WIP fractal-gavoro-pseudoerosion

common/addons/config-noise-function/src/main/java/com/dfsek/terra/addons/noise/NoiseAddon.java

@@ -17,6 +17,7 @@ import com.dfsek.terra.addons.manifest.api.AddonInitializer;
 import com.dfsek.terra.addons.noise.config.CubicSplinePointTemplate;
 import com.dfsek.terra.addons.noise.config.DimensionApplicableNoiseSampler;
 import com.dfsek.terra.addons.noise.config.templates.BinaryArithmeticTemplate;
+import com.dfsek.terra.addons.noise.config.templates.DerivativeNoiseSamplerTemplate;
 import com.dfsek.terra.addons.noise.config.templates.DomainWarpTemplate;
 import com.dfsek.terra.addons.noise.config.templates.FunctionTemplate;
 import com.dfsek.terra.addons.noise.config.templates.ImageSamplerTemplate;
@@ -25,9 +26,11 @@ import com.dfsek.terra.addons.noise.config.templates.LinearHeightmapSamplerTempl
 import com.dfsek.terra.addons.noise.config.templates.TranslateSamplerTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.CellularNoiseTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.ConstantNoiseTemplate;
+import com.dfsek.terra.addons.noise.config.templates.noise.DerivativeFractalTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.DistanceSamplerTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.ExpressionFunctionTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.GaborNoiseTemplate;
+import com.dfsek.terra.addons.noise.config.templates.noise.PseudoErosionTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.SimpleNoiseTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.fractal.BrownianMotionTemplate;
 import com.dfsek.terra.addons.noise.config.templates.noise.fractal.PingPongTemplate;
@@ -63,6 +66,7 @@ import com.dfsek.terra.api.addon.BaseAddon;
 import com.dfsek.terra.api.event.events.config.pack.ConfigPackPreLoadEvent;
 import com.dfsek.terra.api.event.functional.FunctionalEventHandler;
 import com.dfsek.terra.api.inject.annotations.Inject;
+import com.dfsek.terra.api.noise.DerivativeNoiseSampler;
 import com.dfsek.terra.api.noise.NoiseSampler;
 import com.dfsek.terra.api.registry.CheckedRegistry;
 import com.dfsek.terra.api.util.reflection.TypeKey;
@@ -94,7 +98,8 @@ public class NoiseAddon implements AddonInitializer {
                         (type, o, loader, depthTracker) -> DistanceSampler.DistanceFunction.valueOf((String) o))
                     .applyLoader(DimensionApplicableNoiseSampler.class, DimensionApplicableNoiseSampler::new)
                     .applyLoader(FunctionTemplate.class, FunctionTemplate::new)
-                    .applyLoader(CubicSpline.Point.class, CubicSplinePointTemplate::new);
+                    .applyLoader(CubicSpline.Point.class, CubicSplinePointTemplate::new)
+                    .applyLoader(DerivativeNoiseSampler.class, DerivativeNoiseSamplerTemplate::new);
 
                 noiseRegistry.register(addon.key("LINEAR"), LinearNormalizerTemplate::new);
                 noiseRegistry.register(addon.key("NORMAL"), NormalNormalizerTemplate::new);
@@ -117,7 +122,8 @@ public class NoiseAddon implements AddonInitializer {
                 noiseRegistry.register(addon.key("PERLIN"), () -> new SimpleNoiseTemplate(PerlinSampler::new));
                 noiseRegistry.register(addon.key("SIMPLEX"), () -> new SimpleNoiseTemplate(SimplexSampler::new));
                 noiseRegistry.register(addon.key("GABOR"), GaborNoiseTemplate::new);
-
+                noiseRegistry.register(addon.key("PSEUDOEROSION"), PseudoErosionTemplate::new);
+                noiseRegistry.register(addon.key("DERIVATIVE"), DerivativeFractalTemplate::new);
 
                 noiseRegistry.register(addon.key("VALUE"), () -> new SimpleNoiseTemplate(ValueSampler::new));
                 noiseRegistry.register(addon.key("VALUE_CUBIC"), () -> new SimpleNoiseTemplate(ValueCubicSampler::new));

common/addons/config-noise-function/src/main/java/com/dfsek/terra/addons/noise/config/templates/DerivativeNoiseSamplerTemplate.java

