Add r_swirl

prboom2/src/CMakeLists.txt

@@ -388,6 +388,8 @@ set(COMMON_SRC
     r_sky.c
     r_sky.h
     r_state.h
+    r_swirl.c
+    r_swirl.h
     r_things.c
     r_things.h
     scanner.cpp

prboom2/src/r_swirl.c

@@ -0,0 +1,128 @@
+//
+// Copyright(C) 1993-1996 Id Software, Inc.
+// Copyright(C) 2000, 2005-2014 Simon Howard
+// Copyright(C) 2019 Fabian Greffrath
+//
+// 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:
+//	[crispy] add support for SMMU swirling flats
+//
+
+// [crispy] adapted from smmu/r_ripple.c, by Simon Howard
+
+#include "doomstat.h"
+#include "tables.h"
+#include "w_wad.h"
+#include "z_zone.h"
+
+#include "dsda.h"
+
+// swirl factors determine the number of waves per flat width
+
+// 1 cycle per 64 units
+#define swirlfactor  (FINEANGLES / 64)
+
+// 1 cycle per 32 units (2 in 64)
+#define swirlfactor2 (FINEANGLES / 32)
+
+#define SEQUENCE     256
+#define FLATSIZE     (64 * 64)
+
+static int *offsets;
+static int *offset;
+
+#define AMP   2
+#define AMP2  2
+#define SPEED 32
+
+static void R_InitDistortedFlats()
+{
+  int i;
+
+  offsets = Z_Malloc(SEQUENCE * FLATSIZE * sizeof(*offsets));
+  offset = offsets;
+
+  for (i = 0; i < SEQUENCE; i++)
+  {
+    int x, y;
+
+    for (x = 0; x < 64; x++)
+    {
+      for (y = 0; y < 64; y++)
+      {
+        int x1, y1;
+        int sinvalue, sinvalue2;
+
+        sinvalue = (y * swirlfactor + i * SPEED * 5 + 900) & FINEMASK;
+        sinvalue2 = (x * swirlfactor2 + i * SPEED * 4 + 300) & FINEMASK;
+        x1 = x + 128 + ((finesine[sinvalue] * AMP) >> FRACBITS)
+              + ((finesine[sinvalue2] * AMP2) >> FRACBITS);
+
+        sinvalue = (x * swirlfactor + i * SPEED * 3 + 700) & FINEMASK;
+        sinvalue2 = (y * swirlfactor2 + i * SPEED * 4 + 1200) & FINEMASK;
+        y1 = y + 128 + ((finesine[sinvalue] * AMP) >> FRACBITS)
+              + ((finesine[sinvalue2] * AMP2) >> FRACBITS);
+
+        x1 &= 63;
+        y1 &= 63;
+
+        offset[(y << 6) + x] = (y1 << 6) + x1;
+      }
+    }
+
+    offset += FLATSIZE;
+  }
+}
+
+byte *R_DistortedFlat(int flatnum)
+{
+  static int swirltic = -1;
+  static int swirlflat = -1;
+  static byte distortedflat[FLATSIZE];
+
+  if (!offsets)
+  {
+    R_InitDistortedFlats();
+  }
+
+  if (swirltic != leveltime)
+  {
+    if (!dsda_FrozenMode())
+    {
+      offset = offsets + ((leveltime & (SEQUENCE - 1)) * FLATSIZE);
+    }
+    else
+    {
+      offset = offsets;
+    }
+
+    swirltic = leveltime;
+    swirlflat = -1;
+  }
+
+  if (swirlflat != flatnum)
+  {
+    const char *normalflat;
+    int i;
+
+    normalflat = W_LumpByNum(flatnum);
+
+    for (i = 0; i < FLATSIZE; i++)
+    {
+      distortedflat[i] = normalflat[offset[i]];
+    }
+
+    swirlflat = flatnum;
+  }
+
+  return distortedflat;
+}

prboom2/src/r_swirl.h

@@ -0,0 +1,27 @@
+//
+// Copyright(C) 1993-1996 Id Software, Inc.
+// Copyright(C) 2000, 2005-2014 Simon Howard
+// Copyright(C) 2019 Fabian Greffrath
+//
+// 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:
+//	[crispy] add support for SMMU swirling flats
+//
+
+#ifndef __R_SWIRL__
+#define __R_SWIRL__
+
+#include "doomtype.h"
+
+byte *R_DistortedFlat(int flatnum);
+
+#endif