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Use binary operators rather than "Python modulo" in decoding block positions

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This commit is contained in:
ShadowNinja 2014-04-15 16:07:53 -04:00
parent 118e2ae865
commit 54ffe2e5de
2 changed files with 19 additions and 23 deletions
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38
src/database.cpp
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@ -20,33 +20,29 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#include "database.h" #include "database.h"
#include "irrlichttypes.h" #include "irrlichttypes.h"
static s32 unsignedToSigned(s32 i, s32 max_positive) static inline s16 unsigned_to_signed(u16 i, u16 max_positive)
{ {
if(i < max_positive) if (i < max_positive) {
return i; return i;
else } else {
return i - 2*max_positive; return i - (max_positive * 2);
}
} }
// modulo of a negative number does not work consistently in C
static s64 pythonmodulo(s64 i, s64 mod) s64 Database::getBlockAsInteger(const v3s16 pos) const
{ {
if(i >= 0) return (u64) pos.Z * 0x1000000 +
return i % mod; (u64) pos.Y * 0x1000 +
return mod - ((-i) % mod);
}
s64 Database::getBlockAsInteger(const v3s16 pos) {
return (u64) pos.Z * 16777216 +
(u64) pos.Y * 4096 +
(u64) pos.X; (u64) pos.X;
} }
v3s16 Database::getIntegerAsBlock(s64 i) { v3s16 Database::getIntegerAsBlock(const s64 i) const
s32 x = unsignedToSigned(pythonmodulo(i, 4096), 2048); {
i = (i - x) / 4096; v3s16 pos;
s32 y = unsignedToSigned(pythonmodulo(i, 4096), 2048); pos.Z = unsigned_to_signed((i >> 24) & 0xFFF, 0x1000 / 2);
i = (i - y) / 4096; pos.Y = unsigned_to_signed((i >> 12) & 0xFFF, 0x1000 / 2);
s32 z = unsignedToSigned(pythonmodulo(i, 4096), 2048); pos.X = unsigned_to_signed((i ) & 0xFFF, 0x1000 / 2);
return v3s16(x,y,z); return pos;
} }

4
src/database.h
View File

@ -34,8 +34,8 @@ public:
virtual void saveBlock(MapBlock *block)=0; virtual void saveBlock(MapBlock *block)=0;
virtual MapBlock* loadBlock(v3s16 blockpos)=0; virtual MapBlock* loadBlock(v3s16 blockpos)=0;
s64 getBlockAsInteger(const v3s16 pos); s64 getBlockAsInteger(const v3s16 pos) const;
v3s16 getIntegerAsBlock(s64 i); v3s16 getIntegerAsBlock(const s64 i) const;
virtual void listAllLoadableBlocks(std::list<v3s16> &dst)=0; virtual void listAllLoadableBlocks(std::list<v3s16> &dst)=0;
virtual int Initialized(void)=0; virtual int Initialized(void)=0;
virtual ~Database() {}; virtual ~Database() {};