KiCad PCB EDA Suite
mortoncodes.cpp
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1 /*
2  * This program source code file is part of KiCad, a free EDA CAD application.
3  *
4  * Copyright (C) 2015-2016 Mario Luzeiro <mrluzeiro@ua.pt>
5  * Copyright (C) 1992-2016 KiCad Developers, see AUTHORS.txt for contributors.
6  *
7  * This program is free software; you can redistribute it and/or
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9  * as published by the Free Software Foundation; either version 2
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23  */
24 
31 #include "mortoncodes.h"
32 
33 
34 // "Insert" a 0 bit after each of the 16 low bits of x
35 uint32_t Part1By1( uint32_t x )
36 {
37  x &= 0x0000ffff; // x = ---- ---- ---- ---- fedc ba98 7654 3210
38  x = (x ^ (x << 8)) & 0x00ff00ff; // x = ---- ---- fedc ba98 ---- ---- 7654 3210
39  x = (x ^ (x << 4)) & 0x0f0f0f0f; // x = ---- fedc ---- ba98 ---- 7654 ---- 3210
40  x = (x ^ (x << 2)) & 0x33333333; // x = --fe --dc --ba --98 --76 --54 --32 --10
41  x = (x ^ (x << 1)) & 0x55555555; // x = -f-e -d-c -b-a -9-8 -7-6 -5-4 -3-2 -1-0
42 
43  return x;
44 }
45 
46 
47 // "Insert" two 0 bits after each of the 10 low bits of x
48 uint32_t Part1By2( uint32_t x )
49 {
50  x &= 0x000003ff; // x = ---- ---- ---- ---- ---- --98 7654 3210
51  x = (x ^ (x << 16)) & 0xff0000ff; // x = ---- --98 ---- ---- ---- ---- 7654 3210
52  x = (x ^ (x << 8)) & 0x0300f00f; // x = ---- --98 ---- ---- 7654 ---- ---- 3210
53  x = (x ^ (x << 4)) & 0x030c30c3; // x = ---- --98 ---- 76-- --54 ---- 32-- --10
54  x = (x ^ (x << 2)) & 0x09249249; // x = ---- 9--8 --7- -6-- 5--4 --3- -2-- 1--0
55 
56  return x;
57 }
58 
59 
60 // Inverse of Part1By1 - "delete" all odd-indexed bits
61 uint32_t Compact1By1( uint32_t x )
62 {
63  x &= 0x55555555; // x = -f-e -d-c -b-a -9-8 -7-6 -5-4 -3-2 -1-0
64  x = (x ^ (x >> 1)) & 0x33333333; // x = --fe --dc --ba --98 --76 --54 --32 --10
65  x = (x ^ (x >> 2)) & 0x0f0f0f0f; // x = ---- fedc ---- ba98 ---- 7654 ---- 3210
66  x = (x ^ (x >> 4)) & 0x00ff00ff; // x = ---- ---- fedc ba98 ---- ---- 7654 3210
67  x = (x ^ (x >> 8)) & 0x0000ffff; // x = ---- ---- ---- ---- fedc ba98 7654 3210
68 
69  return x;
70 }
71 
72 
73 // Inverse of Part1By2 - "delete" all bits not at positions divisible by 3
74 uint32_t Compact1By2( uint32_t x )
75 {
76  x &= 0x09249249; // x = ---- 9--8 --7- -6-- 5--4 --3- -2-- 1--0
77  x = (x ^ (x >> 2)) & 0x030c30c3; // x = ---- --98 ---- 76-- --54 ---- 32-- --10
78  x = (x ^ (x >> 4)) & 0x0300f00f; // x = ---- --98 ---- ---- 7654 ---- ---- 3210
79  x = (x ^ (x >> 8)) & 0xff0000ff; // x = ---- --98 ---- ---- ---- ---- 7654 3210
80  x = (x ^ (x >> 16)) & 0x000003ff; // x = ---- ---- ---- ---- ---- --98 7654 3210
81 
82  return x;
83 }
84 
85 
86 uint32_t EncodeMorton2( uint32_t x, uint32_t y )
87 {
88  return ( Part1By1( y ) << 1 ) + Part1By1( x );
89 }
90 
91 
92 uint32_t EncodeMorton3( uint32_t x, uint32_t y, uint32_t z )
93 {
94  return ( Part1By2( z ) << 2 ) + ( Part1By2( y ) << 1 ) + Part1By2( x );
95 }
96 
97 
98 uint32_t DecodeMorton2X( uint32_t code )
99 {
100  return Compact1By1( code >> 0 );
101 }
102 
103 
104 uint32_t DecodeMorton2Y( uint32_t code )
105 {
106  return Compact1By1( code >> 1 );
107 }
108 
109 
110 uint32_t DecodeMorton3X( uint32_t code )
111 {
112  return Compact1By2( code >> 0 );
113 }
114 
115 
116 uint32_t DecodeMorton3Y( uint32_t code )
117 {
118  return Compact1By2( code >> 1 );
119 }
120 
121 
122 uint32_t DecodeMorton3Z( uint32_t code )
123 {
124  return Compact1By2( code >> 2 );
125 }
uint32_t EncodeMorton2(uint32_t x, uint32_t y)
Definition: mortoncodes.cpp:86
uint32_t DecodeMorton2X(uint32_t code)
Definition: mortoncodes.cpp:98
uint32_t Compact1By2(uint32_t x)
Definition: mortoncodes.cpp:74
uint32_t DecodeMorton2Y(uint32_t code)
uint32_t DecodeMorton3X(uint32_t code)
uint32_t Part1By2(uint32_t x)
Definition: mortoncodes.cpp:48
uint32_t Compact1By1(uint32_t x)
Definition: mortoncodes.cpp:61
Implementes Morton Codes https://fgiesen.wordpress.com/2009/12/13/decoding-morton-codes/ http://www...
uint32_t EncodeMorton3(uint32_t x, uint32_t y, uint32_t z)
Definition: mortoncodes.cpp:92
uint32_t DecodeMorton3Z(uint32_t code)
uint32_t Part1By1(uint32_t x)
Definition: mortoncodes.cpp:35
uint32_t DecodeMorton3Y(uint32_t code)