DOOM-IOS2/common/prboom/r_data.c

/* Emacs style mode select   -*- C++ -*-
 *-----------------------------------------------------------------------------
 *
 *
 *  PrBoom: a Doom port merged with LxDoom and LSDLDoom
 *  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
 *  Copyright (C) 1999-2002 by
 *  Jess Haas, Nicolas Kalkhof, Colin Phipps, Florian Schulze
 *  Copyright 2005, 2006 by
 *  Florian Schulze, Colin Phipps, Neil Stevens, Andrey Budko
 *
 *  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:
 *      Preparation of data for rendering,
 *      generation of lookups, caching, retrieval by name.
 *
 *-----------------------------------------------------------------------------*/

#include "doomstat.h"
#include "w_wad.h"
#include "r_draw.h"
#include "r_main.h"
#include "r_sky.h"
#include "i_system.h"
#include "r_bsp.h"
#include "r_things.h"
#include "p_tick.h"
#include "lprintf.h"  // jff 08/03/98 - declaration of lprintf
#include "p_tick.h"

//
// Graphics.
// DOOM graphics for walls and sprites
// is stored in vertical runs of opaque pixels (posts).
// A column is composed of zero or more posts,
// a patch or sprite is composed of zero or more columns.
//

//
// Texture definition.
// Each texture is composed of one or more patches,
// with patches being lumps stored in the WAD.
// The lumps are referenced by number, and patched
// into the rectangular texture space using origin
// and possibly other attributes.
//

typedef struct
{
  short originx;
  short originy;
  short patch;
  short stepdir;         // unused in Doom but might be used in Phase 2 Boom
  short colormap;        // unused in Doom but might be used in Phase 2 Boom
} PACKEDATTR mappatch_t;


typedef struct
{
  char       name[8];
  char       pad2[4];      // unused
  short      width;
  short      height;
  char       pad[4];       // unused in Doom but might be used in Boom Phase 2
  short      patchcount;
  mappatch_t patches[1];
} PACKEDATTR maptexture_t;

// A maptexturedef_t describes a rectangular texture, which is composed
// of one or more mappatch_t structures that arrange graphic patches.

// killough 4/17/98: make firstcolormaplump,lastcolormaplump external
int firstcolormaplump, lastcolormaplump;      // killough 4/17/98

int       firstflat, lastflat, numflats;
int       firstspritelump, lastspritelump, numspritelumps;
int       numtextures;
texture_t **textures; // proff - 04/05/2000 removed static for OpenGL
fixed_t   *textureheight; //needed for texture pegging (and TFE fix - killough)
int       *flattranslation;             // for global animation
int       *texturetranslation;

//
// R_GetTextureColumn
//

const byte *R_GetTextureColumn(const rpatch_t *texpatch, int col) {
  while (col < 0)
    col += texpatch->width;
  col &= texpatch->widthmask;
  
  return texpatch->columns[col].pixels;
}

//
// R_InitTextures
// Initializes the texture list
//  with the textures from the world map.
//

static void R_InitTextures (void)
{
  const maptexture_t *mtexture;
  texture_t    *texture;
  const mappatch_t   *mpatch;
  texpatch_t   *patch;
  int  i, j;
  int         maptex_lump[2] = {-1, -1};
  const int  *maptex;
  const int  *maptex1, *maptex2;
  char name[9];
  int names_lump; // cph - new wad lump handling
  const char *names; // cph -
  const char *name_p;// const*'s
  int  *patchlookup;
  int  totalwidth;
  int  nummappatches;
  int  offset;
  int  maxoff, maxoff2;
  int  numtextures1, numtextures2;
  const int *directory;
  int  errors = 0;

  // Load the patch names from pnames.lmp.
  name[8] = 0;
  names = W_CacheLumpNum(names_lump = W_GetNumForName("PNAMES"));
  nummappatches = LONG(*((const int *)names));
  name_p = names+4;
  patchlookup = malloc(nummappatches*sizeof(*patchlookup));  // killough

  for (i=0 ; i<nummappatches ; i++)
    {
      strncpy (name,name_p+i*8, 8);
      patchlookup[i] = W_CheckNumForName(name);
      if (patchlookup[i] == -1)
        {
          // killough 4/17/98:
          // Some wads use sprites as wall patches, so repeat check and
          // look for sprites this time, but only if there were no wall
          // patches found. This is the same as allowing for both, except
          // that wall patches always win over sprites, even when they
          // appear first in a wad. This is a kludgy solution to the wad
          // lump namespace problem.

