godot/modules/opensimplex/open_simplex_noise.h

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/*  open_simplex_noise.h                                                 */
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#ifndef OPEN_SIMPLEX_NOISE_H
#define OPEN_SIMPLEX_NOISE_H

#include "core/io/image.h"
#include "core/object/ref_counted.h"
#include "scene/resources/texture.h"

#include "thirdparty/misc/open-simplex-noise.h"

class OpenSimplexNoise : public Resource {
	GDCLASS(OpenSimplexNoise, Resource);
	OBJ_SAVE_TYPE(OpenSimplexNoise);

	// The maximum number of octaves allowed. Note that these are statically allocated.
	// Higher values become exponentially slower, so this shouldn't be set too high
	// to avoid freezing the editor for long periods of time.
	static const int MAX_OCTAVES = 9;

	osn_context contexts[MAX_OCTAVES];

	int seed = 0;
	float persistence = 0.5; // Controls details, value in [0,1]. Higher increases grain, lower increases smoothness.
	int octaves = 3; // Number of noise layers
	float period = 64.0; // Distance above which we start to see similarities. The higher, the longer "hills" will be on a terrain.
	float lacunarity = 2.0; // Controls period change across octaves. 2 is usually a good value to address all detail levels.

public:
	OpenSimplexNoise();
	~OpenSimplexNoise();

	void _init_seeds();

	void set_seed(int seed);
	int get_seed() const;

	void set_octaves(int p_octaves);
	int get_octaves() const { return octaves; }

	void set_period(float p_period);
	float get_period() const { return period; }

	void set_persistence(float p_persistence);
	float get_persistence() const { return persistence; }

	void set_lacunarity(float p_lacunarity);
	float get_lacunarity() const { return lacunarity; }

	Ref<Image> get_image(int p_width, int p_height, const Vector2 &p_noise_offset = Vector2()) const;
	Ref<Image> get_seamless_image(int p_size) const;

	float get_noise_1d(float x) const;
	float get_noise_2d(float x, float y) const;
	float get_noise_3d(float x, float y, float z) const;
	float get_noise_4d(float x, float y, float z, float w) const;

	_FORCE_INLINE_ float _get_octave_noise_2d(int octave, float x, float y) const { return open_simplex_noise2(&(contexts[octave]), x, y); }
	_FORCE_INLINE_ float _get_octave_noise_3d(int octave, float x, float y, float z) const { return open_simplex_noise3(&(contexts[octave]), x, y, z); }
	_FORCE_INLINE_ float _get_octave_noise_4d(int octave, float x, float y, float z, float w) const { return open_simplex_noise4(&(contexts[octave]), x, y, z, w); }

	// Convenience

	_FORCE_INLINE_ float get_noise_2dv(const Vector2 &v) const { return get_noise_2d(v.x, v.y); }
	_FORCE_INLINE_ float get_noise_3dv(const Vector3 &v) const { return get_noise_3d(v.x, v.y, v.z); }

protected:
	static void _bind_methods();
};

#endif // OPEN_SIMPLEX_NOISE_H