additive translucency for fullbright sprites

Fixes #1968

Author: fabiangreffrath

src/doomstat.c

@@ -65,7 +65,7 @@ demo_version_t demo_version;        // killough 7/19/98: Boom version of demo
 // v1.1-like pitched sounds
 boolean pitched_sounds;  // killough 10/98
 
-boolean translucency;    // killough 10/98
+translucency_t translucency;  // killough 10/98
 
 int  allow_pushers = 1;      // MT_PUSH Things              // phares 3/10/98
 int  default_allow_pushers;  // killough 3/1/98: make local to each game

src/doomstat.h

@@ -122,7 +122,14 @@ extern boolean monkeys, default_monkeys;
 // v1.1-like pitched sounds
 extern boolean pitched_sounds;
 
-extern boolean translucency;
+typedef enum
+{
+    TRANSLUCENCY_OFF,
+    TRANSLUCENCY_BOOM,
+    TRANSLUCENCY_ADD
+} translucency_t;
+
+extern translucency_t translucency;
 
 extern int demo_insurance;      // killough 4/5/98
 

src/mn_setup.c

@@ -357,6 +357,7 @@ enum
     str_bobbing_pct,
     str_screen_melt,
     str_invul_mode,
+    str_translucency,
 };
 
 static const char **GetStrings(int id);
@@ -3242,6 +3243,10 @@ static void SmoothLight(void)
     setsizeneeded = true; // run R_ExecuteSetViewSize
 }
 
+static const char *translucency_strings[] = {
+    "Off", "Boom", "Add"
+};
+
 static const char *exit_sequence_strings[] = {
     "Off", "Sound Only", "PWAD ENDOOM", "On"
 };
@@ -3251,8 +3256,9 @@ static setup_menu_t gen_settings5[] = {
     {"Smooth Pixel Scaling", S_ONOFF, OFF_CNTR_X, M_SPC, {"smooth_scaling"},
      .action = ResetVideo},
 
-    {"Sprite Translucency", S_ONOFF | S_STRICT, OFF_CNTR_X, M_SPC,
-     {"translucency"}},
+    {"Sprite Translucency", S_CHOICE | S_STRICT, OFF_CNTR_X, M_SPC,
+     {"translucency"}, .strings_id = str_translucency,
+     .action = MN_Trans},
 
     {"Translucency Filter", S_NUM | S_ACTION | S_PCT, OFF_CNTR_X, M_SPC,
      {"tran_filter_pct"}, .action = MN_Trans},
@@ -4822,6 +4828,7 @@ static const char **selectstrings[] = {
     bobbing_pct_strings,
     screen_melt_strings,
     invul_mode_strings,
+    translucency_strings,
 };
 
 static const char **GetStrings(int id)

src/r_data.c

@@ -31,6 +31,7 @@
 #include "doomstat.h"
 #include "i_printf.h"
 #include "i_system.h"
+#include "i_video.h"
 #include "info.h"
 #include "m_argv.h" // M_CheckParm()
 #include "m_fixed.h"
@@ -919,133 +920,160 @@ int R_ColormapNumForName(const char *name)
 
 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");
-  //!
-  // @category mod
-  //
-  // Forces a (re-)building of the translucency and color translation tables.
-  //
-  int force_rebuild = M_CheckParm("-tranmap");
+    //!
+    // @category mod
+    //
+    // Forces a (re-)building of the translucency and color translation tables.
+    //
 
-  // If a tranlucency filter map lump is present, use it
+    int force_rebuild = M_CheckParm("-tranmap");
 
-  if (lump != -1 && !force_rebuild)  // Set a pointer to the translucency filter maps.
-    main_tranmap = W_CacheLumpNum(lump, PU_STATIC);   // killough 4/11/98
-  else
-    {   // Compose a default transparent filter map based on PLAYPAL.
-      unsigned char *playpal = W_CacheLumpName("PLAYPAL", PU_STATIC);
-      char *fname = M_StringJoin(D_DoomPrefDir(), DIR_SEPARATOR_S, "tranmap.dat");
-      struct {
-        unsigned char pct;
-        unsigned char playpal[256*3]; // [FG] a palette has 256 colors saved as byte triples
-      } cache;
-      FILE *cachefp = M_fopen(fname,"r+b");
-
-      if (main_tranmap == NULL) // [FG] prevent memory leak
-      {
-      main_tranmap = Z_Malloc(256*256, PU_STATIC, 0);  // killough 4/11/98
-      }
+    // If a tranlucency filter map lump is present, use it
+    int lump = W_CheckNumForName("TRANMAP");
 
