vtkUnstructuredGridPartialPreIntegration.h
Go to the documentation of this file.00001
00002
00003
00004
00005
00006
00007
00008
00009
00010
00011
00012
00013
00014
00015
00016
00017
00018
00019
00020
00021
00022
00023
00024
00054 #ifndef __vtkUnstructuredGridPartialPreIntegration_h
00055 #define __vtkUnstructuredGridPartialPreIntegration_h
00056
00057 #include "vtkUnstructuredGridVolumeRayIntegrator.h"
00058 #include "vtkMath.h"
00059
00060 class vtkPartialPreIntegrationTransferFunction;
00061
00062 class VTK_RENDERING_EXPORT vtkUnstructuredGridPartialPreIntegration : public vtkUnstructuredGridVolumeRayIntegrator
00063 {
00064 public:
00065 vtkTypeRevisionMacro(vtkUnstructuredGridPartialPreIntegration,
00066 vtkUnstructuredGridVolumeRayIntegrator);
00067 static vtkUnstructuredGridPartialPreIntegration *New();
00068 virtual void PrintSelf(ostream &os, vtkIndent indent);
00069
00070 virtual void Initialize(vtkVolumeProperty *property, vtkDataArray *scalars);
00071
00072 virtual void Integrate(vtkDoubleArray *intersectionLengths,
00073 vtkDataArray *nearIntersections,
00074 vtkDataArray *farIntersections,
00075 float color[4]);
00076
00078
00080 static void IntegrateRay(double length,
00081 double intensity_front, double attenuation_front,
00082 double intensity_back, double attenuation_back,
00083 float color[4]);
00084 static void IntegrateRay(double length,
00085 const double color_front[3],
00086 double attenuation_front,
00087 const double color_back[3],
00088 double attenuation_back,
00089 float color[4]);
00091
00096 static float Psi(float taufD, float taubD);
00097
00098 static void BuildPsiTable();
00099
00100 protected:
00101 vtkUnstructuredGridPartialPreIntegration();
00102 ~vtkUnstructuredGridPartialPreIntegration();
00103
00104 vtkVolumeProperty *Property;
00105
00106 vtkPartialPreIntegrationTransferFunction *TransferFunctions;
00107 vtkTimeStamp TransferFunctionsModified;
00108 int NumIndependentComponents;
00109
00110
00111 enum {PSI_TABLE_SIZE = 512};
00112
00113 static float PsiTable[PSI_TABLE_SIZE*PSI_TABLE_SIZE];
00114
00115 private:
00116 vtkUnstructuredGridPartialPreIntegration(const vtkUnstructuredGridPartialPreIntegration&);
00117 void operator=(const vtkUnstructuredGridPartialPreIntegration&);
00118 };
00119
00120 inline float vtkUnstructuredGridPartialPreIntegration::Psi(float taufD,
00121 float taubD)
00122 {
00123 float gammaf = taufD/(taufD+1);
00124 float gammab = taubD/(taubD+1);
00125 int gammafi = vtkMath::Floor(gammaf*PSI_TABLE_SIZE);
00126 int gammabi = vtkMath::Floor(gammab*PSI_TABLE_SIZE);
00127 return PsiTable[gammafi*PSI_TABLE_SIZE + gammabi];
00128 }
00129
00130 inline void vtkUnstructuredGridPartialPreIntegration::IntegrateRay(
00131 double length,
00132 double intensity_front,
00133 double attenuation_front,
00134 double intensity_back,
00135 double attenuation_back,
00136 float color[4])
00137 {
00138 float taufD = length*attenuation_front;
00139 float taubD = length*attenuation_back;
00140 float Psi = vtkUnstructuredGridPartialPreIntegration::Psi(taufD, taubD);
00141 float zeta = (float)exp(-0.5*(taufD+taubD));
00142 float alpha = 1-zeta;
00143
00144 float newintensity = (1-color[3])*( intensity_front*(1-Psi)
00145 + intensity_back*(Psi-zeta) );
00146
00147 color[0] += newintensity;
00148 color[1] += newintensity;
00149 color[2] += newintensity;
00150 color[3] += (1-color[3])*alpha;
00151 }
00152
00153 inline void vtkUnstructuredGridPartialPreIntegration::IntegrateRay(
00154 double length,
00155 const double color_front[3],
00156 double attenuation_front,
00157 const double color_back[3],
00158 double attenuation_back,
00159 float color[4])
00160 {
00161 float taufD = length*attenuation_front;
00162 float taubD = length*attenuation_back;
00163 float Psi = vtkUnstructuredGridPartialPreIntegration::Psi(taufD, taubD);
00164 float zeta = (float)exp(-0.5*(taufD+taubD));
00165 float alpha = 1-zeta;
00166
00167 color[0] += (1-color[3])*(color_front[0]*(1-Psi) + color_back[0]*(Psi-zeta));
00168 color[1] += (1-color[3])*(color_front[1]*(1-Psi) + color_back[1]*(Psi-zeta));
00169 color[2] += (1-color[3])*(color_front[2]*(1-Psi) + color_back[2]*(Psi-zeta));
00170 color[3] += (1-color[3])*alpha;
00171 }
00172
00173 #endif //__vtkUnstructuredGridPartialPreIntegration_h