// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id: R_main.c,v 1.1 2000/04/09 18:15:43 proff_fs Exp $
//
//  PRBOOM/GLBOOM (C) Florian 'Proff' Schulze (florian.proff.schulze@gmx.net)
//  based on
//  BOOM, a modified and improved DOOM engine
//  Copyright (C) 1999 by
//  id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
//
//  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.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 
//  02111-1307, USA.
//
// DESCRIPTION:
//      Rendering main loop and setup functions,
//       utility functions (BSP, geometry, trigonometry).
//      See tables.c, too.
//
//-----------------------------------------------------------------------------

static const char rcsid[] = "$Id: R_main.c,v 1.1 2000/04/09 18:15:43 proff_fs Exp $";

#include "doomstat.h"
#include "r_main.h"
#include "r_things.h"
#include "r_plane.h"
#include "r_bsp.h"
#include "r_draw.h"
#include "m_bbox.h"
#include "r_sky.h"
#include "v_video.h"
#include "st_stuff.h"
#include "lprintf.h"  // jff 08/03/98 - declaration of lprintf

// Fineangles in the SCREENWIDTH wide window.
#define FIELDOFVIEW 2048    

// killough: viewangleoffset is a legacy from the pre-v1.2 days, when Doom
// had Left/Mid/Right viewing. +/-ANG90 offsets were placed here on each
// node, by d_net.c, to set up a L/M/R session.

int viewangleoffset;
int validcount = 1;         // increment every time a check is made
lighttable_t *fixedcolormap;
int      centerx, centery;
fixed_t  centerxfrac, centeryfrac;
fixed_t  projection;
// proff 11/06/98: Added for high-res
fixed_t  projectiony;
fixed_t  viewx, viewy, viewz;
angle_t  viewangle;
fixed_t  viewcos, viewsin;
player_t *viewplayer;
extern lighttable_t **walllights;

//
// precalculated math tables
//

angle_t clipangle;

// The viewangletox[viewangle + FINEANGLES/4] lookup
// maps the visible view angles to screen X coordinates,
// flattening the arc to a flat projection plane.
// There will be many angles mapped to the same X. 

int viewangletox[FINEANGLES/2];

// The xtoviewangleangle[] table maps a screen pixel
// to the lowest viewangle that maps back to x ranges
// from clipangle to -clipangle.

angle_t xtoviewangle[MAX_SCREENWIDTH+1];   // killough 2/8/98

// killough 3/20/98: Support dynamic colormaps, e.g. deep water
// killough 4/4/98: support dynamic number of them as well

int numcolormaps;
lighttable_t *(*c_scalelight)[LIGHTLEVELS][MAXLIGHTSCALE];
lighttable_t *(*c_zlight)[LIGHTLEVELS][MAXLIGHTZ];
lighttable_t *(*scalelight)[MAXLIGHTSCALE];
lighttable_t *(*zlight)[MAXLIGHTZ];
lighttable_t *fullcolormap;
lighttable_t **colormaps;

// killough 3/20/98, 4/4/98: end dynamic colormaps

int extralight;                           // bumped light from gun blasts

void (*colfunc)(void) = R_DrawColumn;     // current column draw function

//
// R_PointOnSide
// Traverse BSP (sub) tree,
//  check point against partition plane.
// Returns side 0 (front) or 1 (back).
//
// killough 5/2/98: reformatted
//

int R_PointOnSide(fixed_t x, fixed_t y, node_t *node)
{
  if (!node->dx)
    return x <= node->x ? node->dy > 0 : node->dy < 0;

  if (!node->dy)
    return y <= node->y ? node->dx < 0 : node->dx > 0;
        
  x -= node->x;
  y -= node->y;
  
  // Try to quickly decide by looking at sign bits.
  if ((node->dy ^ node->dx ^ x ^ y) < 0)
    return (node->dy ^ x) < 0;  // (left is negative)
  return FixedMul(y, node->dx>>FRACBITS) >= FixedMul(node->dy>>FRACBITS, x);
}

// killough 5/2/98: reformatted

int R_PointOnSegSide(fixed_t x, fixed_t y, seg_t *line)
{
  fixed_t lx = line->v1->x;
  fixed_t ly = line->v1->y;
  fixed_t ldx = line->v2->x - lx;
  fixed_t ldy = line->v2->y - ly;

  if (!ldx)
    return x <= lx ? ldy > 0 : ldy < 0;

  if (!ldy)
    return y <= ly ? ldx < 0 : ldx > 0;
  
  x -= lx;
  y -= ly;
        
