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https://github.com/MadeOfJelly/MushMachine.git
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add Squirrel Eiserloh's rng, and own helper
This commit is contained in:
parent
1f483b1752
commit
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2
external/CMakeLists.txt
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2
external/CMakeLists.txt
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@ -15,6 +15,8 @@ add_subdirectory("tracy")
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include("${CMAKE_CURRENT_SOURCE_DIR}/entt.cmake")
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include("${CMAKE_CURRENT_SOURCE_DIR}/glm.cmake")
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add_subdirectory("SquirrelNoise")
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set(JSON_BuildTests OFF CACHE INTERNAL "")
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set(JSON_MultipleHeaders ON CACHE INTERNAL "")
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add_subdirectory("json") # link with "nlohmann_json::nlohmann_json"
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18
external/SquirrelNoise/CMakeLists.txt
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external/SquirrelNoise/CMakeLists.txt
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cmake_minimum_required(VERSION 3.2)
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project(SquirrelNoise)
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add_library(squirrel_noise
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./src/squirrel_noise/RawNoise.hpp
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./src/squirrel_noise/RawNoise.cpp
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# TODO: seperate smooth?
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./src/squirrel_noise/SmoothNoise.hpp
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./src/squirrel_noise/SmoothNoise.cpp
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)
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target_include_directories(squirrel_noise PUBLIC "src")
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target_link_libraries(squirrel_noise
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PRIVATE glm
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)
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37
external/SquirrelNoise/src/squirrel_noise/RawNoise.cpp
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external/SquirrelNoise/src/squirrel_noise/RawNoise.cpp
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//-----------------------------------------------------------------------------------------------
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// RawNoise.cpp
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//
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#include "./RawNoise.hpp"
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namespace SquirrelNoise4 {
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//-----------------------------------------------------------------------------------------------
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// Fast hash of an int32 into a different (unrecognizable) uint32.
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//
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// Returns an uint32_t containing 32 reasonably-well-scrambled bits, based on the hash
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// of a given (signed) integer input parameter (position/index) and [optional] seed. Kind of
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// like looking up a value in an infinitely large table of previously generated random numbers.
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//
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// The bit-noise constants and bit-shifts were evolved by a genetic algorithm using the
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// "BigCrush" test for fitness, and have so far produced excellent test results.
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//
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// I call this particular approach SquirrelNoise (version 4).
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//
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uint32_t Get1dNoiseUint32( int32_t positionX, uint32_t seed ) {
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const uint32_t BIT_NOISE1 = 0xD2A80A23; // 0b1101'0010'1010'1000'0000'1010'0010'0011;
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const uint32_t BIT_NOISE2 = 0xA884F197; // 0b1010'1000'1000'0100'1111'0001'1001'0111;
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const uint32_t BIT_NOISE3 = 0x1B56C4E9; // 0b0001'1011'0101'0110'1100'0100'1110'1001;
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uint32_t mangledBits = (uint32_t) positionX;
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mangledBits *= BIT_NOISE1;
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mangledBits += seed;
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mangledBits ^= (mangledBits >> 7);
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mangledBits += BIT_NOISE2;
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mangledBits ^= (mangledBits >> 8);
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mangledBits *= BIT_NOISE3;
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mangledBits ^= (mangledBits >> 11);
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return mangledBits;
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}
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} // SquirrelNoise4
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165
external/SquirrelNoise/src/squirrel_noise/RawNoise.hpp
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external/SquirrelNoise/src/squirrel_noise/RawNoise.hpp
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@ -0,0 +1,165 @@
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//-----------------------------------------------------------------------------------------------
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// RawNoise.hpp
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//
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#pragma once
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#include <cstdint>
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namespace SquirrelNoise4 {
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/////////////////////////////////////////////////////////////////////////////////////////////////
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// SquirrelNoise4 - Squirrel's Raw Noise utilities (version 4)
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//
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// This code is made available under the Creative Commons attribution 3.0 license (CC-BY-3.0 US):
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// Attribution in source code comments (even closed-source/commercial code) is sufficient.
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// License summary and text available at: https://creativecommons.org/licenses/by/3.0/us/
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//
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// These noise functions were written by Squirrel Eiserloh as a cheap and simple substitute for
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// the [sometimes awful] bit-noise sample code functions commonly found on the web, many of which
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// are hugely biased or terribly patterned, e.g. having bits which are on (or off) 75% or even
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// 100% of the time (or are WAY too overkill-and-slow for our needs, such as MD5 or SHA).
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//
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// Note: This is work in progress, and has not yet been tested thoroughly. Use at your own risk.
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// Please report any bugs, issues, or bothersome cases to SquirrelEiserloh at gmail.com.
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//
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// The following functions are all based on a simple bit-noise hash function which returns an
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// uint32_t containing 32 reasonably-well-scrambled bits, based on a given (signed)
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// integer input parameter (position/index) and [optional] seed. Kind of like looking up a
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// value in an infinitely large [non-existent] table of previously rolled random numbers.
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//
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// These functions are deterministic and random-access / order-independent (i.e. state-free),
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// so they are particularly well-suited for use in smoothed/fractal/simplex/Perlin noise
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// functions and out-of-order (or on-demand) procedural content generation (i.e. that mountain
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// village is the same whether you generated it first or last, ahead of time or just now).
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//
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// The N-dimensional variations simply hash their multidimensional coordinates down to a single
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// 32-bit index and then proceed as usual, so while results are not unique they should
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// (hopefully) not seem locally predictable or repetitive.
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//
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// Modified by Erik Scholz 2021, no change to the license.
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//
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/////////////////////////////////////////////////////////////////////////////////////////////////
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//-----------------------------------------------------------------------------------------------
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// Raw pseudorandom noise functions (random-access / deterministic). Basis of all other noise.
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//
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uint32_t Get1dNoiseUint32( int32_t index, uint32_t seed=0 );
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uint32_t Get2dNoiseUint32( int32_t indexX, int32_t indexY, uint32_t seed=0 );
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uint32_t Get3dNoiseUint32( int32_t indexX, int32_t indexY, int32_t indexZ, uint32_t seed=0 );
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uint32_t Get4dNoiseUint32( int32_t indexX, int32_t indexY, int32_t indexZ, int32_t indexT, uint32_t seed=0 );
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//-----------------------------------------------------------------------------------------------
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// Same functions, mapped to floats in [0,1] for convenience.
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//
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float Get1dNoiseZeroToOne( int32_t index, uint32_t seed=0 );
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float Get2dNoiseZeroToOne( int32_t indexX, int32_t indexY, uint32_t seed=0 );
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float Get3dNoiseZeroToOne( int32_t indexX, int32_t indexY, int32_t indexZ, uint32_t seed=0 );
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float Get4dNoiseZeroToOne( int32_t indexX, int32_t indexY, int32_t indexZ, int32_t indexT, uint32_t seed=0 );
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//-----------------------------------------------------------------------------------------------
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// Same functions, mapped to floats in [-1,1] for convenience.
