cross-fading screen wipe implementation (#1557)

* cross-fading screen wipe implementation

* add config and afjust menu entry

* do not trash the CPU

* fix memory leak

src/d_main.c

@@ -448,12 +448,14 @@ void D_Display (void)
       int nowtime, tics;
       do
         {
+          I_Sleep(1);
           nowtime = I_GetTime();
           tics = nowtime - wipestart;
         }
       while (!tics);
       wipestart = nowtime;
-      done = wipe_ScreenWipe(wipe_Melt, 0, 0, video.unscaledw, SCREENHEIGHT, tics);
+      done = wipe_ScreenWipe(strictmode ? wipe_Melt : screen_melt,
+                             0, 0, video.unscaledw, SCREENHEIGHT, tics);
       M_Drawer();                   // menu is drawn even on top of wipes
       I_FinishUpdate();             // page flip or blit buffer
     }

src/f_wipe.c

@@ -23,6 +23,7 @@
 #include "f_wipe.h"
 #include "i_video.h"
 #include "m_random.h"
+#include "v_flextran.h"
 #include "v_video.h"
 #include "z_zone.h"
 
@@ -57,33 +58,47 @@ static void wipe_shittyColMajorXform(byte *array, int width, int height)
   Z_Free(dest);
 }
 
+// [FG] cross-fading screen wipe implementation
+
+static int fade_tick;
+
 static int wipe_initColorXForm(int width, int height, int ticks)
 {
   V_PutBlock(0, 0, width, height, wipe_scr_start);
+  fade_tick = 0;
   return 0;
 }
 
-// killough 3/5/98: reformatted and cleaned up
 static int wipe_doColorXForm(int width, int height, int ticks)
 {
-  boolean unchanged = true;
-  byte *w   = wipe_scr;
-  byte *e   = wipe_scr_end;
-  byte *end = wipe_scr+width*height;
-  for (;w != end; w++, e++)
-    if (*w != *e)
-      {
-        int newval;
-        unchanged = false;
-        *w = *w > *e ?
-          (newval = *w - ticks) < *e ? *e : newval :
-          (newval = *w + ticks) > *e ? *e : newval ;
-      }
-  return unchanged;
+  for (int y = 0; y < height; y++)
+  {
+    byte *sta = wipe_scr_start + y * width;
+    byte *end = wipe_scr_end + y * width;
+    byte *dst = wipe_scr + y * video.pitch;
+
+    for (int x = 0; x < width; x++)
+    {
+      unsigned int *fg2rgb = Col2RGB8[fade_tick];
+      unsigned int *bg2rgb = Col2RGB8[64 - fade_tick];
+      unsigned int fg, bg;
+
+      fg = fg2rgb[end[x]];
+      bg = bg2rgb[sta[x]];
+      fg = (fg + bg) | 0x1f07c1f;
+      dst[x] = RGB32k[0][0][fg & (fg >> 15)];
+    }
+  }
+
+  fade_tick += 2 * ticks;
+
+  return (fade_tick > 64);
 }
 
-static int wipe_exitColorXForm(int width, int height, int ticks)
+static int wipe_exit(int width, int height, int ticks)
 {
+  Z_Free(wipe_scr_start);
+  Z_Free(wipe_scr_end);
   return 0;
 }
 
@@ -173,8 +188,7 @@ static int wipe_doMelt(int width, int height, int ticks)
 static int wipe_exitMelt(int width, int height, int ticks)
 {
   Z_Free(col_y);
-  Z_Free(wipe_scr_start);
-  Z_Free(wipe_scr_end);
+  wipe_exit(width, height, ticks);
   return 0;
 }
 
@@ -195,13 +209,21 @@ int wipe_EndScreen(int x, int y, int width, int height)
   return 0;
 }
 
+static int wipe_NOP(int x, int y, int t)
+{
+  return 0;
+}
+
 static int (*const wipes[])(int, int, int) = {
-  wipe_initColorXForm,
-  wipe_doColorXForm,
-  wipe_exitColorXForm,
+  wipe_NOP,
+  wipe_NOP,
+  wipe_exit,
   wipe_initMelt,
   wipe_doMelt,
-  wipe_exitMelt
+  wipe_exitMelt,
+  wipe_initColorXForm,
+  wipe_doColorXForm,
+  wipe_exit,
 };
 
 // killough 3/5/98: reformatted and cleaned up

src/f_wipe.h

@@ -25,9 +25,9 @@
 //
 
 enum {
-  // simple gradual pixel change for 8-bit only
-  wipe_ColorXForm,
+  wipe_None,
   wipe_Melt,        // weird screen melt
+  wipe_ColorXForm,
   wipe_NUMWIPES
 };
 

src/m_menu.c

@@ -2022,6 +2022,7 @@ enum
     str_menu_backdrop,
     str_widescreen,
     str_bobbing_pct,
+    str_screen_melt,
     str_invul_mode,
 };
 
@@ -4122,6 +4123,10 @@ static const char *menu_backdrop_strings[] = {
   "Off", "Dark", "Texture"
 };
 
+static const char *screen_melt_strings[] = {
+  "Off", "Melt", "Crossfade"
+};
+
 static const char *invul_mode_strings[] = {
   "Vanilla", "MBF", "Gray"
 };
@@ -4247,7 +4252,8 @@ setup_menu_t gen_settings6[] = {
 
   {"Quality of life", S_SKIP|S_TITLE, m_null, M_X, M_Y},
 
-  {"Screen melt", S_ONOFF|S_STRICT, m_null, M_X, M_SPC, {"screen_melt"}},
+  {"Screen wipe effect", S_CHOICE|S_STRICT, m_null, M_X, M_SPC,
+   {"screen_melt"}, 0, NULL, str_screen_melt},
 
   {"On death action", S_CHOICE, m_null, M_X, M_SPC,
    {"death_use_action"}, 0, NULL, str_death_use_action},
@@ -6919,6 +6925,7 @@ static const char **selectstrings[] = {
     menu_backdrop_strings,
     widescreen_strings,
     bobbing_pct_strings,
+    screen_melt_strings,
     invul_mode_strings,
 };
 

src/m_misc.c

@@ -33,6 +33,7 @@
 #include "doomkeys.h"
 #include "doomstat.h"
 #include "dstrings.h"
+#include "f_wipe.h"
 #include "g_game.h"
 #include "hu_lib.h" // HU_MAXMESSAGES
 #include "hu_obituary.h"
@@ -606,8 +607,8 @@ default_t defaults[] = {
   {
     "screen_melt",
     (config_t *) &screen_melt, NULL,
-    {1}, {0,1}, number, ss_gen, wad_no,
-    "0 to disable screen melt"
+    {wipe_Melt}, {wipe_None, wipe_ColorXForm}, number, ss_gen, wad_no,
+    "screen wipe effect (0 = none, 1 = melt, 2 = crossfade)"
   },
 
   {