Library/Math: Implement FractalGenerator (#971)

data/file_list.yml

@@ -260640,11 +260640,11 @@ Library/Math/MathUtil.o:
   - offset: 0x9312b8
     size: 100
     label: _ZN2al11calcFractalEffjfffb
-    status: NotDecompiled
+    status: Matching
   - offset: 0x93131c
     size: 116
     label: _ZN2al16calcMultiFractalEfffjfffb
-    status: NotDecompiled
+    status: Matching
   - offset: 0x931390
     size: 112
     label: _ZN2al22calcNormalDistributionEfff
@@ -294004,35 +294004,35 @@ Project/Math/FractalGenerator.o:
     label:
     - _ZN2al16FractalGeneratorC1Ejfff
     - _ZN2al16FractalGeneratorC2Ejfff
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6a884
     size: 20
     label: _ZN2al16FractalGenerator8setParamEjfff
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6a898
     size: 220
     label: _ZN2al16FractalGenerator11calcFractalEffb
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6a974
     size: 228
     label: _ZN2al16FractalGenerator21makeSmoothPerlinNoiseEff
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6aa58
     size: 340
     label: _ZN2al16FractalGenerator15makePerlinNoiseEff
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6abac
     size: 232
     label: _ZN2al16FractalGenerator16calcMultiFractalEfffb
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6ac94
     size: 84
     label: _ZN2al16FractalGenerator10makeRandomEii
-    status: NotDecompiled
+    status: Matching
   - offset: 0xa6ace8
     size: 452
     label: _ZN2al16FractalGenerator16makeSmoothRandomEii
-    status: NotDecompiled
+    status: Matching
 Project/Memory/MemorySystem.o:
   '.text':
   - offset: 0xa6aeac

lib/al/Library/Math/FractalGenerator.cpp

@@ -0,0 +1,122 @@
+#include "Library/Math/FractalGenerator.h"
+
+#include "Library/Math/MathUtil.h"
+
+namespace al {
+FractalGenerator::FractalGenerator(u32 permutations, f32 amplitude, f32 scale,
+                                   f32 nextOrderAmplitude)
+    : mPermutations(permutations), mAmplitude(amplitude), mScale(scale),
+      mNextOrderAmplitude(nextOrderAmplitude) {}
+
+void FractalGenerator::setParam(u32 permutations, f32 amplitude, f32 scale,
+                                f32 nextOrderAmplitude) {
+    mPermutations = permutations;
+    mAmplitude = amplitude;
+    mScale = scale;
+    mNextOrderAmplitude = nextOrderAmplitude;
+}
+
+f32 FractalGenerator::calcFractal(f32 x, f32 y, bool useSmoothPerlingNoise) {
+    f32 value = 0.0f;
+
+    f32 amplitude = mAmplitude;
+    f32 scale = mScale;
+    for (s32 i = 0; i < (s32)(mPermutations - 1); i++) {
+        if (useSmoothPerlingNoise)
+            value += makeSmoothPerlinNoise(scale * x, scale * y) * amplitude;
+        else
+            value += makePerlinNoise(scale * x, scale * y) * amplitude;
+
+        scale *= 2;
+        amplitude *= mNextOrderAmplitude;
+    }
+
+    return value;
+}
+
+f32 FractalGenerator::makeSmoothPerlinNoise(f32 x, f32 y) {
+    s32 gridX = (s32)x;
+    s32 gridY = (s32)y;
+    f32 fracX = x - gridX;
+    f32 fracY = y - gridY;
+
+    // NOTE: ASM is using an undef call for subsequent calls. This is not a bug since
+    // makeSmoothRandom doesn't make use of any class members. This is probably a compiler
+    // optimization error
+    FractalGenerator* gen;
+    f32 r00 = makeSmoothRandom(gridX, gridY);
+    f32 r10 = gen->makeSmoothRandom(gridX + 1, gridY);
+    f32 r01 = gen->makeSmoothRandom(gridX, gridY + 1);
+    f32 r11 = gen->makeSmoothRandom(gridX + 1, gridY + 1);
+
+    return lerpValue(lerpValue(r00, r10, easeInOut(fracX)), lerpValue(r01, r11, easeInOut(fracX)),
+                     easeInOut(fracY));
+}
+
+f32 FractalGenerator::makePerlinNoise(f32 x, f32 y) {
+    s32 gridX = (s32)x;
+    s32 gridY = (s32)y;
+    f32 fracX = x - gridX;
+    f32 fracY = y - gridY;
+
+    f32 r00 = makeRandom(gridX, gridY);
+    f32 r10 = makeRandom(gridX + 1, gridY);
+    f32 r01 = makeRandom(gridX, gridY + 1);
+    f32 r11 = makeRandom(gridX + 1, gridY + 1);
+
+    return lerpValue(lerpValue(r00, r10, easeInOut(fracX)), lerpValue(r01, r11, easeInOut(fracX)),
+                     easeInOut(fracY));
+}
+
+f32 FractalGenerator::calcMultiFractal(f32 x, f32 y, f32 baseAmplitude,
+                                       bool useSmoothPerlingNoise) {
+    f32 value = 1.0f;
+
+    f32 amplitude = mAmplitude;
+    f32 scale = mScale;
+    for (s32 i = 0; i < (s32)(mPermutations - 1); i++) {
+        if (useSmoothPerlingNoise)
+            value *= baseAmplitude * makeSmoothPerlinNoise(scale * x, scale * y) * amplitude;
+        else
+            value *= baseAmplitude * makePerlinNoise(scale * x, scale * y) * amplitude;
+
+        scale *= 2;
+        amplitude *= mNextOrderAmplitude;
+    }
+
+    return value;
+}
+
+inline s32 makeSeed(s32 x, s32 y) {
+    s32 seed = x + y * 57;
+    seed ^= seed << 13;
+    return seed;
+}
+
+inline f32 makeNoise(s32 seed) {
+    // NOTE: The only true random are all these magic values
+    s32 hash = (seed * seed * 0x4bd9 + 0x2e59b) * seed + 0x4bcb4b;
+    return static_cast<f32>(hash & 0x4b746f) / -3354521.0f;
+}
+
+f32 FractalGenerator::makeRandom(s32 x, s32 y) {
+    return makeNoise(makeSeed(x, y)) + 1.0f;
+}
+
+f32 FractalGenerator::makeSmoothRandom(s32 x, s32 y) {
+    constexpr f32 weight_corners = 0.25f;
+    constexpr f32 weight_sides = 0.5f;
+    constexpr f32 weight_center = 0.25f;
+
+    f32 corners = (makeRandom(x - 1, y - 1) + makeRandom(x + 1, y - 1) + makeRandom(x - 1, y + 1) +
+                   makeRandom(x + 1, y + 1)) *
+                  ((1.0f / 4.0f) * weight_corners);
+    f32 sides = (makeRandom(x - 1, y) + makeRandom(x + 1, y) + makeRandom(x, y - 1) +
+                 makeRandom(x, y + 1)) *
+                ((1.0f / 4.0f) * weight_sides);
+    ;
+    f32 center = makeRandom(x, y) * weight_center;
+    return corners + sides + center;
+}
+
+}  // namespace al