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//
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float Get1dNoiseNegOneToOne( int32_t index, uint32_t seed=0 );
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float Get2dNoiseNegOneToOne( int32_t indexX, int32_t indexY, uint32_t seed=0 );
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float Get3dNoiseNegOneToOne( int32_t indexX, int32_t indexY, int32_t indexZ, uint32_t seed=0 );
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float Get4dNoiseNegOneToOne( int32_t indexX, int32_t indexY, int32_t indexZ, int32_t indexT, uint32_t seed=0 );
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/////////////////////////////////////////////////////////////////////////////////////////////////
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// Simple functions inlined below
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/////////////////////////////////////////////////////////////////////////////////////////////////
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//-----------------------------------------------------------------------------------------------
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inline uint32_t Get2dNoiseUint32( int32_t indexX, int32_t indexY, uint32_t seed )
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{
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const int32_t PRIME_NUMBER = 198491317; // Large prime number with non-boring bits
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return Get1dNoiseUint32( indexX + (PRIME_NUMBER * indexY), seed );
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}
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//-----------------------------------------------------------------------------------------------
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inline uint32_t Get3dNoiseUint32( int32_t indexX, int32_t indexY, int32_t indexZ, uint32_t seed )
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{
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const int32_t PRIME1 = 198491317; // Large prime number with non-boring bits
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const int32_t PRIME2 = 6542989; // Large prime number with distinct and non-boring bits
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return Get1dNoiseUint32( indexX + (PRIME1 * indexY) + (PRIME2 * indexZ), seed );
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}
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//-----------------------------------------------------------------------------------------------
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inline uint32_t Get4dNoiseUint32( int32_t indexX, int32_t indexY, int32_t indexZ, int32_t indexT, uint32_t seed )
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{
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const int32_t PRIME1 = 198491317; // Large prime number with non-boring bits
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const int32_t PRIME2 = 6542989; // Large prime number with distinct and non-boring bits
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const int32_t PRIME3 = 357239; // Large prime number with distinct and non-boring bits
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return Get1dNoiseUint32( indexX + (PRIME1 * indexY) + (PRIME2 * indexZ) + (PRIME3 * indexT), seed );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get1dNoiseZeroToOne( int32_t index, uint32_t seed )
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{
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const double ONE_OVER_MAX_UINT = (1.0 / (double) 0xFFFFFFFF);
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return (float)( ONE_OVER_MAX_UINT * (double) Get1dNoiseUint32( index, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get2dNoiseZeroToOne( int32_t indexX, int32_t indexY, uint32_t seed )
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{
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const double ONE_OVER_MAX_UINT = (1.0 / (double) 0xFFFFFFFF);
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return (float)( ONE_OVER_MAX_UINT * (double) Get2dNoiseUint32( indexX, indexY, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get3dNoiseZeroToOne( int32_t indexX, int32_t indexY, int32_t indexZ, uint32_t seed )
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{
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const double ONE_OVER_MAX_UINT = (1.0 / (double) 0xFFFFFFFF);
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return (float)( ONE_OVER_MAX_UINT * (double) Get3dNoiseUint32( indexX, indexY, indexZ, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get4dNoiseZeroToOne( int32_t indexX, int32_t indexY, int32_t indexZ, int32_t indexT, uint32_t seed )
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{
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const double ONE_OVER_MAX_UINT = (1.0 / (double) 0xFFFFFFFF);
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return (float)( ONE_OVER_MAX_UINT * (double) Get4dNoiseUint32( indexX, indexY, indexZ, indexT, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get1dNoiseNegOneToOne( int32_t index, uint32_t seed )
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{
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const double ONE_OVER_MAX_INT = (1.0 / (double) 0x7FFFFFFF);
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return (float)( ONE_OVER_MAX_INT * (double) (int32_t) Get1dNoiseUint32( index, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get2dNoiseNegOneToOne( int32_t indexX, int32_t indexY, uint32_t seed )
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{
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const double ONE_OVER_MAX_INT = (1.0 / (double) 0x7FFFFFFF);
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return (float)( ONE_OVER_MAX_INT * (double) (int32_t) Get2dNoiseUint32( indexX, indexY, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get3dNoiseNegOneToOne( int32_t indexX, int32_t indexY, int32_t indexZ, uint32_t seed )
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{
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const double ONE_OVER_MAX_INT = (1.0 / (double) 0x7FFFFFFF);
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return (float)( ONE_OVER_MAX_INT * (double) (int32_t) Get3dNoiseUint32( indexX, indexY, indexZ, seed ) );
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}
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//-----------------------------------------------------------------------------------------------
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inline float Get4dNoiseNegOneToOne( int32_t indexX, int32_t indexY, int32_t indexZ, int32_t indexT, uint32_t seed )
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{
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const double ONE_OVER_MAX_INT = (1.0 / (double) 0x7FFFFFFF);
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return (float)( ONE_OVER_MAX_INT * (double) (int32_t) Get4dNoiseUint32( indexX, indexY, indexZ, indexT, seed ) );
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}
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} // SquirrelNoise4
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756
external/SquirrelNoise/src/squirrel_noise/SmoothNoise.cpp
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external/SquirrelNoise/src/squirrel_noise/SmoothNoise.cpp
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//-----------------------------------------------------------------------------------------------
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// SmoothNoise.cpp
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//
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#include "./RawNoise.hpp"
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#include <glm/vec2.hpp>
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#include <glm/vec3.hpp>
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#include <glm/vec4.hpp>
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#include <glm/common.hpp>
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#include <glm/geometric.hpp>
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/////////////////////////////////////////////////////////////////////////////////////////////////
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// For all fractal (and Perlin) noise functions, the following internal naming conventions
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// are used, primarily to help me visualize 3D and 4D constructs clearly. They need not
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// have any actual bearing on / relationship to actual external coordinate systems.
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//
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// 1D noise: only X (+east / -west)
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// 2D noise: also Y (+north / -south)
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// 3D noise: also Z (+above / -below)
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// 4D noise: also T (+after / -before)
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/////////////////////////////////////////////////////////////////////////////////////////////////
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namespace SquirrelNoise4 {
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namespace Easing {
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static float SmoothStep( float t ) {
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//return 2*(t*t*t) - 3*(t*t);
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return t*t * (2*t-3); // optimised
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}
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} // Easing
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//-----------------------------------------------------------------------------------------------
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float Compute1dFractal( float position, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
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{
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const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
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float totalNoise = 0.f;
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float totalAmplitude = 0.f;
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float currentAmplitude = 1.f;
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float currentPosition = position * (1.f / scale);
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for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
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{
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// Determine noise values at nearby integer "grid point" positions
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float positionFloor = ::glm::floor( currentPosition );
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int32_t indexWest = (int32_t) positionFloor;
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int32_t indexEast = indexWest + 1;
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float valueWest = Get1dNoiseZeroToOne( indexWest, seed );
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float valueEast = Get1dNoiseZeroToOne( indexEast, seed );
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// Do a smoothed (nonlinear) weighted average of nearby grid point values
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float distanceFromWest = currentPosition - positionFloor;
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float weightEast = Easing::SmoothStep( distanceFromWest ); // Gives rounder (nonlinear) results
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float weightWest = 1.f - weightEast;
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float noiseZeroToOne = (valueWest * weightWest) + (valueEast * weightEast);
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float noiseThisOctave = 2.f * (noiseZeroToOne - 0.5f); // Map from [0,1] to [-1,1]
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// Accumulate results and prepare for next octave (if any)