          patchlookup[i] = (W_CheckNumForName)(name, ns_sprites);

          if (patchlookup[i] == -1 && devparm)
            //jff 8/3/98 use logical output routine
            lprintf(LO_WARN,"\nWarning: patch %.8s, index %d does not exist",name,i);
        }
    }
  W_UnlockLumpNum(names_lump); // cph - release the lump

  // Load the map texture definitions from textures.lmp.
  // The data is contained in one or two lumps,
  //  TEXTURE1 for shareware, plus TEXTURE2 for commercial.

  maptex = maptex1 = W_CacheLumpNum(maptex_lump[0] = W_GetNumForName("TEXTURE1"));
  numtextures1 = LONG(*maptex);
  maxoff = W_LumpLength(maptex_lump[0]);
  directory = maptex+1;

  if (W_CheckNumForName("TEXTURE2") != -1)
    {
      maptex2 = W_CacheLumpNum(maptex_lump[1] = W_GetNumForName("TEXTURE2"));
      numtextures2 = LONG(*maptex2);
      maxoff2 = W_LumpLength(maptex_lump[1]);
    }
  else
    {
      maptex2 = NULL;
      numtextures2 = 0;
      maxoff2 = 0;
    }
  numtextures = numtextures1 + numtextures2;

  // killough 4/9/98: make column offsets 32-bit;
  // clean up malloc-ing to use sizeof

  textures = Z_Malloc(numtextures*sizeof*textures, PU_STATIC, 0);
  textureheight = Z_Malloc(numtextures*sizeof*textureheight, PU_STATIC, 0);

  totalwidth = 0;

  for (i=0 ; i<numtextures ; i++, directory++)
    {
      if (i == numtextures1)
        {
          // Start looking in second texture file.
          maptex = maptex2;
          maxoff = maxoff2;
          directory = maptex+1;
        }

      offset = LONG(*directory);

      if (offset > maxoff)
        I_Error("R_InitTextures: Bad texture directory");

      mtexture = (const maptexture_t *) ( (const byte *)maptex + offset);

      texture = textures[i] =
        Z_Malloc(sizeof(texture_t) +
                 sizeof(texpatch_t)*(SHORT(mtexture->patchcount)-1),
                 PU_STATIC, 0);

      texture->width = SHORT(mtexture->width);
      texture->height = SHORT(mtexture->height);
      texture->patchcount = SHORT(mtexture->patchcount);

        /* Mattias Engdegård emailed me of the following explenation of
         * why memcpy doesnt work on some systems:
         * "I suppose it is the mad unaligned allocation
         * going on (and which gcc in some way manages to cope with
         * through the __attribute__ ((packed))), and which it forgets
         * when optimizing memcpy (to a single word move) since it appears
         * to be aligned. Technically a gcc bug, but I can't blame it when
         * it's stressed with that amount of
         * non-standard nonsense."
   * So in short the unaligned struct confuses gcc's optimizer so
   * i took the memcpy out alltogether to avoid future problems-Jess
         */
      /* The above was #ifndef SPARC, but i got a mail from
       * Putera Joseph F NPRI <PuteraJF@Npt.NUWC.Navy.Mil> containing:
       *   I had to use the memcpy function on a sparc machine.  The
       *   other one would give me a core dump.
       * cph - I find it hard to believe that sparc memcpy is broken,
       * but I don't believe the pointers to memcpy have to be aligned
       * either. Use fast memcpy on other machines anyway.
       */
/*
  proff - I took this out, because Oli Kraus (olikraus@yahoo.com) told
  me the memcpy produced a buserror. Since this function isn't time-
  critical I'm using the for loop now.
*/
/*
#ifndef GCC
      memcpy(texture->name, mtexture->name, sizeof(texture->name));
#else
*/
      {
        for(j=0;j<sizeof(texture->name);j++)
          texture->name[j]=mtexture->name[j];
      }
/* #endif */

