skydome object

skydome.h

@@ -0,0 +1,60 @@
+#pragma	once
+
+#include "dumb3d.h"
+#include "float3d.h"
+
+// sky gradient based on "A practical analytic model for daylight" 
+// by A. J. Preetham Peter Shirley Brian Smits (University of Utah)
+
+class CSkyDome {
+public:
+    CSkyDome( int const Tesselation = 54 );
+	~CSkyDome();
+	void Generate();
+	void RebuildColors();
+
+	bool SetSunPosition( Math3D::vector3 const &Direction );
+	
+	void SetTurbidity( const float Turbidity = 5.0f );
+	void SetExposure( const bool Linearexposure, const float Expfactor );		
+	void SetOvercastFactor( const float Overcast = 0.0f );
+	void SetGammaCorrection( const float Gamma = 2.2f );
+
+	// update skydome
+    void Update( Math3D::vector3 const &Sun );
+	// render skydome to screen
+	void Render();
+
+    // retrieves average colour of the sky dome
+    float3 GetAverageColor() { return m_averagecolour; }
+
+private:
+	// shading parametrs
+    float3 m_sundirection;
+    float m_thetasun, m_phisun;
+    float m_turbidity;
+    bool m_linearexpcontrol;
+    float m_expfactor;
+    float m_overcast;
+    float m_gammacorrection;
+    float3 m_averagecolour;
+
+	// data
+    int const m_tesselation;
+    std::vector<float3> m_vertices;
+    std::vector<float3> m_normals;
+    std::vector<float3> m_colours;
+
+	static float m_distributionluminance[ 5 ][ 2 ];
+    static float m_distributionxcomp[ 5 ][ 2 ];
+    static float m_distributionycomp[ 5 ][ 2 ];
+
+    static float m_zenithxmatrix[ 3 ][ 4 ];
+    static float m_zenithymatrix[ 3 ][ 4 ];
+	
+	// coloring
+	void GetPerez( float *Perez, float Distribution[ 5 ][ 2 ], const float Turbidity );
+	float GetZenith( float Zenithmatrix[ 3 ][ 4 ], const float Theta, const float Turbidity );		
+	float PerezFunctionO1( float Perezcoeffs[ 5 ], const float Thetasun, const float Zenithval );
+	float PerezFunctionO2( float Perezcoeffs[ 5 ], const float Icostheta, const float Gamma, const float Cosgamma2, const float Zenithval );
+};