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totalNoise += noiseThisOctave * currentAmplitude;
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totalAmplitude += currentAmplitude;
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currentAmplitude *= octavePersistence;
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currentPosition *= octaveScale;
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currentPosition += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
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++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
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}
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// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
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if( renormalize && totalAmplitude > 0.f )
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{
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totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used!
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totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
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totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
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totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
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}
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return totalNoise;
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}
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//-----------------------------------------------------------------------------------------------
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float Compute2dFractal( float posX, float posY, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
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{
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const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
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float totalNoise = 0.f;
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float totalAmplitude = 0.f;
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float currentAmplitude = 1.f;
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float invScale = (1.f / scale);
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::glm::vec2 currentPos( posX * invScale, posY * invScale );
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for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
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{
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// Determine noise values at nearby integer "grid point" positions
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::glm::vec2 cellMins( ::glm::floor( currentPos.x ), ::glm::floor( currentPos.y ) );
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int32_t indexWestX = (int32_t) cellMins.x;
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int32_t indexSouthY = (int32_t) cellMins.y;
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int32_t indexEastX = indexWestX + 1;
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int32_t indexNorthY = indexSouthY + 1;
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float valueSouthWest = Get2dNoiseZeroToOne( indexWestX, indexSouthY, seed );
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float valueSouthEast = Get2dNoiseZeroToOne( indexEastX, indexSouthY, seed );
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float valueNorthWest = Get2dNoiseZeroToOne( indexWestX, indexNorthY, seed );
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float valueNorthEast = Get2dNoiseZeroToOne( indexEastX, indexNorthY, seed );
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// Do a smoothed (nonlinear) weighted average of nearby grid point values
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::glm::vec2 displacementFromMins = currentPos - cellMins;
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float weightEast = Easing::SmoothStep( displacementFromMins.x );
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float weightNorth = Easing::SmoothStep( displacementFromMins.y );
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float weightWest = 1.f - weightEast;
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float weightSouth = 1.f - weightNorth;
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float blendSouth = (weightEast * valueSouthEast) + (weightWest * valueSouthWest);
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float blendNorth = (weightEast * valueNorthEast) + (weightWest * valueNorthWest);
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float blendTotal = (weightSouth * blendSouth) + (weightNorth * blendNorth);
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float noiseThisOctave = 2.f * (blendTotal - 0.5f); // Map from [0,1] to [-1,1]
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// Accumulate results and prepare for next octave (if any)
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totalNoise += noiseThisOctave * currentAmplitude;
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totalAmplitude += currentAmplitude;
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currentAmplitude *= octavePersistence;
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currentPos *= octaveScale;
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currentPos.x += OCTAVE_OFFSET; // Add "irrational" offsets to noise position components
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currentPos.y += OCTAVE_OFFSET; // at each octave to break up their grid alignment
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++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
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}
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// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
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if( renormalize && totalAmplitude > 0.f )
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{
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totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
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totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
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totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
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totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
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}
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return totalNoise;
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}
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||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
float Compute3dFractal( float posX, float posY, float posZ, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
|
||||
{
|
||||
const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
|
||||
|
||||
float totalNoise = 0.f;
|
||||
float totalAmplitude = 0.f;
|
||||
float currentAmplitude = 1.f;
|
||||
float invScale = (1.f / scale);
|
||||
::glm::vec3 currentPos( posX * invScale, posY * invScale, posZ * invScale );
|
||||
|
||||
for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
|
||||
{
|
||||
// Determine noise values at nearby integer "grid point" positions
|
||||
::glm::vec3 cellMins( ::glm::floor( currentPos.x ), ::glm::floor( currentPos.y ), ::glm::floor( currentPos.z ) );
|
||||
int32_t indexWestX = (int32_t) cellMins.x;
|
||||
int32_t indexSouthY = (int32_t) cellMins.y;
|
||||
int32_t indexBelowZ = (int32_t) cellMins.z;
|
||||
int32_t indexEastX = indexWestX + 1;
|
||||
int32_t indexNorthY = indexSouthY + 1;
|
||||
int32_t indexAboveZ = indexBelowZ + 1;
|
||||
|
||||
// Noise grid cell has 8 corners in 3D
|
||||
float aboveSouthWest = Get3dNoiseZeroToOne( indexWestX, indexSouthY, indexAboveZ, seed );
|
||||
float aboveSouthEast = Get3dNoiseZeroToOne( indexEastX, indexSouthY, indexAboveZ, seed );
|
||||
float aboveNorthWest = Get3dNoiseZeroToOne( indexWestX, indexNorthY, indexAboveZ, seed );
|
||||
float aboveNorthEast = Get3dNoiseZeroToOne( indexEastX, indexNorthY, indexAboveZ, seed );
|
||||
float belowSouthWest = Get3dNoiseZeroToOne( indexWestX, indexSouthY, indexBelowZ, seed );
|
||||
float belowSouthEast = Get3dNoiseZeroToOne( indexEastX, indexSouthY, indexBelowZ, seed );
|
||||
float belowNorthWest = Get3dNoiseZeroToOne( indexWestX, indexNorthY, indexBelowZ, seed );
|
||||
float belowNorthEast = Get3dNoiseZeroToOne( indexEastX, indexNorthY, indexBelowZ, seed );
|
||||
|
||||
// Do a smoothed (nonlinear) weighted average of nearby grid point values
|
||||
::glm::vec3 displacementFromMins = currentPos - cellMins;
|
||||
|
||||
float weightEast = Easing::SmoothStep( displacementFromMins.x );
|
||||
float weightNorth = Easing::SmoothStep( displacementFromMins.y );
|
||||
float weightAbove = Easing::SmoothStep( displacementFromMins.z );
|
||||
float weightWest = 1.f - weightEast;
|
||||
float weightSouth = 1.f - weightNorth;
|
||||
float weightBelow = 1.f - weightAbove;
|
||||
|
||||
// 8-way blend (8 -> 4 -> 2 -> 1)
|
||||
float blendBelowSouth = (weightEast * belowSouthEast) + (weightWest * belowSouthWest);
|
||||
float blendBelowNorth = (weightEast * belowNorthEast) + (weightWest * belowNorthWest);
|
||||
float blendAboveSouth = (weightEast * aboveSouthEast) + (weightWest * aboveSouthWest);
|
||||
float blendAboveNorth = (weightEast * aboveNorthEast) + (weightWest * aboveNorthWest);
|
||||
float blendBelow = (weightSouth * blendBelowSouth) + (weightNorth * blendBelowNorth);
|
||||
float blendAbove = (weightSouth * blendAboveSouth) + (weightNorth * blendAboveNorth);
|
||||
float blendTotal = (weightBelow * blendBelow) + (weightAbove * blendAbove);
|
||||
float noiseThisOctave = 2.f * (blendTotal - 0.5f); // Map from [0,1] to [-1,1]
|
||||
|
||||
// Accumulate results and prepare for next octave (if any)
|
||||
totalNoise += noiseThisOctave * currentAmplitude;
|
||||
totalAmplitude += currentAmplitude;
|
||||
currentAmplitude *= octavePersistence;
|
||||
currentPos *= octaveScale;
|
||||
currentPos.x += OCTAVE_OFFSET; // Add "irrational" offsets to noise position components
|
||||
currentPos.y += OCTAVE_OFFSET; // at each octave to break up their grid alignment
|
||||
currentPos.z += OCTAVE_OFFSET;
|
||||
++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
|
||||
}
|
||||
|
||||
// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
|
||||
if( renormalize && totalAmplitude > 0.f )
|
||||
{
|
||||
totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
|
||||
totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
|
||||
totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
|
||||
totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
|
||||
}
|
||||
|
||||
return totalNoise;
|
||||
}
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
float Compute4dFractal( float posX, float posY, float posZ, float posT, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
|
||||
{
|
||||
const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
|
||||
|
||||
float totalNoise = 0.f;
|
||||
float totalAmplitude = 0.f;
|
||||
float currentAmplitude = 1.f;
|
||||
float invScale = (1.f / scale);
|
||||
::glm::vec4 currentPos( posX * invScale, posY * invScale, posZ * invScale, posT * invScale );
|
||||
|
||||
for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
|
||||
{
|
||||
// Determine noise values at nearby integer "grid point" positions
|
||||
::glm::vec4 cellMins( ::glm::floor( currentPos.x ), ::glm::floor( currentPos.y ), ::glm::floor( currentPos.z ), ::glm::floor( currentPos.w ) );
|
||||
int32_t indexWestX = (int32_t) cellMins.x;
|
||||
int32_t indexSouthY = (int32_t) cellMins.y;
|
||||
int32_t indexBelowZ = (int32_t) cellMins.z;
|
||||
int32_t indexBeforeT = (int32_t) cellMins.w;
|
||||
int32_t indexEastX = indexWestX + 1;
|
||||
int32_t indexNorthY = indexSouthY + 1;
|
||||
int32_t indexAboveZ = indexBelowZ + 1;
|
||||
int32_t indexAfterT = indexBeforeT + 1;
|
||||
|
||||
// Noise grid cell has 16 "corners" in 4D
|
||||
float beforeBelowSW = Get4dNoiseZeroToOne( indexWestX, indexSouthY, indexBelowZ, indexBeforeT, seed );
|
||||
float beforeBelowSE = Get4dNoiseZeroToOne( indexEastX, indexSouthY, indexBelowZ, indexBeforeT, seed );
|
||||
