+// Return value: -1 ... 1
+float noise2d(int x, int y, int seed);
+float noise3d(int x, int y, int z, int seed);
+
+float noise2d_gradient(float x, float y, int seed);
+float noise3d_gradient(float x, float y, float z, int seed);
+
+float noise2d_perlin(float x, float y, int seed,
+ int octaves, float persistence);
+
+float noise2d_perlin_abs(float x, float y, int seed,
+ int octaves, float persistence);
+
+float noise3d_perlin(float x, float y, float z, int seed,
+ int octaves, float persistence);
+
+float noise3d_perlin_abs(float x, float y, float z, int seed,
+ int octaves, float persistence);
+
+inline float easeCurve(float t) {
+ return t * t * t * (t * (6.f * t - 15.f) + 10.f);
+}
+
+#define NoisePerlin2D(np, x, y, s) \
+ ((np)->offset + (np)->scale * noise2d_perlin( \
+ (float)(x) / (np)->spread.X, \
+ (float)(y) / (np)->spread.Y, \
+ (s) + (np)->seed, (np)->octaves, (np)->persist))
+
+#define NoisePerlin2DNoTxfm(np, x, y, s) \
+ (noise2d_perlin( \
+ (float)(x) / (np)->spread.X, \
+ (float)(y) / (np)->spread.Y, \
+ (s) + (np)->seed, (np)->octaves, (np)->persist))
+
+#define NoisePerlin2DPosOffset(np, x, xoff, y, yoff, s) \
+ ((np)->offset + (np)->scale * noise2d_perlin( \
+ (float)(xoff) + (float)(x) / (np)->spread.X, \
+ (float)(yoff) + (float)(y) / (np)->spread.Y, \
+ (s) + (np)->seed, (np)->octaves, (np)->persist))
+
+#define NoisePerlin2DNoTxfmPosOffset(np, x, xoff, y, yoff, s) \
+ (noise2d_perlin( \
+ (float)(xoff) + (float)(x) / (np)->spread.X, \
+ (float)(yoff) + (float)(y) / (np)->spread.Y, \
+ (s) + (np)->seed, (np)->octaves, (np)->persist))
+
+#define NoisePerlin3D(np, x, y, z, s) ((np)->offset + (np)->scale * \
+ noise3d_perlin((float)(x) / (np)->spread.X, (float)(y) / (np)->spread.Y, \
+ (float)(z) / (np)->spread.Z, (s) + (np)->seed, (np)->octaves, (np)->persist))
+