  // Try to quickly decide by looking at sign bits.
  if ((ldy ^ ldx ^ x ^ y) < 0)
    return (ldy ^ x) < 0;          // (left is negative)
  return FixedMul(y, ldx>>FRACBITS) >= FixedMul(ldy>>FRACBITS, x);
}

//
// R_PointToAngle
// To get a global angle from cartesian coordinates,
//  the coordinates are flipped until they are in
//  the first octant of the coordinate system, then
//  the y (<=x) is scaled and divided by x to get a
//  tangent (slope) value which is looked up in the
//  tantoangle[] table. The +1 size of tantoangle[]
//  is to handle the case when x==y without additional
//  checking.
//
// killough 5/2/98: reformatted, cleaned up

angle_t R_PointToAngle(fixed_t x, fixed_t y)
{       
  return (y -= viewy, (x -= viewx) || y) ?
    x >= 0 ?
      y >= 0 ? 
        (x > y) ? tantoangle[SlopeDiv(y,x)] :                      // octant 0 
                ANG90-1-tantoangle[SlopeDiv(x,y)] :                // octant 1
        x > (y = -y) ? -tantoangle[SlopeDiv(y,x)] :                // octant 8
                       ANG270+tantoangle[SlopeDiv(x,y)] :          // octant 7
      y >= 0 ? (x = -x) > y ? ANG180-1-tantoangle[SlopeDiv(y,x)] : // octant 3
                            ANG90 + tantoangle[SlopeDiv(x,y)] :    // octant 2
        (x = -x) > (y = -y) ? ANG180+tantoangle[ SlopeDiv(y,x)] :  // octant 4
                              ANG270-1-tantoangle[SlopeDiv(x,y)] : // octant 5
    0;
}

angle_t R_PointToAngle2(fixed_t viewx, fixed_t viewy, fixed_t x, fixed_t y)
{       
  return (y -= viewy, (x -= viewx) || y) ?
    x >= 0 ?
      y >= 0 ? 
        (x > y) ? tantoangle[SlopeDiv(y,x)] :                      // octant 0 
                ANG90-1-tantoangle[SlopeDiv(x,y)] :                // octant 1
        x > (y = -y) ? -tantoangle[SlopeDiv(y,x)] :                // octant 8
                       ANG270+tantoangle[SlopeDiv(x,y)] :          // octant 7
      y >= 0 ? (x = -x) > y ? ANG180-1-tantoangle[SlopeDiv(y,x)] : // octant 3
                            ANG90 + tantoangle[SlopeDiv(x,y)] :    // octant 2
        (x = -x) > (y = -y) ? ANG180+tantoangle[ SlopeDiv(y,x)] :  // octant 4
                              ANG270-1-tantoangle[SlopeDiv(x,y)] : // octant 5
    0;
}

//
// R_ScaleFromGlobalAngle
// Returns the texture mapping scale
//  for the current line (horizontal span)
//  at the given angle.
// rw_distance must be calculated first.
//
// killough 5/2/98: reformatted, cleaned up

fixed_t R_ScaleFromGlobalAngle(angle_t visangle)
{
  int     anglea = ANG90 + (visangle-viewangle);
  int     angleb = ANG90 + (visangle-rw_normalangle);
  int     den = FixedMul(rw_distance, finesine[anglea>>ANGLETOFINESHIFT]);
// proff 11/06/98: Changed for high-res
  fixed_t num = FixedMul(projectiony, finesine[angleb>>ANGLETOFINESHIFT]);
//  fixed_t num = FixedMul(projection, finesine[angleb>>ANGLETOFINESHIFT]);
  return den > num>>16 ? (num = FixedDiv(num, den)) > 64*FRACUNIT ?
    64*FRACUNIT : num < 256 ? 256 : num : 64*FRACUNIT;
}

//
// R_InitTextureMapping
//
// killough 5/2/98: reformatted

static void R_InitTextureMapping (void)
{
  register int i,x;
  fixed_t focallength;
    
  // Use tangent table to generate viewangletox:
  //  viewangletox will give the next greatest x
  //  after the view angle.
  //
  // Calc focallength
  //  so FIELDOFVIEW angles covers SCREENWIDTH.