@@ -0,0 +1,25 @@
+package com.dfsek.terra.addons.noise.config.templates;
+
+import com.dfsek.tectonic.api.config.template.annotations.Value;
+import com.dfsek.tectonic.api.exception.ValidationException;
+
+import com.dfsek.terra.api.noise.DerivativeNoiseSampler;
+import com.dfsek.terra.api.noise.NoiseSampler;
+
+
+public class DerivativeNoiseSamplerTemplate extends SamplerTemplate<DerivativeNoiseSampler> {
+
+    @Value(".")
+    private NoiseSampler sampler;
+
+    @Override
+    public boolean validate() throws ValidationException {
+        if (!(sampler instanceof DerivativeNoiseSampler)) throw new ValidationException("Provided sampler does not support calculating a derivative");
+        return super.validate();
+    }
+
+    @Override
+    public DerivativeNoiseSampler get() {
+        return (DerivativeNoiseSampler) sampler;
+    }
+}

common/addons/config-noise-function/src/main/java/com/dfsek/terra/addons/noise/config/templates/noise/DerivativeFractalTemplate.java

@@ -0,0 +1,32 @@
+package com.dfsek.terra.addons.noise.config.templates.noise;
+
+import com.dfsek.tectonic.api.config.template.annotations.Default;
+import com.dfsek.tectonic.api.config.template.annotations.Value;
+
+import com.dfsek.terra.addons.noise.config.templates.SamplerTemplate;
+import com.dfsek.terra.addons.noise.samplers.noise.simplex.DerivativeFractal;
+
+
+public class DerivativeFractalTemplate extends SamplerTemplate<DerivativeFractal> {
+
+    @Value("octaves")
+    @Default
+    private int octaves = 3;
+
+    @Value("gain")
+    @Default
+    private double gain = 0.5;
+
+    @Value("lacunarity")
+    @Default
+    private double lacunarity = 2.0;
+
+    @Value("frequency")
+    @Default
+    private double frequency = 0.02;
+
+    @Override
+    public DerivativeFractal get() {
+        return new DerivativeFractal(octaves, gain, lacunarity, frequency);
+    }
+}

common/addons/config-noise-function/src/main/java/com/dfsek/terra/addons/noise/config/templates/noise/PseudoErosionTemplate.java

@@ -0,0 +1,62 @@
+package com.dfsek.terra.addons.noise.config.templates.noise;
+
+import com.dfsek.tectonic.api.config.template.annotations.Default;
+import com.dfsek.tectonic.api.config.template.annotations.Value;
+
+import com.dfsek.terra.addons.noise.config.templates.SamplerTemplate;
+import com.dfsek.terra.addons.noise.samplers.noise.simplex.PseudoErosion;
+import com.dfsek.terra.api.noise.DerivativeNoiseSampler;
+
+
+public class PseudoErosionTemplate extends SamplerTemplate<PseudoErosion> {
+
+    @Value("octaves")
+    @Default
+    private int octaves = 4;
+
+    @Value("lacunarity")
+    @Default
+    private double lacunarity = 2.0;
+
+    @Value("gain")
+    @Default
+    private double gain = 0.5;
+
+    @Value("slope-strength")
+    @Default
+    private double slopeStrength = 1.0;
+
+    @Value("branch-strength")
+    @Default
+    private double branchStrength = 1.0;
+
+    @Value("strength")
+    @Default
+    private double strength = 0.04;
+
+    @Value("erosion-frequency")
+    @Default
+    private double erosionFrequency = 0.02;
+
+    @Value("sampler")
+    private DerivativeNoiseSampler heightSampler;
+
+    @Value("slope-mask.enable")
+    @Default
+    private boolean slopeMask = true;
+
+    @Value("slope-mask.none")
+    @Default
+    private double slopeMaskNone = -0.5;
+
+    @Value("slope-mask.full")
+    @Default
+    private double slopeMaskFull = 1;
+
+    @Override
+    public PseudoErosion get() {
+        return new PseudoErosion(octaves, gain, lacunarity,
+            slopeStrength, branchStrength, strength,
+            erosionFrequency, heightSampler, slopeMask, slopeMaskFull, slopeMaskNone);
+    }
+}

common/addons/config-noise-function/src/main/java/com/dfsek/terra/addons/noise/samplers/noise/simplex/DerivativeFractal.java

