Added easings. Move of math to own folder.

lib/std/math/math.simple_random.c3

@@ -0,0 +1,47 @@
+module math;
+
+struct SimpleRandom
+{
+    long seed;
+}
+
+private const long SIMPLE_RANDOM_MULTIPLIER = 0x5DEECE66D;
+private const long SIMPLE_RANDOM_ADDEND = 0xB;
+private const long SIMPLE_RANDOM_MASK = (1i64 << 48) - 1;
+
+private fn long simple_random_initial_scramble(long seed)
+{
+    return (seed ^ SIMPLE_RANDOM_MULTIPLIER) & SIMPLE_RANDOM_MASK;
+}
+
+private fn int SimpleRandom.next(SimpleRandom* r, int bits)
+{
+    long nextseed = (r.seed * SIMPLE_RANDOM_MULTIPLIER + SIMPLE_RANDOM_ADDEND) & SIMPLE_RANDOM_MASK;
+    r.seed = nextseed;
+    return (int)nextseed >> (48 - bits);
+}
+
+fn void SimpleRandom.set_seed(SimpleRandom* r, long seed)
+{
+    r.seed = simple_random_initial_scramble(seed);
+}
+
+fn int SimpleRandom.next_int(SimpleRandom* r)
+{
+    return r.next(32) @inline;
+}
+
+fn bool SimpleRandom.next_bool(SimpleRandom* r)
+{
+    return r.next(1) != 0;
+}
+
+fn float SimpleRandom.next_float(SimpleRandom* r)
+{
+    return r.next(24) / (float)(1 << 24);
+}
+
+fn double SimpleRandom.next_double(SimpleRandom* r)
+{
+    return (((long)(r.next(26)) << 27) + r.next(27)) * 0x1.0p-53;
+}