      mpatch = mtexture->patches;
      patch = texture->patches;

      for (j=0 ; j<texture->patchcount ; j++, mpatch++, patch++)
        {
          patch->originx = SHORT(mpatch->originx);
          patch->originy = SHORT(mpatch->originy);
          patch->patch = patchlookup[SHORT(mpatch->patch)];
          if (patch->patch == -1)
            {
              //jff 8/3/98 use logical output routine
              lprintf(LO_ERROR,"\nR_InitTextures: Missing patch %d in texture %.8s",
                     SHORT(mpatch->patch), texture->name); // killough 4/17/98
              ++errors;
            }
        }

      for (j=1; j*2 <= texture->width; j<<=1)
        ;
      texture->widthmask = j-1;
      textureheight[i] = texture->height<<FRACBITS;

      totalwidth += texture->width;
    }

  free(patchlookup);         // killough

  for (i=0; i<2; i++) // cph - release the TEXTUREx lumps
    if (maptex_lump[i] != -1)
      W_UnlockLumpNum(maptex_lump[i]);

  if (errors)
    I_Error("R_InitTextures: %d errors", errors);

  // Precalculate whatever possible.
  if (devparm) // cph - If in development mode, generate now so all errors are found at once
    for (i=0 ; i<numtextures ; i++)
    {
      // proff - This is for the new renderer now
      R_CacheTextureCompositePatchNum(i);
      R_UnlockTextureCompositePatchNum(i);
    }

  if (errors)
    I_Error("R_InitTextures: %d errors", errors);

  // Create translation table for global animation.
  // killough 4/9/98: make column offsets 32-bit;
  // clean up malloc-ing to use sizeof

  texturetranslation =
    Z_Malloc((numtextures+1)*sizeof*texturetranslation, PU_STATIC, 0);

  for (i=0 ; i<numtextures ; i++)
    texturetranslation[i] = i;

  // killough 1/31/98: Initialize texture hash table
  for (i = 0; i<numtextures; i++)
    textures[i]->index = -1;
  while (--i >= 0)
    {
      int texturej = W_LumpNameHash(textures[i]->name) % (unsigned) numtextures;
      textures[i]->next = textures[texturej]->index;   // Prepend to chain
      textures[texturej]->index = i;
    }
}

//
// R_InitFlats
//
static void R_InitFlats(void)
{
  int i;

  firstflat = W_GetNumForName("F_START") + 1;
  lastflat  = W_GetNumForName("F_END") - 1;
  numflats  = lastflat - firstflat + 1;

  // Create translation table for global animation.
  // killough 4/9/98: make column offsets 32-bit;
  // clean up malloc-ing to use sizeof

  flattranslation =
    Z_Malloc((numflats+1)*sizeof(*flattranslation), PU_STATIC, 0);

  for (i=0 ; i<numflats ; i++)
    flattranslation[i] = i;
}

//
// R_InitSpriteLumps
// Finds the width and hoffset of all sprites in the wad,
// so the sprite does not need to be cached completely
// just for having the header info ready during rendering.
//
static void R_InitSpriteLumps(void)
{
  firstspritelump = W_GetNumForName("S_START") + 1;
  lastspritelump = W_GetNumForName("S_END") - 1;
  numspritelumps = lastspritelump - firstspritelump + 1;
}

//
// R_InitColormaps
//
// killough 3/20/98: rewritten to allow dynamic colormaps
// and to remove unnecessary 256-byte alignment
//
// killough 4/4/98: Add support for C_START/C_END markers
//

static void R_InitColormaps(void)
{
  int i;
  firstcolormaplump = W_GetNumForName("C_START");
  lastcolormaplump  = W_GetNumForName("C_END");
  numcolormaps = lastcolormaplump - firstcolormaplump;
  colormaps = Z_Malloc(sizeof(*colormaps) * numcolormaps, PU_STATIC, 0);
  colormaps[0] = (const lighttable_t *)W_CacheLumpName("COLORMAP");
  for (i=1; i<numcolormaps; i++)
    colormaps[i] = (const lighttable_t *)W_CacheLumpNum(i+firstcolormaplump);
  // cph - always lock
}

