Implement CRC32 in the new Hash class. Will be useful for Dict and for

the new Shader cache.

src/Makefile.am

@@ -8,7 +8,7 @@ liblol_a_SOURCES = \
     tileset.cpp tileset.h forge.cpp forge.h video.cpp video.h \
     timer.cpp timer.h bitfield.h profiler.cpp profiler.h input.h input.cpp \
     world.cpp world.h sample.cpp sample.h sampler.cpp sampler.h \
-    text.cpp text.h emitter.cpp emitter.h numeric.h \
+    text.cpp text.h emitter.cpp emitter.h numeric.h hash.cpp hash.h \
     worldentity.cpp worldentity.h shader.cpp shader.h \
     \
     sdlinput.cpp sdlinput.h \

src/core.h

@@ -39,6 +39,7 @@
 #include "world.h"
 
 // Other objects
+#include "hash.h"
 #include "dict.h"
 #include "map.h"
 #include "layer.h"

src/hash.cpp

@@ -0,0 +1,58 @@
+//
+// Lol Engine
+//
+// Copyright: (c) 2010-2011 Sam Hocevar <sam@hocevar.net>
+//   This program is free software; you can redistribute it and/or
+//   modify it under the terms of the Do What The Fuck You Want To
+//   Public License, Version 2, as published by Sam Hocevar. See
+//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
+//
+
+#if defined HAVE_CONFIG_H
+#   include "config.h"
+#endif
+
+#include "core.h"
+
+/*
+ * Hash implementation class
+ */
+
+static class HashData
+{
+    friend class Hash;
+
+public:
+    HashData()
+    {
+        /* Initialise CRC32 table */
+        for (int i = 0; i < 256; i++)
+        {
+            uint32_t tmp = i;
+            for (int j = 8; j--; )
+                tmp = (tmp >> 1) ^ ((tmp & 1) ? 0xedb88320 : 0);
+            crc32_table[i] = tmp;
+        }
+    }
+
+private:
+    uint32_t crc32_table[256];
+}
+hashdata;
+
+static HashData * const data = &hashdata;
+
+/*
+ * Public Hash class
+ */
+
+uint32_t Hash::Crc32(char const *str)
+{
+    uint32_t ret = 0xffffffff, ch;
+
+    while ((ch = (uint8_t)*str++))
+        ret = data->crc32_table[(uint8_t)(ret ^ ch)] ^ (ret >> 8);
+
+    return ret ^ 0xffffffff;
+}
+

src/hash.h

@@ -0,0 +1,26 @@
+//
+// Lol Engine
+//
+// Copyright: (c) 2010-2011 Sam Hocevar <sam@hocevar.net>
+//   This program is free software; you can redistribute it and/or
+//   modify it under the terms of the Do What The Fuck You Want To
+//   Public License, Version 2, as published by Sam Hocevar. See
+//   http://sam.zoy.org/projects/COPYING.WTFPL for more details.
+//
+
+//
+// The Hash class
+// --------------
+//
+
+#if !defined __DH_HASH_H__
+#define __DH_HASH_H__
+
+class Hash
+{
+public:
+    static uint32_t Crc32(char const *data);
+};
+
+#endif // __DH_HASH_H__
+

win32/deushax.vcxproj

@@ -25,6 +25,7 @@
     <ClInclude Include="..\src\entity.h" />
     <ClInclude Include="..\src\font.h" />
     <ClInclude Include="..\src\forge.h" />
+    <ClInclude Include="..\src\hash.h" />
     <ClInclude Include="..\src\input.h" />
     <ClInclude Include="..\src\layer.h" />
     <ClInclude Include="..\src\map.h" />
@@ -59,6 +60,7 @@
     <ClCompile Include="..\src\entity.cpp" />
     <ClCompile Include="..\src\font.cpp" />
     <ClCompile Include="..\src\forge.cpp" />
+    <ClCompile Include="..\src\hash.cpp" />
     <ClCompile Include="..\src\input.cpp" />
     <ClCompile Include="..\src\layer.cpp" />
     <ClCompile Include="..\src\map.cpp" />

