@kitware/vtk.js/Rendering/OpenGL/SurfaceLIC/glsl/vtkLineIntegralConvolution2D_EE.glsl.js

Visualization Toolkit for the Web

var vtkLineIntegralConvolution2D_EE = "//VTK::System::Dec\n\n//=========================================================================\n//\n//  Program:   Visualization Toolkit\n//  Module:    vtkLineIntegralConvolution2D_fs2.glsl\n//\n//  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen\n//  All rights reserved.\n//  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.\n//\n//     This software is distributed WITHOUT ANY WARRANTY; without even\n//     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR\n//     PURPOSE.  See the above copyright notice for more information.\n//\n//=========================================================================\n\n// high-pass filter stage employed by vtkLineIntegralConvolution2D\n// between LIC pass 1 and LIC pass 2. filtered LIC pass 1, becomes\n// noise for pass2.\n\n// the output of this shader\nlayout(location = 0) out vec4 EEOutput;\n\nuniform sampler2D texLIC; // most recent lic pass\nuniform float     uDx;    // fragment size\nuniform float     uDy;    // fragment size\n\nin vec2 tcoordVC;\n\n// kernel for simple laplace edge enhancement.\n// p=Laplace(p)+p\nfloat K[9] = float[9](\n  -1.0, -1.0, -1.0,\n  -1.0,  9.0, -1.0,\n  -1.0, -1.0, -1.0\n  );\n\n// determine if the fragment was masked\nbool Masked(float val) { return val != 0.0; }\n\nvoid main(void)\n{\n  // tex coord neighbor offsets\n  vec2 fragDx[9] = vec2[9](\n    vec2(-uDx, uDy), vec2(0.0, uDy), vec2(uDx, uDy),\n    vec2(-uDx, 0.0), vec2(0.0, 0.0), vec2(uDx, 0.0),\n    vec2(-uDx,-uDy), vec2(0.0,-uDy), vec2(uDx,-uDy)\n    );\n\n  vec2 lictc = tcoordVC.st;\n\n  // compute the convolution but don't use convovled values if\n  // any masked fragments on the stencil. Fragments outside\n  // the valid domain are masked during initialization, and\n  // texture wrap parameters are clamp to border with border\n  // color that contains masked flag\n  float conv = 0.0;\n  bool dontUse = false;\n  for (int i=0; i<9; ++i)\n    {\n    vec2 tc = lictc + fragDx[i];\n    vec4 lic = texture2D(texLIC, tc);\n    dontUse = dontUse || Masked(lic.g);\n    conv = conv + K[i] * lic.r;\n    }\n\n  if (dontUse)\n    {\n    EEOutput = vec4(texture2D(texLIC, lictc).rg, 0.0, 1.0);\n    }\n  else\n    {\n    conv = clamp(conv, 0.0, 1.0);\n    EEOutput = vec4(conv,texture2D(texLIC, lictc).g, 0.0, 1.0);\n    }\n\n}\n";

export { vtkLineIntegralConvolution2D_EE as v };