@@ -0,0 +1,104 @@
+package com.dfsek.terra.addons.noise.samplers.noise.simplex;
+
+import com.dfsek.terra.api.noise.DerivativeNoiseSampler;
+
+import static com.dfsek.terra.addons.noise.samplers.noise.simplex.PseudoErosion.dot;
+import static com.dfsek.terra.addons.noise.samplers.noise.simplex.PseudoErosion.hash;
+import static com.dfsek.terra.addons.noise.samplers.noise.simplex.PseudoErosion.hashX;
+import static com.dfsek.terra.addons.noise.samplers.noise.simplex.PseudoErosion.hashY;
+
+
+/**
+ * Temporary sampler that provides derivatives to test pseudoerosion, should be replaced with
+ * derivative versions of existing samplers
+ */
+public class DerivativeFractal implements DerivativeNoiseSampler {
+
+    private final int heightOctaves;
+    private final double heightGain;
+    private final double heightLacunarity;
+    private final double frequency;
+
+    public DerivativeFractal(int octaves, double gain, double lacunarity, double frequency) {
+        this.heightOctaves = octaves;
+        this.heightGain = gain;
+        this.heightLacunarity = lacunarity;
+        this.frequency = frequency;
+    }
+
+    private static float[] baseNoise(float px, float py) {
+        float ix = (float)Math.floor(px);
+        float iy = (float)Math.floor(py);
+        float fx = px - ix;
+        float fy = py - iy;
+
+        float ux = fx * fx * fx * (fx * (fx * 6.0f - 15.0f) + 10.0f);
+        float uy = fy * fy * fy * (fy * (fy * 6.0f - 15.0f) + 10.0f);
+        float dux = fx * fx * 30.0f * (fx * (fx - 2.0f) + 1.0f);
+        float duy = fy * fy * 30.0f * (fy * (fy - 2.0f) + 1.0f);
+
+        float gan = hash(ix, iy);
+        float gax = hashX(gan);
+        float gay = hashY(gan);
+
+        float gbn = hash(ix + 1, iy);
+        float gbx = hashX(gbn);
+        float gby = hashY(gbn);
+
+        float gcn = hash(ix, iy + 1);
+        float gcx = hashX(gcn);
+        float gcy = hashY(gcn);
+
+        float gdn = hash(ix + 1, iy + 1);
+        float gdx = hashX(gdn);
+        float gdy = hashY(gdn);
+
+        float va = dot(gax, gay, fx, fy);
+        float vb = dot(gbx, gby, fx - 1, fy);
+        float vc = dot(gcx, gcy, fx, fy - 1);
+        float vd = dot(gdx, gdy, fx - 1, fy - 1);
+
+        float u2x = gax + (gbx - gax) * ux + (gcx - gax) * uy + (gax - gbx - gcx + gdx) * ux * uy + dux * (uy * (va - vb - vc + vd) + vb - va);
+        float u2y = gay + (gby - gay) * ux + (gcy - gay) * uy + (gay - gby - gcy + gdy) * ux * uy + duy * (ux * (va - vb - vc + vd) + vc - va);
+
+        return new float[] { va + ux * (vb - va) + uy * (vc - va) + ux * uy * (va - vb - vc + vd), u2x, u2y };
+    }
+
+    @Override
+    public double[] noised(long seed, double x, double y) {
+        x *= frequency;
+        y *= frequency;
+        double[] out = { 0.0f, 0.0f, 0.0f };
+        float heightFreq = 1.0f;
+        float heightAmp = 1f;
+        float cumAmp = 0.0f;
+        for (int i = 0; i < heightOctaves; i++) {
+            float[] noise = baseNoise((float) (x * heightFreq), (float) (y * heightFreq));
+            out[0] += noise[0] * heightAmp;
+            out[1] += noise[1] * heightAmp * heightFreq;
+            out[2] += noise[2] * heightAmp * heightFreq;
+            cumAmp += heightAmp;
+            heightAmp *= heightGain;
+            heightFreq *= heightLacunarity;
+        }
+        out[0] /= cumAmp;
+        out[1] /= cumAmp;
+        out[2] /= cumAmp;
+        return out;
+    }
+
+    @Override
+    public double[] noised(long seed, double x, double y, double z) {
+        return noised(seed, x, z);
+    }
+
+    @Override
+    public double noise(long seed, double x, double y) {
+        return noised(seed, x, y)[0];
+    }
+
+    @Override
+    public double noise(long seed, double x, double y, double z) {
+        return noised(seed, x, y, z)[0];
+    }
+}

common/addons/config-noise-function/src/main/java/com/dfsek/terra/addons/noise/samplers/noise/simplex/PseudoErosion.java

