X-Git-Url: http://git.localhorst.tv/?a=blobdiff_plain;f=src%2Fnoise.hpp;h=26e37668b00f609fdfd2747a2ed6a3e044031729;hb=38abfe4f5342f20b56052ac3090694eabf028d16;hp=4c26de92eadf0ae3bacd679cc069e0337bf27861;hpb=42dea80c2cffb75a5721d1cbf0cdd6277f4d520d;p=blank.git

diff --git a/src/noise.hpp b/src/noise.hpp
index 4c26de9..26e3766 100644
--- a/src/noise.hpp
+++ b/src/noise.hpp
@@ -1,11 +1,41 @@
 #ifndef BLANK_NOISE_HPP_
 #define BLANK_NOISE_HPP_
 
+#include <cstdint>
+#include <limits>
 #include <glm/glm.hpp>
 
 
 namespace blank {
 
+class GaloisLFSR {
+
+public:
+	// seed should be non-zero
+	explicit GaloisLFSR(std::uint64_t seed);
+
+	// get the next bit
+	bool operator ()();
+
+	template<class T>
+	void operator ()(T &out) {
+		constexpr int num_bits =
+			std::numeric_limits<T>::digits +
+			std::numeric_limits<T>::is_signed;
+		for (int i = 0; i < num_bits; ++i) {
+			operator ()();
+		}
+		out = static_cast<T>(state);
+	}
+
+private:
+	std::uint64_t state;
+	// bits 64, 63, 61, and 60 set to 1 (counting from 1 lo to hi)
+	static constexpr std::uint64_t mask = 0xD800000000000000;
+
+};
+
+
 /// (3D only) adaptation of Stefan Gustavson's SimplexNoise java class
 class SimplexNoise {
 
@@ -39,6 +69,29 @@ private:
 
 };
 
+
+template<class Noise>
+float OctaveNoise(
+	const Noise &noise,
+	const glm::vec3 &in,
+	int num,
+	float persistence,
+	float frequency = 1.0f,
+	float amplitude = 1.0f,
+	float growth = 2.0f
+) {
+	float total = 0.0f;
+	float max = 0.0f;
+	for (int i = 0; i < num; ++i) {
+		total += noise(in * frequency) * amplitude;
+		max += amplitude;
+		amplitude *= persistence;
+		frequency *= growth;
+	}
+
+	return total / max;
+}
+
 }
 
 #endif