        l.a.x += x;
        l.a.y += y;

        l.b.x = lineguy[i].b.x;
        l.b.y = lineguy[i].b.y;

        if (scale) {
            l.b.x = FixedMul(scale, l.b.x);
            l.b.y = FixedMul(scale, l.b.y);
        }

        if (angle)
            AM_rotate(&l.b.x, &l.b.y, angle);

        l.b.x += x;
        l.b.y += y;

        AM_drawMline(&l, color);
    }
}

void AM_drawPlayers(void) {
    int i;
    player_t* p;
    static int their_colors[] = {GREENS, GRAYS, BROWNS, REDS};
    int their_color = -1;
    int color;

    if (!netgame) {
        if (cheating)
            AM_drawLineCharacter(cheat_player_arrow, arrlen(cheat_player_arrow), 0, plr->mo->angle,
                WHITE, plr->mo->x, plr->mo->y);
        else
            AM_drawLineCharacter(player_arrow, arrlen(player_arrow), 0, plr->mo->angle, WHITE,
                plr->mo->x, plr->mo->y);
        return;
    }

    for (i = 0; i < MAXPLAYERS; i++) {
        their_color++;
        p = &players[i];

        if ((deathmatch && !singledemo) && p != plr)
            continue;

        if (!playeringame[i])
            continue;

        if (p->powers[pw_invisibility])
            color = 246; // *close* to black
        else
            color = their_colors[their_color];

        AM_drawLineCharacter(
            player_arrow, arrlen(player_arrow), 0, p->mo->angle, color, p->mo->x, p->mo->y);
    }
}

void AM_drawThings(int colors, int colorrange) {
    int i;
    mobj_t* t;

    for (i = 0; i < numsectors; i++) {
        t = sectors[i].thinglist;
        while (t) {
            AM_drawLineCharacter(thintriangle_guy, arrlen(thintriangle_guy), 16 << FRACBITS,
                t->angle, colors + lightlev, t->x, t->y);
            t = t->snext;
        }
    }
}

void AM_drawMarks(void) {
    int i, fx, fy, w, h;

    for (i = 0; i < AM_NUMMARKPOINTS; i++) {
        if (markpoints[i].x != -1) {
            //      w = SHORT(marknums[i]->width);
            //      h = SHORT(marknums[i]->height);
            w = 5; // because something's wrong with the wad, i guess
            h = 6; // because something's wrong with the wad, i guess
            fx = CXMTOF(markpoints[i].x);
            fy = CYMTOF(markpoints[i].y);
            if (fx >= f_x && fx <= f_w - w && fy >= f_y && fy <= f_h - h)
                V_DrawPatch(fx, fy, marknums[i]);
        }
    }
}

void AM_drawCrosshair(int color) {
    fb[(f_w * (f_h + 1)) / 2] = color; // single point for now
}

void AM_Drawer(void) {
    if (!automapactive)
        return;

    AM_clearFB(BACKGROUND);
    if (grid)
        AM_drawGrid(GRIDCOLORS);
    AM_drawWalls();
    AM_drawPlayers();
    if (cheating == 2)
        AM_drawThings(THINGCOLORS, THINGRANGE);
    AM_drawCrosshair(XHAIRCOLORS);

    AM_drawMarks();

    V_MarkRect(f_x, f_y, f_w, f_h);
}