float beforeBelowNW = Get4dNoiseZeroToOne( indexWestX, indexNorthY, indexBelowZ, indexBeforeT, seed );
|
||||
float beforeBelowNE = Get4dNoiseZeroToOne( indexEastX, indexNorthY, indexBelowZ, indexBeforeT, seed );
|
||||
float beforeAboveSW = Get4dNoiseZeroToOne( indexWestX, indexSouthY, indexAboveZ, indexBeforeT, seed );
|
||||
float beforeAboveSE = Get4dNoiseZeroToOne( indexEastX, indexSouthY, indexAboveZ, indexBeforeT, seed );
|
||||
float beforeAboveNW = Get4dNoiseZeroToOne( indexWestX, indexNorthY, indexAboveZ, indexBeforeT, seed );
|
||||
float beforeAboveNE = Get4dNoiseZeroToOne( indexEastX, indexNorthY, indexAboveZ, indexBeforeT, seed );
|
||||
|
||||
float afterBelowSW = Get4dNoiseZeroToOne( indexWestX, indexSouthY, indexBelowZ, indexAfterT, seed );
|
||||
float afterBelowSE = Get4dNoiseZeroToOne( indexEastX, indexSouthY, indexBelowZ, indexAfterT, seed );
|
||||
float afterBelowNW = Get4dNoiseZeroToOne( indexWestX, indexNorthY, indexBelowZ, indexAfterT, seed );
|
||||
float afterBelowNE = Get4dNoiseZeroToOne( indexEastX, indexNorthY, indexBelowZ, indexAfterT, seed );
|
||||
float afterAboveSW = Get4dNoiseZeroToOne( indexWestX, indexSouthY, indexAboveZ, indexAfterT, seed );
|
||||
float afterAboveSE = Get4dNoiseZeroToOne( indexEastX, indexSouthY, indexAboveZ, indexAfterT, seed );
|
||||
float afterAboveNW = Get4dNoiseZeroToOne( indexWestX, indexNorthY, indexAboveZ, indexAfterT, seed );
|
||||
float afterAboveNE = Get4dNoiseZeroToOne( indexEastX, indexNorthY, indexAboveZ, indexAfterT, seed );
|
||||
|
||||
// Do a smoothed (nonlinear) weighted average of nearby grid point values
|
||||
::glm::vec4 displacementFromMins = currentPos - cellMins;
|
||||
|
||||
float weightEast = Easing::SmoothStep( displacementFromMins.x );
|
||||
float weightNorth = Easing::SmoothStep( displacementFromMins.y );
|
||||
float weightAbove = Easing::SmoothStep( displacementFromMins.z );
|
||||
float weightAfter = Easing::SmoothStep( displacementFromMins.w );
|
||||
float weightWest = 1.f - weightEast;
|
||||
float weightSouth = 1.f - weightNorth;
|
||||
float weightBelow = 1.f - weightAbove;
|
||||
float weightBefore = 1.f - weightAfter;
|
||||
|
||||
// 16-way blend (16 -> 8 -> 4 -> 2 -> 1)
|
||||
float blendBeforeBelowSouth = (weightEast * beforeBelowSE) + (weightWest * beforeBelowSW);
|
||||
float blendBeforeBelowNorth = (weightEast * beforeBelowNE) + (weightWest * beforeBelowNW);
|
||||
float blendBeforeAboveSouth = (weightEast * beforeAboveSE) + (weightWest * beforeAboveSW);
|
||||
float blendBeforeAboveNorth = (weightEast * beforeAboveNE) + (weightWest * beforeAboveNW);
|
||||
float blendAfterBelowSouth = (weightEast * afterBelowSE) + (weightWest * afterBelowSW);
|
||||
float blendAfterBelowNorth = (weightEast * afterBelowNE) + (weightWest * afterBelowNW);
|
||||
float blendAfterAboveSouth = (weightEast * afterAboveSE) + (weightWest * afterAboveSW);
|
||||
float blendAfterAboveNorth = (weightEast * afterAboveNE) + (weightWest * afterAboveNW);
|
||||
float blendBeforeBelow = (weightSouth * blendBeforeBelowSouth) + (weightNorth * blendBeforeBelowNorth);
|
||||
float blendBeforeAbove = (weightSouth * blendBeforeAboveSouth) + (weightNorth * blendBeforeAboveNorth);
|
||||
float blendAfterBelow = (weightSouth * blendAfterBelowSouth) + (weightNorth * blendAfterBelowNorth);
|
||||
float blendAfterAbove = (weightSouth * blendAfterAboveSouth) + (weightNorth * blendAfterAboveNorth);
|
||||
float blendBefore = (weightBelow * blendBeforeBelow) + (weightAbove * blendBeforeAbove);
|
||||
float blendAfter = (weightBelow * blendAfterBelow) + (weightAbove * blendAfterAbove);
|
||||
float blendTotal = (weightBefore * blendBefore) + (weightAfter * blendAfter);
|
||||
float noiseThisOctave = 2.f * (blendTotal - 0.5f); // Map from [0,1] to [-1,1]
|
||||
|
||||
// Accumulate results and prepare for next octave (if any)
|
||||
totalNoise += noiseThisOctave * currentAmplitude;
|
||||
totalAmplitude += currentAmplitude;
|
||||
currentAmplitude *= octavePersistence;
|
||||
currentPos *= octaveScale;
|
||||
currentPos.x += OCTAVE_OFFSET; // Add "irrational" offsets to noise position components
|
||||
currentPos.y += OCTAVE_OFFSET; // at each octave to break up their grid alignment
|
||||
currentPos.z += OCTAVE_OFFSET;
|
||||
currentPos.w += OCTAVE_OFFSET;
|
||||
++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
|
||||
}
|
||||
|
||||
// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
|
||||
if( renormalize && totalAmplitude > 0.f )
|
||||
{
|
||||
totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
|
||||
totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
|
||||
totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
|
||||
totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
|
||||
}
|
||||
|
||||
return totalNoise;
|
||||
}
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Perlin noise is fractal noise with "gradient vector smoothing" applied.
|
||||
//
|
||||
// In 1D, the gradients are trivial: -1.0 or 1.0, so resulting noise is boring at one octave.
|
||||
//
|
||||
float Compute1dPerlin( float position, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
|
||||
{
|
||||
const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
|
||||
const float gradients[2] = { -1.f, 1.f }; // 1D unit "gradient" vectors; one back, one forward
|
||||
|
||||
float totalNoise = 0.f;
|
||||
float totalAmplitude = 0.f;
|
||||
float currentAmplitude = 1.f;
|
||||
float currentPosition = position * (1.f / scale);
|
||||
|
||||
for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
|
||||
{
|
||||
// Determine random "gradient vectors" (just +1 or -1 for 1D Perlin) for surrounding corners
|
||||
float positionFloor = (float) ::glm::floor( currentPosition );
|
||||
int32_t indexWest = (int32_t) positionFloor;
|
||||
int32_t indexEast = indexWest + 1;
|
||||
float gradientWest = gradients[ Get1dNoiseUint32( indexWest, seed ) & 0x00000001 ];
|
||||
float gradientEast = gradients[ Get1dNoiseUint32( indexEast, seed ) & 0x00000001 ];
|
||||
|
||||
// Dot each point's gradient with displacement from point to position
|
||||
float displacementFromWest = currentPosition - positionFloor; // always positive
|
||||
float displacementFromEast = displacementFromWest - 1.f; // always negative
|
||||
float dotWest = gradientWest * displacementFromWest; // 1D "dot product" is... multiply
|
||||
float dotEast = gradientEast * displacementFromEast;
|
||||
|
||||
// Do a smoothed (nonlinear) weighted average of dot results
|
||||
float weightEast = Easing::SmoothStep( displacementFromWest );
|
||||
float weightWest = 1.f - weightEast;
|
||||
float blendTotal = (weightWest * dotWest) + (weightEast * dotEast);
|
||||
float noiseThisOctave = 2.f * blendTotal; // 1D Perlin is in [-.5,.5]; map to [-1,1]
|
||||
|
||||
// Accumulate results and prepare for next octave (if any)
|
||||
totalNoise += noiseThisOctave * currentAmplitude;
|
||||
totalAmplitude += currentAmplitude;
|
||||
currentAmplitude *= octavePersistence;
|
||||
currentPosition *= octaveScale;
|
||||
currentPosition += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
|
||||
}
|
||||
|
||||
// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
|
||||
if( renormalize && totalAmplitude > 0.f )
|
||||
{
|
||||
totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
|
||||
totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
|
||||
totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
|
||||
totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
|
||||
}
|
||||
|
||||
return totalNoise;
|
||||
}
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Perlin noise is fractal noise with "gradient vector smoothing" applied.
|
||||
//
|
||||
// In 2D, gradients are unit-length vectors in various directions with even angular distribution.
|
||||
//
|
||||
float Compute2dPerlin( float posX, float posY, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
|
||||
{
|
||||
const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
|
||||
const ::glm::vec2 gradients[ 8 ] = // Normalized unit vectors in 8 quarter-cardinal directions
|
||||
{
|
||||
::glm::vec2( +0.923879533f, +0.382683432f ), // 22.5 degrees (ENE)
|
||||
::glm::vec2( +0.382683432f, +0.923879533f ), // 67.5 degrees (NNE)
|
||||
::glm::vec2( -0.382683432f, +0.923879533f ), // 112.5 degrees (NNW)
|
||||
::glm::vec2( -0.923879533f, +0.382683432f ), // 157.5 degrees (WNW)
|
||||
::glm::vec2( -0.923879533f, -0.382683432f ), // 202.5 degrees (WSW)
|
||||
::glm::vec2( -0.382683432f, -0.923879533f ), // 247.5 degrees (SSW)
|
||||
::glm::vec2( +0.382683432f, -0.923879533f ), // 292.5 degrees (SSE)
|
||||
::glm::vec2( +0.923879533f, -0.382683432f ) // 337.5 degrees (ESE)
|
||||
};
|
||||
|
||||
float totalNoise = 0.f;
|
||||
float totalAmplitude = 0.f;
|
||||
float currentAmplitude = 1.f;
|
||||
float invScale = (1.f / scale);
|
||||
::glm::vec2 currentPos( posX * invScale, posY * invScale );
|
||||
|
||||
for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
|
||||
{
|
||||
// Determine random unit "gradient vectors" for surrounding corners
|
||||
::glm::vec2 cellMins( ::glm::floor( currentPos.x ), ::glm::floor( currentPos.y ) );
|
||||
::glm::vec2 cellMaxs( cellMins.x + 1.f, cellMins.y + 1.f );
|
||||
int32_t indexWestX = (int32_t) cellMins.x;
|
||||
int32_t indexSouthY = (int32_t) cellMins.y;
|
||||
int32_t indexEastX = indexWestX + 1;
|
||||
int32_t indexNorthY = indexSouthY + 1;
|
||||
|
||||
uint32_t noiseSW = Get2dNoiseUint32( indexWestX, indexSouthY, seed );
|
||||
uint32_t noiseSE = Get2dNoiseUint32( indexEastX, indexSouthY, seed );
|
||||
uint32_t noiseNW = Get2dNoiseUint32( indexWestX, indexNorthY, seed );
|
||||
uint32_t noiseNE = Get2dNoiseUint32( indexEastX, indexNorthY, seed );
|
||||
|
||||
const ::glm::vec2& gradientSW = gradients[ noiseSW & 0x00000007 ];
|
||||
const ::glm::vec2& gradientSE = gradients[ noiseSE & 0x00000007 ];
|
||||
const ::glm::vec2& gradientNW = gradients[ noiseNW & 0x00000007 ];
|
||||
const ::glm::vec2& gradientNE = gradients[ noiseNE & 0x00000007 ];
|
||||
|
||||
// Dot each corner's gradient with displacement from corner to position
|
||||
::glm::vec2 displacementFromSW( currentPos.x - cellMins.x, currentPos.y - cellMins.y );
|
||||
::glm::vec2 displacementFromSE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y );
|
||||
::glm::vec2 displacementFromNW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y );
|
||||
::glm::vec2 displacementFromNE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y );
|
||||
|
||||
float dotSouthWest = ::glm::dot( gradientSW, displacementFromSW );
|
||||
float dotSouthEast = ::glm::dot( gradientSE, displacementFromSE );
|
||||
float dotNorthWest = ::glm::dot( gradientNW, displacementFromNW );
|
||||
float dotNorthEast = ::glm::dot( gradientNE, displacementFromNE );
|
||||
|
||||
// Do a smoothed (nonlinear) weighted average of dot results
|
||||
float weightEast = Easing::SmoothStep( displacementFromSW.x );
|
||||
float weightNorth = Easing::SmoothStep( displacementFromSW.y );
|
||||
float weightWest = 1.f - weightEast;
|
||||
float weightSouth = 1.f - weightNorth;
|
||||
|
||||
float blendSouth = (weightEast * dotSouthEast) + (weightWest * dotSouthWest);
|
||||
float blendNorth = (weightEast * dotNorthEast) + (weightWest * dotNorthWest);
|
||||
float blendTotal = (weightSouth * blendSouth) + (weightNorth * blendNorth);
|
||||
float noiseThisOctave = blendTotal * (1.f / 0.662578106f); // 2D Perlin is in [-.662578106,.662578106]; map to ~[-1,1]
|
||||
|
||||
// Accumulate results and prepare for next octave (if any)
|
||||
totalNoise += noiseThisOctave * currentAmplitude;
|
||||
totalAmplitude += currentAmplitude;
|
||||
currentAmplitude *= octavePersistence;
|
||||
currentPos *= octaveScale;
|
||||
currentPos.x += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
currentPos.y += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
|
||||
}
|
||||
|
||||
// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
|
||||
if( renormalize && totalAmplitude > 0.f )
|
||||
{
|
||||
totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
|
||||
totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
|
||||
totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
|
||||
totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
|
||||
}
|
||||
|
||||
return totalNoise;
|
||||
}
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Perlin noise is fractal noise with "gradient vector smoothing" applied.
