Animated particlespawners and more (#11545)

Co-authored-by: Lars Mueller <appgurulars@gmx.de>
Co-authored-by: sfan5 <sfan5@live.de>
Co-authored-by: Dmitry Kostenko <codeforsmile@gmail.com>

src/util/numeric.cpp

@@ -46,11 +46,22 @@ void myrand_bytes(void *out, size_t len)
 	g_pcgrand.bytes(out, len);
 }
 
+float myrand_float()
+{
+	u32 uv = g_pcgrand.next();
+	return (float)uv / (float)U32_MAX;
+}
+
 int myrand_range(int min, int max)
 {
 	return g_pcgrand.range(min, max);
 }
 
+float myrand_range(float min, float max)
+{
+	return (max-min) * myrand_float() + min;
+}
+
 
 /*
 	64-bit unaligned version of MurmurHash