@@ -0,0 +1,179 @@
+package com.dfsek.terra.addons.noise.samplers.noise.simplex;
+
+
+import com.dfsek.terra.api.noise.DerivativeNoiseSampler;
+import com.dfsek.terra.api.noise.NoiseSampler;
+import com.dfsek.terra.api.util.MathUtil;
+
+
+public class PseudoErosion implements NoiseSampler {
+    public static final float TAU = (float) (2.0 * Math.PI);
+    private static final float HASH_X = 0.3183099f;
+    private static final float HASH_Y = 0.3678794f;
+    private final int octaves;
+    public final double gain;
+    public final double lacunarity;
+    public final double slopeStrength;
+    public final double branchStrength;
+    public final double erosionStrength;
+    private final double erosionFrequency;
+    private final DerivativeNoiseSampler sampler;
+    private final boolean slopeMask;
+    private final double slopeMaskFullSq;
+    private final double slopeMaskNoneSq;
+
+    public PseudoErosion(int octaves, double gain, double lacunarity, double slopeStrength, double branchStrength, double erosionStrength, double erosionFrequency, DerivativeNoiseSampler sampler,
+                         boolean slopeMask, double slopeMaskFull, double slopeMaskNone) {
+        this.octaves = octaves;
+        this.gain = gain;
+        this.lacunarity = lacunarity;
+        this.slopeStrength = slopeStrength;
+        this.branchStrength = branchStrength;
+        this.erosionStrength = erosionStrength;
+        this.erosionFrequency = erosionFrequency;
+        this.sampler = sampler;
+        this.slopeMask = slopeMask;
+        // Square these values and maintain sign since they're compared to a
+        // squared value, otherwise a sqrt would need to be used
+        this.slopeMaskFullSq = slopeMaskFull * slopeMaskFull * Math.signum(slopeMaskFull);
+        this.slopeMaskNoneSq = slopeMaskNone * slopeMaskNone * Math.signum((slopeMaskNone));
+    }
+
+    public static float hash(float x, float y) {
+        float xx = x * HASH_X + HASH_Y;
+        float yy = y * HASH_Y + HASH_X;
+
+        // Swapped the components here
+        return 16 * (xx * yy * (xx + yy));
+    }
+
+    public static float hashX(float n) {
+        // Swapped the components here
+        float nx = HASH_X * n;
+        return -1.0f + 2.0f * fract(nx);
+    }
+
+    public static float hashY(float n) {
+        float ny = HASH_Y * n;
+        return -1.0f + 2.0f * fract(ny);
+    }
+
+    public static float fract(float x) {
+        return (x - (float)Math.floor(x));
+    }
+
+    public static float[] erosion(float x, float y, float dirX, float dirY) {
+        float gridX = (float) Math.floor(x);
+        float gridY = (float) Math.floor(y);
+        float localX = x - gridX;
+        float localY = y - gridY;
+        float noise = 0.0f;
+        float dirOutX = 0.0f;
+        float dirOutY = 0.0f;
+        float cumAmp = 0.0f;
+
+        for (int cellX = -2; cellX < 2; cellX++) {
+            for (int cellY = -2; cellY < 2; cellY++) {
+                // TODO - Make seed affect hashing
+                float cellHash = hash(gridX - (float) cellX, gridY - (float) cellY);
+                float cellOffsetX = hashX(cellHash) * 0.5f;
+                float cellOffsetY = hashY(cellHash) * 0.5f;
+                float cellOriginDeltaX = cellX - cellOffsetX + localX;
+                float cellOriginDeltaY = cellY - cellOffsetY + localY;
+                float cellOriginDistSq = dot(cellOriginDeltaX, cellOriginDeltaY, cellOriginDeltaX, cellOriginDeltaY);
+                float amp = (float)exp(-cellOriginDistSq * 2.0); // Exponentially decrease amplitude further from cell center
+                cumAmp += amp;
+                float directionalStrength = dot(cellOriginDeltaX, cellOriginDeltaY, dirX, dirY) * TAU;
+                noise += (float) (MathUtil.cos(directionalStrength) * amp);
+                float sinAngle = (float) MathUtil.sin(directionalStrength) * amp;