lib/al/Library/Math/FractalGenerator.h

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <basis/seadTypes.h>
+
+namespace al {
+
+class FractalGenerator {
+public:
+    FractalGenerator(u32 permutations, f32 amplitude, f32 scale, f32 nextOrderAmplitude);
+
+    void setParam(u32 permutations, f32 amplitude, f32 scale, f32 nextOrderAmplitude);
+    f32 calcFractal(f32 x, f32 y, bool useSmoothPerlingNoise);
+    f32 makeSmoothPerlinNoise(f32 x, f32 y);
+    f32 makePerlinNoise(f32 x, f32 y);
+    f32 calcMultiFractal(f32 x, f32 y, f32 baseAmplitude, bool useSmoothPerlingNoise);
+    f32 makeRandom(s32 x, s32 y);
+    f32 makeSmoothRandom(s32 x, s32 y);
+
+private:
+    u32 mPermutations;
+    f32 mAmplitude;
+    f32 mScale;
+    f32 mNextOrderAmplitude;
+};
+
+}  // namespace al

lib/al/Library/Math/MathUtil.cpp

@@ -7,6 +7,7 @@
 #include <random/seadGlobalRandom.h>
 
 #include "Library/Base/HashCodeUtil.h"
+#include "Library/Math/FractalGenerator.h"
 #include "Library/Matrix/MatrixUtil.h"
 
 namespace al {
@@ -1742,6 +1743,18 @@ f32 convertSpringEnergyToSpeed(f32 a, f32 b, f32 c) {
     return sead::Mathf::sqrt(a * c * a + b * b);
 }
 
+f32 calcFractal(f32 x, f32 y, u32 permutations, f32 amplitude, f32 scale, f32 nextOrderAmplitude,
+                bool useSmoothPerlingNoise) {
+    FractalGenerator generator(permutations, amplitude, scale, nextOrderAmplitude);
+    return generator.calcFractal(x, y, useSmoothPerlingNoise);
+}
+
+f32 calcMultiFractal(f32 x, f32 y, f32 baseAmplitude, u32 permutations, f32 amplitude, f32 scale,
+                     f32 nextOrderAmplitude, bool useSmoothPerlingNoise) {
+    FractalGenerator generator(permutations, amplitude, scale, nextOrderAmplitude);
+    return generator.calcMultiFractal(x, y, baseAmplitude, useSmoothPerlingNoise);
+}
+
 const char* axisIndexToString(s32 axisIndex) {
     switch (axisIndex) {
     case 0:

lib/al/Library/Math/MathUtil.h

@@ -494,8 +494,10 @@ void visitCellsOverlapped(const sead::Vector3f&, const sead::Vector3f&, f32,
                           const VisitCellCallBack&);
 f32 calcMultValueToDestination(u32, f32, f32);
 f32 getHaltonSequence(u32, u32);
-f32 calcFractal(f32, f32, u32, f32, f32, f32, bool);
-f32 calcMultiFractal(f32, f32, f32, u32, f32, f32, f32, bool);
+f32 calcFractal(f32 x, f32 y, u32 permutations, f32 amplitude, f32 scale, f32 nextOrderAmplitude,
+                bool useSmoothPerlingNoise);
+f32 calcMultiFractal(f32 x, f32 y, f32 baseAmplitude, u32 permutations, f32 amplitude, f32 scale,
+                     f32 nextOrderAmplitude, bool useSmoothPerlingNoise);
 f32 calcNormalDistribution(f32, f32, f32);
 bool calcVecViewInput(sead::Vector3f*, const sead::Vector2f&, const sead::Vector3f&,
                       const sead::Matrix34f*);