win32/deushax.vcxproj.filters

@@ -39,6 +39,9 @@
     <ClInclude Include="..\src\forge.h">
       <Filter>lolengine</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\hash.h">
+      <Filter>lolengine</Filter>
+    </ClInclude>
     <ClInclude Include="..\src\input.h">
       <Filter>lolengine</Filter>
     </ClInclude>
@@ -130,6 +133,9 @@
     <ClCompile Include="..\src\forge.cpp">
       <Filter>lolengine</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\hash.cpp">
+      <Filter>lolengine</Filter>
+    </ClCompile>
     <ClCompile Include="..\src\input.cpp">
       <Filter>lolengine</Filter>
     </ClCompile>

win32/editor.vcxproj

@@ -25,6 +25,7 @@
     <ClInclude Include="..\src\entity.h" />
     <ClInclude Include="..\src\font.h" />
     <ClInclude Include="..\src\forge.h" />
+    <ClInclude Include="..\src\hash.h" />
     <ClInclude Include="..\src\input.h" />
     <ClInclude Include="..\src\layer.h" />
     <ClInclude Include="..\src\map.h" />
@@ -59,6 +60,7 @@
     <ClCompile Include="..\src\entity.cpp" />
     <ClCompile Include="..\src\font.cpp" />
     <ClCompile Include="..\src\forge.cpp" />
+    <ClCompile Include="..\src\hash.cpp" />
     <ClCompile Include="..\src\input.cpp" />
     <ClCompile Include="..\src\layer.cpp" />
     <ClCompile Include="..\src\map.cpp" />

win32/editor.vcxproj.filters

@@ -39,6 +39,9 @@
     <ClInclude Include="..\src\forge.h">
       <Filter>lolengine</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\hash.h">
+      <Filter>lolengine</Filter>
+    </ClInclude>
     <ClInclude Include="..\src\input.h">
       <Filter>lolengine</Filter>
     </ClInclude>
@@ -130,6 +133,9 @@
     <ClCompile Include="..\src\forge.cpp">
       <Filter>lolengine</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\hash.cpp">
+      <Filter>lolengine</Filter>
+    </ClCompile>
     <ClCompile Include="..\src\input.cpp">
       <Filter>lolengine</Filter>
     </ClCompile>

win32/monsterz.vcxproj

@@ -30,6 +30,7 @@
     <ClInclude Include="..\src\entity.h" />
     <ClInclude Include="..\src\font.h" />
     <ClInclude Include="..\src\forge.h" />
+    <ClInclude Include="..\src\hash.h" />
     <ClInclude Include="..\src\input.h" />
     <ClInclude Include="..\src\layer.h" />
     <ClInclude Include="..\src\map.h" />
@@ -68,6 +69,7 @@
     <ClCompile Include="..\src\entity.cpp" />
     <ClCompile Include="..\src\font.cpp" />
     <ClCompile Include="..\src\forge.cpp" />
+    <ClCompile Include="..\src\hash.cpp" />
     <ClCompile Include="..\src\input.cpp" />
     <ClCompile Include="..\src\layer.cpp" />
     <ClCompile Include="..\src\map.cpp" />

win32/monsterz.vcxproj.filters

@@ -39,6 +39,9 @@
     <ClInclude Include="..\src\forge.h">
       <Filter>lolengine</Filter>
     </ClInclude>
+    <ClInclude Include="..\src\hash.h">
+      <Filter>lolengine</Filter>
+    </ClInclude>
     <ClInclude Include="..\src\input.h">
       <Filter>lolengine</Filter>
     </ClInclude>
@@ -135,6 +138,9 @@
     <ClCompile Include="..\src\forge.cpp">
       <Filter>lolengine</Filter>
     </ClCompile>
+    <ClCompile Include="..\src\hash.cpp">
+      <Filter>lolengine</Filter>
+    </ClCompile>
     <ClCompile Include="..\src\input.cpp">
       <Filter>lolengine</Filter>
     </ClCompile>