|
||||
//
|
||||
// In 3D, gradients are unit-length vectors in random (3D) directions.
|
||||
//
|
||||
float Compute3dPerlin( float posX, float posY, float posZ, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
|
||||
{
|
||||
const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
|
||||
const float fSQRT_3_OVER_3 = 0.577350269189f;
|
||||
const ::glm::vec3 gradients[ 8 ] = // Traditional "12 edges" requires modulus and isn't any better.
|
||||
{
|
||||
::glm::vec3( +fSQRT_3_OVER_3, +fSQRT_3_OVER_3, +fSQRT_3_OVER_3 ), // Normalized unit 3D vectors
|
||||
::glm::vec3( -fSQRT_3_OVER_3, +fSQRT_3_OVER_3, +fSQRT_3_OVER_3 ), // pointing toward cube
|
||||
::glm::vec3( +fSQRT_3_OVER_3, -fSQRT_3_OVER_3, +fSQRT_3_OVER_3 ), // corners, so components
|
||||
::glm::vec3( -fSQRT_3_OVER_3, -fSQRT_3_OVER_3, +fSQRT_3_OVER_3 ), // are all sqrt(3)/3, i.e.
|
||||
::glm::vec3( +fSQRT_3_OVER_3, +fSQRT_3_OVER_3, -fSQRT_3_OVER_3 ), // 0.5773502691896257645091f.
|
||||
::glm::vec3( -fSQRT_3_OVER_3, +fSQRT_3_OVER_3, -fSQRT_3_OVER_3 ), // These are slightly better
|
||||
::glm::vec3( +fSQRT_3_OVER_3, -fSQRT_3_OVER_3, -fSQRT_3_OVER_3 ), // than axes (1,0,0) and much
|
||||
::glm::vec3( -fSQRT_3_OVER_3, -fSQRT_3_OVER_3, -fSQRT_3_OVER_3 ) // faster than edges (1,1,0).
|
||||
};
|
||||
|
||||
float totalNoise = 0.f;
|
||||
float totalAmplitude = 0.f;
|
||||
float currentAmplitude = 1.f;
|
||||
float invScale = (1.f / scale);
|
||||
::glm::vec3 currentPos( posX * invScale, posY * invScale, posZ * invScale );
|
||||
|
||||
for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
|
||||
{
|
||||
// Determine random unit "gradient vectors" for surrounding corners
|
||||
::glm::vec3 cellMins( ::glm::floor( currentPos.x ), ::glm::floor( currentPos.y ), ::glm::floor( currentPos.z ) );
|
||||
::glm::vec3 cellMaxs( cellMins.x + 1.f, cellMins.y + 1.f, cellMins.z + 1.f );
|
||||
int32_t indexWestX = (int32_t) cellMins.x;
|
||||
int32_t indexSouthY = (int32_t) cellMins.y;
|
||||
int32_t indexBelowZ = (int32_t) cellMins.z;
|
||||
int32_t indexEastX = indexWestX + 1;
|
||||
int32_t indexNorthY = indexSouthY + 1;
|
||||
int32_t indexAboveZ = indexBelowZ + 1;
|
||||
|
||||
uint32_t noiseBelowSW = Get3dNoiseUint32( indexWestX, indexSouthY, indexBelowZ, seed );
|
||||
uint32_t noiseBelowSE = Get3dNoiseUint32( indexEastX, indexSouthY, indexBelowZ, seed );
|
||||
uint32_t noiseBelowNW = Get3dNoiseUint32( indexWestX, indexNorthY, indexBelowZ, seed );
|
||||
uint32_t noiseBelowNE = Get3dNoiseUint32( indexEastX, indexNorthY, indexBelowZ, seed );
|
||||
uint32_t noiseAboveSW = Get3dNoiseUint32( indexWestX, indexSouthY, indexAboveZ, seed );
|
||||
uint32_t noiseAboveSE = Get3dNoiseUint32( indexEastX, indexSouthY, indexAboveZ, seed );
|
||||
uint32_t noiseAboveNW = Get3dNoiseUint32( indexWestX, indexNorthY, indexAboveZ, seed );
|
||||
uint32_t noiseAboveNE = Get3dNoiseUint32( indexEastX, indexNorthY, indexAboveZ, seed );
|
||||
|
||||
::glm::vec3 gradientBelowSW = gradients[ noiseBelowSW & 0x00000007 ];
|
||||
::glm::vec3 gradientBelowSE = gradients[ noiseBelowSE & 0x00000007 ];
|
||||
::glm::vec3 gradientBelowNW = gradients[ noiseBelowNW & 0x00000007 ];
|
||||
::glm::vec3 gradientBelowNE = gradients[ noiseBelowNE & 0x00000007 ];
|
||||
::glm::vec3 gradientAboveSW = gradients[ noiseAboveSW & 0x00000007 ];
|
||||
::glm::vec3 gradientAboveSE = gradients[ noiseAboveSE & 0x00000007 ];
|
||||
::glm::vec3 gradientAboveNW = gradients[ noiseAboveNW & 0x00000007 ];
|
||||
::glm::vec3 gradientAboveNE = gradients[ noiseAboveNE & 0x00000007 ];
|
||||
|
||||
// Dot each corner's gradient with displacement from corner to position
|
||||
::glm::vec3 displacementFromBelowSW( currentPos.x - cellMins.x, currentPos.y - cellMins.y, currentPos.z - cellMins.z );
|
||||
::glm::vec3 displacementFromBelowSE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y, currentPos.z - cellMins.z );
|
||||
::glm::vec3 displacementFromBelowNW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y, currentPos.z - cellMins.z );
|
||||
::glm::vec3 displacementFromBelowNE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y, currentPos.z - cellMins.z );
|
||||
::glm::vec3 displacementFromAboveSW( currentPos.x - cellMins.x, currentPos.y - cellMins.y, currentPos.z - cellMaxs.z );
|
||||
::glm::vec3 displacementFromAboveSE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y, currentPos.z - cellMaxs.z );
|
||||
::glm::vec3 displacementFromAboveNW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y, currentPos.z - cellMaxs.z );
|
||||
::glm::vec3 displacementFromAboveNE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y, currentPos.z - cellMaxs.z );
|
||||
|
||||
float dotBelowSW = ::glm::dot( gradientBelowSW, displacementFromBelowSW );
|
||||
float dotBelowSE = ::glm::dot( gradientBelowSE, displacementFromBelowSE );
|
||||
float dotBelowNW = ::glm::dot( gradientBelowNW, displacementFromBelowNW );
|
||||
float dotBelowNE = ::glm::dot( gradientBelowNE, displacementFromBelowNE );
|
||||
float dotAboveSW = ::glm::dot( gradientAboveSW, displacementFromAboveSW );
|
||||
float dotAboveSE = ::glm::dot( gradientAboveSE, displacementFromAboveSE );
|
||||
float dotAboveNW = ::glm::dot( gradientAboveNW, displacementFromAboveNW );
|
||||
float dotAboveNE = ::glm::dot( gradientAboveNE, displacementFromAboveNE );
|
||||
|
||||
// Do a smoothed (nonlinear) weighted average of dot results
|
||||
float weightEast = Easing::SmoothStep( displacementFromBelowSW.x );
|
||||
float weightNorth = Easing::SmoothStep( displacementFromBelowSW.y );
|
||||
float weightAbove = Easing::SmoothStep( displacementFromBelowSW.z );
|
||||
float weightWest = 1.f - weightEast;
|
||||
float weightSouth = 1.f - weightNorth;
|
||||
float weightBelow = 1.f - weightAbove;
|
||||
|
||||
// 8-way blend (8 -> 4 -> 2 -> 1)
|
||||
float blendBelowSouth = (weightEast * dotBelowSE) + (weightWest * dotBelowSW);
|
||||
float blendBelowNorth = (weightEast * dotBelowNE) + (weightWest * dotBelowNW);
|
||||
float blendAboveSouth = (weightEast * dotAboveSE) + (weightWest * dotAboveSW);
|
||||
float blendAboveNorth = (weightEast * dotAboveNE) + (weightWest * dotAboveNW);
|
||||
float blendBelow = (weightSouth * blendBelowSouth) + (weightNorth * blendBelowNorth);
|
||||
float blendAbove = (weightSouth * blendAboveSouth) + (weightNorth * blendAboveNorth);
|
||||
float blendTotal = (weightBelow * blendBelow) + (weightAbove * blendAbove);
|
||||
float noiseThisOctave = blendTotal * (1.f / 0.793856621f); // 3D Perlin is in [-.793856621,.793856621]; map to ~[-1,1]
|
||||
|
||||
// Accumulate results and prepare for next octave (if any)
|
||||
totalNoise += noiseThisOctave * currentAmplitude;
|
||||
totalAmplitude += currentAmplitude;
|
||||
currentAmplitude *= octavePersistence;
|
||||
currentPos *= octaveScale;
|
||||
currentPos.x += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
currentPos.y += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
currentPos.z += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
|
||||
}
|
||||
|
||||
// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
|
||||
if( renormalize && totalAmplitude > 0.f )
|
||||
{
|
||||
totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
|
||||
totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
|
||||
totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
|
||||
totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
|
||||
}
|
||||
|
||||
return totalNoise;
|
||||
}
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Perlin noise is fractal noise with "gradient vector smoothing" applied.
