From 876aa82c29d2e17f8b5a4f74155971cba78c00b6 Mon Sep 17 00:00:00 2001 From: Huw Pascoe Date: Sun, 24 Sep 2017 22:24:45 +0100 Subject: [PATCH] Optimized Morton --- src/video_core/utils.h | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) diff --git a/src/video_core/utils.h b/src/video_core/utils.h index 7ce83a055f..d8567f3148 100644 --- a/src/video_core/utils.h +++ b/src/video_core/utils.h @@ -8,17 +8,11 @@ namespace VideoCore { -/** - * 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/ - */ +// 8x8 Z-Order coordinate from 2D coordinates static inline u32 MortonInterleave(u32 x, u32 y) { - u32 i = (x & 7) | ((y & 7) << 8); // ---- -210 - i = (i ^ (i << 2)) & 0x1313; // ---2 --10 - i = (i ^ (i << 1)) & 0x1515; // ---2 -1-0 - i = (i | (i >> 7)) & 0x3F; - return i; + static const u32 xlut[] = {0x00, 0x01, 0x04, 0x05, 0x10, 0x11, 0x14, 0x15}; + static const u32 ylut[] = {0x00, 0x02, 0x08, 0x0a, 0x20, 0x22, 0x28, 0x2a}; + return xlut[x % 8] + ylut[y % 8]; } /**