/*========================================================================= Program: Visualization Toolkit Module: $RCSfile: vtkVolumeRayCastFunction.h,v $ Language: C++ Date: $Date: 2001/11/13 14:17:33 $ Version: $Revision: 1.24 $ Copyright (c) 1993-2001 Ken Martin, Will Schroeder, Bill Lorensen All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. * Neither name of Ken Martin, Will Schroeder, or Bill Lorensen nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission. * Modified source versions must be plainly marked as such, and must not be misrepresented as being the original software. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. =========================================================================*/ // .NAME vtkVolumeRayCastFunction - a superclass for ray casting functions // .SECTION Description // vtkVolumeRayCastFunction is a superclass for ray casting functions that // can be used within a vtkVolumeRayCastMapper. This includes for example, // vtkVolumeRayCastCompositeFunction, vtkVolumeRayCastMIPFunction, and // vtkVolumeRayCastIsosurfaceFunction. // .SECTION See Also // vtkVolumeRayCastCompositeFunction vtkVolumeRayCastMIPFunction // vtkVolumeRayCastIsosurfaceFunction vtkVolumeRayCastMapper #ifndef __vtkVolumeRayCastFunction_h #define __vtkVolumeRayCastFunction_h #include "vtkObject.h" class vtkRenderer; class vtkVolume; class vtkVolumeRayCastMapper; // Define a couple of structures we need to hold all the important information // This first structure hold the dynamic information - stuff that changes per // ray typedef struct { // These are the return values - RGBA float Color[4]; float ScalarValue; // Ray information transformed into local coordinates float TransformedStart[4]; float TransformedEnd[4]; float TransformedDirection[4]; float TransformedIncrement[3]; // The number of steps we want to take if this is // a ray caster that takes steps int NumberOfStepsToTake; // The number of steps we actually take if this is // a ray caster that takes steps int NumberOfStepsTaken; } VTKVRCDynamicInfo; // This second structure hold the static information - things that don't // change over the whole image typedef struct { // A pointer to the volume vtkVolume *Volume; // A pointer to the renderer vtkRenderer *Renderer; // Matrices for switching from view to volume coordinate, and back float WorldToVoxelsMatrix[16]; float VoxelsToWorldMatrix[16]; float ViewToVoxelsMatrix[16]; float *ClippingPlane; int NumberOfClippingPlanes; // The camera thickness (distance between near and far) is necessary // for computing sampling distance float CameraThickness; // The type of the data and a pointer to it, and the information // about its size, spacing, origin and precomputed increment int ScalarDataType; void *ScalarDataPointer; int DataIncrement[3]; int DataSize[3]; float DataSpacing[3]; float DataOrigin[3]; // Information from the vtkVolumeProperty int Shading; int ColorChannels; float Color[3]; int InterpolationType; float RGBTextureCoefficient; // The shading tables from the vtkEncodedGradientShader // that will be used for shading the volume. float *RedDiffuseShadingTable; float *GreenDiffuseShadingTable; float *BlueDiffuseShadingTable; float *RedSpecularShadingTable; float *GreenSpecularShadingTable; float *BlueSpecularShadingTable; // Info needed to do solid textures - a pointer to the texture // and info about its size, spacing, origin, and precomputed // increments unsigned char *RGBDataPointer; int RGBDataIncrement[3]; int RGBDataSize[3]; float RGBDataSpacing[3]; float RGBDataOrigin[3]; // Info needed from the gradient estimator unsigned short *EncodedNormals; unsigned char *GradientMagnitudes; // Image information int ImageInUseSize[2]; int ImageMemorySize[2]; int ImageViewportSize[2]; int ImageOrigin[2]; unsigned char *Image; int *RowBounds; // Is a MIP ray cast function in use? This will control // how subsegments of the ray are combined when non-subvolume // cropping is used. If maximize opacity is used, the color[3] // value is used to find the max othersize the dynamicInfo->ScalarValue // value is used int MIPFunction; int MaximizeOpacity; } VTKVRCStaticInfo; class VTK_RENDERING_EXPORT vtkVolumeRayCastFunction : public vtkObject { public: vtkTypeMacro(vtkVolumeRayCastFunction,vtkObject); // Description: // Do the basic initialization. This includes saving the parameters // passed in into local variables, as well as grabbing some useful // info from the volume property and normal encoder. This initialize // routine is called once per render. It also calls the // SpecificFunctionInitialize of the subclass function. //BTX void FunctionInitialize( vtkRenderer *ren, vtkVolume *vol, VTKVRCStaticInfo *staticInfo ); virtual void CastRay( VTKVRCDynamicInfo *dynamicInfo, VTKVRCStaticInfo *staticInfo )=0; //ETX // Description: // Get the value below which all scalar values are considered to // have 0 opacity. virtual float GetZeroOpacityThreshold( vtkVolume *vol )=0; protected: vtkVolumeRayCastFunction() {}; ~vtkVolumeRayCastFunction() {}; // Description: // This method gives the subclass a chance to do any special // initialization that it may need to do //BTX virtual void SpecificFunctionInitialize( vtkRenderer *ren, vtkVolume *vol, VTKVRCStaticInfo *staticInfo, vtkVolumeRayCastMapper *mapper )=0; //ETX private: vtkVolumeRayCastFunction(const vtkVolumeRayCastFunction&); // Not implemented. void operator=(const vtkVolumeRayCastFunction&); // Not implemented. }; #endif