|
||||
//
|
||||
// In 4D, gradients are unit-length hyper-vectors in random (4D) directions.
|
||||
//
|
||||
float Compute4dPerlin( float posX, float posY, float posZ, float posT, float scale, uint32_t numOctaves, float octavePersistence, float octaveScale, bool renormalize, uint32_t seed )
|
||||
{
|
||||
const float OCTAVE_OFFSET = 0.636764989593174f; // Translation/bias to add to each octave
|
||||
|
||||
const ::glm::vec4 gradients[ 16 ] = // Hard to tell if this is any better in 4D than just having 8
|
||||
{
|
||||
::glm::vec4( +0.5f, +0.5f, +0.5f, +0.5f ), // Normalized unit 4D vectors pointing toward each
|
||||
::glm::vec4( -0.5f, +0.5f, +0.5f, +0.5f ), // of the 16 hypercube corners, so components are
|
||||
::glm::vec4( +0.5f, -0.5f, +0.5f, +0.5f ), // all sqrt(4)/4, i.e. one-half.
|
||||
::glm::vec4( -0.5f, -0.5f, +0.5f, +0.5f ), //
|
||||
::glm::vec4( +0.5f, +0.5f, -0.5f, +0.5f ), // It's hard to tell whether these are any better
|
||||
::glm::vec4( -0.5f, +0.5f, -0.5f, +0.5f ), // or worse than vectors facing axes (1,0,0,0) or
|
||||
::glm::vec4( +0.5f, -0.5f, -0.5f, +0.5f ), // 3D edges (.7,.7,0,0) or 4D edges (.57,.57,.57,0)
|
||||
::glm::vec4( -0.5f, -0.5f, -0.5f, +0.5f ), // but less-axial gradients looked a little better
|
||||
::glm::vec4( +0.5f, +0.5f, +0.5f, -0.5f ), // with 2D and 3D noise so I'm assuming this is as
|
||||
::glm::vec4( -0.5f, +0.5f, +0.5f, -0.5f ), // good or better as any other gradient-selection
|
||||
::glm::vec4( +0.5f, -0.5f, +0.5f, -0.5f ), // scheme (and is crazy-fast). *shrug*
|
||||
::glm::vec4( -0.5f, -0.5f, +0.5f, -0.5f ), //
|
||||
::glm::vec4( +0.5f, +0.5f, -0.5f, -0.5f ), // Plus, we want a power-of-two number of evenly-
|
||||
::glm::vec4( -0.5f, +0.5f, -0.5f, -0.5f ), // distributed gradients, so we can cheaply select
|
||||
::glm::vec4( +0.5f, -0.5f, -0.5f, -0.5f ), // one from bit-noise (use bit-mask, not modulus).
|
||||
::glm::vec4( -0.5f, -0.5f, -0.5f, -0.5f ) //
|
||||
};
|
||||
|
||||
float totalNoise = 0.f;
|
||||
float totalAmplitude = 0.f;
|
||||
float currentAmplitude = 1.f;
|
||||
float invScale = (1.f / scale);
|
||||
::glm::vec4 currentPos( posX * invScale, posY * invScale, posZ * invScale, posT * invScale );
|
||||
|
||||
for( uint32_t octaveNum = 0; octaveNum < numOctaves; ++ octaveNum )
|
||||
{
|
||||
// Determine random unit "gradient vectors" for 16 surrounding 4D (hypercube) cell corners
|
||||
::glm::vec4 cellMins( ::glm::floor( currentPos.x ), ::glm::floor( currentPos.y ), ::glm::floor( currentPos.z ), ::glm::floor( currentPos.w ) );
|
||||
::glm::vec4 cellMaxs( cellMins.x + 1.f, cellMins.y + 1.f, cellMins.z + 1.f, cellMins.w + 1.f );
|
||||
int32_t indexWestX = (int32_t) cellMins.x;
|
||||
int32_t indexSouthY = (int32_t) cellMins.y;
|
||||
int32_t indexBelowZ = (int32_t) cellMins.z;
|
||||
int32_t indexBeforeT = (int32_t) cellMins.w;
|
||||
int32_t indexEastX = indexWestX + 1;
|
||||
int32_t indexNorthY = indexSouthY + 1;
|
||||
int32_t indexAboveZ = indexBelowZ + 1;
|
||||
int32_t indexAfterT = indexBeforeT + 1;
|
||||
|
||||
// "BeforeBSW" stands for "BeforeBelowSouthWest" below (i.e. 4D hypercube mins), etc.
