Method UpdateShaders

Rendering/OpenGL2/vtkOpenGLPolyDataMapper.cxx:2661–2738

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//------------------------------------------------------------------------------
void vtkOpenGLPolyDataMapper::UpdateShaders(
  vtkOpenGLHelper& cellBO, vtkRenderer* ren, vtkActor* actor)
{
  vtkOpenGLRenderWindow* renWin = vtkOpenGLRenderWindow::SafeDownCast(ren->GetRenderWindow());

  cellBO.VAO->Bind();
  this->LastBoundBO = &cellBO;

  // has something changed that would require us to recreate the shader?
  if (this->GetNeedToRebuildShaders(cellBO, ren, actor))
  {
    // build the shader source code
    std::map<vtkShader::Type, vtkShader*> shaders;
    vtkShader* vss = vtkShader::New();
    vss->SetType(vtkShader::Vertex);
    shaders[vtkShader::Vertex] = vss;
    vtkShader* gss = vtkShader::New();
    gss->SetType(vtkShader::Geometry);
    shaders[vtkShader::Geometry] = gss;
    vtkShader* fss = vtkShader::New();
    fss->SetType(vtkShader::Fragment);
    shaders[vtkShader::Fragment] = fss;

    this->BuildShaders(shaders, ren, actor);

    // compile and bind the program if needed
    vtkShaderProgram* newShader = renWin->GetShaderCache()->ReadyShaderProgram(shaders);
    if (newShader)
    {
      vss->Delete();
      fss->Delete();
      gss->Delete();

      // if the shader changed reinitialize the VAO
      if (newShader != cellBO.Program || cellBO.Program->GetMTime() > cellBO.AttributeUpdateTime)
      {
        cellBO.Program = newShader;
        // reset the VAO as the shader has changed
        cellBO.VAO->ReleaseGraphicsResources();
      }

      cellBO.ShaderSourceTime.Modified();
    }
    else
    {
      vtkErrorMacro("Could not set shader program");
    }
  }
  else
  {
    renWin->GetShaderCache()->ReadyShaderProgram(cellBO.Program);
    if (cellBO.Program->GetMTime() > cellBO.AttributeUpdateTime)
    {
      // reset the VAO as the shader has changed
      cellBO.VAO->ReleaseGraphicsResources();
    }
  }
  vtkOpenGLCheckErrorMacro("failed after UpdateShader");