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Merge pull request #2951 from huwpascoe/perf-4

Optimized Morton
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B3n30 2017-09-25 08:28:55 +02:00 committed by GitHub
commit dc6a365337

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@ -8,17 +8,11 @@
namespace VideoCore { namespace VideoCore {
/** // 8x8 Z-Order coordinate from 2D coordinates
* Interleave the lower 3 bits of each coordinate to get the intra-block offsets, which are
* arranged in a Z-order curve. More details on the bit manipulation at:
* https://fgiesen.wordpress.com/2009/12/13/decoding-morton-codes/
*/
static inline u32 MortonInterleave(u32 x, u32 y) { static inline u32 MortonInterleave(u32 x, u32 y) {
u32 i = (x & 7) | ((y & 7) << 8); // ---- -210 static const u32 xlut[] = {0x00, 0x01, 0x04, 0x05, 0x10, 0x11, 0x14, 0x15};
i = (i ^ (i << 2)) & 0x1313; // ---2 --10 static const u32 ylut[] = {0x00, 0x02, 0x08, 0x0a, 0x20, 0x22, 0x28, 0x2a};
i = (i ^ (i << 1)) & 0x1515; // ---2 -1-0 return xlut[x % 8] + ylut[y % 8];
i = (i | (i >> 7)) & 0x3F;
return i;
} }
/** /**