// killough 4/4/98: get colormap number from name
// killough 4/11/98: changed to return -1 for illegal names
// killough 4/17/98: changed to use ns_colormaps tag

int R_ColormapNumForName(const char *name)
{
  register int i = 0;
  if (strncasecmp(name,"COLORMAP",8))     // COLORMAP predefined to return 0
    if ((i = (W_CheckNumForName)(name, ns_colormaps)) != -1)
      i -= firstcolormaplump;
  return i;
}

/*
 * R_ColourMap
 *
 * cph 2001/11/17 - unify colour maping logic in a single place; 
 *  obsoletes old c_scalelight stuff
 */

static inline int between(int l,int u,int x)
{ return (l > x ? l : x > u ? u : x); }

const lighttable_t* R_ColourMap(int lightlevel, fixed_t spriteyscale)
{
  if (fixedcolormap) return fixedcolormap;
  else {
    if (curline)
      if (curline->v1->y == curline->v2->y)
        lightlevel -= 1 << LIGHTSEGSHIFT;
      else
        if (curline->v1->x == curline->v2->x)
          lightlevel += 1 << LIGHTSEGSHIFT;

    lightlevel += extralight << LIGHTSEGSHIFT;

    /* cph 2001/11/17 -
     * Work out what colour map to use, remembering to clamp it to the number of
     * colour maps we actually have. This formula is basically the one from the
     * original source, just brought into one place. The main difference is it
     * throws away less precision in the lightlevel half, so it supports 32
     * light levels in WADs compared to Doom's 16.
     *
     * Note we can make it more accurate if we want - we should keep all the
     * precision until the final step, so slight scale differences can count
     * against slight light level variations.
     */
    return fullcolormap + between(0,NUMCOLORMAPS-1,
          ((256-lightlevel)*2*NUMCOLORMAPS/256) - 4
          - (FixedMul(spriteyscale,pspriteiscale)/2 >> LIGHTSCALESHIFT)
          )*256;
  }
}

//
// R_InitTranMap
//
// Initialize translucency filter map
//
// By Lee Killough 2/21/98
//

int tran_filter_pct = 66;       // filter percent

#define TSC 12        /* number of fixed point digits in filter percent */

void R_InitTranMap(int progress)
{
  int lump = W_CheckNumForName("TRANMAP");

  // If a tranlucency filter map lump is present, use it

  if (lump != -1)  // Set a pointer to the translucency filter maps.
    main_tranmap = W_CacheLumpNum(lump);   // killough 4/11/98
  else if (W_CheckNumForName("PLAYPAL")!=-1) // can be called before WAD loaded
    {   // Compose a default transparent filter map based on PLAYPAL.
      const byte *playpal = W_CacheLumpName("PLAYPAL");
      byte       *my_tranmap;

      char fname[PATH_MAX+1];
      struct {
        unsigned char pct;
        unsigned char playpal[256];
      } cache;
      FILE *cachefp = fopen(strcat(strcpy(fname, I_DoomExeDir()), "/tranmap.dat"),"rb");

      main_tranmap = my_tranmap = Z_Malloc(256*256, PU_STATIC, 0);  // killough 4/11/98

      // Use cached translucency filter if it's available

      if (!cachefp ||
          fread(&cache, 1, sizeof cache, cachefp) != sizeof cache ||
          cache.pct != tran_filter_pct ||
          memcmp(cache.playpal, playpal, sizeof cache.playpal) ||
          fread(my_tranmap, 256, 256, cachefp) != 256 ) // killough 4/11/98
        {
          long pal[3][256], tot[256], pal_w1[3][256];
          long w1 = ((unsigned long) tran_filter_pct<<TSC)/100;
          long w2 = (1l<<TSC)-w1;

          if (progress)
            lprintf(LO_INFO, "Tranmap build [        ]\x08\x08\x08\x08\x08\x08\x08\x08\x08");

          // First, convert playpal into long int type, and transpose array,
          // for fast inner-loop calculations. Precompute tot array.

          {
            register int i = 255;
            register const unsigned char *p = playpal+255*3;
            do
              {
                register long t,d;
                pal_w1[0][i] = (pal[0][i] = t = p[0]) * w1;
                d = t*t;
                pal_w1[1][i] = (pal[1][i] = t = p[1]) * w1;
                d += t*t;
                pal_w1[2][i] = (pal[2][i] = t = p[2]) * w1;
                d += t*t;
                p -= 3;
                tot[i] = d << (TSC-1);
              }
            while (--i>=0);
          }

          // Next, compute all entries using minimum arithmetic.