+                dirOutX -= sinAngle * (cellOriginDeltaX + dirX);
+                dirOutY -= sinAngle * (cellOriginDeltaY + dirY);
+            }
+        }
+
+        noise /= cumAmp;
+        dirOutX /= cumAmp;
+        dirOutY /= cumAmp;
+
+        return new float[] {noise, dirOutX, dirOutY};
+    }
+
+    public static double exp(double val) {
+        final long tmp = (long) (1512775 * val + 1072632447);
+        return Double.longBitsToDouble(tmp << 32);
+    }
+
+    public static float smoothstep(float edge0, float edge1, float x) {
+        // Scale, bias and saturate x to 0..1 range
+        x = clamp((x - edge0) / (edge1 - edge0), 0.0f, 1.0f);
+        // Evaluate polynomial
+        return x * x * (3 - 2 * x);
+    }
+
+    public static float clamp(float x, float minVal, float maxVal) {
+        return Math.max(minVal, Math.min(maxVal, x));
+    }
+
+    public float heightMap(long seed, float x, float y) {
+        double[] sample = sampler.noised(seed, x, y);
+        float height = (float) sample[0];
+        float heightDirX = (float) sample[1];
+        float heightDirY = (float) sample[2];
+
+        // Take the curl of the normal to get the gradient facing down the slope
+        float baseDirX = heightDirY * (float) slopeStrength;
+        float baseDirY = -heightDirX * (float) slopeStrength;
+
+        float erosion = 0.0f;
+        float dirX = 0.0f;
+        float dirY = 0.0f;
+        float amp = 1.0f;
+        float cumAmp = 0.0f;
+        float freq = 1.0f;
+
+        // Stack erosion octaves
+        for (int i = 0; i < octaves; i++) {
+            float[] erosionResult = erosion(
+                x * freq * (float) erosionFrequency,
+                y * freq * (float) erosionFrequency,
+                baseDirX + dirY * (float) branchStrength,
+                baseDirY - dirX * (float) branchStrength);
+            erosion += erosionResult[0] * amp;
+            dirX += erosionResult[1] * amp * freq;
+            dirY += erosionResult[2] * amp * freq;
+            cumAmp += amp;
+            amp *= gain;
+            freq *= lacunarity;
+        }
+
+        // TODO - Test different output ranges, see how they affect visuals
+        // Normalize erosion noise
+        erosion /= cumAmp;
+        // [-1, 1] -> [0, 1]
+        erosion = erosion * 0.5F + 0.5F;
+
+        // Without masking, erosion noise in areas with small gradients tend to produce mounds,
+        // this reduces erosion amplitude towards smaller gradients to avoid this
+        if (slopeMask) {
+            float dirMagSq = dot(baseDirX, baseDirY, baseDirX, baseDirY);
+            float flatness = smoothstep((float) slopeMaskNoneSq, (float) slopeMaskFullSq, dirMagSq);
+            erosion *= flatness;
+        }
+
+        return (float) (height + erosion * erosionStrength);
+    }
+
+    public static float dot(float x1, float y1, float x2, float y2) {
+        return x1 * x2 + y1 * y2;
+    }
+
+    @Override
+    public double noise(long seed, double x, double y) {
+        return heightMap(seed, (float) x, (float) y);
+    }
+
+    @Override
+    public double noise(long seed, double x, double y, double z) {
+        return noise(seed, x, z);
+    }
+}

common/api/src/main/java/com/dfsek/terra/api/noise/DerivativeNoiseSampler.java

@@ -0,0 +1,22 @@
+package com.dfsek.terra.api.noise;
+
+/**
+ * A NoiseSampler which additionally provides directional derivatives
+ */
+public interface DerivativeNoiseSampler extends NoiseSampler {
+
+    static boolean providesDerivative(NoiseSampler sampler) {
+        if (sampler instanceof DerivativeNoiseSampler dSampler) {
+            return dSampler.isDerivable();
+        }
+        return false;
+    }
+
+    default boolean isDerivable()  {
+        return false;
+    }
+
+    double[] noised(long seed, double x, double y);
+    
+    double[] noised(long seed, double x, double y, double z);
+}