From e84d62416dfae494aab9791e7d857f2bc1091bdc Mon Sep 17 00:00:00 2001
From: terminx <terminx@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Sat, 2 Mar 2019 23:21:37 +0000
Subject: [PATCH] Patch from Striker to allow selective tile redefinition in
 .def files based on the crc of the original tile

This only works for "tilefromtexture" for now.

git-svn-id: https://svn.eduke32.com/eduke32@7370 1a8010ca-5511-0410-912e-c29ae57300e0
---
 source/build/include/build.h |  1 +
 source/build/src/defs.cpp    | 16 ++++++++++++++++
 source/build/src/tiles.cpp   | 21 +++++++++++++++++++++
 3 files changed, 38 insertions(+)

diff --git a/source/build/include/build.h b/source/build/include/build.h
index 83e2aec3a..806736035 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -1068,6 +1068,7 @@ void    artClearMapArt(void);
 void    artSetupMapArt(const char *filename);
 bool    tileLoad(int16_t tilenume);
 void    tileLoadData(int16_t tilenume, int32_t dasiz, char *buffer);
+int32_t tileCRC(int16_t tileNum);
 void    artConvertRGB(palette_t *pic, uint8_t const *buf, int32_t bufsizx, int32_t sizx, int32_t sizy);
 
 int32_t   qloadkvx(int32_t voxindex, const char *filename);
diff --git a/source/build/src/defs.cpp b/source/build/src/defs.cpp
index 8567764c6..643779774 100644
--- a/source/build/src/defs.cpp
+++ b/source/build/src/defs.cpp
@@ -121,6 +121,7 @@ enum scripttoken_t
     T_DST_COLOR, T_ONE_MINUS_DST_COLOR,
     T_SHADERED, T_SHADEGREEN, T_SHADEBLUE,
     T_SHADEFACTOR,
+    T_IFCRC,
 };
 
 static int32_t lastmodelid = -1, lastvoxid = -1, modelskin = -1, lastmodelskin = -1, seenframe = 0;
@@ -792,6 +793,7 @@ static int32_t defsparser(scriptfile *script)
             int32_t havexoffset = 0, haveyoffset = 0;
             int32_t xoffset = 0, yoffset = 0;
             int32_t istexture = 0;
+            int32_t tilecrc = 0, origcrc = 0;
 
             static const tokenlist tilefromtexturetokens[] =
             {
@@ -805,6 +807,7 @@ static int32_t defsparser(scriptfile *script)
                 { "texhitscan",      T_TEXHITSCAN },
                 { "nofullbright",    T_NOFULLBRIGHT },
                 { "texture",         T_TEXTURE },
+                { "ifcrc",           T_IFCRC },
             };
 
             if (scriptfile_getsymbol(script,&tile)) break;
@@ -831,6 +834,9 @@ static int32_t defsparser(scriptfile *script)
                     scriptfile_getsymbol(script,&yoffset);
                     yoffset = clamp(yoffset, -128, 127);
                     break;
+                case T_IFCRC:
+                    scriptfile_getsymbol(script, &tilecrc);
+                    break;
                 case T_TEXHITSCAN:
                     flags |= PICANM_TEXHITSCAN_BIT;
                     break;
@@ -852,6 +858,16 @@ static int32_t defsparser(scriptfile *script)
                 break;
             }
 
+            if (tilecrc)
+            {
+                origcrc = tileCRC(tile);
+                if (origcrc != tilecrc)
+                {
+                    //initprintf("CRC of tile %d doesn't match! CRC: %d, Expected: %d\n", tile, origcrc, tilecrc);
+                    break;
+                }
+            }
+
             if (!fn)
             {
                 // tilefromtexture <tile> { texhitscan }  sets the bit but doesn't change tile data
diff --git a/source/build/src/tiles.cpp b/source/build/src/tiles.cpp
index 1d1982ce7..035a04c68 100644
--- a/source/build/src/tiles.cpp
+++ b/source/build/src/tiles.cpp
@@ -12,6 +12,7 @@
 #include "engine_priv.h"
 #include "cache1d.h"
 #include "lz4.h"
+#include "crc32.h"
 
 #include "vfs.h"
 
@@ -740,6 +741,26 @@ static void tilePostLoad(int16_t tilenume)
 #endif
 }
 
+int32_t tileCRC(int16_t tileNum)
+{
+    char *data;
+
+    if ((unsigned)tileNum >= (unsigned)MAXTILES)
+        return 0;
+    int const dasiz = tilesiz[tileNum].x * tilesiz[tileNum].y;
+    if (dasiz <= 0)
+        return 0;
+
+    data = (char *)Bmalloc(dasiz);
+    tileLoadData(tileNum, dasiz, data);
+
+    int32_t crc = Bcrc32((unsigned char *)data, (unsigned int)dasiz, 0);
+
+    Bfree(data);
+
+    return crc;
+}
+
 // Assumes pic has been initialized to zero.
 void artConvertRGB(palette_t * const pic, uint8_t const * const buf, int32_t const bufsizx, int32_t const sizx, int32_t const sizy)
 {