-      // Use cached translucency filter if it's available
+    if (lump != -1 && W_LumpLength(lump) == 256 * 256 && !force_rebuild)
+    {
+        // Set a pointer to the translucency filter maps.
+        main_tranmap = W_CacheLumpNum(lump, PU_STATIC); // killough 4/11/98
+        add_tranmap = main_tranmap;
+    }
+    else
+    {
+        // Compose a default transparent filter map based on PLAYPAL.
+        unsigned char *playpal = W_CacheLumpName("PLAYPAL", PU_STATIC);
+        char *fname =
+            M_StringJoin(D_DoomPrefDir(), DIR_SEPARATOR_S, "tranmap.dat");
 
-      if (!cachefp ? cachefp = M_fopen(fname,"w+b") , 1 : // [FG] open for writing and reading
-          fread(&cache, 1, sizeof cache, cachefp) != sizeof cache ||
-          cache.pct != tran_filter_pct ||
-          memcmp(cache.playpal, playpal, sizeof cache.playpal) ||
-          fread(main_tranmap, 256, 256, cachefp) != 256 ||  // killough 4/11/98
-          force_rebuild)
+        struct
         {
-          long pal[3][256], tot[256], pal_w1[3][256];
-          long w1 = ((unsigned long) tran_filter_pct<<TSC)/100;
-          long w2 = (1l<<TSC)-w1;
+            unsigned char pct;
+            unsigned char playpal[256 * 3]; // [FG] a palette has 256 colors
+                                            // saved as byte triples
+        } cache;
 
-          // First, convert playpal into long int type, and transpose array,
-          // for fast inner-loop calculations. Precompute tot array.
+        FILE *cachefp = M_fopen(fname, "r+b");
 
-          {
-            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);
-          }
+        if (main_tranmap == NULL) // [FG] prevent memory leak
+        {
+            main_tranmap =
+                Z_Malloc(256 * 256 * 2, PU_STATIC, 0); // killough 4/11/98
+            add_tranmap = main_tranmap + 256 * 256;
+        }
 
-          // Next, compute all entries using minimum arithmetic.
+        // Use cached translucency filter if it's available
 
-          {
-            int i,j;
-            byte *tp = main_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 (!cachefp ? cachefp = M_fopen(fname, "w+b"),
+            true     : // [FG] open for writing and reading
+            fread(&cache, 1, sizeof cache, cachefp) != sizeof cache
+                || cache.pct != tran_filter_pct
+                || memcmp(cache.playpal, playpal, sizeof cache.playpal)
+                || fread(main_tranmap, 256, 256 * 2, cachefp) != 256 * 2
+                || // killough 4/11/98
+                force_rebuild)
+        {
+            byte *tp = main_tranmap, *ap = add_tranmap;
 
+            for (int i = 0; i < 256; i++)
+            {
                 if (!(i & 31) && progress)
-		  I_PutChar(VB_INFO, '.');
+                {
+                    I_PutChar(VB_INFO, '.');
+                }
+
+                if (!(~i & 15))
+                {
+                    if (i & 32) // killough 10/98: display flashing disk
+                    {
+                        I_EndRead();
+                    }
+                    else
+                    {
+                        I_BeginRead(DISK_ICON_THRESHOLD);
+                    }
+                }
+
+                for (int j = 0; j < 256; j++)
+                {
+                    byte *bg = playpal + 3 * i;
+                    byte *fg = playpal + 3 * j;
+                    byte blend[3];
+                    enum {r, g, b};
+
+                    blend[r] = MIN(fg[r] + bg[r], 255);
+                    blend[g] = MIN(fg[g] + bg[g], 255);
+                    blend[b] = MIN(fg[b] + bg[b], 255);
+
+                    *ap++ = I_GetNearestColor(playpal, blend[r], blend[g],
+                                              blend[b]);
+
+                    // [crispy] shortcut: identical foreground and background
+                    if (i == j)
+                    {
+                        *tp++ = i;
+                        continue;
+                    }
+
+                    // [crispy] blended color - emphasize blues
+                    // Colour matching in RGB space doesn't work very well with
+                    // the blues in Doom's palette. Rather than do any colour
+                    // conversions, just emphasize the blues when building the
+                    // translucency table.
+                    int btmp = fg[b] * 1.666 < (fg[r] + fg[g]) ? 0 : 50;
+                    blend[r] = (tran_filter_pct * fg[r]
+                                + (100 - tran_filter_pct) * bg[r])
+                               / (100 + btmp);
+                    blend[g] = (tran_filter_pct * fg[g]
+                                + (100 - tran_filter_pct) * bg[g])
+                               / (100 + btmp);
+                    blend[b] = (tran_filter_pct * fg[b]
+                                + (100 - tran_filter_pct) * bg[b])
+                               / 100;
+
+                    *tp++ = I_GetNearestColor(playpal, blend[r], blend[g],
+                                              blend[b]);
+                }
+            }
 
