ttkCinemaDarkroomIBS.cpp

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#include <ttkCinemaDarkroomIBS.h>
 
#include <vtkImageData.h>
#include <vtkInformation.h>
#include <vtkObjectFactory.h>
 
vtkStandardNewMacro(ttkCinemaDarkroomIBS);
 
ttkCinemaDarkroomIBS::ttkCinemaDarkroomIBS() : ttkCinemaDarkroomShader() {
  this->setDebugMsgPrefix("CinemaDarkroomIBS");
}
 
ttkCinemaDarkroomIBS::~ttkCinemaDarkroomIBS() = default;
 
std::string ttkCinemaDarkroomIBS::GetFragmentShaderCode() {
  return std::string(R"(
//VTK::System::Dec // always start with these lines in your FS
//VTK::Output::Dec // always start with these lines in your FS
 
// #extension GL_OES_standard_derivatives : enable
 
varying vec4 vPos;
 
uniform sampler2D tex0; // color
uniform sampler2D tex1; // depth
uniform sampler2D tex2; // ao
 
float readDepth( const in vec2 coord ){
    return texture2D( tex1, coord ).r;
}
 
void main() {
    vec3 color = texture2D( tex0, vPos.xy ).rgb;
    float ao = texture2D( tex2, vPos.xy ).r;
    float depth = readDepth(vPos.xy);
 
    // Compute Luminance
    vec3 lumcoeff = vec3( 0.299, 0.587, 0.114 );
    vec3 luminance = vec3( dot( color, lumcoeff ) );
 
    // Silhouette Effect
    vec2 pixelSize = 1./cResolution;
    vec3 eps = 2.0*vec3( pixelSize.x, pixelSize.y, 0 );
    float depthN = readDepth(vPos.xy + eps.zy);
    float depthE = readDepth(vPos.xy + eps.xz);
    float depthS = readDepth(vPos.xy - eps.zy);
    float depthW = readDepth(vPos.xy - eps.xz);
 
    float dxdz = abs(depthE-depthW);
    float dydz = abs(depthN-depthS);
    // float dxdz = dFdx(depth);
    // float dydz = dFdy(depth);
 
    vec3 n = normalize( vec3(dxdz, dydz, 1./cStrength) );
    vec3 lightPos = vec3(0,0,1);
    float lightInt = 1.0*dot(n,normalize(lightPos));
 
    vec3 outputColor = vec3( color * mix( vec3(ao), vec3(1.0), luminance * cLuminance ) );
 
    outputColor = outputColor*cAmbient + outputColor*lightInt;
 
    gl_FragColor = vec4(outputColor, depth>0.99 ? 0.0 : 1.0);
}
  )");
}
 
int ttkCinemaDarkroomIBS::RequestData(vtkInformation *ttkNotUsed(request),
                                      vtkInformationVector **inputVector,
                                      vtkInformationVector *outputVector) {
 
  auto inputImage = vtkImageData::GetData(inputVector[0]);
  auto outputImage = vtkImageData::GetData(outputVector);
  outputImage->ShallowCopy(inputImage);
 
  this->InitRenderer(outputImage);
 
  this->AddReplacement("cStrength", {this->Strength});
  this->AddReplacement("cLuminance", {this->Luminance});
  this->AddReplacement("cAmbient", {this->Ambient});
 
  if(!this->AddTexture(outputImage, 0, 0))
    return 0;
  if(!this->AddTexture(outputImage, 1, 1))
    return 0;
  if(!this->AddTexture(outputImage, 2, 2))
    return 0;
 
  this->Render(outputImage, "IBS");
 
  return 1;
}