mixin SHCommon
{
	code
	{
		#define SH_NUM_COEFFS SH_ORDER * SH_ORDER
	
		struct SHVector
		{
			float v[SH_NUM_COEFFS];
		};

		struct SHVectorRGB
		{
			SHVector R;
			SHVector G;
			SHVector B;
		};
		
		void SHZero(inout SHVector v)
		{
			[unroll]
			for(int i = 0; i < SH_NUM_COEFFS; ++i)
				v.v[i] = 0;
		}
		
		void SHZero(inout SHVectorRGB v)
		{
			SHZero(v.R);
			SHZero(v.G);
			SHZero(v.B);
		}				
		
		void SHMultiplyAdd(inout SHVector lhs, SHVector rhs, float c)
		{
			[unroll]
			for(int i = 0; i < SH_NUM_COEFFS; ++i)		
				lhs.v[i] += rhs.v[i] * c;
		}
		
		void SHMultiplyAdd(inout SHVectorRGB lhs, SHVectorRGB rhs, float c)
		{
			SHMultiplyAdd(lhs.R, rhs.R, c);
			SHMultiplyAdd(lhs.G, rhs.G, c);
			SHMultiplyAdd(lhs.B, rhs.B, c);
		}
		
		void SHAdd(inout SHVector lhs, SHVector rhs)
		{
			[unroll]
			for(int i = 0; i < SH_NUM_COEFFS; ++i)		
				lhs.v[i] += rhs.v[i];
		}
				
		void SHAdd(inout SHVectorRGB lhs, SHVectorRGB rhs)
		{
			SHAdd(lhs.R, rhs.R);
			SHAdd(lhs.G, rhs.G);
			SHAdd(lhs.B, rhs.B);
		}
		
		void SHMultiply(inout SHVector lhs, SHVector rhs)
		{
			[unroll]
			for(int i = 0; i < SH_NUM_COEFFS; ++i)
				lhs.v[i] *= rhs.v[i];
		}	
		
		void SHMultiply(inout SHVectorRGB lhs, SHVectorRGB rhs)
		{
			SHMultiply(lhs.R, rhs.R);
			SHMultiply(lhs.G, rhs.G);
			SHMultiply(lhs.B, rhs.B);
		}	
		
		void SHMultiply(inout SHVector lhs, float rhs)
		{
			[unroll]
			for(int i = 0; i < SH_NUM_COEFFS; ++i)		
				lhs.v[i] *= rhs;
		}

		void SHMultiply(inout SHVectorRGB lhs, float rhs)
		{
			SHMultiply(lhs.R, rhs);
			SHMultiply(lhs.G, rhs);
			SHMultiply(lhs.B, rhs);
		}	
				
		#if SH_ORDER == 5
		SHVector SHBasis(float3 dir)
		{
			float x = dir.x;
			float y = dir.y;
			float z = dir.z;

			float x2 = x*x;
			float y2 = y*y;
			float z2 = z*z;

			float z3 = z2 * z;

			float x4 = x2 * x2;
			float y4 = y2 * y2;
			float z4 = z2 * z2;

			SHVector o;
			o.v[0] = 0.282095f;

			o.v[1] = -0.488603f * y;
			o.v[2] =  0.488603f * z;
			o.v[3] = -0.488603f * x;

			o.v[4] =  1.092548f * x * y;
			o.v[5] = -1.092548f * y * z;
			o.v[6] =  0.315392f * (3.0f * z2 - 1.0f);
			o.v[7] = -1.092548f * x * z;
			o.v[8] =  0.546274f * (x2 - y2);

			o.v[9]  = -0.590043f * y * (3.0f * x2 - y2);
			o.v[10] =  2.890611f * y * x * z;
			o.v[11] = -0.646360f * y * (-1.0f + 5.0f * z2);
			o.v[12] =  0.373176f *(5.0f * z3 - 3.0f * z);
			o.v[13] = -0.457045f * x * (-1.0f + 5.0f * z2);
			o.v[14] =  1.445306f *(x2 - y2) * z;
			o.v[15] = -0.590043f * x * (x2 - 3.0f * y2);

			o.v[16] =  2.503340f * x * y * (x2 - y2);
			o.v[17] = -1.770130f * y * z * (3.0f * x2 - y2);
			o.v[18] =  0.946175f * y * x * (-1.0f + 7.0f * z2);
			o.v[19] = -0.669046f * y * z * (-3.0f + 7.0f * z2);
			o.v[20] =  (105.0f * z4 - 90.0f * z2 + 9.0f) / 28.359261f;
			o.v[21] = -0.669046f * x * z * (-3.0f + 7.0f * z2);
			o.v[22] =  0.473087f * (x2 - y2) * (-1.0f + 7.0f * z2);
			o.v[23] = -1.770130f * x * z * (x2 - 3.0f * y2);
			o.v[24] =  0.625836f * (x4 - 6.0f * y2 * x2 + y4);
			
			return o;
		}
		#elif SH_ORDER == 3
		SHVector SHBasis(float3 dir)
		{
			float x = dir.x;
			float y = dir.y;
			float z = dir.z;

			float x2 = x*x;
			float y2 = y*y;
			float z2 = z*z;

			SHVector o;
			o.v[0] = 0.282095f;

			o.v[1] = -0.488603f * y;
			o.v[2] =  0.488603f * z;
			o.v[3] = -0.488603f * x;

			o.v[4] =  1.092548f * x * y;
			o.v[5] = -1.092548f * y * z;
			o.v[6] =  0.315392f * (3.0f * z2 - 1.0f);
			o.v[7] = -1.092548f * x * z;
			o.v[8] =  0.546274f * (x2 - y2);

			return o;
		}
		#endif
	};
};