Initial commit, yay

src/rand/opensimplex.h

@@ -0,0 +1,52 @@
+/*
+ * This code is part of the strategy game operational-space.
+ * operational-space comes with ABSOLUTELY NO WARRANTY and is licensed under GPL-2.0.
+ *    Copyright (C) 2024  VegOwOtenks, Sleppo04
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef OPENSIMPLEX2S_H
+#define OPENSIMPLEX2S_H
+
+#include <stdint.h>
+#include <math.h>
+
+
+#define PRIME_X         (0x5205402B9270C86FL)
+#define PRIME_Y         (0x598CD327003817B5L)
+#define HASH_MULTIPLIER (0x53A3F72DEEC546F5L)
+
+#define ROOT2OVER2 (0.7071067811865476)
+#define SKEW_2D    (0.366025403784439)
+#define UNSKEW_2D  (-0.21132486540518713)
+
+#define N_GRADS_2D_EXPONENT (7)
+#define N_GRADS_2D          (1 << N_GRADS_2D_EXPONENT)
+
+#define NORMALIZER_2D (0.05481866495625118)
+
+#define RSQUARED_2D   (2.0f / 3.0f)
+
+/// @brief Get the standard noise using the at position x and y with seed seed
+/// @param seed 
+/// @param x 
+/// @param y 
+/// @return noise at x, y with seed seed
+// TODO: Don't use this one, it has weird diagonal artifacts
+float OpenSimplex_2DNoise(int64_t seed, double x, double y);
+
+float OpenSimplex_2DNoise_ImprovedX(int64_t seed, double x, double y);
+
+#endif