Semi-working base for bgfx renderer

2015-09-08 16:13:59 +02:00
parent c7f17c8ef0
commit c24b039005
47 changed files with 11176 additions and 43 deletions
@@ -0,0 +1,182 @@
+/*
+ * Copyright 2010-2015 Branimir Karadzic. All rights reserved.
+ * License: http://www.opensource.org/licenses/BSD-2-Clause
+ */
+
+#ifndef BX_RNG_H_HEADER_GUARD
+#define BX_RNG_H_HEADER_GUARD
+
+#include "bx.h"
+#include "fpumath.h"
+
+namespace bx
+{
+	// George Marsaglia's MWC
+	class RngMwc
+	{
+	public:
+		RngMwc(uint32_t _z = 12345, uint32_t _w = 65435)
+			: m_z(_z)
+			, m_w(_w)
+		{
+		}
+
+		void reset(uint32_t _z = 12345, uint32_t _w = 65435)
+		{
+			m_z = _z;
+			m_w = _w;
+		}
+
+		uint32_t gen()
+		{
+			m_z = 36969*(m_z&65535)+(m_z>>16);
+			m_w = 18000*(m_w&65535)+(m_w>>16);
+			return (m_z<<16)+m_w;
+		}
+
+	private:
+		uint32_t m_z;
+		uint32_t m_w;
+	};
+
+	// George Marsaglia's FIB
+	class RngFib
+	{
+	public:
+		RngFib()
+			: m_a(9983651)
+			, m_b(95746118)
+		{
+		}
+
+		void reset()
+		{
+			m_a = 9983651;
+			m_b = 95746118;
+		}
+
+		uint32_t gen()
+		{
+			m_b = m_a+m_b;
+			m_a = m_b-m_a;
+			return m_a;
+		}
+
+	private:
+		uint32_t m_a;
+		uint32_t m_b;
+	};
+
+	// George Marsaglia's SHR3
+	class RngShr3
+	{
+	public:
+		RngShr3(uint32_t _jsr = 34221)
+			: m_jsr(_jsr)
+		{
+		}
+
+		void reset(uint32_t _jsr = 34221)
+		{
+			m_jsr = _jsr;
+		}
+
+		uint32_t gen()
+		{
+			m_jsr ^= m_jsr<<17;
+			m_jsr ^= m_jsr>>13;
+			m_jsr ^= m_jsr<<5;
+			return m_jsr;
+		}
+
+	private:
+		uint32_t m_jsr;
+	};
+
+	/// Returns random number between 0.0f and 1.0f.
+	template <typename Ty>
+	inline float frnd(Ty* _rng)
+	{
+		uint32_t rnd = _rng->gen() & UINT16_MAX;
+		return float(rnd) * 1.0f/float(UINT16_MAX);
+	}
+
+	/// Returns random number between -1.0f and 1.0f.
+	template <typename Ty>
+	inline float frndh(Ty* _rng)
+	{
+		return 2.0f * bx::frnd(_rng) - 1.0f;
+	}
+
+	/// Generate random point on unit sphere.
+	template <typename Ty>
+	static inline void randUnitSphere(float _result[3], Ty* _rng)
+	{
+		float rand0 = frnd(_rng) * 2.0f - 1.0f;
+		float rand1 = frnd(_rng) * pi * 2.0f;
+
+		float sqrtf1 = sqrtf(1.0f - rand0*rand0);
+		_result[0] = sqrtf1 * cosf(rand1);
+		_result[1] = sqrtf1 * sinf(rand1);
+		_result[2] = rand0;
+	}
+
+	/// Generate random point on unit hemisphere.
+	template <typename Ty>
+	static inline void randUnitHemisphere(float _result[3], Ty* _rng, const float _normal[3])
+	{
+		float dir[3];
+		randUnitSphere(dir, _rng);
+
+		float DdotN = dir[0]*_normal[0]
+					+ dir[1]*_normal[1]
+					+ dir[2]*_normal[2]
+					;
+
+		if (0.0f > DdotN)
+		{
+			dir[0] = -dir[0];
+			dir[1] = -dir[1];
+			dir[2] = -dir[2];
+		}
+
+		_result[0] = dir[0];
+		_result[1] = dir[1];
+		_result[2] = dir[2];
+	}
+
+	/// Sampling with Hammersley and Halton Points
+	/// http://www.cse.cuhk.edu.hk/~ttwong/papers/udpoint/udpoints.html
+	///
+	static inline void generateSphereHammersley(void* _data, uint32_t _stride, uint32_t _num, float _scale = 1.0f)
+	{
+		uint8_t* data = (uint8_t*)_data;
+
+		for (uint32_t ii = 0; ii < _num; ii++)
+		{
+			float tt = 0.0f;
+			float pp = 0.5;
+			for (uint32_t jj = ii; jj; jj >>= 1)
+			{
+				tt += (jj & 1) ? pp : 0.0f;
+				pp *= 0.5f;
+			}
+
+			tt = 2.0f * tt - 1.0f;
+
+			const float phi = (ii + 0.5f) / _num;
+			const float phirad =  phi * 2.0f * pi;
+			const float st = sqrtf(1.0f-tt*tt) * _scale;
+
+			float* xyz = (float*)data;
+			data += _stride;
+
+			xyz[0] = st * cosf(phirad);
+			xyz[1] = st * sinf(phirad);
+			xyz[2] = tt * _scale;
+		}
+	}
+
+} // namespace bx
+
+#endif // BX_RNG_H_HEADER_GUARD