          {
            int i,j;
            byte *tp = my_tranmap;
            for (i=0;i<256;i++)
              {
                long r1 = pal[0][i] * w2;
                long g1 = pal[1][i] * w2;
                long b1 = pal[2][i] * w2;
                if (!(i & 31) && progress)
                  //jff 8/3/98 use logical output routine
                  lprintf(LO_INFO,".");
                for (j=0;j<256;j++,tp++)
                  {
                    register int color = 255;
                    register long err;
                    long r = pal_w1[0][j] + r1;
                    long g = pal_w1[1][j] + g1;
                    long b = pal_w1[2][j] + b1;
                    long best = LONG_MAX;
                    do
                      if ((err = tot[color] - pal[0][color]*r
                          - pal[1][color]*g - pal[2][color]*b) < best)
                        best = err, *tp = color;
                    while (--color >= 0);
                  }
              }
          }
          if ((cachefp = fopen(fname,"wb")) != NULL) // write out the cached translucency map
            {
              cache.pct = tran_filter_pct;
              memcpy(cache.playpal, playpal, 256);
              fseek(cachefp, 0, SEEK_SET);
              fwrite(&cache, 1, sizeof cache, cachefp);
              fwrite(main_tranmap, 256, 256, cachefp);
              // CPhipps - leave close for a few lines...
            }
        }

      if (cachefp)              // killough 11/98: fix filehandle leak
        fclose(cachefp);

      W_UnlockLumpName("PLAYPAL");
    }
}

//
// R_InitData
// Locates all the lumps
//  that will be used by all views
// Must be called after W_Init.
//

void R_InitData(void)
{
  lprintf(LO_INFO, "Textures ");
  R_InitTextures();
  lprintf(LO_INFO, "Flats ");
  R_InitFlats();
  lprintf(LO_INFO, "Sprites ");
  R_InitSpriteLumps();
  if (default_translucency)             // killough 3/1/98
    R_InitTranMap(1);                   // killough 2/21/98, 3/6/98
  R_InitColormaps();                    // killough 3/20/98
}

//
// R_FlatNumForName
// Retrieval, get a flat number for a flat name.
//
// killough 4/17/98: changed to use ns_flats namespace
//

int R_FlatNumForName(const char *name)    // killough -- const added
{
  int i = (W_CheckNumForName)(name, ns_flats);
  if (i == -1)
    I_Error("R_FlatNumForName: %.8s not found", name);
  return i - firstflat;
}

//
// R_CheckTextureNumForName
// Check whether texture is available.
// Filter out NoTexture indicator.
//
// Rewritten by Lee Killough to use hash table for fast lookup. Considerably
// reduces the time needed to start new levels. See w_wad.c for comments on
// the hashing algorithm, which is also used for lump searches.
//
// killough 1/21/98, 1/31/98
//

int PUREFUNC R_CheckTextureNumForName(const char *name)
{
  int i = NO_TEXTURE;
  if (*name != '-')     // "NoTexture" marker.
    {
      i = textures[W_LumpNameHash(name) % (unsigned) numtextures]->index;
      while (i >= 0 && strncasecmp(textures[i]->name,name,8))
        i = textures[i]->next;
    }
  return i;
}

// Maps textures with things we can't show in Germany to appropriate textures.
static const char * germanyRemap[][2] = { 
	{ "ZZWOLF2", "ZZWOLF1" },
	{ "ZZWOLF3", "ZZWOLF1" },
	{ "ZZWOLF4", "ZZWOLF1" },
	{ "ZZWOLF6", "ZZWOLF5" },
	{ "ZZWOLF7", "ZZWOLF5" },
	{ "ZZWOLF12", "ZZWOLF11" },
	{ "ZZWOLF13", "ZZWOLF11" },
	{ NULL, NULL }
};
	