|
||||
uint32_t noiseBeforeBSW = Get4dNoiseUint32( indexWestX, indexSouthY, indexBelowZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeBSE = Get4dNoiseUint32( indexEastX, indexSouthY, indexBelowZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeBNW = Get4dNoiseUint32( indexWestX, indexNorthY, indexBelowZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeBNE = Get4dNoiseUint32( indexEastX, indexNorthY, indexBelowZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeASW = Get4dNoiseUint32( indexWestX, indexSouthY, indexAboveZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeASE = Get4dNoiseUint32( indexEastX, indexSouthY, indexAboveZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeANW = Get4dNoiseUint32( indexWestX, indexNorthY, indexAboveZ, indexBeforeT, seed );
|
||||
uint32_t noiseBeforeANE = Get4dNoiseUint32( indexEastX, indexNorthY, indexAboveZ, indexBeforeT, seed );
|
||||
uint32_t noiseAfterBSW = Get4dNoiseUint32( indexWestX, indexSouthY, indexBelowZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterBSE = Get4dNoiseUint32( indexEastX, indexSouthY, indexBelowZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterBNW = Get4dNoiseUint32( indexWestX, indexNorthY, indexBelowZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterBNE = Get4dNoiseUint32( indexEastX, indexNorthY, indexBelowZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterASW = Get4dNoiseUint32( indexWestX, indexSouthY, indexAboveZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterASE = Get4dNoiseUint32( indexEastX, indexSouthY, indexAboveZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterANW = Get4dNoiseUint32( indexWestX, indexNorthY, indexAboveZ, indexAfterT, seed );
|
||||
uint32_t noiseAfterANE = Get4dNoiseUint32( indexEastX, indexNorthY, indexAboveZ, indexAfterT, seed );
|
||||
|
||||
// Mask with 15 (mod 16) to look up in gradients table
|
||||
::glm::vec4 gradientBeforeBSW = gradients[ noiseBeforeBSW & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeBSE = gradients[ noiseBeforeBSE & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeBNW = gradients[ noiseBeforeBNW & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeBNE = gradients[ noiseBeforeBNE & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeASW = gradients[ noiseBeforeASW & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeASE = gradients[ noiseBeforeASE & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeANW = gradients[ noiseBeforeANW & 0x0000000F ];
|
||||
::glm::vec4 gradientBeforeANE = gradients[ noiseBeforeANE & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterBSW = gradients[ noiseAfterBSW & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterBSE = gradients[ noiseAfterBSE & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterBNW = gradients[ noiseAfterBNW & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterBNE = gradients[ noiseAfterBNE & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterASW = gradients[ noiseAfterASW & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterASE = gradients[ noiseAfterASE & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterANW = gradients[ noiseAfterANW & 0x0000000F ];
|
||||
::glm::vec4 gradientAfterANE = gradients[ noiseAfterANE & 0x0000000F ];
|
||||
|
||||
// Dot each corner's gradient with displacement from corner to position
|
||||
::glm::vec4 displacementFromBeforeBSW( currentPos.x - cellMins.x, currentPos.y - cellMins.y, currentPos.z - cellMins.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeBSE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y, currentPos.z - cellMins.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeBNW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y, currentPos.z - cellMins.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeBNE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y, currentPos.z - cellMins.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeASW( currentPos.x - cellMins.x, currentPos.y - cellMins.y, currentPos.z - cellMaxs.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeASE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y, currentPos.z - cellMaxs.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeANW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y, currentPos.z - cellMaxs.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromBeforeANE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y, currentPos.z - cellMaxs.z, currentPos.w - cellMins.w );
|
||||
::glm::vec4 displacementFromAfterBSW( currentPos.x - cellMins.x, currentPos.y - cellMins.y, currentPos.z - cellMins.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterBSE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y, currentPos.z - cellMins.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterBNW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y, currentPos.z - cellMins.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterBNE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y, currentPos.z - cellMins.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterASW( currentPos.x - cellMins.x, currentPos.y - cellMins.y, currentPos.z - cellMaxs.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterASE( currentPos.x - cellMaxs.x, currentPos.y - cellMins.y, currentPos.z - cellMaxs.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterANW( currentPos.x - cellMins.x, currentPos.y - cellMaxs.y, currentPos.z - cellMaxs.z, currentPos.w - cellMaxs.w );
|
||||
::glm::vec4 displacementFromAfterANE( currentPos.x - cellMaxs.x, currentPos.y - cellMaxs.y, currentPos.z - cellMaxs.z, currentPos.w - cellMaxs.w );
|
||||
|
||||
float dotBeforeBSW = ::glm::dot( gradientBeforeBSW, displacementFromBeforeBSW );
|
||||
float dotBeforeBSE = ::glm::dot( gradientBeforeBSE, displacementFromBeforeBSE );
|
||||
float dotBeforeBNW = ::glm::dot( gradientBeforeBNW, displacementFromBeforeBNW );
|
||||
float dotBeforeBNE = ::glm::dot( gradientBeforeBNE, displacementFromBeforeBNE );
|
||||
float dotBeforeASW = ::glm::dot( gradientBeforeASW, displacementFromBeforeASW );
|
||||
float dotBeforeASE = ::glm::dot( gradientBeforeASE, displacementFromBeforeASE );
|
||||
float dotBeforeANW = ::glm::dot( gradientBeforeANW, displacementFromBeforeANW );
|
||||
float dotBeforeANE = ::glm::dot( gradientBeforeANE, displacementFromBeforeANE );
|
||||
float dotAfterBSW = ::glm::dot( gradientAfterBSW, displacementFromAfterBSW );
|
||||
float dotAfterBSE = ::glm::dot( gradientAfterBSE, displacementFromAfterBSE );
|
||||
float dotAfterBNW = ::glm::dot( gradientAfterBNW, displacementFromAfterBNW );
|
||||
float dotAfterBNE = ::glm::dot( gradientAfterBNE, displacementFromAfterBNE );
|
||||
float dotAfterASW = ::glm::dot( gradientAfterASW, displacementFromAfterASW );
|
||||
float dotAfterASE = ::glm::dot( gradientAfterASE, displacementFromAfterASE );
|
||||
float dotAfterANW = ::glm::dot( gradientAfterANW, displacementFromAfterANW );
|
||||
float dotAfterANE = ::glm::dot( gradientAfterANE, displacementFromAfterANE );
|
||||
|
||||
// Do a smoothed (nonlinear) weighted average of dot results
|
||||
float weightEast = Easing::SmoothStep( displacementFromBeforeBSW.x );
|
||||
float weightNorth = Easing::SmoothStep( displacementFromBeforeBSW.y );
|
||||
float weightAbove = Easing::SmoothStep( displacementFromBeforeBSW.z );
|
||||
float weightAfter = Easing::SmoothStep( displacementFromBeforeBSW.w );
|
||||
float weightWest = 1.f - weightEast;
|
||||
float weightSouth = 1.f - weightNorth;
|
||||
float weightBelow = 1.f - weightAbove;
|
||||
float weightBefore = 1.f - weightAfter;
|
||||
|
||||
// 16-way blend (16 -> 8 -> 4 -> 2 -> 1)
|
||||
float blendBeforeBelowSouth = (weightEast * dotBeforeBSE) + (weightWest * dotBeforeBSW);
|
||||
float blendBeforeBelowNorth = (weightEast * dotBeforeBNE) + (weightWest * dotBeforeBNW);
|
||||
float blendBeforeAboveSouth = (weightEast * dotBeforeASE) + (weightWest * dotBeforeASW);
|
||||
float blendBeforeAboveNorth = (weightEast * dotBeforeANE) + (weightWest * dotBeforeANW);
|
||||
float blendAfterBelowSouth = (weightEast * dotAfterBSE) + (weightWest * dotAfterBSW);
|
||||
float blendAfterBelowNorth = (weightEast * dotAfterBNE) + (weightWest * dotAfterBNW);
|
||||
float blendAfterAboveSouth = (weightEast * dotAfterASE) + (weightWest * dotAfterASW);
|
||||
float blendAfterAboveNorth = (weightEast * dotAfterANE) + (weightWest * dotAfterANW);
|
||||
float blendBeforeBelow = (weightSouth * blendBeforeBelowSouth) + (weightNorth * blendBeforeBelowNorth);
|
||||
float blendBeforeAbove = (weightSouth * blendBeforeAboveSouth) + (weightNorth * blendBeforeAboveNorth);
|
||||
float blendAfterBelow = (weightSouth * blendAfterBelowSouth) + (weightNorth * blendAfterBelowNorth);
|
||||
float blendAfterAbove = (weightSouth * blendAfterAboveSouth) + (weightNorth * blendAfterAboveNorth);
|
||||
float blendBefore = (weightBelow * blendBeforeBelow) + (weightAbove * blendBeforeAbove);
|
||||
float blendAfter = (weightBelow * blendAfterBelow) + (weightAbove * blendAfterAbove);
|
||||
float blendTotal = (weightBefore * blendBefore) + (weightAfter * blendAfter);
|
||||
float noiseThisOctave = blendTotal * (1.f / 0.6875f); // 4D Perlin is in [-.6875,.6875]; map to ~[-1,1]
|
||||
|
||||
// Accumulate results and prepare for next octave (if any)
|
||||
totalNoise += noiseThisOctave * currentAmplitude;
|
||||
totalAmplitude += currentAmplitude;
|
||||
currentAmplitude *= octavePersistence;
|
||||
currentPos *= octaveScale;
|
||||
currentPos.x += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
currentPos.y += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
currentPos.z += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
currentPos.w += OCTAVE_OFFSET; // Add "irrational" offset to de-align octave grids
|
||||
++ seed; // Eliminates octaves "echoing" each other (since each octave is uniquely seeded)
|
||||
}
|
||||
|
||||
// Re-normalize total noise to within [-1,1] and fix octaves pulling us far away from limits
|
||||
if( renormalize && totalAmplitude > 0.f )
|
||||
{
|
||||
totalNoise /= totalAmplitude; // Amplitude exceeds 1.0 if octaves are used
|
||||
totalNoise = (totalNoise * 0.5f) + 0.5f; // Map to [0,1]
|
||||
totalNoise = Easing::SmoothStep( totalNoise ); // Push towards extents (octaves pull us away)
|
||||
totalNoise = (totalNoise * 2.0f) - 1.f; // Map back to [-1,1]
|
||||
}
|
||||
|
||||
return totalNoise;
|
||||
}
|
||||
|
||||
} // SquirrelNoise4
|
||||
|
||||
95
external/SquirrelNoise/src/squirrel_noise/SmoothNoise.hpp
vendored
Normal file
95
external/SquirrelNoise/src/squirrel_noise/SmoothNoise.hpp
vendored
Normal file
@ -0,0 +1,95 @@
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// SmoothNoise.hpp
|
||||
//
|
||||
#pragma once
|
||||
|
||||
#include <cstdint>
|
||||
|
||||
namespace SquirrelNoise4 {
|
||||
|
||||
/////////////////////////////////////////////////////////////////////////////////////////////////
|
||||
// Squirrel's Smooth Noise utilities (version 4)
|
||||
//
|
||||
// This code is made available under the Creative Commons attribution 3.0 license (CC-BY-3.0 US):
|
||||
// Attribution in source code comments (even closed-source/commercial code) is sufficient.
