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  1. #include <cstdint>
  2. #include <vector>
  3.  
  4. #define MAXMORTONKEY 321685687669321 //21 bits MAX morton key
  5.  
  6. std::vector<uint32_t> mortonkeyX;
  7. std::vector<uint32_t> mortonkeyY;
  8. std::vector<uint32_t> mortonkeyZ;
  9. /*Compute a 256 array of morton keys at compile time*/
  10. template <uint32_t i, uint32_t offset>
  11. struct morton
  12. {
  13. 	enum
  14. 	{
  15. 		//Use a little trick to calculate next morton key
  16. 		//mortonkey(x+1) = (mortonkey(x) - MAXMORTONKEY) & MAXMORTONKEY
  17. 		value = (morton<i - 1, offset>::value - MAXMORTONKEY) & MAXMORTONKEY
  18. 	};
  19. 	static void add_values(std::vector<uint32_t>& v)
  20. 	{
  21. 		morton<i - 1, offset>::add_values(v);
  22. 		v.push_back(value<<offset);
  23. 	}
  24. };
  25. template <uint32_t offset>
  26. struct morton<0, offset>
  27. {
  28. 	enum
  29. 	{
  30. 		value = 0
  31. 	};
  32. 	static void add_values(std::vector<uint32_t>& v)
  33. 	{
  34. 		v.push_back(value);
  35. 	}
  36. };
  37.  
  38. uint32_t encodeMortonKey(uint8_t x, uint8_t y, uint8_t z)
  39. {
  40. 	/*uint64_t result = 0;
  41. 	result = mortonkeyZ[(z >> 16) & 0xFF] |
  42. 	  mortonkeyY[(y >> 16) & 0xFF] |
  43. 	  mortonkeyX[(x >> 16) & 0xFF];
  44. 	result = result << 48 |
  45. 	  mortonkeyZ[(z >> 8) & 0xFF] |
  46. 	  mortonkeyY[(y >> 8) & 0xFF] |
  47. 	  mortonkeyX[(x >> 8) & 0xFF];
  48. 	result = result << 24 |
  49. 	  mortonkeyZ[(z)& 0xFF] |
  50. 	  mortonkeyY[(y)& 0xFF] |
  51. 	  mortonkeyX[(x)& 0xFF];*/
  52. 	//return result;
  53. 	return mortonkeyX[x] | mortonkeyY[y] | mortonkeyZ[z];
  54. }
  55.  
  56. #include <iostream>
  57.  
  58. #define TESTSIZE 512
  59.  
  60. int main() {
  61.  
  62. 	//init vectors with precomputed morton keys
  63. 	morton<256, 0>::add_values(mortonkeyX);
  64. 	morton<256, 1>::add_values(mortonkeyY);
  65. 	morton<256, 2>::add_values(mortonkeyZ);
  66.  
  67. 	uint32_t key;
  68. 	for (int x = 0; x <= TESTSIZE; ++x)
  69. 	{
  70. 		for (int y = 0; y <= TESTSIZE; ++y)
  71. 		{
  72. 			for (int z = 0; z <= TESTSIZE; ++z)
  73. 			{
  74. 				key = encodeMortonKey(x, y, z);
  75. 			}
  76. 		}
  77. 	}
  78. 	/*std::cout << encodeMortonKey(0, 0, 0) << std::endl;
  79. 	std::cout << encodeMortonKey(1, 0, 0) << std::endl;
  80. 	std::cout << encodeMortonKey(0, 1, 0) << std::endl;
  81. 	std::cout << encodeMortonKey(0, 0, 1) << std::endl;
  82. 	std::cout << encodeMortonKey(5, 2, 5) << std::endl;
  83. 	std::cout << encodeMortonKey(512, 512, 512) << std::endl;
  84. 	std::cout << encodeMortonKey(695837, 6583067, 1836573) << std::endl;*/
  85.  
  86. 	uint32_t last = 0;
  87. 	for(int i=1; i<32; ++i)
  88. 	{
  89. 		std::cout << mortonkeyX[i]-last << ",";
  90. 		last = mortonkeyX[i];
  91. 	}
  92. }
Success #stdin #stdout 0s 3296KB
comments (?)
stdin 
Standard input is empty
stdout 
1,7,1,55,1,7,1,439,1,7,1,55,1,7,1,3511,1,7,1,55,1,7,1,439,1,7,1,55,1,7,1,
https://ideone.com/wHEFTu
Create Morton keys at compile time
language:
C++14 (gcc 8.3)
created:
9 years ago
visibility:
public

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