-		if (!(~i & 15))
-		{
-		  if (i & 32)       // killough 10/98: display flashing disk
-		    I_EndRead();
-		  else
-		    I_BeginRead(DISK_ICON_THRESHOLD);
-		}
-
-                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);
-                  }
-              }
             // [FG] finish progress line
             if (progress)
-              I_PutChar(VB_INFO, '\n');
-          }
-          if (cachefp && !force_rebuild) // write out the cached translucency map
             {
-              cache.pct = tran_filter_pct;
-              memcpy(cache.playpal, playpal, sizeof cache.playpal); // [FG] a palette has 256 colors saved as byte triples
-              fseek(cachefp, 0, SEEK_SET);
-              fwrite(&cache, 1, sizeof cache, cachefp);
-              fwrite(main_tranmap, 256, 256, cachefp);
+                I_PutChar(VB_INFO, '\n');
+            }
+
+            if (cachefp
+                && !force_rebuild) // write out the cached translucency map
+            {
+                cache.pct = tran_filter_pct;
+                memcpy(cache.playpal, playpal,
+                       sizeof cache.playpal); // [FG] a palette has 256 colors
+                                              // saved as byte triples
+                fseek(cachefp, 0, SEEK_SET);
+                fwrite(&cache, 1, sizeof cache, cachefp);
+                fwrite(main_tranmap, 256, 256 * 2, cachefp);
+            }
+        }
+        else
+        {
+            if (progress)
+            {
+                I_Printf(VB_INFO, "........");
             }
         }
-      else
-	if (progress)
-	  I_Printf(VB_INFO, "........");
 
-      if (cachefp)              // killough 11/98: fix filehandle leak
-	fclose(cachefp);
+        if (cachefp) // killough 11/98: fix filehandle leak
+        {
+            fclose(cachefp);
+        }
 
-      Z_ChangeTag(playpal, PU_CACHE);
-      free(fname);
+        Z_ChangeTag(playpal, PU_CACHE);
+        free(fname);
     }
-}
 
+    fullbright_tranmap =
+        (translucency == TRANSLUCENCY_ADD) ? add_tranmap : main_tranmap;
+}
 //
 // R_InitData
 // Locates all the lumps

src/r_data.h

@@ -54,6 +54,7 @@ boolean R_IsPatchLump (const int lump);
 extern int numflats;
 
 extern byte *main_tranmap, *tranmap;
+extern byte *fullbright_tranmap, *add_tranmap;
 
 extern int tran_filter_pct;
 

src/r_draw.c

@@ -60,6 +60,8 @@ static int linesize; // killough 11/98
 byte *tranmap;          // translucency filter maps 256x256   // phares 
 byte *main_tranmap;     // killough 4/11/98
 
+byte *fullbright_tranmap, *add_tranmap;
+
 // Backing buffer containing the bezel drawn around the screen and surrounding
 // background.
 

src/r_main.c

@@ -1034,7 +1034,8 @@ void R_BindRenderVariables(void)
   BIND_BOOL(flashing_hom, true, "Enable flashing of the HOM indicator");
   BIND_NUM(screenblocks, 10, 3, 11, "Size of game-world screen");
 
-  M_BindBool("translucency", &translucency, NULL, true, ss_gen, wad_yes,
+  M_BindNum("translucency", &translucency, NULL, TRANSLUCENCY_BOOM,
+            TRANSLUCENCY_OFF, TRANSLUCENCY_ADD, ss_gen, wad_yes,
              "Translucency for some things");
   M_BindNum("tran_filter_pct", &tran_filter_pct, NULL,
             66, 0, 100, ss_gen, wad_yes,

src/r_things.c

@@ -450,7 +450,8 @@ void R_DrawVisSprite(vissprite_t *vis, int x1, int x2)
           && vis->mobjflags & MF_TRANSLUCENT) // phares
         {
           colfunc = R_DrawTLColumn;
-          tranmap = main_tranmap;       // killough 4/11/98
+          tranmap = (dc_colormap[0] == fullcolormap) ?
+                    fullbright_tranmap : main_tranmap; // killough 4/11/98
         }
       else
         colfunc = R_DrawColumn;         // killough 3/14/98, 4/11/98