  focallength = FixedDiv(centerxfrac, finetangent[FINEANGLES/4+FIELDOFVIEW/2]);
        
  for (i=0 ; i<FINEANGLES/2 ; i++)
    {
      int t;
      if (finetangent[i] > FRACUNIT*2)
        t = -1;
      else
        if (finetangent[i] < -FRACUNIT*2)
          t = viewwidth+1;
      else
        {
          t = FixedMul(finetangent[i], focallength);
          t = (centerxfrac - t + FRACUNIT-1) >> FRACBITS;
          if (t < -1)
            t = -1;
          else
            if (t > viewwidth+1)
              t = viewwidth+1;
        }
      viewangletox[i] = t;
    }
    
  // Scan viewangletox[] to generate xtoviewangle[]:
  //  xtoviewangle will give the smallest view angle
  //  that maps to x.

  for (x=0; x<=viewwidth; x++)
    {
      for (i=0; viewangletox[i] > x; i++)
        ;
      xtoviewangle[x] = (i<<ANGLETOFINESHIFT)-ANG90;
    }
    
  // Take out the fencepost cases from viewangletox.
  for (i=0; i<FINEANGLES/2; i++)
    if (viewangletox[i] == -1)
      viewangletox[i] = 0;
    else 
      if (viewangletox[i] == viewwidth+1)
        viewangletox[i] = viewwidth;
        
  clipangle = xtoviewangle[0];
}

//
// R_InitLightTables
// Only inits the zlight table,
//  because the scalelight table changes with view size.
//

#define DISTMAP 2

void R_InitLightTables (void)
{
  int i;
    
  // killough 4/4/98: dynamic colormaps
  c_zlight = malloc(sizeof(*c_zlight) * numcolormaps);
  c_scalelight = malloc(sizeof(*c_scalelight) * numcolormaps);

  // Calculate the light levels to use
  //  for each level / distance combination.
  for (i=0; i< LIGHTLEVELS; i++)
    {
      int j, startmap = ((LIGHTLEVELS-1-i)*2)*NUMCOLORMAPS/LIGHTLEVELS;
      for (j=0; j<MAXLIGHTZ; j++)
        {
          int scale = FixedDiv ((SCREENWIDTH/2*FRACUNIT), (j+1)<<LIGHTZSHIFT);
          int t, level = startmap - (scale >>= LIGHTSCALESHIFT)/DISTMAP;

          if (level < 0)
            level = 0;
          else
            if (level >= NUMCOLORMAPS)
              level = NUMCOLORMAPS-1;

          // killough 3/20/98: Initialize multiple colormaps
          level *= 256;
          for (t=0; t<numcolormaps; t++)         // killough 4/4/98
            c_zlight[t][i][j] = colormaps[t] + level;
        }
    }
}

//
// R_SetViewSize
// Do not really change anything here,
//  because it might be in the middle of a refresh.
// The change will take effect next refresh.
//

H_boolean setsizeneeded;
int     setblocks;

void R_SetViewSize(int blocks)
{
  setsizeneeded = true;
  setblocks = blocks;
}

//
// R_ExecuteSetViewSize
//

void R_ExecuteSetViewSize (void)
{
  int i;

  setsizeneeded = false;

  if (setblocks == 11)
    {
      scaledviewwidth = SCREENWIDTH;
      viewheight = SCREENHEIGHT;
    }
// proff 09/24/98: Added for high-res
  else if (setblocks == 10)
    {
      scaledviewwidth = SCREENWIDTH;
      viewheight = SCREENHEIGHT-ST_SCALED_HEIGHT;
    }
  else
    {
// proff 08/17/98: Changed for high-res
      scaledviewwidth = setblocks*SCREENWIDTH/10;
      viewheight = (setblocks*(SCREENHEIGHT-ST_SCALED_HEIGHT)/10) & ~7;
//      scaledviewwidth = setblocks*32;
//      viewheight = (setblocks*168/10) & ~7;
    }
    
  viewwidth = scaledviewwidth;
        
  centery = viewheight/2;
  centerx = viewwidth/2;
  centerxfrac = centerx<<FRACBITS;
  centeryfrac = centery<<FRACBITS;
  projection = centerxfrac;
// proff 11/06/98: Added for high-res
	projectiony = ((SCREENHEIGHT * centerx * 320) / 200) / SCREENWIDTH * FRACUNIT;