//
// R_RemapTextureForGermany
// Given a texture name, returns a suitable replacement texture without any images of swastikas
// or Hitler.
//
const char * R_RemapTextureForGermany( const char * name ) {
    return name;
    
	const char ** currentTestPair = germanyRemap[0];
	
	while ( currentTestPair[0] != NULL ) {
		if ( strncmp( currentTestPair[0], name, 8 ) == 0 ) {
			return currentTestPair[1];
		}
		
		currentTestPair += 2;
	}

	return name;
}

//
// R_TextureNumForName
// Calls R_CheckTextureNumForName,
//  aborts with error message.
//

int PUREFUNC R_TextureNumForName(const char *name)  // const added -- killough
{
  const char * remappedName = R_RemapTextureForGermany( name );
  
  int i = R_CheckTextureNumForName(remappedName);
  if (i == -1)
    I_Error("R_TextureNumForName: %.8s not found", remappedName);
  return i;
}

//
// R_SafeTextureNumForName
// Calls R_CheckTextureNumForName, and changes any error to NO_TEXTURE
int PUREFUNC R_SafeTextureNumForName(const char *name, int snum)
{
  const char * remappedName = R_RemapTextureForGermany( name );
  
  int i = R_CheckTextureNumForName(remappedName);
  if (i == -1) {
    i = NO_TEXTURE; // e6y - return "no texture"
    lprintf(LO_DEBUG,"bad texture '%s' in sidedef %d\n",remappedName,snum);
  }
  return i;
}

//
// R_PrecacheLevel
// Preloads all relevant graphics for the level.
//
// Totally rewritten by Lee Killough to use less memory,
// to avoid using alloca(), and to improve performance.
// cph - new wad lump handling, calls cache functions but acquires no locks

static inline void precache_lump(int l)
{
  W_CacheLumpNum(l); W_UnlockLumpNum(l);
}

void R_PrecacheLevel(void)
{
  register int i;
  register byte *hitlist;

  if (demoplayback)
    return;

  {
    size_t size = numflats > numsprites  ? numflats : numsprites;
    hitlist = malloc((size_t)numtextures > size ? numtextures : size);
  }

  // Precache flats.

  memset(hitlist, 0, numflats);

  for (i = numsectors; --i >= 0; )
    hitlist[sectors[i].floorpic] = hitlist[sectors[i].ceilingpic] = 1;

  for (i = numflats; --i >= 0; )
    if (hitlist[i])
      precache_lump(firstflat + i);

  // Precache textures.

  memset(hitlist, 0, numtextures);

  for (i = numsides; --i >= 0;)
    hitlist[sides[i].bottomtexture] =
      hitlist[sides[i].toptexture] =
      hitlist[sides[i].midtexture] = 1;

  // Sky texture is always present.
  // Note that F_SKY1 is the name used to
  //  indicate a sky floor/ceiling as a flat,
  //  while the sky texture is stored like
  //  a wall texture, with an episode dependend
  //  name.

  hitlist[skytexture] = 1;

  for (i = numtextures; --i >= 0; )
    if (hitlist[i])
      {
        texture_t *texture = textures[i];
        int j = texture->patchcount;
        while (--j >= 0)
          precache_lump(texture->patches[j].patch);
      }

  // Precache sprites.
  memset(hitlist, 0, numsprites);

  {
    thinker_t *th = NULL;
    while ((th = P_NextThinker(th,th_all)) != NULL)
      if (th->function == P_MobjThinker)
        hitlist[((mobj_t *)th)->sprite] = 1;
  }

  for (i=numsprites; --i >= 0;)
    if (hitlist[i])
      {
        int j = sprites[i].numframes;
        while (--j >= 0)
          {
            short *sflump = sprites[i].spriteframes[j].lump;
            int k = 7;
            do
              precache_lump(firstspritelump + sflump[k]);
            while (--k >= 0);
          }
      }
  free(hitlist);
}

// Proff - Added for OpenGL
void R_SetPatchNum(patchnum_t *patchnum, const char *name)
{
  const rpatch_t *patch = R_CachePatchName(name);
  patchnum->width = patch->width;
  patchnum->height = patch->height;
  patchnum->leftoffset = patch->leftoffset;
  patchnum->topoffset = patch->topoffset;
  patchnum->lumpnum = W_GetNumForName(name);
  R_UnlockPatchName(name);
}