|
||||
// License summary and text available at: https://creativecommons.org/licenses/by/3.0/us/
|
||||
//
|
||||
// Note: This is work in progress, and has not yet been tested thoroughly. Use at your own risk.
|
||||
// Please report any bugs, issues, or bothersome cases to SquirrelEiserloh at gmail.com.
|
||||
//
|
||||
// The following functions are all based on a simple bit-noise function which returns an unsigned
|
||||
// integer containing 32 reasonably-well-scrambled bits, based on a given (signed) integer
|
||||
// input parameter (position/index) and [optional] seed. Kind of like looking up a value in an
|
||||
// infinitely large [non-existent] table of previously rolled random numbers.
|
||||
//
|
||||
// These functions are deterministic and random-access / order-independent (i.e. state-free),
|
||||
// so they are particularly well-suited for use in out-of-order (or or-demand) procedural
|
||||
// content generation (i.e. that mountain village is the same whether you generated it
|
||||
// first or last, ahead of time or just now).
|
||||
//
|
||||
// My implementations of fractal and Perlin noise include a few improvements over the stock
|
||||
// versions I've seen used:
|
||||
// * Functions can take seeds (independent of index/position) with unique-but-consistent results
|
||||
// * Each octave is offset (translation/bias) to dramatically reduce multi-octave feedback.
|
||||
// * Vector gradients are in power-of-two sets, to avoid modulus ops (uses bitwise masks instead)
|
||||
// * Octave persistence and scale are adjustable (not necessarily 0.5 and 2.0)
|
||||
// * Multi-octave noise can be "normalized" to be mapped back to within [-1,1], or not
|
||||
//
|
||||
// Note: these functions assume the presence of the glm math library;
|
||||
//
|
||||
// Modified by Erik Scholz 2021, no change to the license.
|
||||
//
|
||||
/////////////////////////////////////////////////////////////////////////////////////////////////
|
||||
|
||||
//const float fSQRT_3_OVER_3 = sqrtf(3.f)/3.f;
|
||||
const float fSQRT_3_OVER_3 = 0.57735026918962576450f;
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Smooth/fractal pseudorandom noise functions (random-access / deterministic)
|
||||
//
|
||||
// These are less "organic" (and more axial) than Perlin's functions, but simpler and faster.
|
||||
//
|
||||
// <numOctaves> Number of layers of noise added together
|
||||
// <octavePersistence> Amplitude multiplier for each subsequent octave (each octave is quieter)
|
||||
// <octaveScale> Frequency multiplier for each subsequent octave (each octave is busier)
|
||||
// <renormalize> If true, uses nonlinear (SmoothStep3) renormalization to within [-1,1]
|
||||
//
|
||||
float Compute1dFractalNoise( float position, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
float Compute2dFractalNoise( float posX, float posY, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
float Compute3dFractalNoise( float posX, float posY, float posZ, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
float Compute4dFractalNoise( float posX, float posY, float posZ, float posT, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Perlin noise functions (random-access / deterministic)
|
||||
//
|
||||
// Perlin noise is slightly more expensive, but more organic-looking (less axial) than regular
|
||||
// square fractal noise, through the use of blended dot products vs. randomized gradient vectors.
|
||||
//
|
||||
// <numOctaves> Number of layers of noise added together
|
||||
// <octavePersistence> Amplitude multiplier for each subsequent octave (each octave is quieter)
|
||||
// <octaveScale> Frequency multiplier for each subsequent octave (each octave is busier)
|
||||
// <renormalize> If true, uses nonlinear (SmoothStep3) renormalization to within [-1,1]
|
||||
//
|
||||
float Compute1dPerlinNoise( float position, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
float Compute2dPerlinNoise( float posX, float posY, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
float Compute3dPerlinNoise( float posX, float posY, float posZ, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
float Compute4dPerlinNoise( float posX, float posY, float posZ, float posT, float scale=1.f, uint32_t numOctaves=1, float octavePersistence=0.5f, float octaveScale=2.f, bool renormalize=true, uint32_t seed=0 );
|
||||
|
||||
|
||||
//-----------------------------------------------------------------------------------------------
|
||||
// Simplex noise functions (random-access / deterministic)
|
||||
//
|
||||
// Simplex noise (also by Ken Perlin) is theoretically faster than - and supposedly superior to -
|
||||
// Perlin noise, in that it is more organic-looking. I'm not sure I like the look of it better,
|
||||
// however; examples of cross-sectional 4D simplex noise look worse to me than 4D Perlin does.
|
||||
//
|
||||
// Also, Simplex noise is based on a regular simplex (2D triangle, 3D tetrahedron, 4-simplex/5-cell)
|
||||
// grid, which is slightly more fiddly, so I haven't bothered writing my own yet.
|
||||
//
|
||||
// #TODO: Implement simplex noise in 2D, 3D, 4D (1D simplex is identical to 1D Perlin, I think?)
|
||||
// #TODO: Test actual simplex noise implementation in 2D/3D to compare speeds (branches vs. ops!)
|
||||
//
|
||||
|
||||
} // SquirrelNoise4
|
||||
|
||||
@ -6,6 +6,7 @@ add_subdirectory(logger)
|
||||
add_subdirectory(resource_manager)
|
||||
add_subdirectory(common_components)
|
||||
add_subdirectory(std_utils)
|
||||
add_subdirectory(random)
|
||||
add_subdirectory(screen_director)
|
||||
add_subdirectory(filesystem)
|
||||
add_subdirectory(simple_scene)
|
||||
|
||||
24
framework/random/CMakeLists.txt
Normal file
24
framework/random/CMakeLists.txt
Normal file
@ -0,0 +1,24 @@
|
||||
cmake_minimum_required(VERSION 3.2)
|
||||
project(random CXX)
|
||||
|
||||
add_library(random
|
||||
./src/mm/random/srng.hpp
|
||||
./src/mm/random/srng.cpp
|
||||
)
|
||||
|
||||
target_include_directories(random PUBLIC "src")
|
||||
|
||||
target_compile_features(random PUBLIC cxx_std_17)
|
||||
|
||||
target_link_libraries(random
|
||||
PUBLIC
|
||||
squirrel_noise
|
||||
std_utils
|
||||
)
|
||||
|
||||
##############################
|
||||
|
||||
#if (BUILD_TESTING)
|
||||
#add_subdirectory(test)
|
||||
#endif()
|
||||
|
||||
2
framework/random/src/mm/random/srng.cpp
Normal file
2
framework/random/src/mm/random/srng.cpp
Normal file
@ -0,0 +1,2 @@
|
||||
#include "./srng.hpp"
|
||||
|
||||
57
framework/random/src/mm/random/srng.hpp
Normal file
57
framework/random/src/mm/random/srng.hpp
Normal file
@ -0,0 +1,57 @@
|
||||
#pragma once
|
||||
|
||||
#include <squirrel_noise/RawNoise.hpp>
|
||||
#include <mm/scalar_range2.hpp>
|
||||
|
||||
namespace MM::Random {
|
||||
|
||||
// Seeded (Pseudo-) Random Number Generator
|
||||
struct SRNG {
|
||||
uint32_t seed = 1337;
|
||||
int32_t pos = 0;
|
||||
|
||||
// basic
|
||||
|
||||
uint32_t getNext(void) {
|
||||
return SquirrelNoise4::Get1dNoiseUint32(pos++, seed);
|
||||
}
|
||||
|
||||
float zeroToOne(void) {
|
||||
return SquirrelNoise4::Get1dNoiseZeroToOne(pos++, seed);
|
||||
}
|
||||
|
||||
float negOneToOne(void) {
|
||||
return SquirrelNoise4::Get1dNoiseNegOneToOne(pos++, seed);
|
||||
}
|
||||
|
||||
// advanced
|
||||
|
||||
uint32_t minMax(uint32_t min, uint32_t max) {
|
||||
return (getNext() % ((max - min) + 1)) + min;
|
||||
}
|
||||
|
||||
bool roll(float prob) {
|
||||
return zeroToOne() <= prob;
|
||||
}
|
||||
|
||||
// more advanced
|
||||
|
||||
// inclusive
|
||||
// TODO: test for floats
|
||||
template<typename T>
|
||||
T range(const ScalarRange2<T>& range) {
|
||||
return (getNext() % ((range.max() - range.min()) + 1)) + range.min();
|
||||
}
|
||||
|
||||
// for conviniece
|
||||
uint32_t operator()(void) {
|
||||
return getNext();
|
||||
}
|
||||
|
||||
bool operator()(float prob) {
|
||||
return roll(prob);
|
||||
}
|
||||
};
|
||||
|
||||
} // MM::Random
|
||||
|
||||
@ -22,4 +22,3 @@ if (BUILD_TESTING)
|
||||
add_subdirectory(test)
|
||||
endif()
|
||||
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user