  R_InitBuffer (scaledviewwidth, viewheight);
        
  R_InitTextureMapping();
    
  // psprite scales
// proff 08/17/98: Changed for high-res
/*
  pspritescale = FRACUNIT*viewwidth/320;
  pspriteiscale = FRACUNIT*320/viewwidth;
*/
  pspritescale = FixedDiv(viewwidth,320);
  pspriteiscale = FixedDiv(320,viewwidth);
//  pspritescale = FRACUNIT*viewwidth/SCREENWIDTH;
//  pspriteiscale = FRACUNIT*SCREENWIDTH/viewwidth;
// proff 11/06/98: Added for high-res
	pspriteyscale = (((SCREENHEIGHT*viewwidth)/SCREENWIDTH) << FRACBITS) / 200;
    
  // thing clipping
  for (i=0 ; i<viewwidth ; i++)
    screenheightarray[i] = viewheight;
    
  // planes
  for (i=0 ; i<viewheight ; i++)
    {   // killough 5/2/98: reformatted
      // proff: Changed abs to D_abs (see m_fixed.h)
      fixed_t dy = D_abs(((i-viewheight/2)<<FRACBITS)+FRACUNIT/2);
      yslope[i] = FixedDiv(projectiony, dy);
//      yslope[i] = FixedDiv(viewwidth*(FRACUNIT/2), dy);
    }
        
  for (i=0 ; i<viewwidth ; i++)
    {
      // proff: Changed abs to D_abs (see m_fixed.h)
      fixed_t cosadj = D_abs(finecosine[xtoviewangle[i]>>ANGLETOFINESHIFT]);
      distscale[i] = FixedDiv(FRACUNIT,cosadj);
    }
    
  // Calculate the light levels to use
  //  for each level / scale combination.
  for (i=0; i<LIGHTLEVELS; i++)
    {
      int j, startmap = ((LIGHTLEVELS-1-i)*2)*NUMCOLORMAPS/LIGHTLEVELS;
      for (j=0 ; j<MAXLIGHTSCALE ; j++)
        {
          int t, level = startmap - j*SCREENWIDTH/viewwidth/DISTMAP;
            
          if (level < 0)
            level = 0;

          if (level >= NUMCOLORMAPS)
            level = NUMCOLORMAPS-1;

          // killough 3/20/98: initialize multiple colormaps
          level *= 256;

          for (t=0; t<numcolormaps; t++)     // killough 4/4/98
            c_scalelight[t][i][j] = colormaps[t] + level;
        }
    }
}

//
// R_Init
//

extern int screenblocks;

void R_Init (void)
{
  R_InitData();
  //jff 8/3/98 use logical output routine
  lprintf(LO_INFO,"\nR_InitData\n");
  R_SetViewSize(screenblocks);
  R_InitPlanes();
  lprintf(LO_INFO,"R_InitPlanes\n");
  R_InitLightTables();
  lprintf(LO_INFO,"R_InitLightTables\n");
  R_InitSkyMap();
  lprintf(LO_INFO,"R_InitSkyMap\n");
  R_InitTranslationTables();
  lprintf(LO_INFO,"R_InitTranslationsTables\n");
}

//
// R_PointInSubsector
//
// killough 5/2/98: reformatted, cleaned up

subsector_t *R_PointInSubsector(fixed_t x, fixed_t y)
{
  int nodenum = numnodes-1;
  while (!(nodenum & NF_SUBSECTOR))
    nodenum = nodes[nodenum].children[R_PointOnSide(x, y, nodes+nodenum)];
  return &subsectors[nodenum & ~NF_SUBSECTOR];
}

//
// R_SetupFrame
//

void R_SetupFrame (player_t *player)
{               
  int i, cm;
    
  viewplayer = player;
  viewx = player->mo->x;
  viewy = player->mo->y;
  viewangle = player->mo->angle + viewangleoffset;
  extralight = player->extralight;

  viewz = player->viewz;
    
  viewsin = finesine[viewangle>>ANGLETOFINESHIFT];
  viewcos = finecosine[viewangle>>ANGLETOFINESHIFT];

