Function ShadingSingleInput

Rendering/VolumeOpenGL2/vtkVolumeShaderComposer.h:2628–3013

--------------------------------------------------------------------------

//--------------------------------------------------------------------------
inline std::string ShadingSingleInput(vtkRenderer* vtkNotUsed(ren), vtkVolumeMapper* mapper,
  vtkVolume* vtkNotUsed(vol), vtkImageData* maskInput, vtkVolumeTexture* mask, int maskType,
  int noOfComponents, int independentComponents = 0)
{
  auto glMapper = vtkOpenGLGPUVolumeRayCastMapper::SafeDownCast(mapper);

  std::string shaderStr;

  shaderStr += std::string("\
      \n    if (!g_skip)\
      \n      {\
      \n      vec4 scalar;\
      \n");
  if (vtkRectilinearGrid::SafeDownCast(mapper->GetInput()))
  {
    shaderStr += std::string("\
      \n      // Compute IJK vertex position for current sample in the rectilinear grid\
      \n      vec4 dataPosWorld = in_volumeMatrix[0] * in_textureDatasetMatrix[0] * vec4(g_dataPos, 1.0);\
      \n      dataPosWorld = dataPosWorld / dataPosWorld.w;\
      \n      dataPosWorld.w = 1.0;\
      \n      ivec3 ijk = ivec3(0);\
      \n      vec3 ijkTexCoord = vec3(0.0);\
      \n      vec3 pCoords = vec3(0.0);\
      \n      vec3 xPrev, xNext, tmp;\
      \n      int sz = textureSize(in_coordTexs, 0);\
      \n      vec4 dataPosWorldScaled = dataPosWorld * vec4(in_coordsScale, 1.0) +\
      \n                                vec4(in_coordsBias, 1.0);\
      \n      for (int j = 0; j < 3; ++j)\
      \n        {\
      \n        xPrev = texture1D(in_coordTexs, 0.0).xyz;\
      \n        xNext = texture1D(in_coordTexs, (in_coordTexSizes[j] - 1) / sz).xyz;\
      \n        if (xNext[j] < xPrev[j])\
      \n          {\
      \n          tmp = xNext;\
      \n          xNext = xPrev;\
      \n          xPrev = tmp;\
      \n          }\
      \n        for (int i = 0; i < int(in_coordTexSizes[j]); i++)\
      \n          {\
      \n          xNext = texture1D(in_coordTexs, (i + 0.5) / sz).xyz;\
      \n          if (dataPosWorldScaled[j] >= xPrev[j] && dataPosWorldScaled[j] < xNext[j])\
      \n            {\
      \n            ijk[j] = i - 1;\
      \n            pCoords[j] = (dataPosWorldScaled[j] - xPrev[j]) / (xNext[j] - xPrev[j]);\
      \n            break;\
      \n            }\
      \n          else if (dataPosWorldScaled[j] == xNext[j])\
      \n            {\
      \n            ijk[j] = i - 1;\
      \n            pCoords[j] = 1.0;\
      \n            break;\
      \n            }\
      \n          xPrev = xNext;\
      \n          }\
      \n        ijkTexCoord[j] = (ijk[j] + pCoords[j]) / in_coordTexSizes[j];\
      \n        }\
      \n      scalar = texture3D(in_volume[0], sign(in_cellSpacing[0]) * ijkTexCoord);\
      \n");