Logo ROOT   6.21/01
Reference Guide
transp.C File Reference

Detailed Description

This demo shows how to use transparency.

pict1_transp.C.png
//Includes for ACLiC (cling does not need them).
#include "TCanvas.h"
#include "TColor.h"
#include "TError.h"
#include "TStyle.h"
#include "TH1F.h"
//Aux. functions for tutorials/gl.
#include "customcolorgl.h"
void transp()
{
//1. Try to find free indices for our custom colors.
//We can use hard-coded indices like 1001, 1002, 1003, ... but
//I prefer to find free indices in a ROOT's color table
//to avoid possible conflicts with other tutorials.
Int_t indices[2] = {};
::Error("transp", "failed to create new custom colors");
return;
}
//2. Now that we have indices, create our custom colors.
const Int_t redIndex = indices[0], greeIndex = indices[1];
new TColor(redIndex, 1., 0., 0., "red", 0.85);
new TColor(greeIndex, 0., 1., 0., "green", 0.5);
TCanvas * const cnv = new TCanvas("trasnparency", "transparency demo", 600, 400);
TH1F * const hist = new TH1F("a5", "b5", 10, -2., 3.);
TH1F * const hist2 = new TH1F("c6", "d6", 10, -3., 3.);
hist->FillRandom("landau", 100000);
hist2->FillRandom("gaus", 100000);
hist->SetFillColor(redIndex);
hist2->SetFillColor(greeIndex);
cnv->cd();
hist2->Draw();
hist->Draw("SAME");
}
Author
Timur Pocheptsov

Definition in file transp.C.