triangle.cxx

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/// \file
/// \ingroup tutorial_webcanv
/// User class with custom JavaScript painter in the web canvas.
///
/// Custom class is just triangle which drawn on the frame with NDC coordinates
/// `triangle.mjs` provides JavaScript code for object painting and interactivity
/// It is also possible to use such "simple" class without loading of custom JS code,
/// but then it requires appropriate Paint() method and will miss interactivity in browser
///
/// This macro must be executed with ACLiC like 'root --web triangle.cxx+'
///
/// \macro_image (tcanvas_jsp)
/// \macro_code
///
/// \author Sergey Linev
 
#include <iostream>
 
#include "TNamed.h"
#include "TAttLine.h"
#include "TAttFill.h"
#include "TWebCanvas.h"
#include "TCanvas.h"
#include "TROOT.h"
 
#include "ROOT/RWebWindowsManager.hxx"
 
class TTriangle : public TNamed, public TAttLine, public TAttFill {
   double fX[3] = {0, 0, 0};
   double fY[3] = {0, 0, 0};
 
public:
   TTriangle() {} // =default not allowed !!!
 
   TTriangle(const char *name, const char *title = "") : TNamed(name, title) {}
 
   void SetPoints(double x1, double y1, double x2, double y2, double x3, double y3)
   {
      fX[0] = x1;
      fY[0] = y1;
      fX[1] = x2;
      fY[1] = y2;
      fX[2] = x3;
      fY[2] = y3;
   }
 
   /** In old graphics just provide line drawing */
   void Paint(Option_t *opt) override
   {
      if (!gPad)
         return;
      TAttLine::Modify(); // Change line attributes only if necessary
      TAttFill::Modify(); // Change fill area attributes only if necessary
 
      if (*opt == 'f')
         gPad->PaintFillAreaNDC(3, fX, fY, opt);
      else
         gPad->PaintPolyLineNDC(3, fX, fY, opt);
   }
 
   ClassDefOverride(TTriangle, 1); // Example of triangle drawing in web canvas
};
 
void triangle(bool ignore_jsmodule = false)
{
   if (ignore_jsmodule) {
      printf("Custom JS module will NOT be provided for TTriangle class\n");
      printf("No interactive features will be available\n");
      printf("TTriangle::Paint() method will be used for object painting - also in web case\n");
   } else {
#ifdef __CLING__
      printf("Please run this script in compiled mode by running \".x triangle.cxx+\"\n");
      printf("Requires to properly generate dictionary for TTriangle class\n");
      return;
#endif
 
      std::string fdir = __FILE__;
      auto pos = fdir.find("triangle.cxx");
      if (pos != std::string::npos)
         fdir.resize(pos);
      else
         fdir = gROOT->GetTutorialsDir() + std::string("/webcanv/");
 
      // location required to load files
      // also it is name of modules path used in importmap
      ROOT::RWebWindowsManager::AddServerLocation("tutorials_webcanv", fdir);
 
      // mark TTriangle as supported on the client
      TWebCanvas::AddCustomClass("TTriangle");
 
      // specify which extra module should be loaded,
      // "tutorials_webcanv/" is registered path from server locations
      TWebCanvas::SetCustomScripts("modules:tutorials_webcanv/triangle.mjs");
   }
 
   auto tr1 = new TTriangle("tr1", "first triangle");
   tr1->SetPoints(0.4, 0.5, 0.8, 0.3, 0.8, 0.7);
   tr1->SetLineColor(kRed);
   tr1->SetLineWidth(3);
   tr1->SetFillColor(kBlue);
 
   auto tr2 = new TTriangle("tr2", "second triangle");
   tr2->SetPoints(0.2, 0.2, 0.2, 0.6, 0.5, 0.4);
   tr2->SetLineColor(kGreen);
   tr2->SetLineStyle(kDashed);
   tr2->SetFillColor(kYellow);
 
   auto tr3 = new TTriangle("tr3", "third triangle");
   tr3->SetPoints(0.4, 0.8, 0.6, 0.8, 0.5, 0.2);
   tr3->SetLineColor(kCyan);
   tr3->SetFillColor(kMagenta);
 
   auto c1 = new TCanvas("c1", "Triangles");
   c1->Add(tr1, "f");
   c1->Add(tr2, "f");
   c1->Add(tr3, "f");
 
   // test image saving with web browser, chrome or firefox are required
   // c1->SaveAs("triangle.png");
   // c1->SaveAs("triangle.pdf");
}