  // killough 3/20/98, 4/4/98: select colormap based on player status

  if (player->mo->subsector->sector->heightsec != -1)
    {
      const sector_t *s = player->mo->subsector->sector->heightsec + sectors;
      cm = viewz < s->floorheight ? s->bottommap : viewz > s->ceilingheight ?
        s->topmap : s->midmap;
      if (cm < 0 || cm > numcolormaps)
        cm = 0;
    }
  else
    cm = 0;

  fullcolormap = colormaps[cm];
  zlight = c_zlight[cm];
  scalelight = c_scalelight[cm];

  if (player->fixedcolormap)
    {
      // killough 3/20/98: localize scalelightfixed (readability/optimization)
      static lighttable_t *scalelightfixed[MAXLIGHTSCALE];

      fixedcolormap = fullcolormap   // killough 3/20/98: use fullcolormap
        + player->fixedcolormap*256*sizeof(lighttable_t);
        
      walllights = scalelightfixed;

      for (i=0 ; i<MAXLIGHTSCALE ; i++)
        scalelightfixed[i] = fixedcolormap;
    }
  else
    fixedcolormap = 0;

  validcount++;
}

int autodetect_hom = 0;       // killough 2/7/98: HOM autodetection flag

//
// R_RenderView
//
void R_RenderPlayerView (player_t* player)
{       
  R_SetupFrame (player);

  // Clear buffers.
  R_ClearClipSegs ();
  R_ClearDrawSegs ();
  R_ClearPlanes ();
  R_ClearSprites ();
#ifdef GL_DOOM
  // proff 11/99: clear buffers
  gld_InitDrawScene();
#endif
    
  if (autodetect_hom)
    { // killough 2/10/98: add flashing red HOM indicators
      extern int lastshottic;
      int color = !flashing_hom || (gametic % 20) < 9 ? 0xb0 : 0;
      V_FillBlock(viewwindowy,viewwindowx,0,viewwidth,viewheight,color);
      R_DrawViewBorder();
    }
#ifdef GL_DOOM
  // proff 11/99: switch to perspective mode
  gld_StartDrawScene();
#endif

  // check for new console commands.
  NetUpdate ();

  // The head node is the last node output.
  R_RenderBSPNode (numnodes-1);
    
  // Check for new console commands.
  NetUpdate ();
    
  // proff 11/99: don't use software stuff in OpenGL
#ifndef GL_DOOM
  R_DrawPlanes ();
#endif
    
  // Check for new console commands.
  NetUpdate ();
    
  // proff 11/99: don't use software stuff in OpenGL
#ifndef GL_DOOM
  R_DrawMasked ();
#endif

  // Check for new console commands.
  NetUpdate ();
#ifdef GL_DOOM
  // proff 11/99: draw the scene
	gld_DrawScene(player);
  // proff 11/99: finishing off
  gld_EndDrawScene();
#endif
}

//----------------------------------------------------------------------------
//
// $Log: R_main.c,v $
// Revision 1.1  2000/04/09 18:15:43  proff_fs
// Initial revision
//
// Revision 1.14  1998/09/07  20:11:36  jim
// Logical output routine added
//
// Revision 1.13  1998/05/07  00:47:52  killough
// beautification
//
// Revision 1.12  1998/05/03  23:00:14  killough
// beautification, fix #includes and declarations
//
// Revision 1.11  1998/04/07  15:24:15  killough
// Remove obsolete HOM detector
//
// Revision 1.10  1998/04/06  04:47:46  killough
// Support dynamic colormaps
//
// Revision 1.9  1998/03/23  03:37:14  killough
// Add support for arbitrary number of colormaps
//
// Revision 1.8  1998/03/16  12:44:12  killough
// Optimize away some function pointers
//
// Revision 1.7  1998/03/09  07:27:19  killough
// Avoid using FP for point/line queries
//
// Revision 1.6  1998/02/17  06:22:45  killough
// Comment out audible HOM alarm for now
//
// Revision 1.5  1998/02/10  06:48:17  killough
// Add flashing red HOM indicator for TNTHOM cheat
//
// Revision 1.4  1998/02/09  03:22:17  killough
// Make TNTHOM control HOM detector, change array decl to MAX_*
//
// Revision 1.3  1998/02/02  13:29:41  killough
// comment out dead code, add HOM detector
//
// Revision 1.2  1998/01/26  19:24:42  phares
// First rev with no ^Ms
//
// Revision 1.1.1.1  1998/01/19  14:03:02  rand
// Lee's Jan 19 sources
//
//
//----------------------------------------------------------------------------